Non-osseous incidental findings in low-dose whole-body CT in patients with multiple myeloma

Objective:

The purpose of this study was to identify the frequency and grading of non-osseous incidental findings (NOIF) in non-contrast whole-body low-dose CT (LDCT) in patients with multiple myeloma.

Methods:

In the time period from 2010 to 2013, 93 patients with multiple myeloma were staged by non-contrast whole-body LDCT at our radiological department. LDCT images were analysed retrospectively for NOIF, which also included unsuspected extramedullary manifestation of multiple myeloma. All NOIF were classified as major or clinically significant, moderate or possibly clinically significant and minor or not clinically significant. Medical records were analysed regarding further investigation and follow-up of the identified NOIF.

Results:

In the 93 patients, 295 NOIF were identified (on average, 3.2 NOIF per patient). Most of the NOIF (52.4%) were not clinically significant, 25.8% of the NOIF were possibly clinically significant and 21.8% of the NOIF were clinically significant. Clinically significant NOIF were investigated further by CT after intravenous administration of contrast medium and/or by ultrasound or MRI. In 34 of these cases, extramedullary relapse of myeloma, occult carcinoma or infectious/septic incidental findings were diagnosed (11.5% of all NOIF). In the remaining 10.3% of the NOIF classified as clinically significant, various benign lesions were diagnosed.

Conclusion:

LDCT detected various non-osseous lesions in patients with multiple myeloma. 36.6% of the patients had clinically significant NOIF. Therefore, LDCT examinations in patients with multiple myeloma should be evaluated carefully for the presence of NOIF.

Advances in knowledge:

LDCT identified several NOIF. A total of 36.6% of patients with multiple myeloma had clinically significant NOIF. Radiologists should analyse LDCT examinations in patients with multiple myeloma not only for bone lesions, but also for lesions in other organs.CT is used for screening or staging in several malignancies.^1–8 As reported previously, the staging CT examination also provides additional information regarding the general health status of the patient or so-called incidental findings (IF).^1,3,6,7 Several IF on CT examinations were described in the literature.^1–6 According to previous reports, IF can be classified into five different categories: Group “0”, limited examination, that is, evaluation of IF are severely limited; Group “1”, normal findings or anatomic variant; Group “2”, clinically unimportant findings, such as liver or kidney cysts; Group “3”, likely unimportant findings; and Group “4”, potentially important findings, such as solid renal masses or lymphadenopathy.⁵ In another publication, a three-part classification of IF according to their clinical importance was proposed, namely major, moderate and minor IF.¹Most of the IF are clinically non-significant, such as colonic diverticula or simple cysts.^1–7 However, serious IF, such as aortic aneurysm or dissection, thrombosis, pulmonary embolism and second primary tumours, can also occur,^1,3,6,7 and some of them may be not visible on low-dose CT (LDCT).Most reports regarding IF are based on contrast-enhanced CT.^1,7,9–11 There are only a few reports regarding IF in LDCT.¹² They described IF in screening programmes for lung cancer and based the findings on thoracic LDCT only.¹² In addition, non-contrast LDCT has been established for staging of bone lesions in multiple myeloma.^13–16 However, radiologists should analyse LDCT examinations not only for bone lesions but also for lesions in other organs, which may include extramedullary manifestation of multiple myeloma as well as unrelated IF.Although IF in multiple myeloma have also been described previously,¹⁴ to the best of our knowledge, there exists no analysis focused on frequency and distribution of non-osseous IF (NOIF) on whole-body LDCT. Therefore, the purpose of this study was to identify the frequency and grading of NOIF in non-contrast whole-body LDCT in patients with multiple myeloma.     

The value of dual-time-point 18F-FDG PET/CT for identifying axillary lymph node metastasis in breast cancer patients

Objective

The sensitivity of 18-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET) for detecting axillary lymph node (ALN) metastases in breast cancer is reported to be low. Several studies have shown, however, that dual-time-point ¹⁸F-FDG PET imaging provides improved accuracy in the diagnosis of certain primary tumours when compared with single-scan imaging. The purpose of this study was to assess whether the use of dual-time-point ¹⁸F-FDG PET/CT scans could improve the diagnostic accuracy of ALN metastasis in breast cancer.

Method

The study included 171 breast cancer patients who underwent pre-operative ¹⁸F-FDG PET/CT scans at 2 time-points, the first at 1 h after radiotracer injection and the second 3 h after injection. Where ¹⁸F-FDG uptake was in the ALN perceptibly increased, the maximum standardised uptake values for both time-points (SUVmax1 and SUVmax2) and the retention index (RI) were calculated. Correlation between the PET/CT results and post-operative histological results was assessed.

Results

The performance of 1 h and 3 h PET/CT scans was equal, with sensitivity 60.3% and specificity 84.7%, in detecting ALN metastasis. Out of 171 patients, 60 had ALNs with increased ¹⁸F-FDG uptake on 1 h or 3 h images. There was no significant difference in RI between the metastatic ALN-positive group and the node-negative group. The area under the receiver operating characteristic (ROC) curve for SUVmax1 was 0.90 (p<0.001) and 0.87 for SUVmax2 (p<0.001).

Conclusion

Dual time-point imaging did not improve the overall performance of ¹⁸F-FDG PET/CT in detecting ALN metastasis in breast cancer patients.Axillary lymph node (ALN) involvement is the key prognostic factor in patients with breast cancer [1]. Accurate assessment of axillary node status is therefore essential for both predicting outcome and choosing a therapeutic plan. The most reliable and accurate procedure for the examination of ALN is standard axillary lymph node dissection (ALND). However, the complications associated with ALND, such as lymphoedema, numbness of the skin of the upper arm and impairment of shoulder movement, lead to decreased quality of life [2]. Moreover, a significant proportion of breast cancer patients, especially those with small tumours, are node negative [3,4]. Therefore, a non-invasive modality for accurate staging of ALNs is needed to avoid unnecessary ALND.¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET) and ¹⁸F-FDG PET/CT have a useful role in staging and therapeutic planning in breast cancer patients in that these modalities are used to identify unexpected metastasis and recurrence [5]. The sensitivity of ¹⁸F-FDG PET for detecting ALN metastasis in breast cancer staging is, however, reported to be relatively low [6,7]. Recently, immunohistochemistry and multistep section have improved the detection rate of axillary micrometastasis and the value of ¹⁸F-FDG PET in axillary staging has become more uncertain [6,8,9].Several studies have shown that ¹⁸F-FDG uptake by malignant tumours increases for hours after injection [10,11]. Thus, some investigators suggest advantages of using delayed PET or dual time-point PET images. In breast cancer, Boerner et al [12] reported that PET images made 3 h after ¹⁸F-FDG injection showed higher tumour-to-non-tumour and tumour-to-organ ratios, and enhanced lesion detectability when compared with 1.5 h images.The purpose of this study was to assess whether dual-time-point (1 h and 3 h) ¹⁸F-FDG PET/CT scans could improve the diagnostic accuracy of ALN metastasis in breast cancer.     

Comparison of mammography, sonography, MRI and clinical examination in patients with locally advanced or inflammatory breast cancer who underwent neoadjuvant chemotherapy

Objectives

The purpose of this study was to determine the relative accuracies of mammography, sonography, MRI and clinical examination in predicting residual tumour size and pathological response after neoadjuvant chemotherapy for locally advanced or inflammatory breast cancer. Each prediction method was compared with the gold standard of surgical pathology.

Methods

43 patients (age range, 25–62 years; mean age, 42.7 years) with locally advanced or inflammatory breast cancer who had been treated by neoadjuvant chemotherapy were enrolled prospectively. We compared the predicted residual tumour size and the predicted response on imaging and clinical examination with residual tumour size and response on pathology. Statistical analysis was performed using weighted kappa statistics and intraclass correlation coefficients (ICC).

Results

The ICC values between predicted tumour size and pathologically determined tumour size were 0.65 for clinical examination, 0.69 for mammography, 0.78 for sonography and 0.97 for MRI. Agreement between the response predictions at mid-treatment and the responses measured by pathology had kappa values of 0.28 for clinical examination, 0.32 for mammography, 0.46 for sonography and 0.68 for MRI. Agreement between the final response predictions and the responses measured by pathology had kappa values of 0.43 for clinical examination, 0.44 for mammography, 0.50 for sonography and 0.82 for MRI.

