CT and MR imaging characteristics of infantile hepatic hemangioendothelioma

Aim

This study aims to analyze computed tomography (CT) and magnetic resonance (MR) imaging features of infantile hepatic hemangioendotheliomas before and after treatment.

Materials and methods

CT and MR examinations of seven infants with biopsy proven hepatic hemangioendotheliomas were retrospectively analyzed. The distribution, number, size, imaging appearance, enhancement pattern and post-treatment changes of the tumors were evaluated.

Results

A total of 153 hepatic hemangioendotheliomas were detected on CT (111) and MR (42) imaging. In six infants, 109/111 (98.2%) tumors were hypodense and 2/111 (1.8%) lesions contained calcification on unenhanced CT. On MR imaging, all 42 lesions in one infant were heterogeneously T1-hypointense and T2-hyperintense compared to the normal liver parenchyma. Contrast-enhanced CT and MRI showed peripheral rim (51.6%), uniform (48.4%), fibrillary (33.3%), and nodular (28.8%) contrast enhancement in the hepatic arterial phase. Homogeneous (100%), rim (98.2%) and mixed enhancement patterns were noted in tumors <1.0 cm, >2.0 cm and 1.0-2.0 cm in diameter respectively in the hepatic arterial phase. In three patients who underwent steroid therapy, follow-up CT examination demonstrated tumor size reduction and increased intra-tumoral calcification in two patients.

Conclusion

Infantile hepatic hemangioendotheliomas show some typical imaging features and size-dependent pattern of contrast enhancement on CT and MR imaging, which allow accurate imaging diagnosis and post-treatment evaluation.     

Evaluation of suspicious nipple discharge with MRI: review of 50 cases

Purpose

To determine the role of MRI in the evaluation and management of patients with suspicious nipple discharge and normal mammographic and US evaluation.

Patients and methods

A total of 50 patients with suspicious nipple discharge and normal mammographic and US evaluation prospectively underwent MRI. The first 16 patients underwent routine breast MRI, while MR-ductography with image fusion at the console was added for the last 34 patients.

Results

In 22 of 25 high-risk and malignant lesions, MRI showed enhancement whereas it was normal in three cases. In 25 benign cases (resolution of discharge/benign non-proliferative breast disease), MRI was negative in 22 cases and falsely positive in three cases.

Conclusion

In this clinical setting, MRI shows excellent sensitivity, PPV and NPV. A negative result on MRI would support clinical follow-up as opposed to surgery.     

Detection of hepatocellular carcinoma by Gd-EOB-DTPA-enhanced liver MRI: Comparison with triple phase 64 detector row helical CT

Purpose

To compare the diagnostic performance of Gd-EOB-DTPA-enhanced MRI with that of triple phase 64-MDCT in the detection of hepatocellular carcinoma (HCC).

Patients and methods

Thirty-four patients with 52 surgically proven lesions underwent Gd-EOB-DTPA-enhanced MRI and triple phase 64-MDCT. Two observers independently evaluated MR and CT imaging on a lesion-by-lesion basis. Sensitivity, positive and negative predictive values and reproducibility were evaluated. The diagnostic accuracy of each modality was assessed with alternative-free response receiver operating characteristic (ROC) analysis.

Results

Both observers showed higher sensitivity in detecting lesions with MRI compared to CT, however, only the difference between the two imaging techniques for observer 2 was significant (P = 0.034). For lesions 1 cm or smaller, MRI and CT showed equal sensitivity (both 62.5%) with one observer, and MRI proved superior to CT with the other observer (MRI 75% vs. CT 56.3%), but the latter difference was not significant (P = 0.083). The difference in positive and negative predictive value between the two imaging techniques for each observer was not significant (P > 0.05). The areas under the ROC curve for each observer were 0.843 and 0.861 for MRI vs. 0.800 and 0.833 for CT and the differences were not significant. Reproducibility was higher using MRI for both observers, but the result was not significant (MRI 32/33 vs. CT 29/33, P = 0.083).

Conclusion

Gd-EOB-DTPA-enhanced MRI tended to show higher diagnostic accuracy, sensitivity and reproducibility compared to triple phase 64-MDCT in the detection of hepatocellular carcinoma, however statistical significance was not achieved.     

