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.

Radiology Report Value Equation.

Value in medicine is defined as the ratio of quality and service and health care outcomes to the costs and inefficiencies of providing care. Creating patient-centered value in radiology reporting requires radiologists to provide accurate diagnostic interpretations in an accessible format with useful advice on further imaging, as well as report-embedded reference materials desired by the referring provider. The value- and service-centered radiologist provides urgent communications when appropriate and is readily available for report consultations. Indirect costs or inefficiencies embedded in report style can erode value. Value is preserved when radiologists strive for concise, clear, and timely reporting. ©RSNA, 2018.

The Current State of MR Imaging-targeted Biopsy Techniques for Detection of Prostate Cancer.

Systematic transrectal ultrasonography (US)-guided biopsy is the standard approach for histopathologic diagnosis of prostate cancer. However, this technique has multiple limitations because of its inability to accurately visualize and target prostate lesions. Multiparametric magnetic resonance (MR) imaging of the prostate is more reliably able to localize significant prostate cancer. Targeted prostate biopsy by using MR imaging may thus help to reduce false-negative results and improve risk assessment. Several commercial devices are now available for targeted prostate biopsy, including in-gantry MR imaging-targeted biopsy and real-time transrectal US-MR imaging fusion biopsy systems. This article reviews the current status of MR imaging-targeted biopsy platforms, including technical considerations, as well as advantages and challenges of each technique. © RSNA, 2017.

Familial Cerebral Cavernous Malformations Are Associated with Adrenal Calcifications on CT Scans: An Imaging Biomarker for a Hereditary Cerebrovascular Condition.

Purpose To determine if adrenal calcifications seen at computed tomography (CT) are associated with familial cerebral cavernous malformations (fCCMs) in carriers of the CCM1 Common Hispanic Mutation. Materials and Methods This study was approved by the institutional review board. The authors retrospectively reviewed abdominal CT scans in 38 patients with fCCM, 38 unaffected age- and sex-matched control subjects, and 13 patients with sporadic, nonfamilial cerebral cavernous malformation (CCM). The size, number, and laterality of calcifications and the morphologic characteristics of the adrenal gland were recorded. Brain lesion count was recorded from brain magnetic resonance (MR) imaging in patients with fCCM. The prevalence of adrenal calcifications in patients with fCCM was compared with that in unaffected control subjects and those with sporadic CCM by using the Fisher exact test. Additional analyses were performed to determine whether age and brain lesion count were associated with adrenal findings in patients with fCCM. Results Small focal calcifications (SFCs) (≤5 mm) were seen in one or both adrenal glands in 19 of the 38 patients with fCCM (50%), compared with 0 of the 38 unaffected control subjects (P < .001) and 0 of the 13 subjects with sporadic CCM (P = .001). Adrenal calcifications in patients with fCCM were more frequently left sided, with 17 of 19 patients having more SFCs in the left adrenal gland than the right adrenal gland and 50 of the 61 observed SFCs (82%) found in the left adrenal gland. No subjects had SFCs on the right side only. In patients with fCCM, the presence of SFCs showed a positive correlation with age (P < .001) and number of brain lesions (P < .001). Conclusion Adrenal calcifications identified on CT scans are common in patients with fCCM and may be a clinically silent manifestation of disease. © RSNA, 2017.

Prostate Magnetic Resonance Imaging and Magnetic Resonance Imaging Targeted Biopsy in Patients with a Prior Negative Biopsy: A Consensus Statement by AUA and SAR.

