Prototype Description and Ex Vivo Evaluation of a System for Combined Endorectal Magnetic Resonance Imaging and In-Bore Biopsy of the Prostate.

ABSTRACT: We describe early ex vivo proof-of-concept testing of a novel system composed of a disposable endorectal coil and converging multichannel needle guide with a reusable clamp stand, embedded electronics, and baseplate to allow for endorectal magnetic resonance (MR) imaging and in-bore MRI-targeted biopsy of the prostate as a single integrated procedure. Using prostate phantoms imaged with standard T 2 -weighted sequences in a Siemens 3T Prisma MR scanner, we measured the signal-to-noise ratio in successive 1-cm distances from the novel coil and from a commercially available inflatable balloon coil and measured the lateral and longitudinal deviation of the tip of a deployed MR compatible needle from the intended target point. Signal-to-noise ratio obtained with the novel system was significantly better than the inflatable balloon coil at each of five 1-cm intervals, with a mean improvement of 78% ( P < 0.05). In a representative sampling of 15 guidance channels, the mean lateral deviation for MR imaging-guided needle positioning was 1.7 mm and the mean longitudinal deviation was 2.0 mm. Our ex vivo results suggest that our novel system provides significantly improved signal-to-noise ratio when compared with an inflatable balloon coil and is capable of accurate MRI-guided needle deployment.

Imaging update on gallbladder adenomyomatosis and its mimics.

Radiologists across many imaging modalities commonly encounter gallbladder adenomyomatosis. The classic imaging appearances of gallbladder adenomyomatosis are well described and confirm benignity. However, in clinical practice, adenomyomatosis can be challenging to differentiate from other gallbladder pathologies that require cholecystectomy. In this article, we describe the common and uncommon appearances of gallbladder adenomyomatosis on multimodality imaging, helping differentiate adenomyomatosis from non-benign gallbladder abnormalities. Accurately differentiating adenomyomatosis from its mimics provides the surgical team with important clinical and surgical management information, improving patient outcomes.

Intermediate-term oncological outcomes after a negative endorectal coil multiparametric MRI of the prostate in patients without biopsy proven prostate cancer.

PURPOSE: Investigate the intermediate-term oncological outcome after negative multiparametric MRI (mpMRI) of the prostate in patients without biopsy proven prostate cancer (PCa). METHODS: The retrospective study included 121 patients with negative mpMRI (Prostate Imaging Reporting and Data System version 2.1 category<3) performed at our institution between 2012 and 2017 without known biopsy proven PCa. Clinical and pathological data were collated including post-MRI prostatic tissue diagnoses with highest Grade Group and most recent prostate specific antigen (PSA) levels up to any definitive prostate cancer treatment. Mean PSA velocities between patients with and without a subsequent diagnosis of Grade Group 2 or higher (GG2+) PCa were compared, and an optimal threshold value was calculated. RESULTS: Outcome data available included PSA values in 117 patients and prostate tissue sampling in 52 patients. Over a median follow up interval of 49.8 months, only 11 of 121 patients (9.1%) were diagnosed with GG2+ PCa, 10 patients (8.3%) with GG1 PCa, and 31 patients (25.6%) had negative prostate tissue samples. Mean PSA velocity was significantly higher in the patients diagnosed with GG2+ PCa (3.87 ng/mL/year) compared to those not diagnosed with GG2+ PCa (-0.71 ng/mL/year, p < 0.001). A threshold PSA velocity of 0.27 ng/mL/year had a 100% sensitivity and 69.8% specificity for GG2+ PCa (AUC: 0.898). CONCLUSION: <10% of patients with negative mpMRI without prior biopsy proven PCa were diagnosed with GG2+ PCa over median follow up of over four years and were associated with PSA velocity of ≥0.27 ng/mL/year. PSA monitoring may be a reasonable management strategy in patients with a negative mpMRI without biopsy proven PCa.

Multimodality Imaging of Cholecystectomy Complications.

