A pictorial essay of PI-RADS pearls and pitfalls: toward less ambiguity and better practice.

Prostate Imaging Reporting and Data System (PI-RADS) was designed to standardize the interpretation of multiparametric magnetic resonance imaging (MRI) of the prostate, aiding in assessing the probability of clinically significant prostate cancer. By providing a structured scoring system, it enables better risk stratification, guiding decisions regarding the need for biopsy and subsequent treatment options. In this article, we explore both the strengths and weaknesses of PI-RADS, offering insights into its updated diagnostic performance and clinical applications, while also addressing potential pitfalls using diverse, representative MRI cases.

N-(2,3-dihydroxypropyl) carbamoyl side chain: a potentially significant factor for recurrent iodinated contrast medium-related adverse drug reactions.

PURPOSE: To determine whether switching to contrast media based on the sharing of N-(2,3-dihydroxypropyl) carbamoyl side chain reduces the recurrence of iodinated contrast media (ICM)-associated adverse drug reactions (ADRs). MATERIALS AND METHODS: This single-center retrospective study included 2133 consecutive patients (mean age ± SD, 56.1 ± 11.4 years; male, 1052 [49.3%]) who had a history of ICM-associated ADRs and underwent contrast-enhanced CT examinations. The per-patient and per-exam-based recurrence ADR rates were compared between cases of switching and non-switching the ICM from ICMs that caused the previous ADRs, and between cases that used ICMs with common and different carbamoyl side chains from ICMs that caused the previous ADRs. Downgrade rates (no recurrence or the occurrence of ADR less severe than index ADRs) were also compared. Propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) analysis were additionally performed. RESULTS: In per-patient analysis, switching of ICM showed a lower recurrence rate (switching, 10.4% [100/965] vs. non-switching, 28.4% [332/1168]), with the adjusted odds ratio (OR) of 0.27 (95% CI: 0.21, 0.34; p < 0.001). The result was consistent in PSM (OR, 0.29 [95% CI: 0.22, 0.39]; p < 0.001), IPTW (OR, 0.28 [95% CI: 0.22, 0.36]; p < 0.001), and in per-exam analysis (5.5% vs. 13.8%; OR, 0.32 [95% CI: 0.27, 0.37]; p < 0.001). There was lower per-exam recurrence (5.0% [195/3938] vs. 7.8% [79/1017]; OR, 0.63 [95% CI: 0.47, 0.83]; p = 0.001) and higher downgrade rates (95.6% [3764/3938] vs. 93.3% [949/1017]; OR, 1.51 [95% CI: 1.12, 2.03]; p = 0.006) when using different side chain groups. CONCLUSION: Switching to an ICM with a different carbamoyl side chain reduced the recurrent ADRs and their severity during subsequent examinations. CLINICAL RELEVANCE STATEMENT: Switching to an iodinated contrast media with a different carbamoyl side chain reduced the recurrent adverse drug reactions and their severity during subsequent examinations.

Silent pheochromocytoma in adrenal incidentaloma: unveiling clinical and radiological characteristics.

Purpose: Silent pheochromocytoma refers to tumors without signs and symptoms of catecholamine excess. This study aimed to clarify the clinical, radiological characteristics, and perioperative features of silent pheochromocytomas diagnosed after adrenalectomy for adrenal incidentaloma. Methods: Medical records of patients who underwent adrenalectomy for adrenal incidentaloma and were subsequently diagnosed with silent pheochromocytoma between January 2000 and December 2020 were retrospectively reviewed for demographic, diagnostic, surgical, and pathological findings. Results: Of the 130 patients who underwent adrenalectomy for incidentaloma, 8 (6.1%) were diagnosed with silent pheochromocytoma. Almost all patients had no hypertensive symptoms and their baseline hormonal levels remained within normal ranges. All patients exhibited tumor size >4 cm, precontrast Hounsfield unit >10, and absolute washout <60%. Intraoperative hypertensive events were noted in 2 patients (25.0%) in whom antiadrenergic medications were not administered. All patients in the intraoperative hypertensive event group exhibited atypical features on CT, whereas 83.3% of patients in the non-intraoperative hypertensive event group showed atypical features on CT imaging. Conclusion: Silent pheochromocytomas share radiological traits with malignant adrenal tumors. Suspicious features on CT scans warrant surgical consideration for appropriate treatment. Administering alpha-blockers can enhance hemodynamic stability during adrenalectomy in suspected silent pheochromocytoma cases.

Diagnostic consistency between computed tomography and adrenal vein sampling of primary aldosteronism: leading to successful curative outcome after adrenalectomy; a retrospective study.