PURPOSE: After an initial negative biopsy there is an ongoing need for strategies to improve patient selection for repeat biopsy as well as the diagnostic yield from repeat biopsies. MATERIALS AND METHODS: As a collaborative initiative of the AUA (American Urological Association) and SAR (Society of Abdominal Radiology) Prostate Cancer Disease Focused Panel, an expert panel of urologists and radiologists conducted a literature review and formed consensus statements regarding the role of prostate magnetic resonance imaging and magnetic resonance imaging targeted biopsy in patients with a negative biopsy, which are summarized in this review. RESULTS: The panel recognizes that many options exist for men with a previously negative biopsy. If a biopsy is recommended, prostate magnetic resonance imaging and subsequent magnetic resonance imaging targeted cores appear to facilitate the detection of clinically significant disease over standardized repeat biopsy. Thus, when high quality prostate magnetic resonance imaging is available, it should be strongly considered for any patient with a prior negative biopsy who has persistent clinical suspicion for prostate cancer and who is under evaluation for a possible repeat biopsy. The decision of whether to perform magnetic resonance imaging in this setting must also take into account the results of any other biomarkers and the cost of the examination, as well as the availability of high quality prostate magnetic resonance imaging interpretation. If magnetic resonance imaging is done, it should be performed, interpreted and reported in accordance with PI-RADS version 2 (v2) guidelines. Experience of the reporting radiologist and biopsy operator are required to achieve optimal results and practices integrating prostate magnetic resonance imaging into patient care are advised to implement quality assurance programs to monitor targeted biopsy results. CONCLUSIONS: Patients receiving a PI-RADS assessment category of 3 to 5 warrant repeat biopsy with image guided targeting. While transrectal ultrasound guided magnetic resonance imaging fusion or in-bore magnetic resonance imaging targeting may be valuable for more reliable targeting, especially for lesions that are small or in difficult locations, in the absence of such targeting technologies cognitive (visual) targeting remains a reasonable approach in skilled hands. At least 2 targeted cores should be obtained from each magnetic resonance imaging defined target. Given the number of studies showing a proportion of missed clinically significant cancers by magnetic resonance imaging targeted cores, a case specific decision must be made whether to also perform concurrent systematic sampling. However, performing solely targeted biopsy should only be considered once quality assurance efforts have validated the performance of prostate magnetic resonance imaging interpretations with results consistent with the published literature. In patients with negative or low suspicion magnetic resonance imaging (PI-RADS assessment category of 1 or 2, respectively), other ancillary markers (ie PSA, PSAD, PSAV, PCA3, PHI, 4K) may be of value in identifying patients warranting repeat systematic biopsy, although further data are needed on this topic. If a repeat biopsy is deferred on the basis of magnetic resonance imaging findings, then continued clinical and laboratory followup is advised and consideration should be given to incorporating repeat magnetic resonance imaging in this diagnostic surveillance regimen.

Iron-based superparamagnetic nanoparticle contrast agents for MRI of infection and inflammation.

OBJECTIVE. In this article, we summarize the progress to date on the use of superparamagnetic iron oxide nanoparticles (SPIONs) as contrast agents for MRI of inflammatory processes. CONCLUSION. Phagocytosis by macrophages of injected SPIONs results in a prolonged shortening of both T2 and T2* leading to hypointensity of macrophage-infiltrated tissues in contrast-enhanced MR images. SPIONs as contrast agents are therefore useful for the in vivo MRI detection of macrophage infiltration, and there is substantial research and clinical interest in the use of SPION-based contrast agents for MRI of infection and inflammation. This technique has been used to identify active infection in patients with septic arthritis and osteomyelitis; importantly, the MRI signal intensity of the tissue has been found to return to its unenhanced value on successful treatment of the infection. In SPION contrast-enhanced MRI of vascular inflammation, animal studies have shown decreased macrophage uptake in atherosclerotic plaques after treatment with statin drugs. Human studies have shown that both coronary and carotid plaques that take up SPIONs are more prone to rupture and that abdominal aneurysms with increased SPION uptake are more likely to grow. Studies of patients with multiple sclerosis suggest that MRI using SPIONs may have increased sensitivity over gadolinium for plaque detection. Finally, SPIONs have enabled the tracking and imaging of transplanted stem cells in a recipient host.

Interpretation and reporting multiparametric prostate MRI: a primer for residents and novices.