Conclusion

Predictions of response and residual tumour size made on MRI were better correlated with the assessments of response and residual tumour size made upon pathology than were predictions made on the basis of clinical examination, mammography or sonography. Thus, the evaluation of predicted response using MRI could provide a relatively sensitive early assessment of chemotherapy efficacy.The advantages of neoadjuvant chemotherapy are multiple and it has been used widely during the past few years [1]. Its primary role is to induce tumour shrinkage and permit breast-conserving surgery, primarily in patients with advanced breast cancer [2-4]. Neoadjuvant chemotherapy allows earlier treatment of micrometastatic disease and the study of biological markers that might predict tumour response [5]. The effectiveness of chemotherapeutic agents in treating both primary breast cancer and potential metastatic disease may be enhanced by the presence of tumour neovascularity. If chemotherapy is given before surgery, while tumour vascularity remains intact, the chemotherapeutic agents may be better able to reach the tumour and thus be more effective.Neoadjuvant chemotherapy of locally advanced breast cancer (LABC) has also been shown to improve the resectability rate, offering disease-free and overall survival rates that are at least equivalent to those offered by surgery alone [6,7]. Pathological complete response (pCR) is clinically significant because it is associated with improved long-term prognosis and decreased risk of recurrence [6,8]. Decisions regarding the continuation of current regimens and the appropriate type and timing of surgery depend on the radiological and clinical assessment of residual tumour size during neoadjuvant chemotherapy [9,10]. Until now, many studies have shown that physical examinations, mammography and sonography provide suboptimal evaluations of lesion extent that do not allow accurate assessments of pathological response or residual tumour size [5^,11-13]. In the case of LABC, physical examination, mammography or sonography may be suitable for detecting the larger lesions of non-responders, but they have limited sensitivity for responders with smaller residual lesions [14,15]. For mammography, calcifications may persist or even increase in patients who respond to neoadjuvant chemotherapy [14,16,17].Many previous studies have shown that MRI is the most reliable technique for evaluating residual disease after neoadjuvant chemotherapy, although initial reports described frequent false-negatives with smaller-volume disease [18-27]. Recent studies have increased the sensitivity of MRI, with increased resolution, reduced slice thickness and lower enhancement thresholds being used to minimise the underestimation of residual disease [15^,22-27]. It is still difficult, however, to distinguish residual scarring, necrosis and fibrosis from viable residual malignancy and to predict accurate response after neoadjuvant chemotherapy, especially in responders. Few published studies have described work with patients with inflammatory breast cancer who underwent neoadjuvant chemotherapy because the incidence of this disease is very low [28,29]. The purpose of our study was to determine the relative accuracies of mammography, sonography, MRI and clinical examination in predicting residual tumour size and pathological response after neoadjuvant chemotherapy for locally advanced and inflammatory breast cancer. We compared each prediction method with the gold standard of surgical pathology.     

Towards clinical assessment of velopharyngeal closure using MRI: evaluation of real-time MRI sequences at 1.5 and 3 T

Objective

The objective of this study was to demonstrate soft palate MRI at 1.5 and 3 T with high temporal resolution on clinical scanners.

Methods

Six volunteers were imaged while speaking, using both four real-time steady-state free-precession (SSFP) sequences at 3 T and four balanced SSFP (bSSFP) at 1.5 T. Temporal resolution was 9–20 frames s⁻¹ (fps), spatial resolution 1.6×1.6×10.0–2.7×2.7×10.0 mm³. Simultaneous audio was recorded. Signal-to-noise ratio (SNR), palate thickness and image quality score (1–4, non-diagnostic–excellent) were evaluated.

Results

SNR was higher at 3 T than 1.5 T in the relaxed palate (nasal breathing position) and reduced in the elevated palate at 3 T, but not 1.5 T. Image quality was not significantly different between field strengths or sequences (p=NS). At 3 T, 40% acquisitions scored 2 and 56% scored 3. Most 1.5 T acquisitions scored 1 (19%) or 4 (46%). Image quality was more dependent on subject or field than sequence. SNR in static images was highest with 1.9×1.9×10.0 mm³ resolution (10 fps) and measured palate thickness was similar (p=NS) to that at the highest resolution (1.6×1.6×10.0 mm³). SNR in intensity–time plots through the soft palate was highest with 2.7×2.7×10.0 mm³ resolution (20 fps).

Conclusions

At 3 T, SSFP images are of a reliable quality, but 1.5 T bSSFP images are often better. For geometric measurements, temporal should be traded for spatial resolution (1.9×1.9×10.0 mm³, 10 fps). For assessment of motion, temporal should be prioritised over spatial resolution (2.7×2.7×10.0 mm³, 20 fps).

Advances in knowledge

Diagnostic quality real-time soft palate MRI is possible using clinical scanners and optimised protocols have been developed. 3 T SSFP imaging is reliable, but 1.5 T bSSFP often produces better images.Approximately 450 babies born in the UK every year have an orofacial cleft [1], the majority of which include the palate [2]. While a cleft palate is commonly repaired surgically at around 6 months [3], residual velopharyngeal insufficiencies require follow-up surgery in 15–50% of cases [4]. This residual defect results in an incomplete closure of the velopharyngeal port, which in turns leads to hypernasal speech. Assessment of velopharyngeal closure in speech therapy is commonly performed using X-ray videofluoroscopy or nasendoscopy [5,6]. While nasendoscopy is only minimally invasive, it may be uncomfortable and provides only an en face view of the velopharyngeal port. In contrast, X-ray videofluoroscopy is non-invasive and produces an image which is a projection of the target anatomy. Additional information may be obtained from projections at multiple angles [5,7], but anatomical structures may overlie each other. Furthermore, soft tissue contrast, such as that from the soft palate, is poor, although it may be improved using a barium contrast agent coating [8] at the expense of making the procedure more invasive and unpleasant. Arguably the greatest drawback of X-ray videofluoroscopy is the associated ionising radiation dose, which carries increased risk in paediatric patients [9].An increasing number of research studies have used MRI to image the soft palate [10-13] and upper vocal tract [14-17]. In contrast to X-ray videofluoroscopy and nasendoscopy, MRI provides tomographic images in any plane with flexible tissue contrast. As a result, MRI has been used to obtain images of the musculature of the palate at rest and during sustained phonation [10,18,19]. It has also been used to image the whole vocal tract at rest or during sustained phonation [20-27] and with a single mid-sagittal image dynamically during speech [13,15-17,28-35].For assessment of velopharyngeal closure, dynamic imaging with sufficient temporal resolution and simultaneous audio recording is required. Audio recording during imaging is complicated by the loud noise of the MRI scanner, and both the safety risk and image degradation caused by using an electronic microphone within the magnet. As a result, optical fibre-based equipment with noise cancellation algorithms must be used [36].In order to fully resolve soft palate motion, Narayanan et al [30] suggested that a minimum temporal resolution of 20 frames s⁻¹ (fps) is required. A similar conclusion was reached by Bae et al [13], based on measurements of soft palate motion extracted from X-ray videofluoroscopy. Using segmented MRI, Inoue et al [35] demonstrated that changes in the velar position that were evident at acquired frame rates of 33 fps were not observed at 8 fps. However, MRI is traditionally seen as a slow imaging modality and achieving sufficient temporal resolution at an acceptable spatial resolution is challenging. Furthermore, as the soft palate is bordered on both sides by air, the associated changes in magnetic susceptibility at the interfaces make images prone to related artefacts.Dynamic MRI of the vocal tract has been performed using both segmented [17,33,37] and real-time acquisitions [13,15,16,28,31,38]. Segmented acquisitions [39] acquire only a fraction of the k-space data required for each image during one repetition of the test phrase and, hence, require multiple identical repetitions. While these segmented techniques permit high temporal and spatial resolutions [35], they require reproducible production of the same phrase up to 256 times [34], leading to subject fatigue. Differences between repeats of up to 95 ms in the onset of speech following a trigger have also been demonstrated [36].In contrast to segmented techniques, real-time dynamic methods permit imaging of natural speech, but require extremely rapid acquisition and often advanced reconstruction methods. The turbo spin echo (TSE) zoom technique [40] has been used to perform real-time MRI of the vocal tract [29,31] and is available as a clinical tool. The zoom technique excites a reduced field of view in the phase encode direction, hence allowing a smaller acquisition matrix and shorter scan for a constant spatial resolution. While such spin echo-based techniques are less susceptible to magnetic field inhomogeneity related signal dropout artefacts than other sequences, the frame rates achieved with these sequences are limited to 6 fps [31]. Gradient echo-based techniques have also been used to achieve similar temporal resolution [12,41,42] in the upper vocal tract, but are often used at much higher frame rates in other MRI applications such as cardiac imaging [43,44]. A number of gradient echo sequence variants exist. Fast low-angle shot (FLASH) type sequences [45] spoil any remaining transverse magnetisation at the end of every sequence repetition (TR). In contrast, steady-state free-precession (SSFP) sequences are not spoiled [46] and the remaining transverse magnetisation is used in the next TR to improve the signal-to-noise ratio (SNR), but renders the images sensitive to signal loss in the presence of motion. Balanced SSFP (bSSFP) sequences include additional gradients to bring the transverse magnetisation completely back into phase at the end of every TR [47,48]. The result is that bSSFP sequences have high SNR and are less sensitive to motion than SSFP sequences, but are more sensitive to field inhomogeneities, which cause bands of signal dropout.Both TSE and the gradient echo techniques discussed here sample in a rectilinear or Cartesian fashion, where one line of k-space is sampled in each echo. However, for real-time speech imaging, the highest acquired frame rates have been achieved by sampling k-space along a spiral trajectory [15,16,30,49]. While spiral imaging is an efficient way to sample k-space and is motion-resilient, it is prone to artefacts, particularly blurring caused by magnetic field inhomogeneities and off-resonance protons (i.e. fat) [50]. Recently, one group successfully used spiral imaging with multiple saturation bands and an alternating echo time (TE) to achieve an acquired real-time frame rate of 22 fps [13,16]. The saturation bands were used to allow a small field of view to be imaged without aliasing artefacts. The alternating TE was used to generate dynamic field maps which were incorporated into the reconstruction to compensate for magnetic field inhomogeneities. However, such advanced acquisition and reconstruction techniques are only available in a small number of research centres.The aim of this work is to optimise and demonstrate high-temporal-resolution real-time sequences available on routine clinical MRI scanners for assessment of soft palate motion and velopharyngeal closure. Consequently, radial and spiral acquisitions were excluded and the work focuses on Cartesian gradient echo sequences with parallel imaging techniques. As more clinical MRI departments now have 3 T scanners, imaging was performed at both 1.5 and 3 T to enable comparisons. At each field strength, we optimised sequences and implemented four combinations of spatial and temporal resolution in six subjects with simultaneous audio recordings.     