BACKGROUND: Adrenal computed tomography (CT) is a useful tool for locating adrenal lesion in primary aldosteronism (PA) patients. However, adrenal vein sampling (AVS) is considered as a gold standard for subtype diagnosis of PA. The aim of this study was to investigate the consistency of CT and AVS for the diagnosis of PA subtypes and evaluate the concordance of surgical outcomes. MATERIALS AND METHODS: This retrospective study included 264 PA patients having both CT and AVS. Diagnostic consistency between CT and AVS was accessed, and clinical and biochemical outcomes were evaluated at 6 months after adrenalectomy. RESULTS: Of all, 207 (78%) had a CT unilateral lesion, 31 (12%) CT bilateral lesion, and 26 (10%) CT bilateral normal findings. Among the CT unilateral lesion group, 138 (67%) had ipsilateral AVS lateralization. For CT bilateral lesion and bilateral normal, AVS unilateral lateralization was found in 17 (55%) and 2 (8%), respectively. The consistency between CT lesion and AVS lateralization including CT unilateral with AVS ipsilateral, and CT bilateral lesion with AVS bilateral patients was 63.8% (152/238). Of 77 patients with available data out of 138 patients who underwent adrenalectomy with consistency between CT and AVS, the clinical success rate was 96%, for 17 inconsistency patients out of 22 patients who underwent adrenalectomy, the clinical success rate was 94% after adrenalectomy following the lateralization result of AVS. CONCLUSION: CT is a useful tool to diagnose the adrenal lesion in PA patients. However, AVS is more sufficient to detect the unilateral PA subtype, which could provide curable treatment to surgical candidates of PA such that AVS can identify patients with contralateral PA in CT unilateral lesion and unilateral PA in CT bilateral lesion. The surgical outcome was successful when an adrenalectomy was performed according to the AVS lateralization result.

[Guidelines for Evaluating Treatment Response Based on Bone Scan for Metastatic Castration-Resistant Prostate Cancer: Prostate Cancer Clinical Trial Working Group 3 Recommendations]. / ì „ì´ì„± 거세 ì €í•­ì„± ì „ë¦½ì„ ì•”ì˜ 치료 반응 평가를 위한 뼈스캔 기반의 ì „ì´ì„± 골병변 반응 평가 지침: Prostate Cancer Clinical Trial Working Group 3 권장사항.

In prostate cancer, the bone is the most common site of metastasis, and it is essential to evaluate metastatic bone lesions to assess the tumor burden and treatment response. Castration-resistant prostate cancer refers to the state wherein the cancer continues to progress despite a significant reduction of the sex hormone level and is associated with frequent distant metastasis. The Prostate Cancer Working Group 3 (PCWG3) released guidelines that aimed to standardize the assessment of treatment effects in castration-resistant prostate cancer using bone scintigraphy. However, these guidelines can be challenging to comprehend and implement in practical settings. The purpose of this review was to provide an overview of a specific image acquisition method and treatment response assessment for bone scintigraphy-based evaluation of bone lesions in metastatic castration-resistant prostate cancer, in accordance with the PCWG3 guidelines.

[MR-Guided Targeted Prostate Biopsy from Radiologists' Perspective]. / 영상의학과 의사의 시각에서 본 ìžê¸°ê³µëª ì˜ìƒ 기반 ì „ë¦½ì„ í‘œì  생검.

The prostate cancer diagnosis has traditionally been based on a systematic biopsy method in which tissue samples are randomly obtained from the prostate 10-12 sites. However, there are concerns as the method can fail to diagnose all prostate cancers or lead to over-detection of clinically insignificant cancers. MRI-guided prostate targeted biopsy has been proposed to address these shortcomings. This method involves identifying suspicious lesions using MRI and performing targeted biopsies under ultrasound or MRI guidance. We review the methods of MRI-based targeted biopsy and discuss recent guidelines and trends in prostate cancer diagnosis.

Invasiveness of Upper Tract Urothelial Carcinoma: Clinical Significance and Integrative Diagnostic Strategy.

Purpose: In this study, we aimed to determine the clinicopathologic, radiologic, and molecular significance of the tumor invasiveness to further stratify the patients with high-grade (HG) upper tract urothelial carcinoma (UTUC) who can be treated less aggressively. Materials and Methods: Clinicopathologic and radiologic characteristics of 166 surgically resected HG UTUC (48 non-invasive, and 118 invasive) cases were evaluated. Six non-invasive UTUC cases with intra-tumoral tumor grade heterogeneity were selected for whole exome sequencing (WES) to understand the underlying molecular pathophysiology. Barcode-tagging sequencing (BTSeq) was done for validation of the target genes from WES data. Results: Patients with non-invasive UTUC showed no cancer-specific death with better cancer-specific survival (p<0.001) and recurrence-free survival (p<0.001) compared to the patients with invasive UTUC. Compared to the invasive UTUC, non-invasive UTUC was correlated to a low grade on the preoperative abdominal computed tomography (CT) grading system (p<0.001), histologic intratumoral tumor grade heterogeneity (p=0.018), discrepancy in preoperative urine cytology diagnosis (p=0.018), and absence of urothelial carcinoma in situ (p<0.001). WES of the heterogeneous components showed mutually shared HRAS and FGFR3 mutations shared between the HG and LG components. HRAS mutation was associated with the lower grade on preoperative abdominal CT and intratumoral tumor grade heterogeneity (p=0.045 and p<0.001, respectively), whereas FGFR3 mutation was correlated to the absence of carcinoma in situ (p<0.001). Conclusion: According to our comprehensive analysis, HG non-invasive UTUC can be preoperatively suspected based on distinct preoperative radiologic, cytologic, histologic, and molecular features. Non-invasive HG UTUC shows excellent prognosis and thus should be treated less aggressively.

