Part II: Effect of different evaluation methods to the application of a computer-aided prostate MRI detection/diagnosis (CADe/CADx) device on reader performance.

INTRODUCTION: The construction and results of a multiple-reader multiple-case prostate MRI study are described and reported to illustrate recommendations for how to standardize artificial intelligence (AI) prostate studies per the review constituting Part I1. METHODS: Our previously reported approach was applied to review and report an IRB approved, HIPAA compliant multiple-reader multiple-case clinical study of 150 bi-parametric prostate MRI studies across 9 readers, measuring physician performance both with and without the use of the recently FDA cleared CADe/CADx software ProstatID. RESULTS: Unassisted reader AUC values ranged from 0.418 - 0.759, with AI assisted AUC values ranging from 0.507 - 0.787. This represented a statistically significant AUC improvement of 0.045 (α = 0.05). A free-response ROC (FROC) analysis similarly demonstrated a statistically significant increase in θ from 0.405 to 0.453 (α = 0.05). The standalone performance of ProstatID performed across all prostate tissues demonstrated an AUC of 0.929, while the standalone lesion level performance of ProstatID at all biopsied locations achieved an AUC of 0.710. CONCLUSION: This study applies and illustrates suggested reporting and standardization methods for prostate AI studies that will make it easier to understand, evaluate and compare between AI studies. Providing radiologists with the ProstatID CADe/CADx software significantly increased diagnostic performance as assessed by both ROC and free-response ROC metrics. Such algorithms have the potential to improve radiologist performance in the detection and localization of clinically significant prostate cancer.

Part I: prostate cancer detection, artificial intelligence for prostate cancer and how we measure diagnostic performance: a comprehensive review.

MRI has firmly established itself as a mainstay for the detection, staging and surveillance of prostate cancer. Despite its success, prostate MRI continues to suffer from poor inter-reader variability and a low positive predictive value. The recent emergence of Artificial Intelligence (AI) to potentially improve diagnostic performance shows great potential. Understanding and interpreting the AI landscape as well as ever-increasing research literature, however, is difficult. This is in part due to widely varying study design and reporting techniques. This paper aims to address this need by first outlining the different types of AI used for the detection and diagnosis of prostate cancer, next deciphering how data collection methods, statistical analysis metrics (such as ROC and FROC analysis) and end points/outcomes (lesion detection vs. case diagnosis) affect the performance and limit the ability to compare between studies. Finally, this work explores the need for appropriately enriched investigational datasets and proper ground truth, and provides guidance on how to best conduct AI prostate MRI studies. Published in parallel, a clinical study applying this suggested study design was applied to review and report a multiple-reader multiple-case clinical study of 150 bi-parametric prostate MRI studies across nine readers, measuring physician performance both with and without the use of a recently FDA cleared Artificial Intelligence software.1.

Statin therapy in patients with early-stage autosomal dominant polycystic kidney disease: Design and baseline characteristics.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is characterized by the development and continued growth of multiple cysts in the kidneys leading to ultimate loss of kidney function in most patients. Currently, tolvaptan is the only agency approved therapy to slow kidney disease advancement in patients with faster progressing disease underscoring the need for additional ADPKD therapies suitable for all patients. We previously showed that pravastatin slowed kidney disease progression in children and young adults with ADPKD. However, the intervention has not been tested in an adult cohort. AIMS: The aim of the study is to conduct a single center, randomized, placebo-controlled double-blinded clinical trial to determine the efficacy of pravastatin on slowing kidney disease progression in adult patients with early stage ADPKD. METHODS: One hundred and fifty adult patients with ADPKD and eGFR ≥60 ml/min/1.73m2 will be enrolled in the study and randomized to receive 40 mg/day pravastatin or placebo for a period of 2-years. OUTCOMES: The primary outcome of the trial is change in total kidney volume assessed by magnetic resonance imaging (MRI). Secondary outcomes include change in kidney function by iothalamate GFR and renal blood flow and markers of inflammation and oxidative stress. CONCLUSION: This study will assess the kidney therapeutic benefits of pravastatin in adult patients with ADPKD. The recruitment goal of 150 subjects was attained and the study is ongoing. REGISTRATION: This study is registered on Clinicaltrials.gov # NCT03273413.