The utility of MRI for pre-operative T and N staging of gastric carcinoma: a systematic review and meta-analysis

Objective:

To perform a meta-analysis and literature review regarding the diagnostic accuracy of MRI for pre-operative tumour depth invasion (T) and regional lymph node invasion (N) staging of gastric carcinoma (GC).

Methods:

Articles were identified through systematic search of Medline, PubMed, Cochrane Library, Web of Science, Springerlink and several Chinese databases. The study quality was assessed by the quality assessment for studies of diagnostic accuracy. 2 reviewers independently extracted and assessed the data from 11 eligible studies. A meta-analysis was then carried out. Subgroup and sensitivity analyses were also performed.

Results:

11 studies (439 patients) were finally included in the current review. Among these studies, the significant evidence of heterogeneity was only discovered for specificity in T4 stage (I² = 59.8%). Pooled sensitivity and specificity of MRI to diagnose T stage tumour (T3–4 vs T1–2) were 0.93 [95% confidence interval (CI), 0.89–0.96] and 0.91 (95% CI, 0.87–0.95), respectively. Pooled estimates of sensitivity and specificity of MRI to diagnose N stage tumour (N0 vs N+) were 0.86 (95% CI, 0.80–0.92) and 0.67 (95% CI, 0.54–0.79), respectively. Subgroup analyses showed that diffusion-weighted imaging was more helpful for T staging.

Conclusion:

The present systematic review suggests that MRI has a good diagnostic accuracy for pre-operative T staging of GC and should be widely used in clinical work. However, the ability for N staging is relatively poor on MRI.

Advances in knowledge:

In the pre-operative staging of GC, MRI was a useful tool and may enhance accuracy for the T staging of advanced GC.Gastric carcinoma (GC) is the fourth most common cancer and the second leading cause of cancer-related death with a 5-year survival rate of <20% around the world.¹ The disease is more common in Asian countries, especially China, Japan and Republic of Korea.^2,3 Accurate assessment of local tumour depth invasion (T) and regional lymph node invasion (N) plays an essential role in predicting prognosis and determining the most appropriate treatment planning.^4,5The pre-operative staging of GC has been based on a multimodality approach, such as endoscopic ultrasonography (EUS), CT, MRI and positron emission tomography (PET).^6,7 EUS and CT have been widely used for GC staging in previous years.⁸ Of course, different imaging modalities have themselves relative merits. CT with ionized radiation requires the injection of iodine contrast medium.⁹ EUS is an invasive technique requiring sedation¹ and is highly operator dependent.¹⁰ PET highly depends upon the standardized uptake value and the pathological subtype of the cancer.¹¹MRI is a powerful imaging method with high soft-tissue contrast, with technical versatility for sequence selection and modification, and without ionizing radiation. However, it was unsuitable for the staging of GC owing to its long acquisition time and susceptibility to motion artefacts in previous years. With technology improved and shorter imaging time, these limitations have recently been partially overcome.¹²Recently, there has been much research using MRI to assess pre-operative staging of GC. Nevertheless, the number of patients in each study has been insufficient, and the results varied among the articles. Also, the limited imaging field of view of MRI in a single session makes it difficult to stage the distant metastasis (M).¹³ Therefore, the objective of this study was to perform a systematic review and meta-analysis regarding the diagnostic accuracy of MRI for pre-operative T and N staging of GC.     

Correlation of the apparent diffusion coefficiency values on diffusion-weighted imaging with prognostic factors for breast cancer

Objective

The aim of this study was to correlate the apparent diffusion coefficient (ADC) value of breast cancer with prognostic factors.

Methods

335 patients with invasive ductal carcinoma not otherwise specified (IDC NOS) and ductal carcinoma in situ (DCIS) who underwent breast MRI with diffusion-weighted imaging were included in this study. ADC of breast cancer was calculated using two b factors (0 and 1000 s mm^–2). Mean ADCs of IDC NOS and DCIS were compared and evaluated. Among cases of IDC NOS, mean ADCs were compared with lymph node status, size and immunochemical prognostic factors using Student''s t-test. ADC was also correlated with histological grade using the Kruskal–Wallis test.

Results

Mean ADC of IDC NOS was significantly lower than that of DCIS (p<0.001). However, the mean ADC of histological grade of IDC NOS was not significantly different (p=0.564). Mean ADC of oestrogen receptor (ER)-positive or progesterone receptor (PR)-positive cancer was significantly lower than that of ER-negative or PR-negative cancer (p=0.003 vs p=0.032). Mean ADC of Ki-67 index-positive cancer was significantly lower than that of Ki-67 index-negative cancer (p=0.028). Mean ADC values of cancers with increased microvascular density (MVD) were significantly lower than those of cancer with no MVD increase (p=0.009). No correlations were observed between mean ADC value and human growth factor receptor 2 expression, tumour size and lymph node metastasis.

Conclusion

Low ADC value was correlated with positive expression of ER, PR, increased Ki-67 index, and increased MVD of breast cancer.Breast MRI is an established supplemental technique to mammography and ultrasonography for evaluation of suspicious breast lesions. Diffusion-weighted MRI (DWI) has recently been integrated into the standard breast MRI for discrimination of benign and malignant breast lesions obtained with dynamic contrast-enhanced MRI [1-13]. DWI is a non-invasive technique that represents the biological character of the mainly Brownian movement of protons in bulk water molecules in vivo. Apparent diffusion coefficient (ADC) values are quantified by measurement of mean diffusivity along three orthogonal directions, which are affected by cellularity of the tissue, fluid viscosity, membrane permeability and blood flow [7,9-11]. Microstructural characteristics, including water diffusion and blood microcirculations in capillary networks, were associated with ADC value. Decreased movement of molecules in highly cellular tissue showed correlation with a low ADC value [3,4]. Several studies of DWI of the breast have reported significantly lower ADC values in malignant tumours, compared with benign breast lesions and normal tissue [1-3,5-11,14]. Classic prognostic markers, including tumour size and grade, and lymph node status in patients with breast cancer, and molecular markers, including oestrogen receptor (ER), progesterone receptor (PR), Ki-67 index, human growth factor receptor 2 (HER2) protein and angiogenic molecular markers, have been reported [1,15,16]. Few studies have examined the correlation between ADC values and prognostic factors [1,8]. The purpose of this study is to compare ADC values of DWI of breast cancer with prognostic factors.     

Prognostic factors associated with a subchondral insufficiency fracture of the femoral head

Objective

The aim of this study was to identify the risk factors associated with the prognosis of a subchondral insufficiency fracture of the femoral head (SIF).

Methods

Between June 2002 and July 2009, 25 patients diagnosed with SIF were included in this study. Sequential radiographs were evaluated for the progression of collapse. Clinical profiles, including age, body mass index, follow-up period and Singh’s index, were documented. The morphological characteristics of the low-intensity band on T₁ weighted MRI were also examined with regards to four factors: band length, band thickness, the length of the weight-bearing portion and the band length ratio (defined as the proportion of the band length to the weight-bearing portion of the femoral head in the slice through the femoral head centre).

Results

Radiographically, a progression of collapse was observed in 15 of 25 (60.0%) patients. The band length in patients with progression of collapse [22.5 mm; 95% confidence interval (CI) 17.7, 27.3] was significantly larger than in patients without a progression of collapse (13.4 mm; 95% CI 7.6, 19.3; p<0.05). The band length ratio in patients with progression of collapse (59.8%; 95% CI 50.8, 68.9) was also significantly higher than in patients without a progression of collapse (40.9%; 95% CI 29.8, 52.0; p<0.05). No significant differences were present in the other values.