Focal nodular enhancement on DCE MRI of the prostatectomy bed: radiologic-pathologic correlations and prognostic value.

OBJECTIVES: To determine the concordance of dynamic contrast-enhanced (DCE) imaging findings with clinico-pathologic characteristics and their prognostic impact for predicting biochemical recurrence (BCR) in patients who underwent radical prostatectomy (RP) for prostate cancer. METHODS: This retrospective study included patients who underwent MRI within 1 year after RP between November 2019 and October 2020. DCE findings and their concordance with the presence and location of positive surgical margin (PSM) were assessed using RP specimens. Kaplan-Meier and logistic regression analyses were used to evaluate the prognostic impact of DCE findings for BCR. RESULTS: Among the 272 men (mean age ± standard deviation, 66.6 ± 7.4 years), focal nodular enhancement was more frequently observed in those with PSM compared to those with negative margin (85.4% versus 14.6%; p < 0.001). The sites of focal nodular enhancement were 72.9% (35/48) concordant with the PSM locations. Focal nodular enhancement was associated with a higher Gleason score, higher preoperative PSA (≥ 10 ng/mL), higher Gleason grade at the surgical margin, and non-limited margin involvement (p = 0.002, 0.006, 0.032, and 0.001, respectively). In patients without BCR at the time of MRI, focal nodular enhancement was associated with a shorter time to BCR (p < 0.001) and a significant factor predicting 1-year BCR in both univariate (odds ratio = 8.4 [95% CI: 2.5-28.3]; p = 0.001) and multivariate (odds ratio = 5.49 [1.56-19.3]; p = 0.008) analyses. CONCLUSIONS: Focal nodular enhancement on post-prostatectomy MRI was associated with adverse clinico-pathologic characteristics of high risk for recurrence and can be a predictor for 1-year BCR in patients undergoing RP. KEY POINTS: • Focal nodular enhancement (PI-RR DCE score ≥ 4) was 72.9% (35/48) concordant with the site of positive resection margin by radiologic-histologic correlation. • Focal nodular enhancement (PI-RR DCE score ≥ 4) was associated with higher Gleason score ( ≥ 8), preoperative PSA ( > 10 ng/mL), and Gleason grade 4 or 5 at the surgical margin and non-limited margin involvement (p ≤ 0.032). • In patients without BCR at the time of MRI, focal nodular enhancement was a significant factor predicting 1-year BCR (odds ratio = 5.49; 95% CI: 1.56-19.3; p = 0.008).

Biopsy-Integrated 3D Magnetic Resonance Imaging Modeling of Prostate Cancer and Its Application for Gleason Grade and Tumor Laterality Assessment.

CONTEXT.­: Grade Group assessed using Gleason combined score and tumor extent is a main determinant for risk stratification and therapeutic planning of prostate cancer. OBJECTIVE.­: To develop a 3-dimensional magnetic resonance imaging (MRI) model regarding Grade Group and tumor extent in collaboration with uroradiologists and uropathologists for optimal treatment planning for prostate cancer. DESIGN.­: We studied the data from 83 patients with prostate cancer who underwent multiparametric MRI and subsequent MRI-transrectal ultrasound fusion biopsy and radical prostatectomy. A 3-dimensional MRI model was constructed by integrating topographic information of MRI-based segmented lesions, biopsy paths, and histopathologic information of biopsy specimens. The multiparametric MRI-integrated Grade Group and laterality were assessed by using the 3-dimensional MRI model and compared with the radical prostatectomy specimen. RESULTS.­: The MRI-defined index tumor was concordant with radical prostatectomy in 94.7% (72 of 76) of cases. The multiparametric MRI-integrated Grade Group revealed the highest agreement (weighted κ, 0.545) and a significantly higher concordance rate (57.9%) than the targeted (47.8%, P = .008) and systematic (39.4%, P = .01) biopsies. The multiparametric MRI-integrated Grade Group showed significantly less downgrading rates than the combined biopsy (P = .001), without significant differences in upgrading rate (P = .06). The 3-dimensional multiparametric MRI model estimated tumor laterality in 66.2% (55 of 83) of cases, and contralateral clinically significant cancer was missed in 9.6% (8 of 83) of cases. The tumor length measured by multiparametric MRI best correlated with radical prostatectomy as compared with the biopsy-defined length. CONCLUSIONS.­: The 3-dimensional model incorporating MRI and MRI-transrectal ultrasound fusion biopsy information easily recognized the spatial distribution of MRI-visible and MRI-nonvisible cancer and provided better Grade Group correlation with radical prostatectomy specimens but still requires validation.

