Interreader variability in prostate MRI reporting using Prostate Imaging Reporting and Data System version 2.1.

OBJECTIVES: To evaluate the agreement among readers with different expertise in detecting suspicious lesions at prostate multiparametric MRI using Prostate Imaging Reporting and Data System (PI-RADS) version 2.1. METHODS: We evaluated 200 consecutive biopsy-naïve or previously negative biopsy men who underwent MRI for clinically suspected prostate cancer (PCa) between May and September 2017. Of them, 132 patients underwent prostate biopsy. Seven radiologists (four dedicated uro-radiologists and three non-dedicated abdominal radiologists) reviewed and scored all MRI examinations according to PI-RADS v2.1. Agreement on index lesion detection was evaluated with Conger's k coefficient, agreement coefficient 1 (AC1), percentage of agreement (PA), and indexes of specific positive and negative agreement. Clinical and radiological features that may influence variability were evaluated. RESULTS: Agreement in index lesion detection among all readers was substantial (AC1 0.738; 95% CI 0.695-0.782); dedicated radiologists showed higher agreement compared with non-dedicated readers. Clinical and radiological parameters that positively influenced agreement were PSA density ≥ 0.15 ng/mL/cc, pre-MRI high risk for PCa, positivity threshold of PI-RADS score 4 + 5, PZ lesions, homogeneous signal intensity of the PZ, and subjectively easy interpretation of MRI. Positive specific agreement was significantly higher among dedicated readers, up to 93.4% (95% CI 90.7-95.4) in patients harboring csPCa. Agreement on absence of lesions was excellent for both dedicated and non-dedicated readers (respectively 85.1% [95% CI 78.4-92.3] and 82.0% [95% CI 77.2-90.1]). CONCLUSIONS: Agreement on index lesion detection among radiologists of various experiences is substantial to excellent using PI-RADS v2.1. Concordance on absence of lesions is excellent across readers' experience. KEY POINTS: • Agreement on index lesion detection among radiologists of various experiences is substantial to excellent using PI-RADS v2.1. • Concordance between experienced readers is higher than between less-experienced readers. • Concordance on absence of lesions is excellent across readers' experience.

Tailored breast cancer screening program with microdose mammography, US, and MR Imaging: short-term results of a pilot study in 40-49-year-old women.

PURPOSE: To evaluate the feasibility, performance, and cost of a breast cancer screening program aimed at 40-49-year-old women and tailored to their risk profile with supplemental ultrasonography (US) and magnetic resonance (MR) imaging. MATERIALS AND METHODS: The institutional review board approved this study, and informed written consent was obtained. A total of 3017 40-49-year-old women were invited to participate. The screening program was tailored to lifetime risk (Gail test) and mammographic density (according to Breast Imaging Reporting and Data Systems [BI-RADS] criteria) with supplemental US or MR imaging and bilateral two-view microdose mammography. The indicators suggested by European guidelines, US incremental cancer detection rate (CDR), and estimated costs were evaluated. RESULTS: A total of 1666 women (67.5% participation rate) were recruited. The average lifetime risk of breast cancer was 11.6%, and nine women had a high risk of breast cancer; 917 women (55.0%) had a high density score (BI-RADS density category 3 or 4). The average glandular dose for screening examinations was 1.49 mGy. Screening US was performed in 835 study participants (50.1%), mostly due to high breast density (800 of 1666 women [48.0%]). Screening MR imaging was performed in nine women (0.5%) at high risk for breast cancer. Breast cancer was diagnosed in 14 women (8.4 cases per 1000 women). Twelve diagnoses were made with microdose mammography, and two were made with supplemental US in dense breasts (2.4 cases per 1000 women). All patients were submitted for surgery, and 10 underwent breast-conserving surgery. The sentinel lymph node was evaluated in 11 patients, resulting in negative findings in six. Pathologic analysis resulted in the diagnosis of four ductal carcinomas in situ and 10 invasive carcinomas (five at stage I). CONCLUSION: A tailored breast cancer screening program in 40-49-year-old women yielded a greater-than-expected number of cancers, most of which were low-stage disease.

Takayasu arteritis: intravascular contrast medium for MR angiography in the evaluation of disease activity.

OBJECTIVE: Takayasu arteritis is difficult to diagnose, and the evaluation of disease activity is even more challenging. Laboratory, clinical, and radiologic criteria are limited indicators of disease activity. Gadofosveset trisodium is a recently introduced intravascular contrast agent. In this study we sought to investigate a correlation between clinical activity and enhancement of vascular wall thickening in patients with Takayasu arteritis who underwent MR angiography with gadofosveset. SUBJECTS AND METHODS: Twenty-three consecutively registered patients (21 women, two men) with Takayasu arteritis underwent MR angiography of the supraaortic trunks, aorta, and visceral vessels. Intravascular contrast medium was used to correlate thickened vessel wall enhancement with clinical criteria of disease activity. ECG-triggered black-blood first-pass high-resolution steady-state imaging was performed for all patients. RESULTS: Before MR angiography, 14 patients were considered to have active disease. Heterogeneous structural involvement of the vascular tree was found. Twenty of 23 patients (87.0%) had supraaortic trunk involvement, including 12 of the 14 patients (85.7%) with active disease. Seventeen of the 23 patients (73.9%) had aortic and visceral vessel involvement, including 12 of the 14 patients (85.7%) with active disease. On steady state images in the active disease group, the mean signal-to-noise-ratio increased from 17.4 to 35.3 after gadofosveset injection (p > 0.0001), while in the nonactive disease group it increased from 52.8 to 69.6 (p = 0.08). A cutoff of 40% was best for differentiating active from inactive disease (sensitivity, 100%; specificity, 89%; positive predictive value, 92%; negative predictive value, 100%). CONCLUSION: Use of intravascular contrast medium significantly increases the effectiveness of MR angiography in differentiating active and inactive disease.