Uterine cervical carcinoma: a comparison of two- and three-dimensional T2-weighted turbo spin-echo MR imaging at 3.0 T for image quality and local-regional staging

Objective

To compare three-dimensional (3D) T2-weighted turbo spin-echo (TSE) with multiplanar two-dimensional (2D) T2-weighted TSE for the evaluation of invasive cervical carcinoma.

Methods

Seventy-five patients with cervical carcinoma underwent MRI of the pelvis at 3.0 T, using both 5-mm-thick multiplanar 2D (total acquisition time?=?12 min 25 s) and 1-mm-thick coronal 3D T2-weighted TSE sequences (7 min 20 s). Quantitative analysis of signal-to-noise ratio (SNR) and qualitative analysis of image quality were performed. Local-regional staging was performed in 45 patients who underwent radical hysterectomy.

Results

The estimated SNR of cervical carcinoma and the relative tumour contrast were significantly higher on 3D imaging (P?<?0.0001). Tumour conspicuity was better with the 3D sequence, but the sharpness of tumour margin was better with the 2D sequence. No significant difference in overall image quality was noted between the two sequences (P?=?0.38). There were no significant differences in terms of the diagnostic accuracy, sensitivity, and specificity of parametrial invasion, vaginal invasion, and lymph node metastases.

Conclusion

Multiplanar reconstruction 3D T2-weighted imaging is largely equivalent to 2D T2-weighted imaging for overall image quality and staging accuracy of cervical carcinoma with a shorter MR data acquisition, but has limitations with regard to the sharpness of the tumour margin.

Key Points

? 3D T2-weighted MR sequence is equivalent to 2D for cervical carcinoma staging. ? Coronal 3D acquisitions can reduce the examination time. ? SNR and relative tumour conspicuity were significantly higher on 3D sequences. ? Reformatted 3D T2-weighted imaging had limitations in sharpness of tumour margin.     

3-T breast magnetic resonance imaging in patients with suspicious microcalcifications on mammography

Objective

To investigate the diagnostic value of 3-Tesla (T) breast MRI in patients presenting with microcalcifications on mammography.

Methods

Between January 2006 and May 2009, 123 patients with mammographically detected BI-RADS 3–5 microcalcifications underwent 3-T breast MRI before undergoing breast biopsy. All MRIs of the histopathologically confirmed index lesions were reviewed by two breast radiologists. The detection rate of invasive carcinoma and ductal carcinoma in situ (DCIS) was evaluated, as well as the added diagnostic value of MRI over mammography and breast ultrasound.

Results

At pathology, 40/123 (33 %) lesions proved malignant; 28 (70 %) DCIS and 12 (30 %) invasive carcinoma. Both observers detected all invasive malignancies at MRI, as well as 79 % (observer 1) and 86 % (observer 2) of in situ lesions. MRI in addition to conventional imaging led to a significant increase in area under the receiver operating characteristic (ROC) curve from 0.67 (95 % CI 0.56–0.79) to 0.79 (95 % CI 0.70–0.88, observer 1) and to 0.80 (95 % CI 0.71–0.89, observer 2), respectively.

Conclusions

3-T breast MRI was shown to add significant value to conventional imaging in patients presenting with suspicious microcalcifications on mammography.

Key points

? 3-T MRI is increasingly used for breast imaging in clinical practice. ? On 3-T breast MRI up to 86 % of DCIS lesions are detected. ? 3-T MRI increases the diagnostic value in patients with mammographically detected microcalcifications.     

Magnetic resonance imaging for detection of parametrial invasion in cervical cancer: An updated systematic review and meta-analysis of the literature between 2012 and 2016

Objective

To review the diagnostic performance of MRI for detection of parametrial invasion (PMI) in cervical cancer patients.

Methods

MEDLINE and EMBASE databases were searched for studies providing diagnostic performance of MRI for detecting PMI in patients with cervical cancer. Studies published between 2012 and 2016 using surgico-pathological results as reference standard were included. Study quality was evaluated using QUADAS-2. Sensitivity and specificity of all studies were calculated. Results were pooled and plotted in a hierarchical summary receiver operating characteristic plot. Meta-regression and subgroup analyses were performed.