Magnetic resonance imaging in fetal anomalies: What does it add to 3D and 4D US?

Objective

The objective of our study is to evaluate the contribution of adding MRI findings to sonographic data when assessing fetal anomalies and to determine how this addition may affect the management of pregnancy.

Study design

We prospectively examined 26 fetuses who had sonographically suspected congenital anomalies over a period of 1 year. 2D/3D and 4D ultrasound, Doppler and magnetic resonant imaging was done for all patients. MRI was done within 1 week following US examination. The maternal age range was 18-39 years. The gestational age range was 15-38 weeks (mean age = 29 weeks). Ultrasound and magnetic resonance findings were compared together.

Results

We reported different types of congenital anomalies including eight cases of isolated central nervous system anomalies, four abdominal, five musculoskeletal anomalies, seven cases of renal anomalies and two cases of Meckel Gruber syndrome. MRI and sonography showed concordant findings in 18 cases. MRI changed the diagnosis in five cases and provided additional information in three cases. Ultrasound was superior to magnetic resonance imaging in three cases.

Conclusion

Our results showed that fetal MR imaging can be used as a complementary modality to US in diagnosing fetal abnormality in which US findings are inconclusive or equivocal.     

Hepatic caudate vein in Budd-Chiari syndrome: Depiction by using magnetic resonance imaging

Objective

To study the visibility of the caudate vein and its diameter on MR imaging in healthy people and in patients with Budd-Chiari syndrome.

Materials and methods

In this study there were 14 patients with Budd-Chiari syndrome and 54 healthy subjects without hepatic lesion or liver disease, all of whom had upper abdominal enhanced MRI. The visibility of the caudate vein and its diameter on MR images was compared between Budd-Chiari patients and healthy subjects, and among Budd-Chiari patients, the correlation between the visibility of caudate vein and extrahepatic collaterals were compared.

Results

Caudate vein was noted in 64% of patients with Budd-Chiari syndrome and in 7% of healthy subjects (P = 0.000). The diameter of the caudate vein visualized on MR imaging in Budd-Chiari syndrome was significantly larger than that in healthy group (7.3 ± 3.9 mm vs 2.6 ± 0.6 mm, P = 0.037). Among Budd-Chiari patients, both caudate vein and extrahepatic collateral veins were noted in 9 patients, only extrahepatic collateral veins were noted in 4 patients and neither caudate vein nor extrahepatic collateral veins were noted in 1 patient. No correlation was found between the visibility of caudate vein and that of extrahepatic collateral vein in patients with Budd-Chiari (P = 0.375).

Conclusion

Gadolinium enhanced dynamic MR imaging can visualize hepatic caudate vein frequently. The visibility and dilation of hepatic caudate veins on MR imaging in Budd-Chiari syndrome were more frequent than in control subjects. MR depiction of a caudate vein may help differentiate Budd-Chiari from cirrhosis.     

Assessment of left ventricular function with single breath-hold highly accelerated cine MRI combined with guide-point modeling

Purpose

To prospectively assess the performance of highly accelerated cine MRI in multi-orientations combined with a new guide-point modeling post-processing technique (GPM approach) for assessment of left ventricular (LV) function compared to the standard summation of slices method based on a stack of short axis views (SoS approach).

Materials and methods

33 consecutive patients were examined on a 1.5 T scanner with a standard steady state free precession (SSFP) sequence (TR, 3.0 ms; TE, 1.5 m; flip angle (FA), 60°; acceleration factor (AF), 2) analyzed with the SoS method and a highly accelerated, single breath-hold temporal parallel acquisition SSFP sequence (TR, 4.6 ms; TE, 1.1 ms; AF, 3) post-processed with the GPM method. LV function values were measured by two independent readers with different experience in cardiac MRI and compared by using the paired t-test and F-test. Inter- and intraobserver agreements were calculated using Bland-Altman-Plots.

Results

Mean acquisition and post-processing time was significantly shorter with the GPM approach (15 s/3 min versus 360 s/6 min). For all LV function parameters interobserver agreement between the experienced and non-experienced reader was significantly improved when the GPM approach was used. However, end-diastolic and end-systolic volumes were larger for the GPM technique when compared to the SoS method (P < 0.001), whereas ejection fraction estimation yielded equivalent results (P > 0.121). In both readers and for all parameters variances did not differ significantly (P ≥ 0.409) and the two approaches showed an excellent linear correlation (r > 0.951).