Cholecystectomy is one of the most common surgeries performed in the United States. Although complications are uncommon, the high incidence of this surgery means that a radiologist will likely encounter these complications in practice. Complications may arise in the immediate postoperative period or can be delayed for weeks, months, or years after surgery. Vague and nonspecific symptoms make clinical diagnosis challenging. As a result, multimodality imaging is important in postoperative evaluation. US and multidetector CT are the usual first-line imaging modalities. Hepatobiliary scintigraphy, SPECT/CT, and MRI with conventional or gadoxetate hepatobiliary contrast material are important and complementary modalities that are used for workup. The authors begin with a brief discussion of surgical technique and expected postoperative findings and then describe complications organized into four groups: (a) biliary complications, (b) stone-related complications, (c) iatrogenic complications, and (d) gallbladder complications. Biliary complications include bile leaks and bilomas, acute biliary obstruction, and biliary stricture. Stone-related complications include retained and recurrent stones and spillage of stones into the peritoneum. Iatrogenic complications include hemorrhage, vasculobiliary injury, arterial pseudoaneurysms, duodenal injury, and migration of clips. Gallbladder complications include recurrent cholecystitis after subtotal reconstituting cholecystectomy and unexpected gallbladder cancer. An invited commentary by Mullens and Ibrahim is available online. Online supplemental material is available for this article. ©RSNA, 2022.

MRI appearance of BRCA-associated prostate cancer.

Despite advances in diagnosis and treatment, prostate cancer remains the second leading cause of cancer related mortality in men. Prognosis is variable and dependent on several clinical and genetic factors, including BRCA gene mutations. Recent clinical studies have reported that BRCA-associated prostate cancer is a more aggressive subtype with a higher probability of nodal involvement and distant metastases at the time of diagnosis, but radiological findings have not been described. Accurate recognition of those tumors could help guide clinical management and prompt testing and counseling for BRCA mutations. We have recently encountered four patients with BRCA-associated prostate cancer who underwent multiparametric MRI. The MRI appearances of these tumors, which were generally locally advanced and aggressive in appearance, are presented to facilitate recognition of BRCA-associated prostate cancer and guide potential genetic testing and counseling.

Cowper's gland hyperplasia: A potential pitfall at MRI of the prostate.

MRI features are presented in a multicenter retrospective series of five patients with a unilateral masslike lesion seen in the genitourinary diaphragm at MRI performed for known or suspected prostate cancer. In all cases, the lesion appeared as an encapsulated 1.3 to 3.0 cm mass of heterogeneous low or intermediate T2 signal intensity in the genitourinary diaphragm, and targeted biopsy demonstrated benign Cowper's gland tissue. This entity is a potential imaging pitfall that could result in a diagnosis of an exophytic nodule of benign prostatic hyperplasia or local spread of prostate cancer. We present these cases to facilitate correct identification of Cowper's gland hyperplasia as an occasional finding at MRI of the prostate.

Performance of transgluteal CT-guided biopsy of prostate lesions in men without rectal access: A retrospective study.

OBJECTIVE: To retrospectively study the performance of CT-guided biopsy of target prostate lesions at a single institution. METHODS: Between May 2016 and February 2021, we retrospectively identified all men without rectal access who underwent transgluteal CT-guided biopsy of PIRADS 4 or 5 targets detected on multiparametric MRI (n = 9). Clinical, radiological, and pathological details were collected by review of the electronic medical record, and included age, pre-biopsy prostate specific antigen (PSA) value, prior biopsy history, biopsy targeting technique and procedural details, complications, and final histologic diagnosis. Two targeting techniques were used: Localizing with anatomic landmarks or localizing with contrast enhancement. RESULTS: Mean patient age was 69 years (range, 49-74) and mean PSA was 14.6 ng/mL (range 7-23). Four lesions were targeted using anatomic landmarks and 5 were targeted using contrast enhancement. All biopsies were technically successful and all resulted as prostate cancer. Three biopsies showed Gleason 6 cancer and 6 biopsies showed clinically significant prostate cancers with Gleason 7 or above. There were no major complications. 7 patients went on to definitive treatment with surgery or radiation. CONCLUSION: Transgluteal CT-guided biopsy of MRI detected prostate lesions diagnoses clinically significant prostate cancer without complication and therefore should be considered for patients without a rectum.

Adenomyosis in Pregnancy: Diagnostic Pearls and Pitfalls.

Adenomyosis is a common benign uterine disorder in which ectopic endometrial glands extend into the myometrium. Adenomyosis is increasingly diagnosed in young women, affecting 20%-35% of women of reproductive age. Features of adenomyosis can be seen with either US or MRI, especially with newer imaging technology. With advances in reproductive endocrinology as well as a trend toward later maternal age, adenomyosis is increasingly noted during pregnancy, often while performing imaging for other reasons. Hormonal changes during pregnancy alter the appearance of adenomyosis, which includes diffuse, focal, and cystic adenomyosis. Recognizing these imaging changes in pregnancy proves essential for accurately diagnosing adenomyosis as a benign condition, as it mimics serious placental and myometrial abnormalities. Using a lower-frequency US transducer or MRI can be helpful in distinguishing among these entities. Describing the location of adenomyosis in relationship to the site of placentation is also important. Diagnosing adenomyosis is crucial because it can be associated with poor pregnancy outcomes, including spontaneous abortion, preterm birth, and fetal growth restriction. Adenomyosis is also a risk factor for preeclampsia. Intramural ectopic pregnancy is a rare but serious condition that can mimic cystic adenomyosis, and comparison with prepregnancy images can help differentiate the two conditions. The authors review the unique imaging characteristics of adenomyosis in pregnancy, focusing on accurate diagnosis of an underrecognized benign condition that can mimic myometrial and placental pathologic conditions.©RSNA, 2021.

