3 Tesla breast MR imaging as a problem-solving tool: Diagnostic performance and incidental lesions.

PURPOSE: To investigate the diagnostic performance and incidental lesion yield of 3T breast MRI if used as a problem-solving tool. METHODS: This retrospective, IRB-approved, cross-sectional, single-center study comprised 302 consecutive women (mean: 50±12 years; range: 20-79 years) who were undergoing 3T breast MRI between 03/2013-12/2014 for further workup of conventional and clinical breast findings. Images were read by experienced, board-certified radiologists. The reference standard was histopathology or follow-up ≥ two years. Sensitivity, specificity, PPV, and NPV were calculated. Results were stratified by conventional and clinical breast findings. RESULTS: The reference standard revealed 53 true-positive, 243 true-negative, 20 false-positive, and two false-negative breast MRI findings, resulting in a sensitivity, specificity, PPV, and NPV of 96.4% (53/55), 92.4% (243/263), 72.6% (53/73), and 99.2% (243/245), respectively. In 5.3% (16/302) of all patients, incidental MRI lesions classified BI-RADS 3-5 were detected, 37.5% (6/16) of which were malignant. Breast composition and the imaging findings that had led to referral had no significant influence on the diagnostic performance of breast MR imaging (p>0.05). CONCLUSION: 3T breast MRI yields excellent diagnostic results if used as a problem-solving tool independent of referral reasons. The number of suspicious incidental lesions detected by MRI is low, but is associated with a substantial malignancy rate.

Breast MRI used as a problem-solving tool reliably excludes malignancy.

PURPOSE: To evaluate the diagnostic performance of breast MRI if used as a problem-solving tool in BI-RADS 0 cases. MATERIAL AND METHODS: In this IRB-approved, single-center study, 687 women underwent high-resolution-3D, dynamic contrast-enhanced breast magnetic resonance imaging (MRI) between January 2012 and December 2012. Of these, we analyzed 111 consecutive patients (mean age, 51 ± 12 years; range, 20-83 years) categorized as BI-RADS 0. Breast MRI findings were stratified by clinical presentations, conventional imaging findings, and breast density. MRI results were compared to the reference standard, defined as histopathology or an imaging follow-up of at least 1 year. RESULTS: One hundred eleven patients with BI-RADS 0 conventional imaging findings revealed 30 (27%) mammographic masses, 57 (51.4%) mammographic architectural distortions, five (4.5%) mammographic microcalcifications, 17 (15.3%) ultrasound-only findings, and two palpable findings without imaging correlates. There were 15 true-positive, 85 true-negative, 11 false-positive, and zero false-negative breast MRI findings, resulting in a sensitivity, specificity, PPV, and NPV of 100% (15/15), 88.5% (85/96), 57.7% (15/26), and 100% (85/85), respectively. Breast density and reasons for referral had no significant influence on the diagnostic performance of breast MRI (p>0.05). CONCLUSION: Breast MRI reliably excludes malignancy in conventional BI-RADS 0 cases resulting in a NPV of 100% (85/85) and a PPV of 57.7% (15/26).

MR arthrography of the shoulder: do we need local anesthesia?