Proportion of malignancy in Bosniak classification of cystic renal masses version 2019 (v2019) classes: systematic review and meta-analysis.

OBJECTIVES: Determine the proportion of malignancy within Bosniak v2019 classes. METHODS: MEDLINE and EMBASE were searched. Eligible studies contained patients with cystic renal masses undergoing CT or MRI renal protocol examinations with pathology confirmation, applying Bosniak v2019. Proportion of malignancy was estimated within Bosniak v2019 class. Risk of bias was assessed using QUADAS-2. RESULTS: We included 471 patients with 480 cystic renal masses. No class I malignant masses were observed. Pooled proportion of malignancy were class II, 12% (6/51, 95% CI 5-24%); class IIF, 46% (37/85, 95% CI 28-66%); class III, 79% (138/173, 95% CI 68-88%); and class IV, 84% (114/135, 95% CI 77-90%). Proportion of malignancy differed between Bosniak v2019 II-IV classes (p = 0.004). Four studies reported the proportion of malignancy by wall/septa feature. The pooled proportion of malignancy with 95% CI were class III thick smooth wall/septa, 77% (41/56, 95% CI 53-91%); class III obtuse protrusion ≤ 3 mm (irregularity), 83% (97/117, 95% CI 75-89%); and class IV nodule with acute angulation, 86% (50/58, 95% CI 75-93%) or obtuse angulation ≥ 4 mm, 83%, (64/77, 95% CI 73-90%). Subgroup analysis by wall/septa feature was limited by sample size; however, no differences were found comparing class III masses with irregularity to class IV masses (p = 0.74) or between class IV masses by acute versus obtuse angles (p = 0.62). CONCLUSION: Preliminary data suggest Bosniak v2019 class IIF masses have higher proportion of malignancy compared to the original classification, controlling for pathologic reference standard. There are no differences in proportion of malignancy comparing class III masses with irregularities to class IV masses with acute or obtuse nodules. KEY POINTS: • The proportion of malignancy in Bosniak v2019 class IIF cystic masses is 46% (37 malignant/85 total IIF masses, 95% confidence intervals (CI) 28-66%). • The proportion of malignancy in Bosniak v2019 class III cystic masses is 79% (138/173, 95% CI 68-88%) and in Bosniak v2019 class IV cystic masses is 84% (114/135, 95% CI 77-90%). • Class III cystic masses with irregularities had similar proportion of malignancy (83%, 97/117, 95% CI 75-89%) compared to Bosniak class IV masses (84%, 114/135, 95% CI 77-90%) overall (p = 0.74) with no difference within class IV masses by acute versus obtuse angulation (p = 0.62).

Hyperoxia-Induced ΔR1: MRI Biomarker of Histological Infarction in Acute Cerebral Stroke.

OBJECTIVE: To evaluate whether hyperoxia-induced ΔR1 (hyperO2ΔR1) can accurately identify histological infarction in an acute cerebral stroke model. MATERIALS AND METHODS: In 18 rats, MRI parameters, including hyperO2ΔR1, apparent diffusion coefficient (ADC), cerebral blood flow and volume, and 18F-fluorodeoxyglucose uptake on PET were measured 2.5, 4.5, and 6.5 hours after a 60-minutes occlusion of the right middle cerebral artery. Histological examination of the brain was performed immediately following the imaging studies. MRI and PET images were co-registered with digitized histological images. The ipsilateral hemisphere was divided into histological infarct (histological cell death), non-infarct ischemic (no cell death but ADC decrease), and non-ischemic (no cell death or ADC decrease) areas for comparisons of imaging parameters. The levels of hyperO2ΔR1 and ADC were measured voxel-wise from the infarct core to the non-ischemic region. The correlation between areas of hyperO2ΔR1-derived infarction and histological cell death was evaluated. RESULTS: HyperO2ΔR1 increased only in the infarct area (p ≤ 0.046) compared to the other areas. ADC decreased stepwise from non-ischemic to infarct areas (p = 0.002 at all time points). The other parameters did not show consistent differences among the three areas across the three time points. HyperO2ΔR1 sharply declined from the core to the border of the infarct areas, whereas there was no change within the non-infarct areas. A hyperO2ΔR1 value of 0.04 s-1 was considered the criterion to identify histological infarction. ADC increased gradually from the infarct core to the periphery, without a pronounced difference at the border between the infarct and non-infarct areas. Areas of hyperO2ΔR1 higher than 0.04 s-1 on MRI were strongly positively correlated with histological cell death (r = 0.862; p < 0.001). CONCLUSION: HyperO2ΔR1 may be used as an accurate and early (2.5 hours after onset) indicator of histological infarction in acute stroke.