Multiparametric MRI has developed as a tool for prostate cancer lesion detection, characterization, staging, surveillance, and imaging of local recurrence. Given the disease frequency and the growing importance of imaging, as reliance on PSA declines, radiologists involved in prostate MRI imaging must become proficient with the fundamentals of multiparametric prostate MRI (T2WI, DWI, DCE-MRI, and MR spectroscopy). Interpretation and reporting must yield accuracy, consistency, and add value to clinical care. This review provides a primer to novices and trainees learning about multiparametric prostate MRI. MRI technique is presented along with the use of particular MRI sequences. Relevant prostate anatomy is outlined and imaging features of prostate cancer with staging are discussed. Finally structured reporting is introduced, and some limitations of prostate MRI are discussed.

Oncology imaging in the abdomen and pelvis: where cancer hides.

As the incidence of cancer continues to increase, imaging will play an ever more important role in the detection, diagnosis, staging, surveillance, and therapeutic monitoring of cancer. Diagnostic errors in the initial discovery of cancer or at follow-up assessments can lead to missed opportunities for curative treatments or altering or reinitiating therapies, as well as adversely impact clinical trials. Radiologists must have an understanding of cancer biology, treatments, and imaging appearance of therapeutic effects and be mindful that metastatic disease can involve virtually any organ system. Knowledge of patient history and tumor biology allows for optimizing imaging protocols. The majority of cancer imaging utilizes computed tomography, where contrast enhancement characteristics of lesions can be exploited and detection of subtle lesions can involve manipulation of window width and level settings, multiplanar reconstruction, and maximum intensity projections. For magnetic resonance imaging, diffusion-weighted imaging can render lesions more conspicuous, improve characterization, and help assess therapeutic response. Positron emission tomography with (18)F-labeled fluorodeoxyglucose and sodium fluoride are invaluable in detecting occult existing and new cancerous lesions, characterizing indeterminate lesions, and assessing treatment effects. The most common anatomic "hiding places" for cancer include metastases to solid organs, such as the kidneys and pancreas, gastrointestinal tract, peritoneum and retroperitoneum, neural axis, muscular body wall, and bones. Consistent work habits, employment of appropriate technologies, and particular attention to the above anatomic areas can enhance detection, staging, and reassessments of these complex and often stealthy diseases, ensuring the radiologists' integral role in the cancer care team.

Unilateral axillary lymphadenopathy following COVID-19 vaccination: A case report and imaging findings.

As more people receive coronavirus disease 2019 (COVID-19) vaccinations, the side effects of the vaccines will become more apparent. One reported side effect that has come to light is unilateral axillary lymphadenopathy ipsilateral to the vaccination site. In general, unilateral axillary lymphadenopathy has a broad differential including malignancy, infection, autoimmune disorder, and iatrogenic etiologies. We present a case of a previously healthy 38-year-old woman who received her first dose of Pfizer COVID-19 vaccination 3 days prior to presenting to the emergency department complaining of 2 weeks of abdominal pain and 20-pound unintentional weight loss. Unilateral axillary lymphadenopathy, ipsilateral to the vaccination site, was found on a contrast-enhanced computed tomography examination of the chest, abdomen, and pelvis. Subsequent diagnostic mammograms did not demonstrate evidence of malignancy; however, axillary ultrasound again revealed nonspecific lymphadenopathy. A short-term follow-up axillary ultrasound was recommended, rather than a lymph node biopsy, given the history of recent vaccination. At clinical follow-up, the patient's abdominal pain resolved and no further weight loss was noted. This case report discusses the key components and workup recommendation of unilateral axillary lymphadenopathy in the setting of COVID-19 vaccination.

Peer Learning Through Multi-Institutional Web-based Case Conferences: Perceived Value (and Challenges) From Abdominal, Cardiothoracic, and Musculoskeletal Radiology Case Conference Participants.