Conclusion

These results indicate that the band length and the band length ratio might be predictive for the progression of collapse in SIF.Subchondral insufficiency fractures of the femoral head (SIF) often occur in osteoporotic elderly patients [1-9]. Patients usually suffer from acute hip pain without any obvious antecedent trauma. Radiologically, a subchondral fracture is seen primarily in the superolateral portion of the femoral head [4,5,10]. T₁ weighted MRI reveal a very low-intensity band in the subchondral area of the femoral head, which tends to be irregular, disconnected and convex to the articular surface [2,4,5,7,9,11]. This low-intensity band in SIF was histologically proven to correspond with the fracture line and associated repair tissue [5,9]. Some cases of SIF resolve after conservative treatment [5,11-14]; other cases progress until collapse, thereby requiring surgical treatment [4-10,15]. The prognosis of SIF patients remains unclear.The current study investigated the risk factors that influence the prognosis of SIF based on the progression to collapse.     

Diffusion-weighted imaging in the assessment of tumour grade in endometrial cancer

Objective

Endometrial cancer is the most common gynaecological malignancy in developed countries. Histological grade and subtype are important prognostic factors obtained by pipelle biopsy. However, pipelle biopsy “samples” tissue and a high-grade component that requires more aggressive treatment may be missed. The purpose of the study was to assess the use of diffusion-weighted MRI (DW-MRI) in the assessment of tumour grade in endometrial lesions.

Method

42 endometrial lesions including 23 endometrial cancers and 19 benign lesions were evaluated with DW-MRI (1.5T with multiple b-values between 0 and 750 s mm⁻²). Visual evaluation and the calculation of mean and minimum apparent diffusion coefficient (ADC) value were performed and correlated with histology.

Results

The mean and minimum ADC values for each histological grade were 1.02 ± 0.29×10⁻³ mm² s⁻¹ and 0.74 ± 0.24×10⁻³ mm² s⁻¹ (grade 1), 0.88 ± 0.39×10⁻³ mm² s⁻¹ and 0.64 ± 0.36×10⁻³ mm² s⁻¹ (grade 2), and 0.94 ± 0.32×10⁻³ mm² s⁻¹ and 0.72 ± 0.36×10⁻³ mm² s⁻¹ (grade 3), respectively. There was no statistically significant difference between tumour grades. However, the mean ADC value for endometrial carcinoma was 0.97 ± 0.31, which was significantly lower (p<0.0001) than that of benign endometrial pathology (1.50 ± 0.14). Applying a cut-off mean ADC value of less than 1.28 × 10⁻³ mm² s⁻¹we obtained a sensitivity, specificity, positive predictive value and negative predictive value for malignancy of 87%, 100%, 100% and 85.7%, respectively.

Conclusion

Tumour mean and minimum ADC values are not useful in differentiating histological tumour grade in endometrial carcinoma. However, mean ADC measurement can provide useful information in differentiating benign from malignant endometrial lesions. This information could be clinically relevant in those patients where pre-operative endometrial sampling is not possible.Endometrial carcinoma is the commonest gynaecological malignancy in developed countries [1,2]. The majority of patients present with intermenstrual or post-menopausal bleeding, with approximately 70–80% having early (Stage I) disease at presentation [1,3]. Despite the relatively high incidence, endometrial cancer is not a common cause of cancer death with a 5 year survival of approximately 80% when all stages are considered together [4].The most important prognostic indicators in endometrial cancer are FIGO (International Federation of Gynecology and Obstetrics) stage, lymphovascular invasion, histological subtype and grade, and the presence of lymph node metastases [4-8]. FIGO staging of endometrial cancer is a surgico-pathological staging system that includes total hysterectomy, bilateral salpingo-oophrectomy and peritoneal washings with full pelvic lymphadenectomy [9]. The overall rate of lymph node involvement in endometrial cancer is low (5–8%) and lymphadenectomy carries a reported complication risk of up to 17–19% [10,11], which is particularly marked in patients who are at high surgical risk, such as those who are obese, diabetic or suffer from ischaemic heart disease [12]. As a result, only around 30% of endometrial cancer patients undergo lymphadenectomy in the USA as a whole, increasing to 48.3% in specialised cancer centres [13]. The role of lymphadenectomy in the management of endometrial cancer is currently an area of controversy in gynaecological oncology with no clear evidence regarding the survival benefits associated with the procedure [14-17]. However, in patients who are at high risk of nodal metastases most centres continue to perform lymphadenectomy.Accurate pre-operative identification of patients at high risk of nodal metastases would allow the selection of patients for lymphadenectomy, while those at low risk could be treated with simple hysterectomy. Histological tumour grade is a strong predictor of nodal invasion and thereby prognosis in endometrial cancer [18,19]. In patients with FIGO Stage 1 disease, grade 1 or grade 2 histology carries a less than 10% risk of nodal metastases. However, grade 3 histology carries an overall risk of 18% in Stage 1 disease, which increases to 34% when considering patients with deep myometrial invasion [18,19]. Pre-operative cytology from pipelle or curettage specimens only samples the endometrial tissue and therefore does not always provide accurate assessment [20,21]. In a study of patients with grade 1 histology pre-operatively 19% were upgraded following surgical resection [22].Diffusion-weighted MRI (DW-MRI) is a functional imaging technique that looks at the Brownian motion of water in tissues. In biological tissues this is restricted by interactions with cell membranes and macromolecules on a microscopic level. Increased tissue cellularity, as seen in tumours, restricts Brownian motion, which can be quantified by calculation of the apparent diffusion coefficient (ADC) [23].Previous publications have demonstrated that endometrial carcinoma may be distinguished from normal endometrium on DW-MRI [24-30]. It has also been suggested that DW-MRI may be useful in the pre-operative assessment of tumour grade [26,31]. The purpose of this study is to determine if there is a correlation between histological tumour grade and ADC value in endometrial cancer.     

Embolisation of the right gastric artery in patients undergoing hepatic arterial infusion chemotherapy using two possible approach routes

We used a retrospective non-randomised study to investigate the clinical effect of selective embolisation of the right gastric artery before hepatic arterial infusion chemotherapy (HAIC) using a port-catheter system. We evaluated whether the hepatic artery or the left gastric artery is the better approach for selecting the right gastric artery. A total of 367 patients (244 men and 123 women; mean age, 64.1 years) with unresectable advanced liver cancer underwent percutaneous implantation of a port-catheter system. In 294 of these patients, right gastric arterial embolisation with microcoils was attempted before placement of the port-catheter system to prevent gastric mucosal lesions. Approach was either through the hepatic artery (175 patients) or through the left gastric artery (119 patients), with success rates in catheterising the right gastric artery of 78.3% and 77.3%, respectively. If the attempt was unsuccessful, the catheter was redirected to the alternative approach, which increased the final success rate to 96.3%. Only seven patients experienced gastroduodenal mucosal lesions acutely after HAIC, as revealed by endoscopy. Embolisation of the right gastric artery is a feasible procedure that can reduce the incidence of gastric mucosal lesions associated with HAIC. Approach through either the hepatic artery or the left gastric artery is equally acceptable.Long-term hepatic arterial infusion chemotherapy (HAIC) via an implanted port-catheter system is a treatment option for patients with unresectable advanced liver cancer [1, 2]. In the past, such catheter placement was done by surgical laparotomy under general anaesthesia [3–6], an invasive procedure. However, recent advances in interventional techniques allow the implantation of port-catheter systems percutaneously under local anaesthesia [7–14].A frequent complication is reactive gastric or duodenal mucosal lesions, which result from chemical irritation caused by infusion of chemotherapeutic agents into adjacent organs through arteries originating from the common hepatic artery [15–24]. One such complication is a gastric mucosal lesion caused by inflow of chemotherapeutic agents into the right gastric artery [15–24]. To prevent this complication, the efficacy of selectively embolising the right gastric artery with coils at the time of implantation of the port-catheter system has been noted [21, 25–27].In many cases, however, the right gastric artery is slender and angulated, with anatomical variations [26, 28–31]. Hence, it is occasionally difficult to insert a catheter selectively into the right gastric artery by antegrade catheterisation via the site of the hepatic artery. This is the approach most commonly used by interventional radiologists. Failure to embolise the right gastric artery can result [26]. As an alternative method, a retrograde approach to the right gastric artery via the left gastric artery has been introduced [32, 33].Because HAIC with an implanted port-catheter system is performed in a relatively large number of cases in our institution, we have many opportunities to embolise the right gastric artery using both approaches. The aim of the present retrospective non-randomised study, which included a large number of subjects, was to evaluate the usefulness of right gastric arterial embolisation and to determine whether the antegrade or retrograde approach is more useful.     

Iron overload: accuracy of in-phase and out-of-phase MRI as a quick method to evaluate liver iron load in haematological malignancies and chronic liver disease

Objectives

The purpose of this prospective study was to evaluate the accuracy of in-phase and out-of-phase imaging to assess hepatic iron concentration in patients with haematological malignancies and chronic liver disease.