The Prognosis and the Role of Adjuvant Chemotherapy for Node-Positive Bladder Cancer Treated with Neoadjuvant Chemotherapy Followed by Surgery.

PURPOSE: This study aims to evaluate the prognosis of pathologically node-positive bladder cancer after neoadjuvant chemotherapy, the role of adjuvant chemotherapy in these patients, and the value of preoperative clinical evaluation for lymph node metastases. MATERIALS AND METHODS: Patients who received neoadjuvant chemotherapy followed by partial/radical cystectomy and had pathologically confirmed lymph node metastases between January 2007 and December 2019 were identified and analyzed. RESULTS: A total of 53 patients were included in the study. The median age was 61 years (range, 34 to 81 years) with males comprising 86.8%. Among the 52 patients with post-neoadjuvant/pre-operative computed tomography results, only 33 patients (63.5%) were considered positive for lymph node metastasis. Sixteen patients (30.2%) received adjuvant chemotherapy (AC group), and 37 patients did not (no AC group). With the median follow-up duration of 67.7 months, the median recurrence-free survival (RFS) and the median overall survival (OS) was 8.5 months and 16.2 months, respectively. The 2-year RFS and OS rates were 23.3% and 34.6%, respectively. RFS and OS did not differ between the AC group and no AC group (median RFS, 8.8 months vs. 6.8 months, p=0.772; median OS, 16.1 months vs. 16.3 months, p=0.479). Thirty-eight patients (71.7%) experienced recurrence. Distant metastases were the dominant pattern of failure in both the AC group (91.7%) and no AC group (76.9%). CONCLUSION: Patients with lymph node-positive disease after neoadjuvant chemotherapy followed by surgery showed high recurrence rates with limited survival outcomes. Little benefit was observed with the addition of adjuvant chemotherapy.

Fast T2-Weighted Imaging With Deep Learning-Based Reconstruction: Evaluation of Image Quality and Diagnostic Performance in Patients Undergoing Radical Prostatectomy.

BACKGROUND: Deep learning-based reconstruction (DLR) can potentially improve image quality by reduction of noise, thereby enabling fast acquisition of magnetic resonance imaging (MRI). However, a systematic evaluation of image quality and diagnostic performance of MRI using short acquisition time with DLR has rarely been investigated in men with prostate cancer. PURPOSE: To assess the image quality and diagnostic performance of MRI using short acquisition time with DLR for the evaluation of extraprostatic extension (EPE). STUDY TYPE: Retrospective. POPULATION: One hundred and nine men. FIELD STRENGTH/SEQUENCE: 3 T; turbo spin echo T2-weighted images (T2WI), echo-planar diffusion-weighted, and spoiled gradient echo dynamic contrast-enhanced images. ASSESSMENT: To compare image quality, signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) and subjective analysis using Likert scales on three T2WIs (MRI using conventional acquisition time, MRI using short acquisition time [fast MRI], and fast MRI with DLR) were performed. The diagnostic performance for EPE was evaluated by three independent readers. STATISTICAL TESTS: SNR, CNR, and image quality scores across the three imaging protocols were compared using Friedman tests. The diagnostic performance for EPE was assessed using the area under receiver operating characteristic curves (AUCs). P < 0.05 was considered statistically significant. RESULTS: Fast MRI with DLR demonstrated significantly higher SNR (mean ± SD, 14.7 ± 6.8 vs. 8.8 ± 4.9) and CNR (mean ± SD, 6.5 ± 6.3 vs. 3.4 ± 3.6) values and higher image quality scores (median, 4.0 vs. 3.0 for three readers) than fast MRI. The AUCs for EPE were significantly higher with the use of DLR (0.86 vs. 0.75 for reader 2 and 0.82 vs. 0.73 for reader 3) compared with fast MRI, whereas differences were not significant for reader 1 (0.81 vs. 0.74; P = 0.09). DATA CONCLUSION: DLR may be useful in reducing the acquisition time of prostate MRI without compromising image quality or diagnostic performance. LEVEL OF EVIDENCE: 4 TECHNICAL EFFICACY: Stage 3.

Impact of diagnostic errors on adverse outcomes: learning from emergency department revisits with repeat CT or MRI.