Results

Fourteen studies (1,028 patients) were included. Study quality was generally moderate. Pooled sensitivity was 0.76 (95% CI 0.67–0.84) and specificity was 0.94 (95% CI 0.91–0.95). The possibility of heterogeneity was considered low: Cochran’s Q-test (p?=?0.471), Tau² (0.240), Higgins I² (0%). With meta-regression analysis, magnet strength, use of DWI, and antispasmodic drugs were significant factors affecting heterogeneity (p?<?0.01). Subgroup analysis for studies solely using radical hysterectomy as reference standard yielded pooled sensitivity and specificity of 0.73 (95% CI 0.60–0.83) and 0.93 (95% CI 0.90–0.95), respectively.

Conclusions

MRI shows good performance for detection of PMI in cervical cancer. Using 3-T scanners and DWI may improve diagnostic performance.

Key Points

? MRI shows good performance for detection of parametrial invasion in cervical cancer. ? Subgroup of studies using only radical hysterectomy showed consistent results. ? Using 3-Tesla scanners and diffusion-weighted imaging may improve diagnostic performance.

     

Whole-body MRI for the detection of bone marrow involvement in lymphoma: prospective study in 116 patients and comparison with FDG-PET

Objective

To assess and compare the value of whole-body MRI with FDG-PET for detecting bone marrow involvement in lymphoma.

Methods

A total of 116 patients with newly diagnosed lymphoma prospectively underwent whole-body MRI and blind bone marrow biopsy (BMB) of the posterior iliac crest. Of 116 patients, 80 also underwent FDG-PET. Patient-based sensitivities of whole-body MRI for detecting bone marrow involvement were calculated using BMB as reference standard and compared with FDG-PET in aggressive and indolent lymphomas separately.

Results

Sensitivity of whole-body MRI in all lymphomas was 45.5 % [95 % confidence interval (CI): 29.8–62.0 %]. Sensitivity of whole-body MRI in aggressive lymphoma [88.9 % (95 % CI: 54.3–100 %)] was significantly higher (P?=?0.0029) than that in indolent lymphoma [23.5 % (95 % CI: 9.1–47.8 %)]. Sensitivity of FDG-PET in aggressive lymphoma [83.3 % (95 % CI: 41.8–98.9 %)] was also significantly higher (P?=?0.026) than that in indolent lymphoma [12.5 % (95 % CI: 0–49.2 %)]. There were no significant differences in sensitivity between whole-body MRI and FDG-PET (P?=?1.00)

Conclusion

Sensitivity of whole-body MRI for detecting lymphomatous bone marrow involvement is too low to (partially) replace BMB. Sensitivity of whole-body MRI is significantly higher in aggressive lymphoma than in indolent lymphoma and is equal to FDG-PET in both entities.

Key Points

? Bone marrow involvement in lymphoma has prognostic and therapeutic implications. ? Blind bone marrow biopsy (BMB) is standard for bone marrow assessment. ? Neither whole-body MRI nor FDG-PET can yet replace BMB. ? Both techniques have higher sensitivity in aggressive than in indolent lymphoma. ? Both imaging techniques are complementary to BMB.     

The value of diffusion-weighted imaging in the detection of prostate cancer: a meta-analysis

Objectives

To evaluate the diagnostic performance of diffusion-weighted imaging (DWI) as a single non-invasive method in detecting prostate cancer (PCa) and to deduce its clinical utility.

Methods

A systematic literature search was performed to identify relevant original studies. Quality of included studies was assessed by QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies). Data were extracted to calculate sensitivity and specificity as well as running the test of heterogeneity and threshold effect. The summary receiver operating characteristic (SROC) curve was drawn and area under SROC curve (AUC) served as a determination of the diagnostic performance of DWI for the detection of PCa.

Results

A total of 21 studies were included, with 27 subsets of data available for analysis. The pooled sensitivity and specificity with corresponding 95 % confidence interval (CI) were 0.62 (95 % CI 0.61–0.64) and 0.90 (95 % CI 0.89–0.90), respectively. Pooled positive likelihood ratio and negative likelihood ratio were 5.83 (95 % CI 4.61–7.37) and 0.30 (95 % CI 0.23–0.39), respectively. The AUC was 0.8991. Significant heterogeneity was observed. There was no notable publication bias.

Conclusions

DWI is an informative MRI modality in detecting PCa and shows moderately high diagnostic accuracy. General clinical application was limited because of the absence of standardized DW-MRI techniques.

