Quality Comparison of 3 Tesla multiparametric MRI of the prostate using a flexible surface receiver coil versus conventional surface coil plus endorectal coil setup.

PURPOSE: To subjectively and quantitatively compare the quality of 3 Tesla magnetic resonance imaging of the prostate acquired with a novel flexible surface coil (FSC) and with a conventional endorectal coil (ERC). METHODS: Six radiologists independently reviewed 200 pairs of axial, high-resolution T2-weighted and diffusion-weighted image data sets, each containing one examination acquired with the FSC and one with the ERC, respectively. Readers selected their preferred examination from each pair and assessed every single examination using six quality criteria on 4-point scales. Signal-to-noise ratios were measured and compared. RESULTS: Two readers preferred FSC acquisition (36.5-45%) over ERC acquisition (13.5-15%) for both sequences combined, and four readers preferred ERC acquisition (41-46%). Analysis of pooled responses for both sequences from all readers shows no significant preference for FSC or ERC. Analysis of the individual sequences revealed a pooled preference for the FSC in T2WI (38.7% vs 17.8%) and for the ERC in DWI (50.9% vs 19.6%). Patients' weight was the only weak predictor of a preference for the ERC acquisition (p = 0.04). SNR and CNR were significantly higher in the ERC acquisitions (p<0.001) except CNR differentiating tumor lesions from benign prostate (p=0.1). CONCLUSION: Although readers have strong individual preferences, comparable subjective image quality can be obtained for prostate MRI with an ERC and the novel FSC. ERC imaging might be particularly valuable for sequences with inherently lower SNR as DWI and larger patients whereas the FSC is generally preferred in T2WI. FSC imaging generates a lower SNR than with an ERC.

Multiparametric magnetic resonance imaging can exclude prostate cancer progression in patients on active surveillance: a retrospective cohort study.

OBJECTIVES: To assess the ability of multiparametric MRI (mp-MRI) of the prostate to exclude prostate cancer (PCa) progression during monitoring patients on active surveillance (AS). METHODS: One hundred forty-seven consecutive patients on AS with mp-MRI (T2WI, DWI, DCE-MRI) at 3T were initially enrolled. Fifty-five received follow-up mp-MRI after a minimum interval of 12 months and subsequent targeted MR/US fusion-guided biopsy (FUS-GB) plus concurrent systematic transrectal ultrasound-guided (TRUS-GB) biopsy as reference standard. Primary endpoint was the negative predictive value (NPV) of the follow-up mp-MRI to exclude histopathologic tumor progression using PRECISE recommendations. Secondary endpoints were the positive predictive value (PPV), sensitivity, specificity, Gleason score (GS) upgrades, and comparison of biopsy method. RESULTS: Of 55 patients, 29 (53%) had a GS upgrade on re-biopsy. All 29 patients showed a tumor progression on follow-up mp-MRI. Fifteen of 55 patients (27%) displayed signs of tumor progression, but had stable GS on re-biopsy. None of the 11 patients (20%) without signs of progression on follow-up mp-MRI had a GS upgrade on re-biopsy. The NPV was 100%, PPV was 66%, sensitivity was 100%, and specificity 42%. FUS-GB resulted in GS upgrade significantly more often (n = 28; 51%) compared with TRUS-GB (n = 12; 22%; p < 0.001). CONCLUSIONS: (Follow-up) Mp-MRI can reliably exclude PCa progression in patients on AS. Standard serial re-biopsies might be waived if follow-up mp-MRIs are stable. Over 60% of patients with signs of tumor progression on mp-MRI during AS had a GS upgrade on re-biopsy. Targeted re-biopsies should be performed if cancer progression or higher-grade PCa is suspected on mp-MRI. KEY POINTS: • None of the patients with unsuspicious mp-MRI had a GS upgrade in re-biopsy and mp-MRI might replace serial biopsies in these cases • More than 60% of patients with mp-MRI signs of tumor progression had subsequent Gleason score (GS) upgrades • Targeted re-biopsies should be performed in case of higher GS cancer suspicion on mp-MRI.

Hypoenhancing prostate cancers on dynamic contrast-enhanced MRI are associated with poor outcomes in high-risk patients: results of a hypothesis generating study.