Use of Imaging and Biopsy in Prostate Cancer Diagnosis: A Survey From the Asian Prostate Imaging Working Group.

OBJECTIVE: To elucidate the use of radiological studies, including nuclear medicine, and biopsy for the diagnosis and staging of prostate cancer (PCA) in clinical practice and understand the current status of PCA in Asian countries via an international survey. MATERIALS AND METHODS: The Asian Prostate Imaging Working Group designed a survey questionnaire with four domains focused on prostate magnetic resonance imaging (MRI), other prostate imaging, prostate biopsy, and PCA backgrounds. The questionnaire was sent to 111 members of professional affiliations in Korea, Japan, Singapore, and Taiwan who were representatives of their working hospitals, and their responses were analyzed. RESULTS: This survey had a response rate of 97.3% (108/111). The rates of using 3T scanners, antispasmodic agents, laxative drugs, and prostate imaging-reporting and data system reporting for prostate MRI were 21.6%-78.9%, 22.2%-84.2%, 2.3%-26.3%, and 59.5%-100%, respectively. Respondents reported using the highest b-values of 800-2000 sec/mm² and fields of view of 9-30 cm. The prostate MRI examinations per month ranged from 1 to 600, and they were most commonly indicated for biopsy-naïve patients suspected of PCA in Japan and Singapore and staging of proven PCA in Korea and Taiwan. The most commonly used radiotracers for prostate positron emission tomography are prostate-specific membrane antigen in Singapore and fluorodeoxyglucose in three other countries. The most common timing for prostate MRI was before biopsy (29.9%). Prostate-targeted biopsies were performed in 63.8% of hospitals, usually by MRI-ultrasound fusion approach. The most common presentation was localized PCA in all four countries, and it was usually treated with radical prostatectomy. CONCLUSION: This survey showed the diverse technical details and the availability of imaging and biopsy in the evaluation of PCA. This suggests the need for an educational program for Asian radiologists to promote standardized evidence-based imaging approaches for the diagnosis and staging of PCA.

Adenocarcinoma of the uterine cervix, gastric-type (GAS): a review of the literature focused on pathology and multimodality imaging.

Adenocarcinoma of the uterine cervix, gastric-type (GAS) is a rare, well-differentiated subtype of HPV-independent endocervical adenocarcinoma. It classically arises in middle-aged women with symptoms, including profuse watery vaginal discharge and abnormal uterine bleeding. Given the rarity of this disease, misdiagnosis is common and prognosis remains poorly defined. Distinct pathology and imaging findings can aid in diagnosis. A literature review was performed to ascertain recurring pathologic and radiologic characteristics of GAS. Key pathologic features of GAS include cytologically benign appearing mucinous glands that infiltrate into the deep stroma and may demonstrate lymphovascular or perineural invasion. Multiple imaging modalities including transvaginal ultrasound, CT, and MRI may aid in diagnosis of GAS, which characteristically is seen as a multicystic mass with solid components. MRI in particular is the preferred imaging study because it offers the best chance of identifying a potential solid component, which is key to making the diagnosis of GAS and distinguishing it from other endocervical diseases processes. Careful attention to histopathologic and radiologic details, in conjunction with clinical correlation, is necessary to distinguish GAS from other multicystic cervical lesions.

Clinical Importance of Incidental Homogeneous Renal Masses That Measure 10-40 mm and 21-39 HU at Portal Venous Phase CT: A 12-Institution Retrospective Cohort Study.