Key points

? DWI provides incremental information for the detection and evaluation of PCa ? DWI has moderately high diagnostic accuracy in detecting PCa ? Patient condition, imaging protocols and study design positively influence diagnostic performance ? General clinical application requires optimization of image acquisition and interpretation     

Diffusion-weighted MR imaging for the diagnosis of abscess complicating fistula-in-ano: preliminary experience

Objective

To investigate the role of diffusion-weighted magnetic resonance imaging (DWMRI) in the diagnosis of abscess-complicating fistula-in-ano.

Methods

This retrospective study was approved by our Institutional Review Board and informed consent was waived. MRI examinations, including fat-suppressed T2-weighted turbo spin-echo (T2-TSE) MRI and DWMRI, of 24 patients with a fistula-in-ano, were reviewed by two independent readers for the presence and number of visible fistulas, conspicuity and apparent diffusion coefficient (ADC) measurement of suspected fistula tracks and pelvic collections. The reference standard was surgical with follow-up findings.

Results

Sensitivity was 91.2 % [95 % CI: 76 %-98 %] for T2-weighted TSE MRI and 100 % [95 % CI: 90 %-100 %] for DWMRI detecting fistulas. ADC values were lower in abscesses than in inflammatory masses (P?=?0.714.10^-6). The area under the ROC curve was 0.971 and the optimal cut-off ADC value was 1.186?×?10^-3 mm²/s, yielding a sensitivity of 100 % [95 % CI: 77 %-100 %], a specificity of 90 % [95 % CI: 66 %-100 %], a positive predictive value of 93 % [95 % CI: 82.8 %-100 %] and a negative predictive value of 90 % [95 % CI: 78 %-100 %] for an abscess diagnosis. Fistula conspicuity was greater with DWMRI than with T2-TSE MRI for the two observers (P?=?0.0034 and P?=?0.0007).

Conclusion

DWMRI shows high sensitivity and specificity for the diagnosis of perianal abscesses and helps discriminate between an abscess and inflammatory mass. Conspicuity of fistulas-in-ano is greater with DWMRI than with T2-weighted TSE MRI.

Key Points

? DWMRI can differentiate between pelvic abscess and inflammatory mass. ? DWMRI helps avoid gadolinium-chelate administration in patients with a suspected fistula-in-ano. ? DWMRI provides high degrees of conspicuity for fistula-in-ano. ? Conspicuity of fistulas is better with DWMRI imaging than with T2-TSE-weighted MRI.     

Preoperative PET/CT FDG standardized uptake value of pelvic lymph nodes as a significant prognostic factor in patients with uterine cervical cancer

Purpose

Using integrated PET/CT, we evaluated the prognostic relevance in uterine cervical cancer of preoperative pelvic lymph node (LN) [¹⁸F]FDG uptake.

Methods

Patients with FIGO stage IB to IIA uterine cervical cancer were imaged with FDG PET/CT before radical surgery. We used Cox proportional hazards regression to examine the relationship between recurrence and the FDG maximum standardized uptake value (SUV_max) in the pelvic LN (SUV_LN) on PET/CT.

Results

Clinical data, treatment modalities, and results in 130 eligible patients were reviewed. The median postsurgical follow-up was 34 months (range 6 to 109 months). Receiver operating characteristic analysis identified SUV_LN 2.36 as the most significant cut-off value for predicting recurrence. SUV_LN was correlated with SUV_tumour (P?=?0.002), primary tumour size (P?=?0.004), and parametrial invasion (P?=?0.013). Univariate analyses showed significant associations between recurrence and SUV_LN (P?=?0.001), SUV_tumour (P?=?0.007), pelvic LN metastasis (P?=?0.002), parametrial invasion (P?<?0.001), primary tumour size (P?=?0.007), suspected LN metastasis on MRI (P?=?0.024), and FIGO stage (P?=?0.026). Multivariate analysis identified SUV_LN (P?=?0.013, hazard ratio, HR, 4.447, 95 % confidence interval, CI, 1.379 – 14.343) and parametrial invasion (P?=?0.013, HR 6.728, 95 % CI 1.497 – 30.235) as independent risk factors for recurrence. Patients with SUV_LN ≥2.36 and SUV_LN <2.36 differed significantly in terms of recurrence (HR 15.20, P?<?0.001).