Conclusion

Due to its accurate, fast and reproducible assessment of LV function parameters highly accelerated MRI combined with the GPM technique may become the technique of first choice for assessment of LV function in clinical routine.     

Effects of respiratory manoeuvres on hepatic vein Doppler waveform and flow velocities in a healthy population

Objective

This study was performed to determine the variations in Doppler waveforms and flow velocity during respiratory manoeuvres in healthy individuals with no liver disease.

Materials and methods

In total, 100 individuals (75 women and 25 men) without known cardiac or liver disease were examined prospectively with duplex Doppler ultrasonography (US). We recorded the Doppler waveforms and peak systolic velocities (V_max) of the middle hepatic vein during normal respiration, during breath-holding after quiet expiration and also during deep inspiration. Doppler waveforms are categorised as triphasic, biphasic or monophasic.

Results

During normal respiration, hepatic venous waveforms were triphasic in 93% of subjects, monophasic in 6% and biphasic in 1%. During breath-holding after quiet expiration, the percentages were 91%, 6% and 3%, respectively. During deep inspiration, they were 80%, 18% and 2%, respectively. Although significant differences were noted between rates during deep inspiration and normal respiration, they were quite similar during normal respiration and breath-holding after quiet expiration (P < 0.05). The values of V_max were significantly higher during normal respiration compared to quiet expiration and during quiet expiration compared to deep inspiration (P < 0.05).

Conclusion

The velocities and waveforms of hepatic veins varied during respiratory manoeuvres. The status of respiration must be taken into consideration whilst examining the hepatic vein waveforms and velocities with duplex Doppler US.     

Parenchymal lymphoma of the brain on initial MR imaging: A comparative study between primary and secondary brain lymphoma

Background and purpose

Parenchymal lymphomatous brain masses have not been investigated considering if they are primary or as a part of systemic lymphoma (secondary) on imaging studies previously. We aimed to determine characteristics of the secondary parenchymal lymphomatous involvement of the brain and to find if there is any radiologic feature to help discrimination of untreated primary and secondary central nervous system lymphoma on patients’ initial magnetic resonance imaging.

Materials and methods

We evaluated MR images of 18 patients with the diagnosis of primary (n = 12) and secondary central nervous system lymphoma (n = 6). We considered the number, localization, enhancement pattern, signal characteristics, diffusion properties, presence of hemorrhage and presence of butterfly pattern on MR imaging at initial presentation.

Results

Secondary central nervous system lymphomas predominantly presented as multiple (n = 4, 66.7%) lesions. Homogenous nodular enhancement and supratentorial white matter involvement were present in all patients with butterfly pattern and infiltrative/perivenular enhancement in half (n = 3) of the patients. Deep gray matter (n = 1, 16.7%) and infratentorial involvement (n = 1, 16.7%) were scarce and no ring enhancement was observed. There was no statistically significant difference in any of the investigated MR features between the two groups.

Conclusion

Statistical analyses revealed no significant distinctive radiologic characteristics between primary and secondary lymphoma of the brain parenchyma.     

Ileal Crohn's disease: MRI with endoscopic correlation

Purpose

To evaluate activity staging of Crohn's disease (CD) measured with MR-enterography using ileoscopy as reference standard.

Materials and methods

A prospective study was made of 61 patients with CD. All patients underwent MR-enterography and ileoscopy. MRI activity was measured by means of an ad hoc developed score, as well as by analysis of the imaging findings, and was compared with the SES-CD score obtained via ileoscopy. Examinations were performed using a 1.0 T scanner.

Results

MRI score discriminates between active and inactive disease with an area under the ROC curve of 0.941. Overall correlation with the standard reference SES-CD score was moderate to strong (Spearman's r = 0.62 p < 0.001).Agreement between both methods in staging patients with ileal CD as inactive, mild or moderate to severe was good (Cohen's κ = 0.60). Differences in means of the MRI activity scores of the three groups showed statistical significance (p < 0.01).

Conclusions

The MRI score is a reliable predictor of activity in ileal CD and can stage patients in a way comparable to endoscopy. 1.0 T scans are valid for performing radiological evaluation of ileal Crohn's disease.     