BACKGROUND: To investigate diagnostic errors and their association with adverse outcomes (AOs) during patient revisits with repeat imaging (RVRIs) in the emergency department (ED). RESULTS: Diagnostic errors stemming from index imaging studies and AOs within 30 days in 1054 RVRIs (≤ 7 days) from 2005 to 2015 were retrospectively analyzed according to revisit timing (early [≤ 72 h] or late [> 72 h to 7 days] RVRIs). Risk factors for AOs were assessed using multivariable logistic analysis. The AO rate in the diagnostic error group was significantly higher than that in the non-error group (33.3% [77 of 231] vs. 14.8% [122 of 823], p < .001). The AO rate was the highest in early revisits within 72 h if diagnostic errors occurred (36.2%, 54 of 149). The most common diseases associated with diagnostic errors were digestive diseases in the radiologic misdiagnosis category (47.5%, 28 of 59) and neurologic diseases in the delayed radiology reporting time (46.8%, 29 of 62) and clinician error (27.3%, 30 of 110) categories. In the matched set of the AO and non-AO groups, multivariable logistic regression analysis revealed that the following diagnostic errors contributed to AO occurrence: radiologic error (odds ratio [OR] 3.56; p < .001) in total RVRIs, radiologic error (OR 3.70; p = .001) and clinician error (OR 4.82; p = .03) in early RVRIs, and radiologic error (OR 3.36; p = .02) in late RVRIs. CONCLUSION: Diagnostic errors in index imaging studies are strongly associated with high AO rates in RVRIs in the ED.

Bosniak Classification of Cystic Renal Masses Version 2019: Comparison With Version 2005 for Class Distribution, Diagnostic Performance, and Interreader Agreement Using CT and MRI.

BACKGROUND. The Bosniak classification system for cystic renal masses (CRMs) was updated in 2019, requiring further investigation. OBJECTIVE. The purpose of this study was to compare versions 2005 and 2019 of the Bosniak classification system in terms of class distribution, diagnostic performance, interreader agreement, and intermodality agreement between CT and MRI. METHODS. This retrospective study included 100 patients (mean age, 52.4 ± 11.6 years; 68 men, 32 women) with 104 CRMs (74 malignant) who underwent CT, MRI, and resection between 2010 and 2019. Two radiologists independently evaluated CRMs in separate sessions for each combination of version and modality and assigned a Bosniak class. Diagnostic performance was compared using McNemar tests. Interreader and intermodality agreement were analyzed using weighted kappa coefficients. RESULTS. Across readers and modalities, the proportion of class IIF CRMs was higher for version 2019 than version 2005 (reader 1: 28.8-30.8% vs 6.7-12.5%; reader 2: 26.0-28.8% vs 8.7-19.2%), although 95% CIs overlapped for reader 2 on CT. The proportion of class III CRMs was lower for version 2019 than version 2005 (reader 1: 33.7-35.6% vs 49.0-51.9%; reader 2: 31.7-40.4% vs 37.5-52.9%), although 95% CIs overlapped for all comparisons. Version 2019 showed lower sensitivity for malignancy than version 2005 across readers and modalities (all p < .05); for example, using CT, sensitivity was 75.7% for both readers with version 2019 versus 85.1-87.8% with version 2005. However, version 2019 showed higher specificity than version 2005, which was significant (all p < .05) for reader 1. For example, using CT, specificity was 73.3% (reader 1) and 70.0% (reader 2) with version 2019 versus 50.0% (reader 1) and 56.7% (reader 2) with version 2005. Diagnostic accuracy was not different between versions (version 2005: 76.9-85.6%; version 2019: 74.0-78.8%). Interreader and intermodality agreement were substantial for version 2005 (κ = 0.676-0.782 and 0.711-0.723, respectively) and version 2019 (κ = 0.756-0.804 and 0.704-0.781, respectively). CONCLUSION. Use of version 2019 versus version 2005 of the Bosniak classification system results in a shift in CRM assignment from class III to class IIF. Version 2019 results in lower sensitivity, higher specificity, and similar accuracy versus version 2005. Interreader and intermodality agreement are similar between versions. CLINICAL IMPACT. Version 2019 facilitates recommending imaging surveillance for more CRMs.

Preoperative Assessment of Renal Sinus Invasion by Renal Cell Carcinoma according to Tumor Complexity and Imaging Features in Patients Undergoing Radical Nephrectomy.