Conclusion

Preoperative pelvic LN FDG uptake showed a strong significant association with uterine cervical cancer recurrence.     

Accuracy of CT angiography in the diagnosis of acute gastrointestinal bleeding: systematic review and meta-analysis

Objective

To assess the diagnostic accuracy of computed tomography (CT) angiography in the evaluation of patients with an episode of acute gastrointestinal haemorrhage.

Methods

Systematic review and meta-analysis to estimate pooled accuracy indices. A bivariate random effects model was adjusted to obtain a summary receiver-operating characteristic (sROC) curve and the corresponding area under the curve (AUC).

Results

Twenty-two studies were included and provided data on 672 patients (range of age 5–74) with a mean age of 65 years. The overall sensitivity of CT angiography for detecting active acute GI haemorrhage was 85.2 % (95 % CI 75.5 % to 91.5 %). The overall specificity of CT angiography was 92.1 % (95 % CI 76.7 % to 97.7 %). The likelihood ratios for positive and negative test results were 10.8 (95 % CI 3.4 to 34.4) and 0.16 (95 % CI 0.1 to 0.27) respectively, with an AUC of 0.935 (95 % CI 0.693 to 0.989). The sources of heterogeneity explored had no significant impact on diagnostic performance.

Conclusions

CT shows high diagnostic accuracy and is an excellent diagnostic tool for detection and localising of intestinal bleeding sites. It is highly available, provides fast detection and localisation of the bleeding site, and is minimally invasive.

Key Points

? CT angiography is increasingly used for investigating severe gastrointestinal bleeding. ? This systematic review and meta-analysis updates previous ones. ? In patients with massive gastrointestinal bleeding, CT angiography/MDCT detects bleeding accurately. ? CT angiography is useful in locating the bleeding site and determining appropriate treatment.     

Suspected invasive placenta: evaluation with magnetic resonance imaging

Purpose

To determine the utility of magnetic resonance imaging (MRI) in diagnosing invasive placenta (IP).

Materials and methods

MRI findings in 32 women with suspected IP were evaluated independently by four readers. Interobserver agreement was calculated with kappa (κ) statistics. Associations between MRI findings and IP were assessed by univariate and multivariate analyses. Sensitivity, specificity and accuracy of MRI for the diagnosis of IP were estimated.

Results

Sixteen women (16/32; 50 %) had confirmed IP. Interobserver correlation for the diagnosis of IP was fair (κ?=?0.40). Univariate analysis revealed that thinning or focal defect of the uteroplacental interface (P?P?=?0.0006; OR?=?64.99).

Conclusion

MR imaging has 84 % sensitivity [95 % CI: 75–94 %] and 80 % specificity [95 % CI: 66–93 %] for the diagnosis of IP. Thinning or focal defect of the uteroplacental interface is the most discriminating independent MR variable in differentiating between normal placenta and IP.

Key points

? MR imaging has acceptable degrees of accuracy to diagnose invasive placenta. ? Focal uteroplacental interface defect is the best finding to diagnose invasive placenta. ? Focal uteroplacental interface defect is the single independent predictor of invasive placenta.     

Magnetic resonance imaging for the clinical management of rectal cancer patients: recommendations from the 2012 European Society of Gastrointestinal and Abdominal Radiology (ESGAR) consensus meeting

Objectives

To develop guidelines describing a standardised approach regarding the acquisition, interpretation and reporting of magnetic resonance imaging (MRI) for clinical staging and restaging of rectal cancer.

Methods

A consensus meeting of 14 abdominal imaging experts from the European Society of Gastrointestinal and Abdominal Radiology (ESGAR) was conducted following the RAND-UCLA Appropriateness Method. Two independent (non-voting) chairs facilitated the meeting. Two hundred and thirty-six items were scored by participants for appropriateness and classified subsequently as appropriate or inappropriate (defined by ≥ 80 % consensus) or uncertain (defined by < 80 % consensus). Items not reaching 80 % consensus were noted.

Results

Consensus was reached for 88 % of items: recommendations regarding hardware, patient preparation, imaging sequences, angulation, criteria for MRI assessment and MRI reporting were constructed from these.