In-Bore Versus Fusion MRI-Targeted Biopsy of PI-RADS Category 4 and 5 Lesions: A Retrospective Comparative Analysis Using Propensity Score Weighting.

BACKGROUND. Few published studies have compared in-bore and fusion MRI-targeted prostate biopsy, and the available studies have had conflicting results. OBJECTIVE. The purpose of this study was to compare the target-specific cancer detection rate of in-bore prostate biopsy with that of fusion MRI-targeted biopsy. METHODS. The records of men who underwent in-bore or fusion MRI-targeted biopsy of PI-RADS category 4 or 5 lesions between August 2013 and September 2019 were retrospectively identified. PI-RADS version 2.1 assessment category, size, and location of each target were established by retrospective review by a single experienced radiologist. Patient history and target biopsy results were obtained by electronic medical record review. Only the first MRI-targeted biopsy of the dominant lesion was included for patients with repeated biopsies or multiple targets. In-bore and fusion biopsy were compared by propensity score weights and multivariable regression to adjust for imbalances in patient and target characteristics between biopsy techniques. The primary endpoint was target-specific prostate cancer detection rate. Secondary endpoints were detection rate after application of propensity score weighting for cancers in International Society of Urological Pathology (ISUP) grade group 2 (GG2) or higher and detection rate with the use of off-target systematic sampling results. RESULTS. The study sample included 286 men (in-bore biopsy, 191; fusion biopsy, 95). Compared with fusion biopsy, in-bore biopsy was associated with significantly greater likelihood of detection of any cancer (odds ratio, 2.28 [95% CI, 1.04-4.98]; p = .04) and nonsignificantly greater likelihood of detection of ISUP GG2 or higher cancer (odds ratio, 1.57 [95% CI, 0.88-2.79]; p = .12) in a target. When off-target sampling was included, in-bore biopsy and combined fusion and systematic biopsy were not different for detection of any cancer (odds ratio, 1.16 [95% CI, 0.54-2.45]; p = .71) or ISUP GG2 and higher cancer (odds ratio, 1.15 [95% CI, 0.66-2.01]; p = .62). CONCLUSION. In this retrospective study in which propensity score weighting was used, in-bore MRI-targeted prostate biopsy had a higher target-specific cancer detection rate than did fusion biopsy. CLINICAL IMPACT. Pending a larger prospective randomized multicenter comparison between in-bore and fusion biopsy, in-bore may be the preferred approach should performing only biopsy of a suspicious target, without concurrent systematic biopsy, be considered clinically appropriate.

MRI of prostatic urethral mucinous urothelial carcinoma: Expanding the differential diagnosis for T2 hyperintense prostatic masses.

We report the case of a 66-year-old previously healthy man presenting with blood and mucus in his urine. Cystoscopy revealed a mass in the prostatic urethra, and endoscopic biopsy showed adenocarcinoma in situ with mucinous features. Endorectal multiparametric prostate MRI demonstrated a 1.9 cm T2 hyperintense mass in the peripheral zone of the left prostatic apex with extension into the urethral lumen. No diffusion restriction or early enhancement was seen in the mass. Radical prostatectomy was performed, and final pathology demonstrated a mucin-producing urothelial adenocarcinoma arising from the prostatic urethra. The peripheral zone T2 hyperintense abnormality correlated with abundant pools of mucin extending into the prostatic stroma and surrounded by neoplastic prostatic glandular cells. We conclude prostatic urethral mucinous urothelial carcinoma should be included in the differential diagnosis for T2 hyperintense prostatic masses.

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.

Impact of Direct MRI-Guided Biopsy of the Prostate on Clinical Management.