The thickness of the A1 pulleys reflects the disability of hand mobility in scleroderma. A pilot study using high-frequency ultrasound

Background

Hand involvement in scleroderma is a serious concern. Clinical tests to asses hand dysfunction are based on the experience of the clinician.

Objective

To asses if utrasonographic (US) measurement of A1 pulley thickness may be used as an indicator of hand mobility in scleroderma.

Materials and methods

Institutional review board approval and patient informed consent was obtained. Twenty-eight patients affected suffering from scleroderma and 40 healthy controls were prospectively evaluated by two blinded radiologists with US, with a transducer operating at 17 MHz. A1 pulley thickness was measured and correlated with the Hand Mobility in Scleroderma Test (HAMIS) and disease duration.

Results

The thickness of the A1 pulley was greater in sclerodermic patients than in controls (p < 0.05). Intra and inter-observer agreement were better for ultrasound (0.94;0.88) than for HAMIS tests (0.71;0.70). A good correlation between pulley thickness, hand mobility and disease duration was found (r = 0.78, p < 0.018; r = 0.54, p < 0.05).

Conclusion

A1 pulley thickness measured on ultrasound correlates with hand mobility and disease duration. Ultrasound is an useful tool to evaluate hand disability in scleroderma.     

Preoperative detection of colorectal liver metastases in fatty liver: MDCT or MRI?

Objective

To compare the diagnostic value of multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) in the preoperative detection of colorectal liver metastases in diffuse fatty infiltration of the liver, associated with neoadjuvant chemotherapy.

Materials and methods

Twenty preoperative tri-phasic MDCT (4-64-row, Siemens) and dynamic contrast-enhanced MRI (1.5 T or 3.0 T, Siemens) examinations of patients with colorectal cancer and liver metastases in diffuse steatosis were retrospectively evaluated. All patients underwent surgical resection for liver metastases (time interval 1-60 days). The amount of fatty infiltration of the liver was determined histopathologically by semi-quantitative percent-wise estimation and ranged from 25 to 75%.

Results

Overall, 51 metastases were found by histopathology of the resected liver segments/lobes. The size of the metastases ranged from 0.4 to 13 cm, with 18 (35%) being up to 1 cm in diameter. In the overall rating, MDCT detected 33/51 lesions (65%), and MRI 45/51 (88%). For lesions up to 1 cm, MDCT detected only 2/18 (11%) and MRI 12/18 (66%). One false positive lesion was detected by MDCT. Statistical analysis showed that MRI is markedly superior to MDCT, with a statistically significant difference (p < .001), particularly for the detection of small lesions (≤1 cm; p < .004). There was no significant difference between the two modalities in the detection of lesions > 1 cm.

Conclusion

For the detection of colorectal liver metastases after neoadjuvant chemotherapy and consecutive diffuse fatty infiltration of the liver, MRI is superior to MDCT, especially for the detection of small lesions.     

Comparison of peritoneal tumor imaging using conventional MR imaging and diffusion-weighted MR imaging with different b values

Purpose

The aim of this study was to evaluate the utility of DW MRI with two different b values in identifying peritoneal tumors in oncology patients.

Materials and methods

Nineteen patients with known malignancy underwent abdominal and pelvic MRI before surgery. MRI included free-breathing DWI with b values of 400 and 800 s/mm², T1-weighted fat-suppressed spoiled gradient-echo, T2-weighted fat-saturated turbo spin-echo, and 5-min delayed gadolinium-enhanced imaging. Two observers reviewed images for peritoneal tumors at ten anatomic sites within consensus. The results of laparatomy and histopathological evaluation were compared with MRI results. Sensitivity, specificity, and accuracy of identifying peritoneal metastases were calculated for conventional MRI, combined DWI with a b value of 400 s/mm² and conventional MRI, and combined DWI with a b value of 800 s/mm² and conventional MRI by consensus of two observers.