Conclusions

These expert consensus recommendations can be used as clinical guidelines for primary staging and restaging of rectal cancer using MRI.

Key Points

? These guidelines recommend standardised imaging for staging and restaging of rectal cancer. ? The guidelines were constructed through consensus amongst 14 abdominal imaging experts. ? Consensus was reached by in 88 % of 236 items discussed.     

Contrast-enhanced MRI compared with the physical examination in the evaluation of disease activity in juvenile idiopathic arthritis

Objectives

To assess the value of magnetic resonance imaging (MRI) in discriminating between active and inactive juvenile idiopathic arthritis (JIA) patients and to compare physical examination outcomes with MRI outcomes in the assessment of disease status in JIA patients.

Methods

Consecutive JIA patients with knee involvement were prospectively studied using an open-bore MRI. Imaging findings from 146 JIA patients were analysed (59.6 % female; mean age, 12.9 years). Patients were classified as clinically active or inactive. MRI features were evaluated using the JAMRIS system, comprising validated scores for synovial hypertrophy, bone marrow oedema, cartilage lesions and bone erosions.

Results

Inter-reader reliability was good for all MRI features (intra-class correlation coefficient [ICC]?=?0.87–0.94). No differences were found between the two groups regarding MRI scores of bone marrow oedema, cartilage lesions or bone erosions. Synovial hypertrophy scores differed significantly between groups (P?=?0.016). Nonetheless, synovial hypertrophy was also present in 14 JIA patients (35.9 %) with clinically inactive disease. Of JIA patients considered clinically active, 48.6 % showed no signs of MRI-based synovitis.

Conclusions

MRI can discriminate between clinically active and inactive JIA patients. However, physical examination is neither very sensitive nor specific in evaluating JIA disease activity compared with MRI. Subclinical synovitis was present in >35 % of presumed clinically inactive patients.

Key points

? MRI is sensitive for evaluating juvenile idiopathic arthritis (JIA) disease activity. ? Contrast-enhanced MRI can distinguish clinically active and inactive JIA patients. ? Subclinical synovitis is present in 35.9?% of presumed clinically inactive patients. ? Physical examination is neither sensitive nor specific in evaluating JIA disease activity.     

Assessment of therapeutic response in ankylosing spondylitis patients undergoing anti-tumour necrosis factor therapy by whole-body magnetic resonance imaging

Objectives

Multifocal musculoskeletal inflammation is common in ankylosing spondylitis (AS) and is effectively treated by expensive anti-TNF (tumour necrosis factor) therapy. This study evaluated assessment of response by whole-body (WB) MRI compared with clinical assessment in AS patients during etanercept therapy.

Methods

Ten patients with AS underwent a 12-month therapy with etanercept. Clinical markers were monitored [Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and C-reactive protein (CRP)] and patients underwent WBMRI (1.5 T, STIR and T1-weighted) at three different time points (0, 26 and 52 weeks). WBMRI was evaluated and correlated with clinical scores.

Results

The BASDAI index decreased under therapy from 5.5?±?0.5 (week 0) to 1.7?±?0.5 (week 52, P?<?0.05). CRP declined from 15.7?±?2.2 mg/dl (week 0) to 0.9?±?0.9 mg/dl (week 52, P?<?0.05). In WBMRI, the sum of all lesions showed a significant decrease from week 0 (38.9?±?3.4) to week 52 (2.2?±?0.9, 94.3 % reduction). WBMRI detected more areas of synovitis and enthesitis than clinical examination alone.

Conclusions

AS activity significantly decreased under etanercept therapy, which was proven by clinical examination and WBMRI. WBMRI detected more inflammatory lesions than clinical examination alone. The results suggest that WBMRI improves the detection of inflammatory changes and the assessment of their course under therapy.

Key Points

? Multifocal musculoskeletal inflammation in AS is effectively treated by anti-TNF therapy. ? Inflammatory lesions can be assessed by clinical examination and whole-body MRI. ? AS activity significantly decreased under therapy as shown by WBMRI/clinical examination. ? WBMRI detected more inflammatory lesions than clinical examination alone. ? WBMRI improves detection of inflammatory changes and may help evaluation of therapy.     

Value of diffusion-weighted imaging in predicting parametrial invasion in stage IA2–IIA cervical cancer

Objective

To investigate the value of diffusion-weighted imaging (DWI) in evaluating parametrial invasion (PMI) in stage IA2–IIA cervical cancer.