Methods

MRI-based hepatic iron concentration (M-HIC, μmol g^–1) was used as a reference standard. 42 patients suspected of having iron overload and 12 control subjects underwent 1.5 T in- and out-of-phase and M-HIC liver imaging. Two methods, semi-quantitative visual grading made by two independent readers and quantitative relative signal intensity (rSI) grading from the signal intensity differences of in-phase and out-of-phase images, were used. Statistical analyses were performed using the Spearman and Kruskal–Wallis tests, receiver operator curves and κ coefficients.

Results

The correlations between M-HIC and visual gradings of Reader 1 (r=0.9534, p<0.0001) and Reader 2 (r=0.9456, p<0.0001) were higher than the correlations of the rSI method (r=0.7719, p<0.0001). There was excellent agreement between the readers (weighted κ=0.9619). Both visual grading and rSI were similar in detecting liver iron overload: rSI had 84.85% sensitivity and 100% specificity; visual grading had 85% sensitivity and 100% specificity. The differences between the grades of visual grading were significant (p<0.0001) and the method was able to distinguish different degrees of iron overload at the threshold of 151 μmol g^–1 with 100% positive predictive value and negative predictive value.

Conclusion

Detection and grading of liver iron can be performed reliably with in-phase and out-of-phase imaging. Liver fat is a potential pitfall, which limits the use of rSI.Iron overload is a clinically recognised condition with variety of aetiologies and clinical manifestations [1-4]. Liver iron concentration correlates closely with the total body iron stores [5]. The excess iron accumulates mainly in the liver and the progressive accumulation of toxic iron can lead to organ failure if untreated [2,4]. Several diseases causing iron overload, such as transfusion-dependent anaemia, haematological malignancies, thalassaemia, haemochromatosis and chronic liver disease, result in a large number of patients with a potentially treatable iron overload [1,2,4].Several quantitative MRI methods for iron overload measurement by multiple sequences have been established, such as proportional signal intensity (SI) methods and proton transverse relaxation rates (R₂, R₂*) [4,6,7]. A gradient echo liver-to-muscle SI-based algorithm [8] has been widely validated and used for quantitative liver iron measurement [8-11]. MRI-based hepatic iron concentration (M-HIC, μmol g^–1 liver dry weight) with corresponding R₂* [9] can be calculated with this method which is a directly proportional linear iron indicator, virtually independent of the fat fraction, as the echo times are taken in-phase [8,9]. This method showed a high accuracy in calibrations with the biochemical analysis of liver biopsies (3–375 μmol g^–1) of 174 patients. The mean difference of 0.8 μmol g^–1 (95% confidence interval of –6.3 to 7.9) between this method and the biochemical analysis is quite similar [8] to the intra-individual variability found in histological samples [12].The quantitative MRI methods are based on progressive SI decay, with the longer echo times due to relaxing properties of iron. Interestingly, this iron-induced effect is seen in MR images with multiple echoes [4,6-11], but also in dual-echo images, namely in-phase and out-of-phase imaging [13,14]. In-phase and out-of-phase imaging has become a routine part of liver MRI, performed initially for liver fat detection [6,13,15]. Quite recently some investigators have noticed an alternative approach of the sequence to detect liver iron overload due to the more pronounced SI decrease on in-phase images with the longer echo time [13,14]. Yet, to our knowledge, this is the first prospective study evaluating the accuracy of in-phase and out-of-phase imaging to assess hepatic iron concentration.The purpose of the study was to evaluate the capability and accuracy of dual-echo in-phase and out-of-phase imaging to assess hepatic iron concentration at 1.5 T in patients with haematological malignancies and chronic liver disease. MRI-based hepatic iron concentration (M-HIC, μmol g^–1) was used as a reference standard [8,9].     

Pattern and predictors of volumetric change of parotid glands during intensity modulated radiotherapy

Objective:

To describe the pattern and predictors of volumetric change of parotid glands during intensity modulated radiotherapy (IMRT) for oropharyngeal cancer.

Methods:

A cohort of patients undergoing weekly CT scans during dose-painted IMRT was considered. The parotid glands were contoured at the time of treatment planning (baseline) and on all subsequent scans. For a given patient, the parotid glands were labelled as higher (H) and lower (L), based on the mean dose at planning. The volume of each gland was determined for each scan and the percent change from baseline computed. Data were fit to both linear and quadratic functions. The role of selected covariates was assessed with both logistic regression and pair-wise comparison between the sides. The analyses were performed considering the whole treatment duration or each separate half.

Results:

85 patients, 170 glands and 565 scans were analysed. For all parotids except one, the quadratic function provided a better fit than the linear one. Moreover, according to both the logistic regression and pair-wise comparison, the cumulative mean dose of radiation is independently correlated with the parotid shrinkage during the first but not the second half of the treatment. Conversely, age and weight loss are predictors of relative parotid shrinkage during the entire course of the treatment.

Conclusion:

Parotid gland shrinkage during IMRT is not linear. Age, weight loss and radiation dose independently predict parotid shrinkage during a course of IMRT.

Advances in knowledge:

The present study adds to the pathophysiology of parotid shrinkage during radiotherapy.Fractionated radiotherapy is based on the assumption that the dose distribution obtained at planning is delivered during each treatment session. However, both set-up errors and tissue deformation can modify the dose that is administered. Shifts in the location of isodose levels compared with planning become critical for techniques that are highly conformal to the target(s), such as IMRT, justifying the interest in image guidance and adaptive radiotherapy [1]. Because of the sharp dose gradient around the target(s), subtle changes in the relative position or in the volume of organs at risk may alter the planned dose that the volume of an organ receives, as has been shown for the parotid glands [2–6].In a study by Ricchetti et al [7], we found that the parotid glands are the regions of interest that undergo the largest absolute and relative changes in volume during treatments. Although at least 16 articles have documented a significant percent reduction in the volume of the parotid gland during the course of fractionated radiotherapy [2,3,7–20], there are still several unanswered questions. It is unclear why some parotid glands shrink to about 50–60% during treatment, while others show only minimal changes. Studies that have investigated predictors of shrinkage have suggested weight loss during treatment, patient age and dose of radiation to the parotid as potential factors [2,9,16–19]. However, results are inconsistent [3,8,10,14]. Some studies have suggested that dosimetrically spared parotid glands undergo only minimal volume changes during treatment [16,18], whereas others describe a similar behaviour regardless of the radiation dose [7,8,10]. Furthermore, it is unclear whether the daily percent volume change is constant [8,10,16,19] or variable [7,10,13] during the course of treatment. A variable daily percent change in the volume may indicate that there are predictive factors specific to certain portions of the fractionated radiation schedule. In the present article, we attempt to clarify these points.     

Accessory or additional renal arteries show no relevant effects on the width of the upper urinary tract: a 64-slice multidetector CT study in 1072 patients with 2132 kidneys

Objective

The aim of this study was to find out on an unselected patient group whether crossing vessels have an influence on the width of the renal pelvis and what independent predictors of these target variables exist.

Methods

In this cross-sectional study, 1072 patients with arterially contrasted CT scans were included. The 2132 kidneys were supplied by 2736 arteries.

Results

On the right side, there were 293 additional and accessory arteries in 286 patients, and on the left side there were 304 in 271 patients. 154 renal pelves were more than 15 mm wide. The greatest independent factor for hydronephrosis on one side was hydronephrosis on the contralateral side (p<0.0001 each). Independent predictors for the width of the renal pelvis on the right side were the width of the renal pelvis on the left, female gender, increasing age and height; for the left side, predictors were the width of the renal pelvis on the right, concrements, parapelvic cysts and great rotation of the upper pole of the kidney to dorsal. Crossing vessels had no influence on the development of hydronephrosis. Only anterior crossing vessels on the right side are associated with widening of the renal pelvis by 1 mm, without making it possible to identify the vessel as an independent factor in multivariate regression models.

Conclusion

The width of the renal pelvis on the contralateral side is the strongest independent predictor for hydronephrosis and the width of the renal pelvis. There is no link between crossing vessels and the width of the renal pelvis.Obstructions of the ureteropelvic junction (UPJ) can be caused by intrinsic or extrinsic factors [1]. Although there are no studies of this to date, crossing the UPJ by an aberrant crossing vessel is considered the most important [2] of the extrinsic factors [3]. Crossing vessels, which are thought to cause from 40% to over 50% of the extrinsic UPJ obstructions in adults [4, 5], are located ventral more often than dorsal to the UPJ. These are usually normal vessels of the lower pole segment [4, 6–9], which can be divided into additional renal arteries arising from the aorta, and accessoric renal arteries arising from branches of the aorta [10, 11]. The primary surgical therapy of choice is endoscopic endopyelotomy [12]. The success rate of 89–90% [12, 13] is thought to be noticeably poorer in patients with crossing vessels [12, 13]; however, this is not undisputed [14, 15]. Be that as it may, to prevent bleeding complications it is necessary to be familiar with the vascular situation around the UPJ prior to the procedure [3, 16–18]. CT angiography is used for this purpose, as it is highly accurate, quick to perform and shows all relevant anatomical structures in relation to one another [3, 19, 20]. The objective of this study was to determine whether or not there are vascular morphological patterns or other factors that influence the width of the renal collecting system, regardless of the definitions of hydronephrosis.     