BACKGROUND. Incidental homogeneous renal masses are frequently encountered at portal venous phase CT. The American College of Radiology Incidental Findings Committee's white paper on renal masses recommends additional imaging for incidental homogeneous renal masses greater than 20 HU, but single-center data and the Bosniak classification version 2019 suggest the optimal attenuation threshold for detecting solid masses should be higher. OBJECTIVE. The purpose of this article is to determine the clinical importance of small (10-40 mm) incidentally detected homogeneous renal masses measuring 21-39 HU at portal venous phase CT. METHODS. We performed a 12-institution retrospective cohort study of adult patients who underwent portal venous phase CT for a nonrenal indication. The date of the first CT at each institution ranged from January 1, 2008, to January 1, 2014. Consecutive reports from 12,167 portal venous phase CT examinations were evaluated. Images were reviewed for 4529 CT examinations whose report described a focal renal mass. Eligible masses were 10-40 mm, well-defined, subjectively homogeneous, and 21-39 HU. Of these, masses that were shown to be solid without macroscopic fat; classified as Bosniak IIF, III, or IV; or confirmed to be malignant were considered clinically important. The reference standard was renal mass protocol CT or MRI, ultrasound of definitively benign cysts or solid masses, single-phase contrast-enhanced CT or unenhanced MRI showing no growth or morphologic change for 5 years or more, or clinical follow-up 5 years or greater. A reference standard was available for 346 masses in 300 patients. The 95% CIs were calculated using the binomial exact method. RESULTS. Eligible masses were identified in 4.2% of patients (514/12,167; 95% CI, 3.9-4.6%). Of 346 masses with a reference standard, none were clinically important (0%; 95% CI, 0-0.9%). Mean mass size was 17 mm; 72% (248/346) measured 21-30 HU, and 28% (98/346) measured 31-39 HU. CONCLUSION. Incidental small homogeneous renal masses measuring 21-39 HU at portal venous phase CT are common and highly likely benign. CLINICAL IMPACT. The change in attenuation threshold signifying the need for additional imaging from greater than 20 HU to greater than 30 HU proposed by the Bosniak classification version 2019 is supported.

Tips to start an MR-US fusion biopsy program.

There is growing evidence that MRI-ultrasound (MR-US)-targeted biopsy (TB) has high detection rates of clinically significant prostate cancer (PCa) compared to standard transrectal ultrasound (TRUS)-guided biopsy. A radiologist plays a significant role in MR-US fusion biopsy planning. Here, we discuss six simple steps that can help set up a successful MR-US fusion biopsy program in collaboration with the urologist.

Variability of the Positive Predictive Value of PI-RADS for Prostate MRI across 26 Centers: Experience of the Society of Abdominal Radiology Prostate Cancer Disease-focused Panel.

Background Prostate MRI is used widely in clinical care for guiding tissue sampling, active surveillance, and staging. The Prostate Imaging Reporting and Data System (PI-RADS) helps provide a standardized probabilistic approach for identifying clinically significant prostate cancer. Despite widespread use, the variability in performance of prostate MRI across practices remains unknown. Purpose To estimate the positive predictive value (PPV) of PI-RADS for the detection of high-grade prostate cancer across imaging centers. Materials and Methods This retrospective cross-sectional study was compliant with the HIPAA. Twenty-six centers with members in the Society of Abdominal Radiology Prostate Cancer Disease-focused Panel submitted data from men with suspected or biopsy-proven untreated prostate cancer. MRI scans were obtained between January 2015 and April 2018. This was followed with targeted biopsy. Only men with at least one MRI lesion assigned a PI-RADS score of 2-5 were included. Outcome was prostate cancer with Gleason score (GS) greater than or equal to 3+4 (International Society of Urological Pathology grade group ≥2). A mixed-model logistic regression with institution and individuals as random effects was used to estimate overall PPVs. The variability of observed PPV of PI-RADS across imaging centers was described by using the median and interquartile range. Results The authors evaluated 3449 men (mean age, 65 years ± 8 [standard deviation]) with 5082 lesions. Biopsy results showed 1698 cancers with GS greater than or equal to 3+4 (International Society of Urological Pathology grade group ≥2) in 2082 men. Across all centers, the estimated PPV was 35% (95% confidence interval [CI]: 27%, 43%) for a PI-RADS score greater than or equal to 3 and 49% (95% CI: 40%, 58%) for a PI-RADS score greater than or equal to 4. The interquartile ranges of PPV at these same PI-RADS score thresholds were 27%-44% and 27%-48%, respectively. Conclusion The positive predictive value of the Prostate Imaging and Reporting Data System was low and varied widely across centers. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Milot in this issue.