OBJECTIVE: To identify the association between renal tumor complexity and pathologic renal sinus invasion (RSI) and evaluate the usefulness of computed tomography tumor features for predicting RSI in patients with renal cell carcinoma (RCC). MATERIALS AND METHODS: This retrospective study included 276 consecutive patients who underwent radical nephrectomy for RCC with a size of ≤ 7 cm between January 2014 and October 2017. Tumor complexity and anatomical renal sinus involvement were evaluated using two standardized scoring systems: the radius (R), exophytic or endophytic (E), nearness to collecting system or sinus (N), anterior or posterior (A), and location relative to polar lines (RENAL) nephrometry and preoperative aspects and dimensions used for anatomical classification (PADUA) system. CT-based tumor features, including shape, enhancement pattern, margin at the interface of the renal sinus (smooth vs. non-smooth), and finger-like projection of the mass, were also assessed by two independent radiologists. Univariable and multivariable logistic regression analyses were performed to identify significant predictors of RSI. The positive predictive value, negative predictive value (NPV), accuracy of anatomical renal sinus involvement, and tumor features were evaluated. RESULTS: Eighty-one of 276 patients (29.3%) demonstrated RSI. Among highly complex tumors (RENAL or PADUA score ≥ 10), the frequencies of RSI were 42.4% (39/92) and 38.0% (71/187) using RENAL and PADUA scores, respectively. Multivariable analysis showed that a non-smooth margin and the presence of a finger-like projection were significant predictors of RSI. Anatomical renal sinus involvement showed high NPVs (91.7% and 95.2%) but low accuracy (40.2% and 43.1%) for RSI, whereas the presence of a non-smooth margin or finger-like projection demonstrated comparably high NPVs (90.0% and 91.3% for both readers) and improved accuracy (67.0% and 73.9%, respectively). CONCLUSION: A non-smooth margin or the presence of a finger-like projection can be used as a preoperative CT-based tumor feature for predicting RSI in patients with RCC.

Performance of Prostate Imaging Reporting and Data System Version 2.1 for Diagnosis of Prostate Cancer: A Systematic Review and Meta-Analysis.

BACKGROUND: The Prostate Imaging Reporting and Data System (PI-RADS) was introduced in 2012 and updated to version 2.1 (v2.1) in early 2019 to improve diagnostic performance and interreader reliability. PURPOSE: To evaluate the diagnostic performance of PI-RADS v2.1 in comparison with v2. METHODS: A systematic review and meta-analysis of the literature was performed using MEDLINE, EMBASE, and Cochrane databases to identify studies evaluating the diagnostic performance of PI-RADS v2.1 for diagnosing clinically significant prostate cancer (csPCa). STUDY TYPE: Systematic review and meta-analysis. SUBJECT: One thousand two hundred forty-eight patients with 1406 lesions from 10 eligible articles. FIELD STRENGTH/SEQUENCE: Conventional MR sequences at 1.5 T and 3 T. ASSESSMENT: Two reviewers independently identified and reviewed the original articles reporting diagnostic performance of PI-RADS v2.1. STATISTICAL TESTS: Meta-analytic summary sensitivity and specificity were calculated using a bivariate random effects model. Meta-analytic sensitivity and specificity between PI-RADS v2 and v2.1 were compared. RESULTS: The pooled sensitivity and specificity of PI-RADS v2.1 were 87% (95% confidence intervals, 82-91%) and 74% (63-82%), respectively. In five studies available for a head-to-head comparison between PI-RADS v2.1 and v2, there were no significant differences in either sensitivity (90% [86-94%] vs. 88% [83-93%], respectively) or specificity (76% [59-93%] vs. 61% [39-83%], respectively; P = 0.37). The sensitivity and specificity were 81% (73-87%) and 82% (68-91%), respectively, for a PI-RADS score cutoff of ≥4, and 94% (88-97%) and 56% (35-97%) for ≥3. Regarding the zonal location, the sensitivity and specificity for the transitional zone only were 90% (84-96%) and 76% (62-90%) respectively, whereas for the whole gland they were 85% (79-91%) and 71% (57-85%). DATA CONCLUSION: PI-RADS v2.1 demonstrated good overall performance for the diagnosis of csPCa. PI-RADS v2.1 tended to show higher specificity than v2, but the difference lacked statistical significance. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY STAGE: 3.

Preoperative MRI-based estimation of risk for positive resection margin after radical prostatectomy in patients with prostate cancer: development and validation of a simple scoring system.

OBJECTIVES: To develop a simplified MRI-based model to predict the risk for positive surgical margins (PSMs) after radical prostatectomy (RP) in patients with prostate cancer (PCa). METHODS: Consecutive patients who underwent RP for PCa were retrospectively identified from a tertiary referral hospital. Patients who underwent RP between January 2014 and June 2014 were assigned as derivation cohort (n = 330) and those between January 2018 and February 2018 were assigned as validation cohort (n = 100). MRI-based predictors associated with PSM were assessed: tumor size, tumor-capsule contact length, the Prostate Imaging Reporting and Data System (PI-RADS) category, tumor location (tumor contact to the apex or posterolateral side near the neurovascular bundle), apical depth, and prostate volume. A prediction model was developed by using multivariable logistic regression, and then it was transformed into a scoring system. The prediction and calibration performance of this scoring system was evaluated using the C statistics and Hosmer-Lemeshow goodness-of-fit test. RESULTS: A total of 121 (36.7%) and 32 (32.0%) of patients in the derivation and validation cohorts had PSMs after RP. The scoring system consisted of the following variables: tumor-capsule contact length, PI-RADS category, tumor located at the apex and/or posterolateral side. This scoring system provided good prediction performance for PSM in the derivation (C statistics, 0.80 [95% CI: 0.76, 0.85]) and validation (C statistics, 0.77 [95% CI: 0.68, 0.87]) cohorts, and also showed good calibration in both cohorts (p = 0.83 and 0.86, respectively). CONCLUSIONS: An MRI-based scoring system can help estimate the risk of PSM after RP. KEY POINTS: • An MRI-based scoring system served as a tool to estimate the risk of positive surgical margin (C statistics, 0.80 and 0.77 in the derivation and validation cohorts, respectively) after radical prostatectomy. • Tumor with contact to the apex or posterolateral aspect, the tumor contact length to capsule, and higher PI-RADS category were independent predictors for the presence of positive resection margins after radical prostatectomy in men with prostate cancer. • High-risk patients as determined by the scoring system demonstrated adverse post-surgical outcomes compared with low- or intermediate-risk patients, in regard to longer length (mean length, 13.0 mm versus 3.9 mm in low risk or 6.2 mm in intermediate risk; p ≤ 0.001) and higher Gleason grade at the margin (grades 4 and 5 in 69.4% and 20.4% versus 16.7% and 16.7% in low risk or 46.7% and 5.4% in intermediate risk; p < 0.001).