Multimodality imaging of obliterative portal venopathy: what every radiologist should know

Obliterative portal venopathy (OPV) is an important cause of non-cirrhotic portal hypertension, which is often erroneously misdiagnosed as cryptogenic cirrhosis. It has a worldwide distribution with majority of cases hailing from the Asian subcontinent. However, recently the disease has gained global attention particularly because of its association with human immunodeficiency virus infection and use of antiretroviral drug therapy (didanosine). As the name suggests, the disorder is characterized by sclerosis and obliteration of the intrahepatic portal vein branches (with attendant periportal fibrosis) leading to portal hypertension amid intriguingly little liver dysfunction. It primarily affects young adults who present with clinically significant portal hypertension in the form of episodes of variceal bleed; however, contrasting liver cirrhosis, the liver function and liver structure remain normal or near normal until late in the disease process. Radiological findings during advanced disease are often indistinguishable from cirrhosis often warranting a liver biopsy. Nevertheless, recent studies have suggested that certain imaging manifestations, if present, can help us to prospectively suggest the possibility of OPV. At imaging, OPV is characterized by a wide range of intrahepatic and/or extrahepatic portal venous abnormalities with attendant changes in liver and splenic volume and stiffness. We shall, through this pictorial review, appraise the literature and illustrate the germane radiological manifestations of OPV that can be seen using different imaging modalities including ultrasonography, CT, MRI, elastography and hepatic haemodynamic studies.It is important to recognize that not all varices mean liver cirrhosis. Although liver cirrhosis constitutes the commonest cause of portal hypertension, we should be aware that portal hypertension can occur in the absence of liver cirrhosis—a condition termed as non-cirrhotic portal hypertension (NCPH).^1,2 NCPH represents a heterogeneous group of (primarily vascular) disorders where portal hypertension manifests amid absent liver cirrhosis. Pathologically, the insult is either pre- or intrahepatic involving the main portal vein or its smaller branches and/or the perisinusoidal area.^1–3Obliterative portal venopathy (OPV) represents an important cause of NCPH that is characterized by sclerosis and obliteration of the medium-sized portal venous branches leading to portal hypertension.^1–10 Liver biopsy characteristically shows phlebosclerosis and periportal and perisinusoidal fibrosis amid absent cirrhosis (Figure 1).^1–3 Although, the exact aetiology is contentious, infections and prothrombotic states have been implicated in eastern and western patients, respectively.^1,2 Additionally, xenobiotic exposure, autoimmune and genetic factors have also been incriminated.^1–4 Although the disease has a worldwide distribution, it continues to remain poorly understood primarily owing to its relative rarity.^1–3,5–8 Another potential reason is the use of diverse terminologies under which the entity has been described from various parts of the globe, such as non-cirrhotic portal fibrosis in India, idiopathic portal hypertension in Japan and hepatoportal sclerosis in the USA.Open in a separate windowFigure 1.(a) Atrophic small portal tract (arrow) showing absent portal vein [haematoxylin and eosin stain (HE), ×200]. (b) Two small portal tract (arrows) approximations (×100, HE). (c) Portal and central vein approximation (×100, HE). (d) Parenchymal extinction suggested by portal–portal and portal–central approximation (Masson''s trichrome stain, ×200).More recently, the disease has gained global attention because of escalating number of cases being reported in human immunodeficiency virus (HIV)-infected patients.^1–3,8–10 Also, US Food and Drug Administration has recently issued a warning regarding the potential association of OPV in patients with HIV on didanosine (antiretroviral therapy).³OPV primarily affects young patients usually in their third or fourth decades of life. The affected individuals typically present with clinically significant portal hypertension characterized by multiple episodes of well-controlled upper gastrointestinal (GI) bleed, massive splenomegaly and/or hypersplenism.^1–3 Advanced stages of the disease are often indistinguishable from liver cirrhosis especially on imaging. However, discrimination from cirrhosis is crucial in clinical practice because of differences in management. Management of OPV is primarily symptomatic, that is, focused on management of an acute episode of variceal bleed. The risk of rebleeding and bleeding-related mortality is low. Intriguingly, in contrast to liver cirrhosis, the liver function and liver structure remain normal or near normal until late in the disease process leading to a better prognosis and higher survival rates; the 10-year survival rate is around 86–95%.^1,2 Development of jaundice, ascites and hepatic encephalopathy is uncommon and if at all is seen only after an episode of GI bleeding.^1,2 Liver failure and the incidence of developing hepatocellular carcinoma are also much lower.^1–3,8–10 Nonetheless, in 20–33% of patients, the liver gradually atrophies and shows functional decompensation, occasionally needing liver transplantation.^1,2Although limited literature is available on the radiological manifestations of OPV, recent studies have suggested certain imaging manifestations to be more prevalent in OPV that can allow discrimination from cirrhosis. Moreover, use of newer techniques, including transient elastography, can allow prospective non-invasive diagnosis of OPV based upon the differential changes in liver and splenic stiffness. The aim of this review is to appraise the imaging findings of OPV described in the literature and illustrate them across a wide array of imaging modalities, including ultrasonography, CT, MRI and elastography, in a group of biopsy-proven cases of OPV diagnosed at our institute.     

Simplified rules for everyday delineation of lymph node areas for breast cancer radiotherapy

The aim of this study was to present the simplified rules of delineation of lymph node (LN) volumes in breast irradiation. Practical rules of delineation of LN areas were developed in the Department of Radiation Oncology of the Institut Curie. These practical guidelines of delineation were based on different specific publications in the field of breast and LN anatomy. The principal characteristic of these rules is their clearly established relationship with anatomical structure, which is easy to find on CT slices. The simplified rules of delineation have been published in pocket format as the illustrated atlas “Help of delineation for breast cancer treatment”. In this small pocket guide, delineation using the practical rules is illustrated, with examples from anatomical CT slices. It is shown that there is an improvement in delineation after the use of these simplified rules and the guide. In conclusion, this small guide is useful for improving everyday practice and decreasing the differences in target delineation for breast irradiation between institutions and observers.The value of lymph node irradiation has already been demonstrated by various studies and meta-analyses [1–3]. In the age of new conformal techniques, there is a real need for a clear definition of treated volumes, such as breast, tumour bed, lymph node areas and organs at risk (OAR) [4–10]. Many teams have been working for several years on the definition of treated volumes. Some delineation studies are exclusively theoretical and some provide a good anatomical atlas, but this information is difficult to use in everyday practice [4–15]. The treatment position has also been shown to be an important factor of variability in the depth and situation of lymph node volumes [5, 6]. Conformal and intensity-modulated radiotherapy (IMRT) require an exact definition of target volumes in terms of their anatomical limits for delineation on CT scans. Some authors have proposed anatomically based landmarks specific for breast cancer radiotherapy in order to delineate all regional lymph nodes and the breast [5, 6, 8, 10, 15, 16]. Despite this work, two recent papers have demonstrated the individual interobserver variability and differences in target and OAR delineation for breast irradiation, especially in lymph node areas [7, 8].This study was designed to propose a practical method to improve and facilitate the everyday delineation process for the clinicians of our department.     

Diffusion-weighted MRI in the follow-up of chronic periaortitis

Objective:

To evaluate the usefulness of diffusion-weighted MRI (DWI) for the assessment of the intraindividual follow-up in patients with chronic periaortitis (CP) under medication.

Methods:

MRI data of 21 consecutive patients with newly diagnosed untreated disease were retrospectively examined before and after medical therapy, with a median follow-up of 16 weeks. DWI parameters [b800 signal, apparent diffusion coefficient (ADC) values] of the CP and psoas muscle were analysed together with the extent and contrast enhancement. Pre- and post-treatment laboratory inflammation markers were acquired parallel to each MR examination.

Results:

Statistically significant lower b800 signal intensities (p ≤ 0.0001) and higher ADC values (p ≤ 0.0001) were observed after medical treatment within the fibrous periaortic tissue. Extent and contrast enhancement of the CP showed also a statistically significant decrease (p ≤ 0.0001) in the follow-up examinations, while the control parameters within the psoas muscle showed no differences.

Conclusion:

DWI seems to be a useful method for the evaluation of response to treatment without contrast agents. The technique may be helpful in the assessment of disease activity to guide further therapeutic strategies.