Risk Threshold Algorithm for Thyroid Nodule Management Demonstrates Increased Specificity and Diagnostic Accuracy as Compared With American College of Radiology Thyroid Imaging, Reporting and Data System; Society of Radiologists in Ultrasound; and American Thyroid Association Management Guidelines.

We studied diagnostic performance of an algorithm guiding thyroid nodule management using a malignancy risk model as compared with extant management guidelines. Single-institution, retrospective study was performed with sequential cases from pathology registry from 2012 to 2015. Seventy-eight patients were enrolled, with benign and malignant groups defined by aspiration results. Risk Threshold Algorithm determined management based off of a logistic regression model and a risk threshold. American College of Radiology Thyroid Imaging, Reporting and Data System (ACR TI-RADS), Society of Radiologists in Ultrasound (SRU), and American Thyroid Association (ATA) guidelines were used in comparison. Sensitivity, specificity, positive/negative predictive values, receiver operating characteristic (ROC) values were derived, with significance assessed via McNemar and permutation tests. Forty-four benign nodules and 40 papillary thyroid carcinomas were included. Risk Threshold Algorithm area under the ROC curve was 0.80 versus 0.59 (ACR TI-RADS), 0.49 (SRU), and 0.44 (ATA); all areas under the ROC curve differences were statistically significant. Risk Threshold Algorithm demonstrates sensitivity, specificity, positive predictive value, and negative predictive values of 63%, 91%, 86%, and 73% at the risk threshold maximizing diagnostic performance, compared with 85%, 39%, 56%, and 74% (ACR TI-RADS); 85%, 18%, 50%, and 57% (SRU); and 89%, 11%, 50%, and 83% (ATA). Sensitivity and specificity were significantly different between all groups except SRU versus TI-RADS. The Risk Threshold Algorithm, based on a malignancy risk model, demonstrates increased overall diagnostic accuracy as compared with ACR TI-RADS, SRU, and ATA management guidelines. Through eliminating unnecessary biopsy, patient anxiety, and morbidity can be reduced.

Case Report: Hepatic Fascioliasis in a Young Afghani Woman with Severe Wheezing, High-Grade Peripheral Eosinophilia, and Liver Lesions: A Brief Literature Review.

A 23-year-old recent emigrant from Afghanistan presented in August 2017 with severe wheezing and dyspnea that required hospital admission. Her illness was associated with marked peripheral blood eosinophilia (9,900-15,600/µL; 45.2-68%), as well as mild nausea, epigastric pain, and decreased appetite. She had lived until 3 months earlier in close proximity to cattle in her home in Kabul and did not recall eating watercress or other leafy plants associated with Fasciola hepatica transmission. Computerized tomography scanning showed bilateral ground-glass lung consolidations and multiple distinctive hypo-attenuating linear, tubuliform, and nodular liver lesions, including a large subcapsular hematoma. Numerous tests for rheumatological and malignant disorders were negative. Fasciola hepatica infestation was suspected on epidemiological, clinical, and radiographic grounds, and was confirmed by immunoblotting at the Centers for Disease Control (CDC). Multiple stool ova and parasite examinations were negative and endoscopic retrograde cholangiopancreatography did not identify trematodes. Her acute respiratory illness resolved with asthma-targeted therapies and her eosinophilia resolved with triclabendazole, which was obtained from CDC via an FDA Investigational New Drug application. Fascioliasis is uncommon in the United States, but the prolonged warfare and civil strife in Afghanistan and adjacent areas may lead to increased incidence outside the endemic region. Her case also demonstrates how hepatic imaging features of fascioliasis can be pathognomonic in clinical scenarios with eosinophilia and appropriate epidemiology and clinical features. We also highlight her relatively unusual presentation with symptoms of Loeffler-like syndrome alone.

