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.

Preoperative multiparametric MRI of the prostate for the prediction of lymph node metastases in prostate cancer patients treated with extended pelvic lymph node dissection.

OBJECTIVES: To assess the role of preoperative multiparametric MRI (mpMRI) of the prostate in the prediction of nodal metastases in patients treated with radical prostatectomy (RP) and extended pelvic lymph node dissection (ePLND). METHODS: We retrospectively analyzed 101 patients who underwent both preoperative mpMRI of the prostate and RP with ePLND at our institution. For each patient, complete preoperative clinical data and tumour characteristics at mpMRI were recorded. Final histopathologic stage was considered the standard of reference. Univariate and multivariate logistic regression analyses were performed. RESULTS: Nodal metastases were found in 23/101 (22.8%) patients. At univariate analyses, all clinical and radiological parameters were significantly associated to nodal invasion (all p<0.03); tumour volume at MRI (mrV), tumour ADC and tumour T-stage at MRI (mrT) were the most accurate predictors (AUC = 0.93, 0.86 and 0.84, respectively). A multivariate model including PSA levels, primary Gleason grade, mrT and mrV showed high predictive accuracy (AUC = 0.956). Observed prevalence of nodal metastases was very low among tumours with mrT2 stage and mrV<1cc (1.8%). CONCLUSION: Preoperative mpMRI of the prostate can predict nodal metastases in prostate cancer patients, potentially allowing a better selection of candidates to ePLND. KEY POINTS: • Multiparametric-MRI of the prostate can predict nodal metastases in prostate cancer • Tumour volume and stage at MRI are the most accurate predictors • Prevalence of nodal metastases is low for T2-stage and <1cc tumours • Preoperative mpMRI may allow a better selection of candidates to lymphadenectomy.

A multimodal diagnostic approach to inverted papilloma: Proposal of a novel diagnostic flow-chart.

PURPOSE: Inverted papilloma (IP) is a tumor usually arising from sinonasal cavities, with tendency for recurrence and possible malignant transformation. Along with endoscopy, computed tomography (CT) and magnetic resonance imaging (MRI) play a crucial role in defining preoperative staging, tumor origin, and possible differential diagnosis, with significant repercussions on therapeutic planning. However, at present no consensus has been reached concerning IP diagnostic workup. Aim of this study is to assess CT and MRI sensitivity and specificity in identifying IP imaging hallmarks, evaluating their global diagnostic accuracy in order to define a novel diagnostic flowchart. METHODS: We retrospectively analyzed multimodal imaging of patients with histologically confirmed IP and mimics. Two neuroradiologists in consensus retrospectively rated the presence of typical imaging features of IP, both on CT and MRI scans. Sensitivity, specificity and diagnostic accuracy were assessed for both the techniques. Final results were expressed as ROC curves and relative areas under the curve (AUC). RESULTS: The AUC considering CT parameters were 0.42, whereas the AUC considering MRI parameters were 0.54. Combining the 2 techniques and limiting the evaluation to the most distinctive features such as focal hyperostosis and CCP, the AUC was 0.79. CONCLUSION: MRI can provide better tissue characterization and higher diagnostic accuracy in case of suspected IP, whereas CT is more useful in determining bony involvement. Here we propose a possible diagnostic flowchart for IP, based on the assumption that the combination of the imaging techniques allows to optimize the clinical assessment and the subsequent therapeutic planning.

Multi-parametric magnetic resonance imaging characterization of orbital lesions: a triple blind study.

Background: Multi-parametric MRI used for preoperative assessment of orbital lesions does not routinely include DCE-MRI, since its accuracy in differential diagnosis of orbital mass is still under debate. Aim of this study is to characterize orbital lesions by multi-parametric MRI, analysing the incremental predictive value of DCE-MRI in differential diagnosis of orbital lesions.Methods: In this prospective triple-blind study, 43 consecutive patients with unilateral orbital lesion underwent conventional multimodal MRI and DCE-MRI before biopsy in a tertiary referral centre. Pre-operative MRI examination including conventional unenhanced MRI protocol, DWI with ADC maps, static CE 3D-T1 w and dynamic CE T1 w sequences, was performed within 1 week from surgery (anterior/lateral orbitotomy depending on location of the lesion, to carry out incisional/excisional biopsy).Results: Comparison between conventional T1 w/T2 w, DWI, CE 3D-T1 w and DCE-MRI groups showed a statistically significant difference in scores distribution (p < .001). Statistically significant difference was found between conventional T1 w/T2 w and DWI (p < .005), as well as between DWI and CE 3D-T1 w (p < .001). Conversely, no significant difference was found between CE 3D-T1 w and DCE (p < .005).Conclusions and Relevance: This study confirmed the positive effect of DWI and CE 3D-T1 w on orbital lesions diagnosis when added to conventional T1 w/T2 w sequences, whereas no substantial impact on diagnostic performance was observed with the further addition of DCE-MRI. DCE does not strongly influence diagnostic performance and inter-rater agreement in characterizing orbital lesions; therefore, it should be recommended in selected patients whose assessment of flow dynamics is particularly useful for management.Abbreviations: US = ultrasonography; MRI = magnetic resonance imaging; CT = computed tomography; STIR = Short-TI Inversion Recovery; DWI = diffusion weighted imaging; DCE-MRI = dynamic contrast-enhanced MRI; SE = Spin-Echo; TSE = Turbo Spin-Echo; THRIVE = T1-weighted high resolution Isotropic Volume Examination (dynamic contrast-enhanced ultrafast spoiled gradient echo); ROI = regions of interest; IRR = inter-rater reliability; TIC = time-intensity curve.

Can DCE-MRI reduce the number of PI-RADS v.2 false positive findings? Role of quantitative pharmacokinetic parameters in prostate lesions characterization.

PURPOSE: To test the potential impact of pharmacokinetic parameters, derived from DCE-MRI analysis, on the diagnostic performance of PI-RADSv.2 classification in prostate lesions characterization. METHOD: Among patients who underwent multiparametric prostate MRI (mpMRI) (January 2016-March 2018) followed by histological evaluation (targeted biopsies/prostatectomy), 103 men were retrospectively selected. For each patient the index lesion was identified and pharmacokinetic parameters (Ktrans, Kep, Ve, Vp) were assessed. MRI diagnostic performance in the detection of significant tumors [Gleason Score (GS)≥7] was assessed, considering PI-RADS≥3 as positive. RESULTS: GS ≥ 7 (n = 59) showed higher Ktrans (p < 0.01) and Kep (p = 0.01) compared to GS < 7. At ROC curve analysis, a Ktrans cut-off of 191 × 10-3/min was identified to predict the presence of GS ≥ 7 (AUC:0.75; sensitivity:95%; specificity:61%). Sensitivity and PPV of mpMRI using PI-RADSv.2 were 98% and 61%. Reclassifying PI-RADS≥3 lesions according to Ktrans cut-off, 22 false positives were shifted to true negatives with 3 false negative findings; PPV raised to 79%. Appling Ktrans cut-off to PI-RADS 3 lesions of peripheral zone (n = 18), 12 true negatives, 4 true positives, 2 false positives were identified. CONCLUSIONS: Despite its high sensitivity prostate mpMRI generates many false positive cases: Ktrans in addition to PIRADS v.2 seems to improve MRI-PPV and may help in avoiding redundant biopsies.