Methods

A total of 117 patients with stage IA2–IIA cervical cancer who underwent preoperative MRI and radical hysterectomy were included in this study. Preoperative clinical variables and MRI variables were analysed and compared between the groups with and without pathologically proven PMI.

Results

All variables except age were significantly different between patients with and without pathologic PMI (P?<?0.05). All variables except squamous cell carcinoma (SCC) antigen were also significantly correlated with pathologic PMI on univariate analysis (P?<?0.05). Multivariate analysis indicated that PMI on MRI (P?<?0.001) and tumour apparent diffusion coefficient (ADC) (P?=?0.029) were independent predictors of pathologic PMI. Area under the curve of PMI on MRI increased significantly from 0.793 to 0.872 when combined with tumour ADC (P?=?0.002). When PMI on MRI was further stratified by tumour ADC, the false negative rate was 2.0 % (1/49).

Conclusion

In stage IA2–IIA cervical cancer, tumour ADC and PMI on MRI seem to be independent predictors of pathologic PMI. Combining the two predictors improved the diagnostic performance of identifying patients at low risk of pathologic PMI.

Key points

? Accurate PMI prediction is essential for appropriate treatment planning ? Tumour ADC appears to be an independent predictor of pathologic PMI ? Adding DWI to MRI improves accuracy for identifying low-risk patients for PMI     

Assessing liver function by liver enhancement during the hepatobiliary phase with Gd-EOB-DTPA-enhanced MRI at 3 Tesla

Objectives

The purpose of this study was to evaluate the usefulness of Gd-EOB-DTPA-enhanced 3-T MRI to determine the hepatic functional reserve expressed by the model for end-stage liver disease (MELD) score.

Methods

A total of 121 patients with normal liver function (NLF; MELD score?≤?10) and 29 patients with impaired liver function (ILF; MELD score?>?10) underwent contrast-enhanced MRI with a hepatocyte-specific contrast agent at 3T. T1-weighted volume interpolated breath-hold examination (VIBE) sequences with fat suppression were acquired before and 20 min after contrast injection. Relative enhancement (RE) between plain signal intensity and contrast-enhanced signal intensity was calculated and was used to determine Gd-EOB-DTPA uptake into the liver parenchyma for patients with different MELD scores.

Results

RE differed significantly (p?≤?0.001) between patients with NLF (87.2?±?29.5 %) and patients with ILF (45.4?±?26.5 %). The optimal cut-off value for RE to differentiate NLF from ILF was 47.7 % (AUC 0.87). This cut-off value showed a sensitivity of 82.8 % and a specificity of 92.7 % for the differentiation of the analysed groups.

Conclusion

Gd-EOB-DTPA uptake in hepatocytes is strongly affected by liver function. Gd-EOB-DTPA-enhanced MRI and assessment of RE during the hepatobiliary phase (HBP) may serve as a useful image-based test in liver imaging for determining regional and global liver function.

Key points

• Hepatic uptake of Gd-EOB-DTPA is strongly affected by liver function.
• Relative enhancement during HBP in GD-EOB-DTPA MRI correlates with the MELD score.
• Assessment of relative enhancement may help improve treatment in routine clinical practice.

     

Staging of colorectal liver metastases after preoperative chemotherapy. Diffusion-weighted imaging in combination with Gd-EOB-DTPA MRI sequences increases sensitivity and diagnostic accuracy

Objectives

To compare the diagnostic accuracy and sensitivity of Gd-EOB-DTPA MRI and diffusion-weighted (DWI) imaging alone and in combination for detecting colorectal liver metastases in patients who had undergone preoperative chemotherapy.

Methods

Thirty-two consecutive patients with a total of 166 liver lesions were retrospectively enrolled. Of the lesions, 144 (86.8 %) were metastatic at pathology. Three image sets (1, Gd-EOB-DTPA; 2, DWI; 3, combined Gd-EOB-DTPA and DWI) were independently reviewed by two observers. Statistical analysis was performed on a per-lesion basis.