Results

One-hundred and twenty-five peritoneal metastasis sites were confirmed by surgical and histopathological findings. Conventional MRI alone identified 72 peritoneal metastases (sensitivity, 0.58; specificity, 0.87; accuracy, 0.67). Combined DWI with a b value of 400 s/mm² and conventional MRI revealed 106 peritoneal metastases (sensitivity, 0.85; specificity, 0.88; accuracy, 0.85). Finally, combined DWI with a b value of 800 s/mm² and conventional MRI revealed 103 peritoneal metastases (sensitivity, 0.83; specificity, 0.94; accuracy, 0.86).

Conclusion

DWI with a high b value provides complementary information that can improve the detection of peritoneal tumors when combined with conventional MRI. We recommend combined MRI and DWI with a high b value for increasing the sensitivity and accuracy of the preoperative detection of peritoneal tumors.     

Computer-aided diagnosis with textural features for breast lesions in sonograms

Rationale and objectives

Computer-aided diagnosis (CAD) systems provided second beneficial support reference and enhance the diagnostic accuracy. This paper was aimed to develop and evaluate a CAD with texture analysis in the classification of breast tumors for ultrasound images.

Materials and methods

The ultrasound (US) dataset evaluated in this study composed of 1020 sonograms of region of interest (ROI) subimages from 255 patients. Two-view sonogram (longitudinal and transverse views) and four different rectangular regions were utilized to analyze each tumor. Six practical textural features from the US images were performed to classify breast tumors as benign or malignant. However, the textural features always perform as a high dimensional vector; high dimensional vector is unfavorable to differentiate breast tumors in practice. The principal component analysis (PCA) was used to reduce the dimension of textural feature vector and then the image retrieval technique was performed to differentiate between benign and malignant tumors. In the experiments, all the cases were sampled with k-fold cross-validation (k = 10) to evaluate the performance with receiver operating characteristic (ROC) curve.

Results

The area (A_Z) under the ROC curve for the proposed CAD system with the specific textural features was 0.925 ± 0.019. The classification ability for breast tumor with textural information is satisfactory.

Conclusions

This system differentiates benign from malignant breast tumors with a good result and is therefore clinically useful to provide a second opinion.     

Dynamic magnetic resonance imaging for assessment of minimally invasive pelvic floor reconstruction with polypropylene implant

Introduction

The purpose of the study was to assess the usefulness of dynamic MRI in patients with pelvic organ prolapse after pelvic floor repair with polypropylene mesh.

Materials and methods

Fifteen consecutive patients (mean age 66.5 years) who were scheduled for either anterior (n = 9) or posterior (n = 6) pelvic floor repair were prospectively evaluated by clinical assessment and dynamic MRI 1 day before and 3 months after surgery. MRI diagnoses and MRI measurements of relevant anatomical points at rest and on straining were analysed before and after surgery.

Results

At follow-up assessment 93.3% of all patients were clinically cured. Dynamic MRI showed newly developed (n = 6) or increased (n = 6) pelvic organ prolapse in 80% (n = 12) of all patients 3 months after pelvic floor repair. Most of them (n = 11; 91.7%) affected the untreated pelvic floor compartment. On straining anatomical points of reference in the anterior pelvic floor compartment were significantly (p < 0.05) elevated after anterior repair and rectal bulging was significantly (p = 0.036) reduced after posterior pelvic floor repair.

Conclusions

In this study dynamic MRI could verify the effective support of anterior and posterior pelvic floor structures by anterior and posterior polypropylene implant respectively. But dynamic MRI demonstrates if one compartment of the pelvic floor is repaired another compartment frequently (73.3%) develops dysfunction. These results did not correspond to clinical symptoms on short-term follow-up (3 months). Studies with long-term follow-up are necessary to prove if dynamic MRI can reliably identify clinically significant pelvic organ prolapse after pelvic floor repair before the onset of symptoms.     

Observer variation of magnetic resonance imaging and diffusion weighted imaging in pelvic lymph node detection

Aim

Conventional MRI and the recently developed diffusion weighted imaging (DWI) technique both are being used for the detection of pelvic lymph node metastasis in gynaecologic cancers. Little is known about the reproducibility of DWI. This study assesses the reproducibility of pelvic lymph node detection by conventional MRI and DWI.

Materials and methods

17 patients with gynaecological malignancies eligible for curative surgery were selected as population of interest. They had undergone preoperative conventional MRI and DWI on a 3.0 T MR scanner. All images were evaluated by two experienced radiologists. Inter- and intra-observer agreements were assessed, and whether lymph node size and region were related to reproducibility. Differences were tested by Chi-square statistics.