OBJECTIVE. The purpose of this study is to investigate the impact of direct MRI-guided biopsy of the prostate on clinical management in practice. MATERIALS AND METHODS. We retrospectively identified 127 patients with unknown (n = 98) or untreated prostate cancer with a Gleason score of 6 (n = 29) who underwent direct MRI-guided biopsy of the prostate at our institution between August 2013 and January 2018, after initial multiparametric endorectal MRI examination revealed one or more Prostate Imaging Reporting and Data System (PI-RADS or PI-RADSv2) category 4 or 5 target lesion. All available medical and imaging records were reviewed to determine pertinent clinical details, biopsy findings, and postbiopsy management. RESULTS. The mean patient age was 68 years (interquartile range, 63-73 years). Findings from MRI-guided biopsy were positive for 93 of 127 patients (73%), with prostate cancer of Gleason score of 7 or higher diagnosed in 84 of these 93 patients (90%). When stratified by clinical scenario, the rate of positive biopsy findings was 66% (57/86) for patients who had negative findings from one or more prior transrectal ultrasound-guided biopsies, 83% (10/12) for biopsy-naive patients, and 90% (26/29) for patients undergoing active surveillance. Overall, 90 of 127 patients (71%) received a new (n = 67) or upgraded (n = 23) diagnosis of prostate cancer, and 57 of these 90 patients (63%) proceeded to receive treatment with prostatectomy, radiation, or androgen deprivation therapy. CONCLUSION. The results of this study suggest that direct MRI-guided biopsy is associated with high rates of significant prostate cancer detection and subsequent definitive treatment across common clinical scenarios and should be considered an important supplementary diagnostic tool in the appropriate setting.

Kidney Biopsy Adequacy: A Metric-based Study.

There are differences in renal biopsy yield related to on-site evaluation, tissue division, and operator, among others. To understand these variations, we collected adequacy-associated data (%cortex, glomeruli, arteries, length) from consecutive native and allograft kidney biopsies over a 22-month period. In total, 1332 biopsies (native: 873, allograft: 459) were included, 617 obtained by nephrologists, 663 by radiologists, and 559 with access to on-site division. Proceduralists with access to on-site evaluation had significantly lower inadequacy rates and better division of tissue for light microscopy (LM), immunofluorescence, and electron microscopy than those without access to on-site evaluation. Radiologists in our region were significantly less likely to have access to on-site evaluation than nephrologists. On multivariate analysis for native kidney biopsies, the effect of having a radiologist perform the biopsy and having access to on-site division were both significant predictors of obtaining greater calculated amount of cortex for LM. Despite the trend for radiologists to obtain more tissue in general, biopsies from nephrologists contained a greater percentage of cortex and were more likely to be considered adequate for LM (native kidney inadequacy rate for LM: 1.11% vs. 5.41%, P=0.0086). Biopsies in which inadequate or marginal cortical tissue was submitted for LM had only minor decreases in the amount of cortex submitted for immunofluorescence and electron microscopy, revealing an opportunity for improved specimen triaging when limited tissue is obtained. In conclusion, both on-site evaluation/division and proceduralist significantly affect quantitative kidney biopsy metrics, which in turn affects the pathologist's ability to render an accurate diagnosis with appropriate prognostic information for the patient and treating nephrologist.

Endoscopic Interventions in Acute Pancreatitis: What the Advanced Endoscopist Wants to Know.

Endoscopic interventions play an important role in the modern management of pancreatic fluid collections. Successful management of pancreatitis is dependent on proper classification of the disease and its local complications. The 2012 revised Atlanta classification divides acute pancreatitis into subtypes of necrotizing pancreatitis and interstitial edematous pancreatitis (IEP) on the basis of the radiologic presence or absence of necrosis, respectively. Local complications of IEP include acute pancreatic fluid collections and pseudocysts, which contain fluid only and are differentiated by the time elapsed since the onset of symptoms. Local complications of necrotizing pancreatitis include acute necrotic collections and walled-off necrosis, which contain nonliquefied necrotic debris and are differentiated by the time elapsed since the onset of symptoms. Endoscopic techniques are used to treat local complications of pancreatitis, often in a step-up approach, by which less invasive techniques are preferred initially with potential subsequent use of more invasive procedures, dependent on the patient's clinical response and collection evolution. Common interventions performed by the advanced endoscopist include endoscopic transmural drainage and endoscopic transmural necrosectomy. However, some collections require a multimodal approach with adjunctive placement of percutaneous drainage catheters or the use of videoscopic-assisted retroperitoneal débridement. Additional endoscopic interventions may be required in the setting of pancreatic or biliary duct stones or strictures. Common complications of endoscopic intervention in the setting of pancreatitis include bleeding, infection, perforation, and stent migration. This article reviews the classification of acute pancreatitis, familiarizes radiologists with the common endoscopic techniques used in its management, and improves identification of the clinically relevant imaging findings and procedural complications related to endoscopic interventions in pancreatitis. ©RSNA, 2018.