Ancillary imaging and clinical features for the characterization of prostate lesions: A proposed approach to reduce false positives.

The relatively low specificity and positive predictive value of the Prostate Imaging-Reporting and Data System (PI-RADS) can lead to considerable false-positive results and unnecessary biopsies. The aim of this study was to propose ancillary features (AFs) indicating clinically significant prostate cancer (csPCa) or benign tissues in PI-RADS category ≥3 lesions and determine the usefulness of these AFs in reducing false-positive assessments of suspicious lesions in men at csPCa risk. This was a retrospective study, which included 199 men. A 3T, including turbo spin echo T2 -weighted, echo-planar diffusion-weighted, and spoiled gradient echo dynamic contrast-enhanced (DCE) images, was used. Five AFs (prostate-specific antigen density ≥0.15 ng/mL2 ; size ≥10 mm; heterogeneous T2 signal intensity; circumscribed nodule in the junction of peripheral and transition zone; and DCE time curves) indicating csPCa or non-csPCa were evaluated by three independent readers. The sensitivity and specificity of each AF were calculated. Inter-reader agreement was evaluated using κ statistics. Univariate and multivariate logistic regression analyses were conducted to determine significant AFs. The reduction in positive call rates and csPCa detection rates with combined AF use were calculated and compared with the findings obtained with PI-RADS use alone. The sensitivities and specificities of the AFs indicating csPCa were 72.1%-96.5% and 27.4%-75.2% for reader 1, 66.3%-96.5% and 23.9%-62.0% for reader 2, and 67.4%-96.5% and 34.5%-78.8% for reader 3, with moderate to substantial inter-reader agreement (Fleiss κ, 0.551-0.643). The combined use of two or more AFs for assessing PI-RADS ≥3 lesions resulted in a 19.6%-30.7% reduction in positive calls (p < .05) compared to PI-RADS use alone while preserving the csPCa detection rates (p ≥ .06) for three readers. The use of AFs in combination with PI-RADS can reduce positive calls and false positives without csPCa under-detection.

Comparison of biopsy strategies for prostate biopsy according to lesion size and PSA density in MRI-directed biopsy pathway.

PURPOSE: To investigate whether the detection of clinically significant prostate cancer (csPCa) and the added value of focal saturation biopsy and systematic biopsy (SBx) differ according to index lesion size, and to compare the current guidelines for csPCa detection. METHODS: This retrospective study included consecutive men who underwent MRI and subsequent SBx and MRI-targeted biopsy (TBx) for a suspicious lesion between April 2019 and February 2020. Lesion visibility on transrectal ultrasound (US) and added value of focal saturation biopsy and SBx were compared according to index lesion size using chi-square and McNemar tests. csPCa detection rates and the proportion of biopsy-indicated men were compared among four biopsy strategies based on current guidelines. RESULTS: Of 313 men evaluated (median age, 65; interquartile range 60‒71), csPCa was detected in 110 (35%). In lesions < 10 mm, greater US invisibility (42.7% of lesions < 10 mm versus 20.0% of lesions ≥ 10 mm; p < 0.001) and higher added value of focal saturation biopsy and SBx (11.1% and 17.1% in lesions < 10 mm versus 4.2% and 6.3% in lesions ≥ 10 mm) were observed, compared with lesions ≥ 10 mm. Consideration of prostate-specific antigen (PSA) density > 0.15 ng/mL/mL as a cutoff in unsuspicious MRI led to a 14% reduction (44/313) in men who needed biopsy. CONCLUSION: Determination of the biopsy strategy in terms of the need for focal saturation biopsy or SBx should be made considering lesion size. The use of PSA density in non-suspicious MRI can lead to a reduction in biopsy-indicated men.