Results

The reproducibility ranged between 42% and 65% for the two observers and for the two imaging tests, conventional MRI and DWI. Higher percentages of agreement were found for larger lymph nodes, i.e. for long as well as short axis diameter exceeding 5 mm. Also, agreement was better for lymph nodes in the external iliac region and the obturator region compared to detection of lymph nodes in the common iliac area. Results for the newer technique, DWI, were comparable to the results of the more conventional MRI sequences.

Conclusion

Reproducibility of MRI and DWI in the detection of pelvic lymph nodes in patients with a gynaecological malignancy was similar. For lymph nodes exceeding 5 mm in both long and short axis diameter the agreement was considerably better than for smaller nodes.     

Incremental value of arterial and equilibrium phase compared to hepatic venous phase CT in the preoperative staging of colorectal liver metastases: An evaluation with different reference standards

Purpose

To evaluate the incremental value of arterial and equilibrium phase compared to hepatic venous phase multidetector row CT (MDCT) in the preoperative staging of colorectal liver metastases (CLM) and to determine the influence of the reference standard.

Materials and methods

Fifty-three consecutive CLM patients underwent 16 detector row CT in hepatic arterial, venous, and equilibrium phase before surgery between March 2003 and January 2007. Detected lesions were characterized by three independent radiologists. The reference standard consisted of intraoperative palpation and ultrasound of the liver, and histopathological examination of the resected specimen. Additionally, data of follow-up CT was added. Statistical analysis was performed on a per-lesion basis.

Results

According to the reference standard 251 lesions were present, of which 203 (81%) were malignant (mean size: 29.4 ± 22.5 mm), and 41 (16%) were benign (mean size: 8.3 ± 7.7 mm). Sensitivity rates for CLM were comparable between triphasic and hepatic venous phase CT (P > 0.05). Sensitivity for the detection of CLM lowered from 60-77% to 52-68% when follow-up CT was added to the reference standard.

Conclusion

Arterial and equilibrium phase CT have no incremental value compared to hepatic venous phase MDCT in the detection of CLM. Sensitivity rates are, however, influenced by the type of reference standard used.     

Dual energy CTA of the supraaortic arteries: Technical improvements with a novel dual source CT system

Objectives

Computed tomography angiography (CTA) is a well-accepted imaging modality to evaluate the supraaortic vessels. Initial reports have suggested that dual energy CTA (DE-CTA) can enhance diagnosis by creating bone-free data sets, which can be visualized in 3D, but a number of limitations of this technique have also been addressed. We sought to describe the performance of DE-CTA of the supraaortic vessels with a novel dual source CT system with special emphasis on image quality and post-processing related artifacts.

Materials and methods

Thirty-three patients underwent carotid CT angiography on a second generation dual source CT system. Simultaneous acquisitions of 100 and 140 kV data sets in arterial phase were performed. Two examiners evaluated overall bone suppression with a 3-point scale (1 = poor; 3 = excellent) and image quality regarding integrity of the vessel lumen of different vessel segments (n = 26) with a 5-point scale (1 = poor; 5 = excellent), CTA source data served as the reference.

Results

Excellent bone suppression could be achieved in the head and neck. Only minor bone remnants occurred, mean score for bone removal was 2.9. Mean score for vessel integrity was 4.3. Eight hundred fifty-seven vessel segments could be evaluated. Six hundred thirty-five segments (74%) showed no lumen alteration, 65 segments (7.6%) lumen alterations <10%, 27 segments (3.1%) lumen alterations >10% resulting in a total luminal reduction <50%, 17 segments (2%) lumen alterations of more than 10% resulting in a total luminal reduction >50%, and 113 segments (13.2%) showed a gap in the vessel course (100% total lumen reduction). Artificial gaps of the vessel lumen occurred in 28 vessel segments due to artifacts caused by dental hardware and in all but one (65) ophthalmic arteries.

Conclusions

Excellent bone suppression could be achieved, DE imaging with 100 and 140 kV lead to improved image quality and vessel integrity in the shoulder region than previously reported. The ophthalmic artery still cannot be adequately visualized.     