Advances in knowledge:

DWI detects significant differences in the intraindividual follow-up of CP under medical therapy.Chronic periaortitis (CP) is a proliferating fibroinflammatory disease of the perivascular retroperitoneal space and aortic wall.^1–4 Owing to adventitial inflammation, some recent theories consider CP as a large vessel vasculitis.⁵ Clinical manifestations of CP include idiopathic retroperitoneal fibrosis, inflammatory aortic aneurysm and perianeurysmal retroperitoneal fibrosis.^2,6,7 The three manifestations with very similar histopathological characteristics are distinguished by the diameter of the abdominal aorta and concomitant ureteral affection.^1,3,7Specific clinical symptoms are caused by extrinsic compression of the ureters or retroperitoneal veins, resulting in hydronephrosis, oliguria, lower extremity oedema and deep vein thrombosis.^1,8Under medical treatment with steroids, CP has a good prognosis.⁷ Today tamoxifen is suggested as a safe and effective therapeutic alternative, and immunosuppressive drugs can be considered in patients with suboptimal responses to these drugs or multiple relapses.^9–11CT and MRI are the modalities of first choice for diagnosis and follow-up of CP.^1,7,12 The fibrotic para-aortic tissue shows significant contrast uptake in gadolinium-enhanced MRI.^12–14 Dynamic contrast-enhanced MRI was suggested for the assessment of the disease activity.^15,16 However, in cases with impaired renal function (e.g. by ureteral compression), gadolinium-independent imaging methods should be preferred owing to the potential development of a nephrogenic systemic fibrosis.¹⁷Diffusion-weighted MRI (DWI) is a non-contrast MR modality that has been successfully applied for the assessment of retroperitoneal masses, inflammatory abdominal aortic aneurysms and for the differentiation between retroperitoneal fibrosis and malignant retroperitoneal neoplasms.^18–21DWI indicates restricted diffusion of water, for example caused by a high cellularity in malignant disease or active inflammation. The apparent diffusion coefficient (ADC) is a quantitative parameter for the level of restricted diffusion, which is calculated from the signals of different diffusion gradients (b-values).²²In the context of untreated CP diffusion-weighted MRI may detect restricted inflammation as a sign of high cellularity caused by active inflammation.There are no data for the evaluation of intraindividual follow-up and the response to treatment by DWI of CP so far. Therefore, the aim of the present study was to analyse differences in DWI signals during follow-up in patients with CP before and after treatment. In addition, we sought to elucidate the potential of DWI in the therapy monitoring of CP.     

Use of 99mTc-doxorubicin scintigraphy in females with breast cancer: a pilot study

Objective:

Doxorubicin (Eurofarma, São Paulo, Brazil) is an antitumour agent widely used in the treatment of breast cancer and can be used for tumour tracking when labelled with a radionuclide. Here, we present the results obtained with technetium-99m (^99mTc)-doxorubicin, using the direct method, to evaluate its uptake in breast cancer.

Methods:

Four females with confirmed breast carcinoma diagnosis and breast image reporting and data system Category 5 on mammography underwent whole-body and thorax single-photon emission CT/CT imaging 1 and 3 h after ^99mTc-doxorubicin administration.

Results:

We observed increased uptake in breast carcinoma lesions and elimination via renal and hepatic pathways.

Conclusion:

These preliminary results suggest that ^99mTc-doxorubicin may be a promising radiopharmaceutical for the evaluation of patients with breast cancer. Further studies are ongoing.

Advances in knowledge:

To our knowledge, this is the first study to evaluate the use of a directly labelled doxorubicin tracer in humans. ^99mTc-doxorubicin could provide information on the response of tumours to doxorubicin.Breast cancer is the most common cancer in females worldwide, with an estimated 1.67 million new cases in 2012.¹ In order to improve the treatment and prognosis of breast cancer, early detection is extremely important. However, the techniques most often used for cancer evaluation, such as mammography, ultrasonography and MRI, have limitations and are not always capable of differentiating benign from malignant lesions. Breast scintigraphy has some clinical indications and, in association with other imaging methods, can increase the accuracy of diagnoses and reduce unnecessary biopsies.²Advances in imaging modalities have contributed to the improvement of early breast cancer diagnosis.³ The use of positron emission tomography (PET) and its new radiopharmaceuticals is an important advance in cancer detection.⁴ Hybrid acquisition of PET with CT (PET/CT) allows evaluation of morphological parameters, increasing the sensitivity and specificity of PET findings.⁴ However, the uptake of fluorine-18-fludeoxyglucose (¹⁸F-FDG), the radiopharmaceutical most often used for PET, changes according to different variables, such as the histological type. In breast cancer, infiltrating ductal carcinoma shows higher uptake than infiltrating lobular carcinoma, while in ductal carcinoma, uptake is usually low.^{5–7 18}F-FDG uptake also depends on the grade of breast cancer.^6,8 Hybrid PET/CT has low sensitivity for tumours <1 cm, owing to limitations in spatial resolution and tumour variables,^7,8 and ¹⁸F-FDG uptake may occur in benign lesions such as inflammatory granulomatous mastitis.⁹ Although PET/CT is limited in the evaluation of tumour size and the presence of multifocal disease, this might change with the advent of positron emission mammography (PEM). Eo et al¹⁰ reported that PEM diagnosed more malignant breast lesions than PET/CT, particularly in tumours <2 cm.Unfortunately, PET scanners are not available in all nuclear medicine services, notably in developing countries. Conventional gamma cameras, on the other hand, are widely available and therefore single-photon emission CT (SPECT) radiopharmaceuticals have the potential to benefit a larger number of patients. Another promising tool is the use of dedicated apparatus for conventional nuclear medicine of the breast, called molecular breast imaging (MBI), which can detect malignant breast lesions <1 cm.^11,12Doxorubicin (Eurofarma, São Paulo, Brazil) is a potent antitumour agent that is widely used in chemotherapy for several types of cancer.¹³ It acts by intercalating nucleotide bases, binding to the lipid membrane, and also inhibits the biosynthesis of macromolecules.¹⁴ Among the main side effects of this drug is possible cardiotoxicity.¹⁵ Technetium-99m (^99mTc) is the radionuclide most often used in conventional nuclear medicine; our research group has used ^99mTc to radiolabel different types of cells and molecules.^16–23 We previously reported a technique for labelling the thymidine precursor thymine with ^99mTc, with good specificity and high predictive value.^16–18 We have also used ^99mTc-doxorubicin in dogs and cats in order to evaluate its uptake in different kinds of tumours, with promising results, which led to the approval of this pilot trial.²⁴     

Walking on thin ice! Identifying methamphetamine “drug mules” on digital plain radiography

Objective:

The purpose of this study was to retrospectively evaluate the sensitivity, specificity and accuracy of identifying methamphetamine (MA) internal payloads in “drug mules” by plain abdominal digital radiography (DR).

Methods:

The study consisted of 35 individuals suspected of internal MA drug containers. A total of 59 supine digital radiographs were collected. An overall calculation regarding the diagnostic accuracy for all “drug mules” and a specific evaluation concerning the radiological appearance of drug packs as well as the rate of clearance and complications in correlation with the reader''s experience were performed. The gold standard was the presence of secured drug packs in the faeces.

Results:

There were 16 true-positive “drug mules” identified. DR of all drug carriers for Group 1 (forensic imaging experienced readers, n = 2) exhibited a sensitivity of 100%, a mean specificity of 76.3%, positive predictive value (PPV) of 78.5%, negative predictive value (NPV) of 100% and a mean accuracy 87.2%. Group 2 (inexperienced readers, n = 3) showed a lower sensitivity (93.7%), a mean specificity of 86%, a PPV of 86.5%, an NPV of 94.1% and a mean accuracy of 89.5%. The interrater agreement within Group 1 was 0.72 and within Group 2 averaged to 0.79, indicating a fair to very good agreement.

Conclusion:

DR is a valuable screening tool in cases of MA body packers with huge internal payloads being associated with a high diagnostic insecurity. Diagnostic insecurity on plain films may be overcome by low-dose CT as a cross-sectional imaging modality and addressed by improved radiological education in reporting drug carriers on imaging.