Assessment of PI-RADS v2 categories ≥ 3 for diagnosis of clinically significant prostate cancer.

PURPOSE: To assess the diagnostic accuracy of PI-RADS v2 categories ≥ 3 to detect clinically significant prostate cancer (csPCa) against histopathology of Transperineal Mapping Biopsy (TPMB). MATERIALS AND METHODS: IRB-approved retrospective cohort study included 47 men who had 3.0 T multi-parametric MRI (mpMRI) and TPMB of prostate. Two radiologists independently evaluated T2, DWI, ADC map, and DCE images using PI-RADS v2 categories. A third radiologist served as tie-breaker. PI-RADS v2 score (PS) ≥ 3 lesions were correlated with 3D model of TPMB (3DTPMB) results based on prostate sectors. Two groups of csPCa status were separately analyzed for accuracy measures at lesion and person levels: Group 1 with GS (Gleason Score) ≥ 7 and group 2 with tumor volume ≥ 0.5 cc. Inter-rater reliability for PS and MR lexicon was calculated. RESULTS: Forty-seven patients with 3DTPMB had at least one lesion with PS ≥ 3 on mpMRI. PS of 5 had high PPV and high specificity of 100% at the lesion and person levels. Sensitivity of a PS ≥ 3 was 68.27% for group 1 and was 48.39% for group 2. Specificity was 93.56% for group 1 and was 95.53% for group 2. At the person level, sensitivity of PS ≥ 3 was 81.25% for group 1 and was 82.35% for group 2. Specificity was 32.26% for group 1 and was 53.85% for group 2. CONCLUSION: PI-RADS v2 category of 5 had high PPV and specificity; however, combined PS ≥ 3 had mixed performance in detection of csPCa.

Radiologists' preferences regarding content of prostate MRI reports: a survey of the Society of Abdominal Radiology.

PURPOSE: To evaluate radiologist preferences regarding specific content that warrants inclusion in prostate MRI reports. METHODS: Sixty-one members of the Society of Abdominal Radiology responded to a 74-item survey regarding specific content warranted in prostate MRI reports, conducted in August 2016. RESULTS: General items deemed essential report content by ≥ 50% of respondents were prostate volume (80%), extent of prostate hemorrhage (74%), TURP defects (69%), coil type (64%), BPH (61%), contrast dose (61%), contrast agent (59%), medications administered (59%), and magnet strength (54%). Details regarding lesion description deemed essential by ≥ 50% were overall PI-RADS category (88%), DCE (±) (82%), subjective degree of diffusion restriction (72%), T2WI intensity (72%), T2WI margins (65%), T2WI shape (52%), DWI 1-5 score (50%), and T2WI 1-5 score (50%). Details deemed essential to include in the report Impression by ≥ 50% of respondents were lymphadenopathy and metastases (100%), EPE (98%), SVI (98%), neurovascular bundle involvement (93%), index lesion location (93%), PI-RADS category of index lesion (82%), number of suspicious lesions (78%), significance of index lesion PI-RADS category (53%), and PI-RADS category of non-index lesions (52%). Preferred methods for lesion localization were slice/image number (68%), 3-part craniocaudal level (68%), zonal location (65%), anterior vs. posterior location (57%), and medial vs. lateral position (56%). Least preferred methods for localization were numeric sector from the PI-RADS sector map (8%), annotated screen capture (10%), and graphical schematic of PI-RADS sector map (11%). CONCLUSION: Radiologists generally deemed a high level of detail warranted in prostate MRI reports. The PI-RADS v2 sector map was disliked for lesion localization.

A Comparison of Radiologists' and Urologists' Opinions Regarding Prostate MRI Reporting: Results From a Survey of Specialty Societies.