Results

Evaluation of image set 1 correctly identified 127/166 lesions (accuracy 76.5 %; 95 % CI 69.3–82.7) and 106/144 metastases (sensitivity 73.6 %, 95 % CI 65.6–80.6). Evaluation of image set 2 correctly identified 108/166 (accuracy 65.1 %, 95 % CI 57.3–72.3) and 87/144 metastases (sensitivity of 60.4 %, 95 % CI 51.9–68.5). Evaluation of image set 3 correctly identified 148/166 (accuracy 89.2 %, 95 % CI 83.4–93.4) and 131/144 metastases (sensitivity 91 %, 95 % CI 85.1–95.1). Differences were statistically significant (P?<?0.001). Notably, similar results were obtained analysing only small lesions (<1 cm).

Conclusions

The combination of DWI with Gd-EOB-DTPA-enhanced MRI imaging significantly increases the diagnostic accuracy and sensitivity in patients with colorectal liver metastases treated with preoperative chemotherapy, and it is particularly effective in the detection of small lesions.

Key Points

? Accurate detection of colorectal liver metastases is essential to determine resectability. ? Almost 80 % of patients are candidates for neoadjuvant chemotherapic treatment at diagnosis. After chemotherapy, metastases usually decrease, and drug-induced liver steatosis may be present. ? The sensitivity of imaging is significantly inferior to that in chemotherapy-naïve patients. ? DWI combined with Gd-EOB-DTPA increases sensitivity in detecting small metastases after chemotherapy.     

Time-of-flight angiography: a viable alternative to contrast-enhanced MR angiography and fat-suppressed T1w images for the diagnosis of cervical artery dissection?

Objectives

To compare the use of an unenhanced high-resolution time-of-flight MR angiography sequence (Hr-TOF MRA) with fat-suppressed axial/coronal T1-weighted images and contrast-enhanced angiography (standard MRI) for the diagnosis of cervical artery dissection (cDISS).

Methods

Twenty consecutive patients (9 women, 11 men, aged 24–66 years) with proven cDISS on standard MRI underwent Hr-TOF MRA at 3.0 T using dedicated surface coils. Sensitivity (SE), specificity (SP), positive and negative predictive values (PPV, NPV), Cohen’s kappa (к) and accuracy of Hr-TOF MRA were calculated using the standard protocol as the gold standard. Image quality and diagnostic confidence were assessed on a four-point scale.

Results

Image quality was rated better for standard MRI (P?=?0.02), whereas diagnostic confidence did not differ significantly (P?=?0.27). There was good agreement between Hr-TOF images and the standard protocol for the presence/absence of cDISS, with к?=?0.95 for reader 1 and к?=?0.89 for reader 2 (P?<?0.001). This resulted in SE, SP, PPV, NPV and accuracy of 97 %, 98 %, 97 %, 98 % and 97 % for reader 1 and 93 %, 96 %, 93 %, 96 % and 95 % for reader 2.

Conclusions

Hr-TOF MRA can be used to diagnose cDISS with excellent agreement compared with the standard protocol. This might be useful in patients with renal insufficiency or if contrast-enhanced MR angiography is of insufficient image quality.

Key Points

? New magnetic resonance angiography sequences are increasingly used for vertebral artery assessment. ? A high-resolution time-of-flight sequence allows the diagnosis of cervical artery dissection. ? This technique allows the diagnosis without intravenous contrast medium. ? It could help in renal insufficiency or when contrast-enhanced MRA fails.     

Standard 1.5-T MRI of endometrial carcinomas: modest agreement between radiologists

Objectives

To evaluate pelvic magnetic resonance imaging (MRI) interobserver agreement for the detection of deep myometrial invasion, cervical stroma invasion and lymph node metastases in endometrial carcinoma patients in relation to surgical staging.

Methods

Fifty-seven patients with histologically confirmed endometrial carcinoma were prospectively included in a study of preoperative 1.5-T MRI. Four radiologists, blinded to patient data, independently reviewed the images for the presence of deep myometrial invasion, cervical stroma invasion and lymph node metastases. Kappa coefficients for interobserver agreement and diagnostic performances for each observer were calculated using final surgical staging results (FIGO 09) as reference standard.

Results

Overall agreement among all observers was moderate for cervical stroma invasion (κ?=?0.50 [95% CI 0.27–0.73]) and lymph node metastases (κ?=?0.56 [0.09–0.80]) and fair for deep myometrial invasion (κ?=?0.39 [0.26–0.55]). Sensitivity (specificity) values for the four observers were 72–92% (44–63%) for deep myometrial invasion, 38–63% (82–94%) for cervical stroma invasion and 25–38% (90–100%) for lymph node metastases.