Dominant intraprostatic cancer confirmed by direct MRI-guided biopsy: Concordance with histopathological findings.

PURPOSE: To investigate the concordance between dominant intraprostatic cancer seen on endorectal multiparametric MRI and confirmed by MRI-targeted biopsy with histopathological findings at radical prostatectomy, since existing literature has emphasized the miss rather than the concordance rate of MRI. MATERIALS AND METHODS: We retrospectively identified 20 patients who underwent radical prostatectomy after a dominant intraprostatic cancer focus was identified at endorectal multiparametric MRI and confirmed by MRI-targeted biopsy. Concordance was determined by comparing the location and Gleason grade group of dominant tumor at MRI with the location and Gleason grade group determined at histopathological review. RESULTS: Mean patient age was 65 years (range, 48 to 76) and median serum prostatic specific antigen level was 9.4 ng/mL (range, 4.6 to 58.0). In all 20 patients, the location of dominant tumor based on MRI and targeted biopsy corresponded with the dominant tumor location at histopathology. In 9 patients, Gleason grade group was the same at targeted biopsy and final histopathology. In 9 patients, final Gleason grade group was higher and in two patients it was lower. CONCLUSION: Our preliminary results suggest dominant tumor as determined by endorectal multiparametric MRI and confirmed by a positive MRI-targeted biopsy has high concordance with histopathological findings at radical prostatectomy for location, and reasonable concordance for Gleason grade group.

Endorectal MR imaging of prostate cancer: Evaluation of tumor capsular contact length as a sign of extracapsular extension.

OBJECTIVE: To evaluate the length of contact between dominant tumor foci and the prostatic capsule as a sign of extracapsular extension at endorectal multiparametric MR imaging. MATERIALS AND METHODS: We retrospectively identified 101 patients over a three-year interval who underwent endorectal multiparametric prostate MR imaging prior to radical prostatectomy for prostate cancer. Two readers identified the presence of dominant tumor focus (largest lesion with PI-RADS version 2 score of 4 or 5), and measured the length of tumor capsular contact and likelihood of extracapsular extension by standard criteria (1-5 Likert scale). Results were analyzed using histopathological review as reference standard. RESULTS: Extracapsular extension was found at histopathological review in 27 patients. Reader 1 (2) identified dominant tumor in 79 (73) patients, with mean tumor capsular contact length of 18.2 (14.0) mm. The area under the receiver operating characteristic curve for identification of extracapsular extension by tumor capsular contact length was 0.76 for reader 1 and 0.77 for reader 2, with optimal discrimination at values of 18 mm and 21 mm, respectively. In the subset of patients without obvious extracapsular extension by standard criteria (Likert scores 1-3), corresponding values were 0.74 and 0.66 with optimal thresholds of 24 and 21 mm. CONCLUSION: Length of contact between the dominant tumor focus and the capsule is a moderately useful sign of extracapsular extension at endorectal multiparametric prostate MR imaging, including the subset of patients without obvious extracapsular extension by standard criteria, with optimal discrimination at threshold values of 18 to 24 mm.

Nongynecologic Findings Seen at Pelvic US.

Ultrasonography (US) is frequently the first imaging modality used to examine women with symptoms involving the pelvis. It is widely available and involves no exposure to ionizing radiation. Images can be acquired with a transabdominal, endovaginal, or translabial approach, and the use of video clips and three-dimensional reconstructions can be helpful. US is excellent for assessment of the uterus, ovaries, and adnexa. Occasionally, nongynecologic pelvic diseases arising from the gastrointestinal, genitourinary, and musculoskeletal systems and the pelvic peritoneal and extraperitoneal spaces may be detected and can be a source of diagnostic dilemma. US can be helpful not only in the detection but also occasionally in the characterization of such entities. Computed tomography and magnetic resonance imaging are useful in complicated cases. In this article, the normal US appearance of the bowel and US signs of bowel disease and specific entities, including appendicitis, diverticular disease, bowel obstruction, appendiceal mucocele, and intestinal tumors, are reviewed. The lower urinary tract is included in the field of view in every pelvic US examination; commonly encountered entities related to the urinary bladder, distal ureter, and urethra are illustrated. In addition to arising in the gastrointestinal and genitourinary tracts, pathologic conditions in the pelvis can arise in the peritoneal or extraperitoneal space. Although conditions of the pelvic peritoneal and extraperitoneal spaces are rare, it is important to recognize these entities and distinguish them from the more common gynecologic diseases. Owing to the implications for diagnosis and management, radiologists and other physicians who perform pelvic US should be aware of the spectrum of nongynecologic pathologic entities that can be detected. ©RSNA, 2017.