OBJECTIVE: The purpose of this study is to compare radiologists' and urologists' opinions regarding prostate MRI reporting. SUBJECTS AND METHODS: Radiologist members of the Society of Abdominal Radiology and urologist members of the Society of Urologic Oncology received an electronic survey regarding prostate MRI reporting. RESULTS: The response rate was 12% (135/1155) for Society of Abdominal Radiology and 8% (54/663) for Society of Urologic Oncology members. Most respondents in both specialties prefer Prostate Imaging Reporting and Data System version 2 (PI-RADSv2) (radiologists, 84%; urologists, 84%), indicate that it is used at their institution (radiologists, 84%; urologists, 78%), understand its implications for patient care (radiologists, 89%; urologists, 71%), and agree that radiologists apply PI-RADSv2 categories correctly (radiologists, 57%; urologists, 61%). Both specialties agreed regarding major barriers to PI-RADSv2 adoption: radiologist inexperience using PI-RADSv2 (radiologists, 51%; urologists, 51%), urologist inexperience using PI-RADSv2 (radiologists, 46%; urologists, 51%), and lack of standardized templates (radiologists, 47%; urologists, 52%). The specialties disagreed (p ≤ 0.039) regarding whether reports should include the following management recommendations: targeted biopsy (radiologists, 58%; urologists, 34%), follow-up imaging (radiologists, 46%; urologists, 28%), and time interval for follow-up imaging (radiologists, 35%; urologists, 16%). There was also disagreement (p = 0.037) regarding report style: 54% of urologists preferred fully structured reports, whereas 53% of radiologists preferred hybrid structured and free-text reports. CONCLUSION: Radiologists and urologists both strongly prefer PI-RADSv2 for prostate MRI reporting, despite recognizing barriers to its adoption. Urologists more strongly preferred a fully structured report and disagreed with radiologists' preference to include management recommendations. Collaborative radiologist-urologist educational efforts are warranted to help optimize the effect of prostate MRI reporting in patient care.

CT findings of human Fasciola hepatica infection: case reports and review of the literature.

Due to increasing rates of international travel, hepatic fascioliasis is appearing in nonendemic areas, where diagnosis can be difficult. We present two confirmed cases of hepatic fascioliasis in a nonendemic region. The purposes of this report are to discuss computed tomography (CT) findings of hepatic fascioliasis and to review the literature. While travel history is most important, characteristic findings of hypoattenuating tracts extending from liver capsule into the parenchyma on contrast-enhanced CT scan strongly suggest hepatic fascioliasis.

Ultrasound-based clinical prediction rule model for detecting papillary thyroid cancer in cervical lymph nodes: A pilot study.

PURPOSE: To identify sonographic features of cervical lymph nodes (LNs) that are associated with papillary thyroid cancer (PTC) and to develop a prediction model for classifying nodes as metastatic or benign. METHODS: This retrospective study included the records of postthyroidectomy patients with PTC who had undergone cervical ultrasound and LN biopsy. LN location, size, shape, hilum, echopattern, Doppler flow, and microcalcifications were assessed. Model selection was used to identify features associated with malignant LNs and to build a predictive, binary-outcome, generalized linear mixed model. A cross-validated receiver operating characteristic analysis was conducted to assess the accuracy of the model for classifying metastatic nodes. RESULTS: We analyzed records from 71 LNs (23 metastatic) in 44 patients (16 with PTC). The predictive model included a nonhomogeneous echopattern (odds ratio [OR], 5.73; 95% confidence interval [CI], 1.07-30.74; p = 0.04), microcalcifications (OR, 4.91; 95% CI, 0.91-26.54; p = 0.06), and volume (OR, 2.57; 95% CI, 0.66-9.99; p = 0.16) as predictors. The model had an area under the curve of 0.74 (95% CI, 0.60-0.85), sensitivity of 65% (95% CI, 50% to 78%), and specificity of 85% (95% CI, 73% to 94%) at the Youden optimal cut point of 0.38. CONCLUSIONS: Nonhomogeneous echopattern, microcalcifications, and node volume were predictive of malignant LNs in patients with PTC. A larger sample is needed to validate this model.