Advances in knowledge:

Diagnostic signs (double-condom and halo signs) on digital plain radiography are specific in MA “drug mules”, although DR is associated with high diagnostic insecurity and underreports the total internal payload.For the past decade, significant worldwide manufacturing of amphetamine-type stimulants has been reported to the United Nations Office on Drugs and Crime, Vienna, Austria, with a predominance of methamphetamine (MA) and its derivatives, which are also known as “syabu” or “ice”, throughout East and South East Asia.¹ In this region, the use of this synthetic drug is more prevalent than that of cocaine or heroin, which are more common in relatively developed areas, such as Europe and the USA.² During the course of this development, an increase in the number of drug carriers being intercepted by law enforcement at the borders of Malaysia has been observed. Drug carriers or “drug mules” are generally referred to as a human harbouring internal illicit drug packet(s). Internal body concealment of illegal drugs is one of the methods used to smuggle this illicit drug across the border.^3,4 “Drug mules” are generally known as body packers.^5,6 However, for correct terminology, one should differentiate between the terms body packer, body pusher and body stuffer. A body packer swallows a large amount of specially prepared drug packets to smuggle the packets in their gastrointestinal tract across a national border.^5,6 A body pusher hides a few containers in easily accessible body cavities, such as the rectum or vagina. Body stuffers, including traffickers and users, ingest intentionally small amounts of loosely wrapped drug pellets (typically initially hidden in the mouth), usually immediately before an unexpected encounter with law enforcement.^5–10The generally accepted radiological examination is a plain abdominal radiograph in the supine projection.^4–6 This technique is widely available at a low cost and is a simple method of detecting drug-filled packets within the alimentary tract. Radiation exposure to the patient is relatively moderate. In the literature, the detection rate for drug-filled packets is highly variable, and sensitivities from 58.3% to 90% have been reported.^4,5,11 Hence, plain abdominal radiography is a flawed screening method for identifying “drug mules”. Examining the bowel for foreign bodies, such as drug containers with variable sizes and radiodensities, is problematic, even for an experienced radiologist because the drug-filled packets may have an appearance similar to that of stool and gas and may be superimposed. Specific appearances described in the literature, such as the “double-condom”, “halo” and “rosette” signs, may be diagnostic for drug packages but are not necessarily so.^{4–6,11–13} Other modalities employed worldwide for the identification of body packers include CT, ultrasound, MRI and low-dose linear slit digital radiography (LSDR or LODOX®; Lodox Systems, Johannesburg, South Africa).^4,5,14–18Recent research has mainly concentrated on cocaine and heroin drug trafficking, which occurs predominantly in Western countries.^{3,4,6,7,11,14,19} There is little research on the accuracy of plain abdominal radiography in MA drug carriers, although there has been a significant increase of MA in Asia, accompanied by draconian legal measures in cases of drug trafficking.^1,2 The purpose of this study was to retrospectively evaluate the sensitivity, specificity and accuracy of plain abdominal digital radiography (DRL) for identifying the internal payloads of MA in “drug mules”.     

Impact of biplane versus single-plane imaging on radiation dose,contrast load and procedural time in coronary angioplasty

Coronary angioplasties can be performed with either single-plane or biplane imaging techniques. The aim of this study was to determine whether biplane imaging, in comparison to single-plane imaging, reduces radiation dose and contrast load and shortens procedural time during (i) primary and elective coronary angioplasty procedures, (ii) angioplasty to the main vascular territories and (iii) procedures performed by operators with various levels of experience. This prospective observational study included a total of 504 primary and elective single-vessel coronary angioplasty procedures utilising either biplane or single-plane imaging. Radiographic and clinical parameters were collected from clinical reports and examination protocols. Radiation dose was measured by a dose–area–product (DAP) meter intrinsic to the angiography system. Our results showed that biplane imaging delivered a significantly greater radiation dose (181.4±121.0 Gycm²) than single-plane imaging (133.6±92.8 Gycm², p<0.0001). The difference was independent of case type (primary or elective) (p = 0.862), vascular territory (p = 0.519) and operator experience (p = 0.903). No significant difference was found in contrast load between biplane (166.8±62.9 ml) and single-plane imaging (176.8±66.0 ml) (p = 0.302). This non-significant difference was independent of case type (p = 0.551), vascular territory (p = 0.308) and operator experience (p = 0.304). Procedures performed with biplane imaging were significantly longer (55.3±27.8 min) than those with single-plane (48.9±24.2 min, p = 0.010) and, similarly, were not dependent on case type (p = 0.226), vascular territory (p = 0.642) or operator experience (p = 0.094). Biplane imaging resulted in a greater radiation dose and a longer procedural time and delivered a non-significant reduction in contrast load than single-plane imaging. These findings did not support the commonly perceived advantages of using biplane imaging in single-vessel coronary interventional procedures.The use of biplane imaging during diagnostic coronary angiography and coronary interventions has been reported to reduce the total contrast load to the patient compared with single-plane imaging [1–8]. Additionally, acquiring two simultaneous images from two orthogonal planes has been reported to be more efficient than single-plane imaging [2, 8–11]. However, there are conflicting reports as to whether the radiation dose to the patient differs between biplane and single-plane imaging during coronary studies [3, 10, 11].Biplane imaging allows two cineangiography runs to be recorded simultaneously with a single injection of contrast. With single-plane imaging, however, the same information can be acquired only by carrying out the two cineangiography runs serially with two separate injections of contrast [1, 2, 8, 10]. Biplane imaging enables the operator to visualise the target lesion in orthogonal planes simultaneously and was presumed to be more efficient than single-plane imaging, particularly in difficult procedures [1, 4, 9, 12]. Accordingly, examinations would become faster, use of fluoroscopy would be reduced, fewer cineangiography runs would be required and the average radiation dose to the patient would be comparatively lower than in the case of procedures performed with single-plane imaging. The contrast load with biplane imaging was also expected to be significantly reduced [3, 4, 11].These perceived advantages of biplane imaging have led to recommendations for its use in paediatric and adult cardiac catheter laboratories [1, 4, 5, 10, 12, 13]. A previous study comparing biplane and single-plane imaging in 1156 diagnostic coronary angiography procedures found a small, but notable, reduction in contrast load accompanied by significantly longer table times and screening times with biplane imaging, although radiation dose was not examined [14].Contrast-induced nephropathy (CIN) is a complication associated with prolonged hospitalisation and development of end-stage renal failure [15]. Patients with pre-existing renal disease, diabetes, congestive heart failure or older age are at the greatest risk in developing CIN [16–18]. These high-risk patients have a calculated incidence of CIN ranging from 10% to 30% [4, 18–20]. Pre-hydration is the primary intervention for preventing contrast nephropathy [18], but is not possible in the setting of emergency (primary) angioplasty procedures. The total contrast load during interventional procedures has been established as an independent predictor of CIN and could be effectively controlled by the operator during primary angioplasty cases [18, 21, 22]. Biplane imaging is commonly employed to minimise the contrast load, especially in patients with renal impairment and those who require primary coronary angioplasty procedures [1, 6, 7, 18, 23].Numerous studies have found that the radiation dose varies significantly according to tube angulations, particularly in the combination of steep left anterior oblique (LAO) with cranial or caudal angulations [24–27]. However, there are no published data on whether the radiation dose with biplane or single-plane imaging during coronary angioplasty differs between the three vascular territories: right coronary artery (RCA), left anterior descending (LAD) and left circumflex/intermediate (LCX). Furthermore, interventional cardiac procedures are operator dependent [28–30]. Hence, it was postulated that senior cardiologists would be more familiar with biplane equipment and thereby more able to reduce radiation dose, contrast load and procedural time than less experienced operators. To our knowledge, no studies have been published that compare the impact of biplane and single-plane imaging in coronary angioplasty procedures.The aims of this study were to determine whether biplane imaging reduces both contrast load and radiation dosage and shortens procedural time in patients undergoing primary or elective coronary angioplasty compared with single-plane imaging. We also investigated if there was a significant difference in radiation dose, contrast load and procedural time between biplane and single-plane imaging during coronary angioplasty in the three main vascular territories (RCA, LAD and LCX) and in procedures performed by operators with various levels of experience.     

Cardiac MR assessment of cardiac myxomas

Cardiac myxomas are the most common benign primary cardiac tumour to present in adulthood. While most patients present with symptoms of cardiac obstruction, embolic phenomena or constitutional impairment, up to a fifth of patients remain asymptomatic and are incidentally diagnosed on imaging. Although echocardiography is usually the initial imaging modality used to evaluate these patients, cardiac MRI (CMR) has emerged over the past decade as the primary imaging modality in the assessment of patients with cardiac tumours. The superior tissue characterization capability of CMR means that it is able to determine the nature of some tumours pre-operatively and performs well in differentiating myxomas from thrombus. We present a pictorial review highlighting the key CMR features of myxomas and show how these lesions can be differentiated from thrombus and other cardiac masses.Primary cardiac tumours are uncommon with a reported prevalence at autopsy of 0.002%.¹ The majority are benign, with myxomas accounting for almost 50% of all primary cardiac tumours.² Myxomas are more common in female patients, and while they can occur at any age, they usually present in adults between the fourth and seventh decades of life.^3,4 Most patients typically present with at least one manifestation of the classic triad of cardiac obstructive symptoms, embolic phenomena and constitutional symptoms, but 20% are identified in asymptomatic patients as an incidental imaging finding.³Echocardiography is usually the initial imaging modality used in the assessment of a suspected cardiac mass but remains rather operator dependent with a restricted field of view and can be particularly challenging in patients with large body habitus.^2,4,5 Cardiac MRI (CMR) enables accurate assessment of the location and functional impact of cardiac masses in any imaging plane without exposing patients to ionizing radiation.^2,5 In particular, CMR performs better than echocardiography at determining the nature of cardiac lesions and can differentiate myxomas from thrombus.^2,5 Given that most cardiac lesions are not easily amenable to catheter-directed biopsy, accurate imaging differentiation of cardiac myxomas from other types of cardiac masses is of vital importance in guiding further management.