Unenhanced MR Imaging in adults with clinically suspected acute appendicitis

Purpose

The purpose of the study was to evaluate unenhanced Magnetic Resonance Imaging (MRI) for the diagnosis of appendicitis or another surgery-requiring condition in an adult population scheduled for emergency appendectomy based on a clinical diagnosis of suspected acute appendicitis.

Materials and methods

The prospective study included 48 consecutive patients (29 female, 19 male, 18-70 years old, mean age = 37.1 years). MRI examination was designed to be comfortable and fast; no contrast was administered. The sequences were performed during quiet respiration. The MRI findings were reviewed by two radiologists and one surgeon independent of each other and compared with surgical and pathological records.

Results

According to the surgical and histopathological findings 30 of 48 patients (63%) had acute appendicitis. Of the remaining 18 patients, 4 patients had no reasons for the clinical symptoms and 14 patients had other pathology.For the three reviewers the performance of MRI in the diagnosis of acute appendicitis showed the following sensitivity, specificity and accuracy ranges: 83-93%, 50-83% and 77-83%. Moderate (κ = 0.51) and fair (κ = 0.31) interobserver agreements in the MR diagnosis of acute appendicitis were found between the reviewers. Sensitivity, specificity and accuracy values for overall performance of MRI in detecting pelvic abnormalities were 100%, 75% (3 of 4 healthy patients were identified by MRI) and 98%, respectively.

Conclusion

Unenhanced fast MRI is feasible as an additional fast screening before the appendectomy. It may prevent unnecessary surgeries. The fast MRI examination can be adequately performed on an MRI unit of broad range of field strengths.     

Diffusion-weighted imaging of breast tumors: Differentiation of benign and malignant tumors

Objective

The aim of this study was to evaluate the role of diffusion-weighted images (DWI) in the differentiation between benign and malignant breast tumors.

Patients and methods

This study included 62 females with focal breast lesions according to mammography or sonomamography. All patients underwent dynamic contrast enhanced MRI (DCE-MRI), and DWI of the breast. The mean apparent diffusion coefficient (ADC) values were calculated for all lesions and were correlated with the final histopathological results. The sensitivity and specificity of DWI in the differentiation between benign and malignant breast tumors were calculated.

Results

Seventy-eight lesions were detected in the examined 62 patients included in this study. Fifty one lesions were benign and 27 lesions were malignant according to the final histopathological results. (25/27) lesions were correctly diagnosed by ADC as malignant lesions with mean ADC value (0.92 ± 0.23 × 10⁻³ mm²/s) which was significantly lower than the mean ADC value for benign tumors (1.46 ± 0.48 × 10⁻³ mm²/s) and was correctly diagnosed in (50/51) lesions. The sensitivity and specificity of DWI in the differentiation between benign and malignant breast tumors were 92.6% and 98%, respectively.

Conclusion

DWI offers a useful method for differentiation of benign and malignant breast lesions with high sensitivity and specificity. Being a short unenhanced scan DWI can be safely added to the standard breast MRI protocol.     

MRI assessment of changes in liver iron deposition post-venesection

Objective

The aim of this study was to determine if changes in hepatic iron content in patients with hemochromatosis pre- and post-venesection could be detected by changes in liver signal intensity with MRI.

Materials and methods

The study was performed with institutional ethics approval and with informed consent. Gradient echo images were performed on 20 patients with hemochromatosis pre- and post-venesection and 10 control subjects: gradient echo T1-weighted in- and out-phases (4.54 (in)/2.27 (out), 167 [TE/TR], Flip 70°) and gradient echo T2* (5/18 [TE/TR], Flip 10°). The liver to muscle signal ratio was compared pre- and post-venesection.

Results

All MRI sequences showed significant correlation between the liver to muscle signal intensity ratio and the serum ferritin pre-venesection [r = −0.70, −0.65, −0.74, −0.72, in/out/T2*r/T2*, respectively]. There was a significant increase on all sequences in the liver to muscle signal intensity ratio post-venesection (p < 0.001). The control group and patients post-venesection had almost identical liver to muscle signal intensity ratios.

Conclusion

The reduction in liver signal intensity caused by iron excess in hemochromatosis returns to normal post-venesection. Measurement of liver to muscle signal intensity ratios may be a useful tool in assessing treatment response in iron overload states.