PURPOSE: To assess pain intensity with and without subcutaneous local anesthesia prior to intraarticular administration of contrast medium for magnetic resonance arthrography (MRa) of the shoulder. MATERIALS AND METHODS: This single-center study was conducted after an IRB waiver of authorization, between January 2010 and December 2012. All patients provided written, informed consent for the procedure. Our prospectively populated institutional database was searched, based on our inclusion criteria. There were 249 outpatients (178 men and 71 women; mean age, 44.4 years ± 14.6; range, 15-79) who underwent MRa and were enrolled in this study. Patients were excluded if they had received surgery of the shoulder before MRa, had undergone repeated MRa of the same shoulder, and/or had undergone MRa of both shoulders on the same day. Patients were randomly assigned into one of three groups. Patients in group A (n=61) received skin infiltration with local anesthesia. Patients in control group B (n=92) and group C (n=96) did not receive local anesthesia. Pain levels were immediately assessed after the injection for MRa using a horizontal visual analog scale (VAS) that ranged from 0 to 10. To compare the pain scores of the three groups for male and female patients, a two-way analysis of variance was used. A p-value equal to or less than 0.05 was considered to indicate a significant result. RESULTS: Patients who received local anesthesia (group A) showed a mean pain level on the VAS of 2.6 ± 2.3. In patients who did not receive local anesthetics (groups B and C), a mean pain level on the VAS of 2.6 ± 2.2 and 2.7 ± 2.4 were detected, respectively. Between the three groups, no statistically significant difference in pain intensity was detected (p=.960). There were significant differences in subjective pain perception between men and women (p=.009). Moreover, the sex difference in all three groups was equal (p=.934). CONCLUSION: Local anesthesia is not required to lower a patient's pain intensity when applying intra-articular contrast media for MR arthrography of the shoulder. This could result in reduced costs and a reduced risk of adverse reactions, without an impact on patient comfort.

Rate of malignancy in MRI-detected probably benign (BI-RADS 3) lesions.

OBJECTIVE: The purpose of this study was to evaluate the malignancy rate in MRI-detected probably benign (BI-RADS 3) lesions in women without a history of breast cancer. MATERIALS AND METHODS: In this study, 1265 patients underwent breast MRI during a 7-year period. One hundred and eight (8.5%) patients with a nonpalpable breast lesion classified as BI-RADS 3 at MRI and with a needle biopsy or adequate follow-up of at least 24 months were included. Statistical analysis included calculation of the negative predictive value with its 95% CI. RESULTS: Of 108 lesions, 107 (99.1%) were correctly assessed as probably benign, resulting in a negative predictive value of 99.1% (95% CI, 94.99-99.98%). Histopathology was requested by the patient or referring physician in 44 patients. Of these, 43 (39.8%) lesions were classified as benign and one (0.9%) as malignant. There were no changes evident in any of the remaining 64 (59.2%) lesions during follow-up (range, 2-9 years). CONCLUSION: In MRI-detected probably benign (BI-RADS 3) lesions, the malignancy rate is low and within the accepted cancer rate for mammographically or sonographically detected BI-RADS 3 lesions. Short-term follow-up MRI at intervals of 6, 12, and 24 months in MRI BI-RADS 3 lesions remains a strong tool with which to detect suspicious lesions. Interval changes in size, morphology, or enhancement are regarded as indicative of malignancy.

Routine use of three-dimensional contrast-enhanced moving-table MR angiography in patients with peripheral arterial occlusive disease: comparison with selective digital subtraction angiography.

PURPOSE: To compare the diagnostic accuracy of contrast-enhanced (CE) three-dimensional (3D) moving-table magnetic resonance (MR) angiography with that of selective digital subtraction angiography (DSA) for routine clinical investigation in patients with peripheral arterial occlusive disease. METHODS: Thirty-eight patients underwent CE 3D moving-table MR angiography of the pelvic and peripheral arteries. A commercially available large-field-of-view adapter and a dedicated peripheral vascular phased-array coil were used. MR angiograms were evaluated for grade of arterial stenosis, diagnostic quality, and presence of artifacts. MR imaging results for each patient were compared with those of selective DSA. RESULTS: Two hundred and twenty-six arterial segments in 38 patients were evaluated by both selective DSA and MR angiography. No complications related to MR angiography were observed. There was agreement in stenosis classification in 204 (90.3%) segments; MR angiography overgraded 16 (7%) segments and undergraded 6 (2.7%) segments. Compared with selective DSA, MR angiography provided high sensitivity and specificity and excellent interobserver agreement for detection of severe stenosis (97% and 95%, kappa = 0.9 +/- 0.03) and moderate stenosis (96.5% and 94.3%, kappa = 0.9 +/- 0.03). CONCLUSION: Compared with selective DSA, moving-table MR angiography proved to be an accurate, noninvasive method for evaluation of peripheral arterial occlusive disease and may thus serve as an alternative to DSA in clinical routine.