PURPOSE: To investigate the association of hypoenhancement on dynamic Contrast enhanced (DCE) with prostate cancer patient outcomes. MATERIAL AND METHODS: This was a single-institution retrospective Institutional Review Board (IRB)-approved cohort study of 54 men who had prostate Magnetic Resonance Imaging (MRI) within 6 months of cancer diagnosis between 01/2012 to 03/2014. Two readers independently identified the dominant MRI-lesions utilizing Prostate Imaging-Reporting and Data System-version2- guidelines. These lesions were classified as hypoenhancing or hyperenhancing, compared to normal peripheral zone using quantitative DCE analysis. The t test for unequal sample sizes and the two-sample Wilcoxon rank-sum tests were used to compare groups. Logistic regression determined if DCE characteristics predict the development of metastases or prostate cancer death. RESULTS: Time-to-progression was significantly shorter for hypoenhancing tumors (6.2 vs. 24.8 months, p = 0.05). Men with these lesions had a higher odds of having poor outcome (univariate logistic regression, odds ratio (OR) 6.79, 95% confidence interval (CI) 1.45-31.72, p = 0.02; multivariate analysis, OR 2.05, 95% CI 0.30-13.72, p = 0.47). Hypoenhancing tumors were larger (33.1 vs. 19.1 mm, p < 0.001) and more likely to be intermediate (Gleason scores 3 + 4 and 4 + 3) and high-grade (Gleason scores ≥ 4 + 4) prostate cancers (p = 0.05). Men in the hypoenhancing group had a higher mean prostate-specific antigen (PSA) value (87.6 vs. 24.8 ng/dL, p = 0.01) and PSA density (1.54 vs. 0.72, p = 0.03). The mean Ktrans and kep of hypoenhancing lesion were lower when compared to hyperenhancing lesions (p = 0.03 and p = 0.04). Ve values did not differ (p = 0.25). CONCLUSION: Men with hypoenhancing prostate cancers may have a worse prognosis than men with hyperenhancing tumors.

Comparison of PI-RADS 2, ADC histogram-derived parameters, and their combination for the diagnosis of peripheral zone prostate cancer.

PURPOSE: The purpose of this study was to compare the PI-RADS V2 scores, ADC histogram-derived parameters, and their combination for the diagnosis of clinically significant peripheral zone prostate cancer (PCa). MATERIALS AND METHODS: The IRB approved this retrospective study of 47 men who underwent 1.5 Tesla endorectal prostate magnetic resonance imaging (MRI). Informed consent was waived. Two readers identified and scored MRI lesions using PI-RADS V2. Their mean, median, 10th, 25th, 75th percentile ADC values, and normalized ratio were also calculated. Multilevel logistic regression and receiver-operating characteristic (ROC) curve analyses assessed their diagnostic performance. Clinically significant PCa was defined as tumor volume over 0.5 cc and Gleason grade of 4 or 5 on prostatectomy. RESULTS: The area under the ROC curve (A z) of the overall and diffusion-weighted imaging (DWI) PI-RADS V2 scores were 0.69 and 0.84 (reader-1), and 0.68 and 0.73 (reader-2). The A z of ADC parameters ranged from 0.68 to 0.75 for both readers. Compared to other predictors, DWI PI-RADS V2 yielded the highest A z for identification of significant cancer; but, except for reader-1 75th percentile ADC, the differences were not statistically significant (P > 0.05). Adding ADC parameters to PI-RADS V2 scores did not improve their diagnostic ability. CONCLUSION: DWI PI-RADS V2 score may a better predictor of clinically significant PCa than the overall PI-RADS V2 score, but its diagnostic performance was not significantly improved by the addition of objective ADC value measurements.

Peritoneal coccidioidomycosis: a potential CT mimic of peritoneal malignancy.

Peritoneal involvement is a rare extrapulmonary manifestation of coccidioidomycosis. We report a patient with meningeal coccidioidomycosis who was found to have multiple, globular, peripherally enhancing deposits in the peritoneal cavity at abdominal computed tomography, raising the consideration of peritoneal malignancy. Aspiration biopsy demonstrated peritoneal coccidioidomycosis. The particular computed tomographic findings of peritoneal coccidioidomycosis seen in this patient have not been previously described.