Conclusions

Conventional MRI showed only modest interobserver agreement and diagnostic accuracy for detection of deep myometrial invasion, cervical stroma invasion and lymph node metastases. Improved methods are needed for preoperative imaging in the staging of endometrial carcinomas.

Key Points

? MRI is an important tool for preoperative endometrial cancer staging. ? Staging agreement based on pelvic MRI was modest among different observers. ? Preoperative MRI alone was suboptimal in identifying high-risk patients. ? Improved imaging and biomarkers may refine preoperative risk stratification in endometrial cancer.     

Helical CT-enteroclysis in the detection of small-bowel tumours: a meta-analysis

Objective

To perform a meta-analysis to determine sensitivity and specificity estimates of helical CT-enteroclysis in the detection of small-bowel tumours.

Methods

A search for relevant articles published from January 1992 to November 2010 was performed. Study design, patient characteristics and 2?×?2 contingency tables were recorded for eligible studies. Heterogeneity was assessed with the I ² statistic. A bivariate generalised linear random-effects model was used to summarise sensitivity and specificity estimates for small-bowel tumour detection on a per-patient basis. Sensitivity and specificity estimates were compared in different subgroups.

Results

Twelve studies (696 patients) were eligible. The mean small-bowel tumour prevalence was 22.6 % (range 7.7–45.8 %). Inter-study heterogeneity was substantial for sensitivity (I ²?=?66.9 %; 95 % CI 28.7–88.5 %) and low for specificity (I ²?=?10.6 %; 95 % CI 0.0–55.0 %). On a per-patient basis, pooled sensitivity was 92.8 % (95 % CI 71.3–98.5 %) and pooled specificity 99.2 % (95 % CI 94.2–99.9 %) for the diagnosis of small-bowel tumour. Subgroup analysis revealed that small-bowel preparation, more than one imaging pass and large volumes (≥2 L) of enteral contrast agent did not improve tumour detection.

Conclusion

Our meta-analysis confirms that helical CT-enteroclysis has high degrees of sensitivity and specificity for small-bowel tumour detection. However, our findings reinforce the need for more standardised individual studies.

Key Points

? Helical CT-enteroclysis is highly sensitive for the diagnosis of small-bowel tumours. ? Helical CT-enteroclysis is highly specific for the diagnosis of small-bowel tumours, ? Helical CT-enteroclysis can be used as a first-line investigation. ? A single enteric phase examination provides optimal tumour detection.     

Diagnostic accuracy and patient acceptance of MRI in children with suspected appendicitis

Objective

To compare magnetic resonance imaging (MRI) and ultrasound in children with suspected appendicitis.

Methods

In a single-centre diagnostic accuracy study, children with suspected appendicitis were prospectively identified at the emergency department. All underwent abdominal ultrasound and MRI within 2 h, with the reader blinded to other imaging findings. An expert panel established the final diagnosis after 3 months. We evaluated the diagnostic accuracy of three imaging strategies: ultrasound only, conditional MRI after negative or inconclusive ultrasound, and MRI only. Significance between sensitivity and specificity was calculated using McNemar’s test statistic.

Results

Between April and December 2009 we included 104 consecutive children (47 male, mean age 12). According to the expert panel, 58 patients had appendicitis. The sensitivity of MRI only and conditional MRI was 100 % (95 % confidence interval 92–100), that of ultrasound was significantly lower (76 %; 63–85, P?<?0.001). Specificity was comparable among the three investigated strategies; ultrasound only 89 % (77–95), conditional MRI 80 % (67–89), MRI only 89 % (77–95) (P values 0.13, 0.13 and 1.00).

Conclusion

In children with suspected appendicitis, strategies with MRI (MRI only, conditional MRI) had a higher sensitivity for appendicitis compared with a strategy with ultrasound only, while specificity was comparable.

Key Points

? In children, MRI has a higher sensitivity for appendicitis than ultrasound. ? Ultrasound followed by MRI in negative or inconclusive findings is accurate. ? The tolerance for ultrasound and MRI in children is comparable. ? MRI can be performed in children in an emergency setting.