Initial Experience of Targeted Focal Interstitial Laser Ablation of Prostate Cancer with MRI Guidance.

INTRODUCTION: To develop and evaluate a technique of 3.0 Tesla magnetic resonance (MR) guided laser ablation based on 3-dimentional mapping biopsy (3DMB) for low risk prostate cancer. MATERIALS AND METHODS: The study was approved by the institutional review board and was the Health Insurance Portability and Accountability Act compliant. The prospective study was performed on seven 3DMB proven low risk prostate cancer patients. In the first phase of the procedure the patient's prostate was aligned to a position concordant with prior 3DMB using the transperineal grid and fiduciary golden marker coordinates. In the second phase ablation was performed using MR thermometry to determine the ablation endpoint and lesion coverage. Immediately after treatment dynamic contrast-enhanced MR imaging was done. Prostate-specific antigen testing was performed 3 and 12 months after the treatment and compared by ANOVA test. A follow up biopsy was done one year following ablation. RESULTS: The entire procedure took less than 2 hours and all patients tolerated the procedure well. There was a significant difference in prostate-specific antigen value before and 3 months after the treatment (p = 0.005). Four out of 6 patients had positive follow up biopsy for cancer. CONCLUSION: This study verifies the feasibility and safety of treating low risk prostate cancer with laser therapy guided by 3.0T MR imaging based on 3DMB.

Multi-parametric MRI findings of transitional zone prostate cancers: correlation with 3-dimensional transperineal mapping biopsy.

PURPOSE: A preliminary project to correlate MR findings with mapping prostate biopsy to help differentiate malignant transitional zone lesions form benign prostatic hyperplasia (BPH) nodules. MATERIALS AND METHODS: Institutional IRB approved retrospective study with 14 patients suspected of having prostate cancer who underwent both prostate 3T MRI using endorectal coil and 3D transperineal mapping prostate biopsy. MR exams were independently reviewed by two abdominal radiologists blinded to pathology with disagreement resolved by consensus. An MRI lesion was defined as having hypointense T2 signal subjectively without corresponding T1 high signal intensity and low signal on ADC maps in the central gland. Mapping biopsy consisted of systematic transperineal US guided biopsy with 55-108 cores per patient. RESULTS: Twenty-nine lesions were detected on MRI. Of these, 13 correlated with Gleason 6 or higher biopsy samples. 16 were biopsy negative. Among the various MRI characteristics assessed, lack of T2 hypointense rim demonstrated the highest specificity (93%) and positive predictive value (89%). Highest sensitivity (85%) and negative predictive value (78%) were seen with ill-defined nodules. When suspicious MR characteristics were combined, the specificity and PPV rose to 100% while sensitivity decreased to 45% and NPV decreased to 73%. CONCLUSIONS: Preliminary study indicates MR findings which can help differentiate a BPH nodule from transitional zone prostate cancers which could help direct biopsy in the large and growing number of people suspected of having prostate cancer. Further work will be needed for validation.

Renal relevant radiology: use of ultrasonography in patients with AKI.

As judged by the American College of Radiology Appropriateness Criteria, renal Doppler ultrasonography is the most appropriate imaging test in the evaluation of AKI and has the highest level of recommendation. Unfortunately, nephrologists are rarely specifically trained in ultrasonography technique and interpretation, and important clinical information obtained from renal ultrasonography may not be appreciated. In this review, the strengths and limitations of grayscale ultrasonography in the evaluation of patients with AKI will be discussed with attention to its use for (1) assessment of intrinsic causes of AKI, (2) distinguishing acute from chronic kidney diseases, and (3) detection of obstruction. The use of Doppler imaging and the resistive index in patients with AKI will be reviewed with attention to its use for (1) predicting the development of AKI, (2) predicting the prognosis of AKI, and (3) distinguishing prerenal azotemia from intrinsic AKI. Finally, pediatric considerations in the use of ultrasonography in AKI will be reviewed.