RATIONALE AND OBJECTIVES: Peer learning is a case-based group-learning model intended to improve performance. In this descriptive paper, we describe multi-institutional, multi-subspecialty, web-based radiology case conferences and summarize the participants' experiences. MATERIALS AND METHODS: A semi-structured, 27-question survey was administered to radiologists participating in abdominal, cardiothoracic, and musculoskeletal case conferences. Survey questions included demographics, perceived educational value and challenges experienced. Survey question formats were continuous, binary, five-point Likert scale or text-based. The measures of central tendencies, proportions of responses and patterns were tabulated. RESULTS: From 57 responders, 12/57 (21.1%) were abdominal, 16/57 (28.1%) were cardiothoracic, and 29/57 (50.8%) were musculoskeletal conference participants; 50/56 (89.3%) represented academic practice. Median age was 45 years (range 35-74); 43/57 (75.4%) were male. Geographically, 16/52 (30.8%) of participants were from the East Coast, 16/52 (30.8%) Midwest, 18/52 (34.6%) West Coast, and 2/52 (3.8%) International. The median reported educational value was 5/5 (interquartile range 5-5). Benefits of the case conference included education (50/95, 52.6%) and networking (39/95, 41.1%). Participants reported presenting the following cases: "great call" 32/48 (66.7%), learning opportunity 32/48 (66.7%), new knowledge 41/49 (83.7%), "zebras" 46/49 (93.9%), and procedural-based 16/46 (34.8%). All 51/51 (100%) of responders reportedly gained new knowledge, 49/51 (96.1%) became more open to group discussion, 34/51 (66.7%) changed search patterns, and 50/51 (98%) would continue to participate. Reported challenges included time zone differences and support from departments for a protected time to participate. CONCLUSION: Peer learning through multi-institutional case conferences provides educational and networking opportunities. Current challenges and desires include having department-supported protected time and ability to receive continuing medical education credit.

Restoration of continence by pessaries: magnetic resonance imaging assessment of mechanism of action.

OBJECTIVE: The objective of the study was to determine incontinence pessaries' mechanism of action by measuring changes on urodynamic studies (UDS) and dynamic magnetic resonance imaging (MRI) with and without pessaries in place. STUDY DESIGN: Women with stress incontinence had UDS and MRI performed with and without incontinence dish pessaries. RESULTS: Fifteen women were evaluated. Pessary insertion resulted in increased urethral resistance; detrusor pressures increased (33-45 cm H(2)O) and maximal flow rates decreased (30 to 19 mL/second). With Valsalva on MRI, pessaries were associated with decreased posterior urethrovesical angles (175-130 degrees), bladder neck elevation (0.3 below to 0 .8 cm above the pubococcygeal line) and increased urethral lengths (2.4 to 2.97 cm). Bladder neck funneling with cough occurred in 14 patients without pessaries and 3 with pessaries. CONCLUSION: On UDS and MRI following pessary placement, continence restoration was associated with decreased posterior urethrovesical angles, bladder neck descent and funneling, and increased urethral lengths and resistance to urine flow.

ACR Appropriateness Criteria® Pretreatment Staging of Muscle-Invasive Bladder Cancer.

Muscle-invasive bladder cancer (MIBC) has a tendency toward urothelial multifocality and is at risk for local and distant spread, most commonly to the lymph nodes, bone, lung, liver, and peritoneum. Pretreatment staging of MIBC should include imaging of the urothelial upper tract for synchronous lesions; imaging of the chest, abdomen, and pelvis for metastases; and MRI pelvis for local staging. CT abdomen and pelvis without and with contrast (CT urogram) is recommended to assess the urothelium and abdominopelvic organs. Pelvic MRI can improve local bladder staging accuracy. Chest imaging is also recommended with chest radiograph usually being adequate. FDG-PET/CT may be appropriate to identify nodal and metastatic disease. Chest CT may be useful in high-risk patients and those with findings on chest radiograph. Nonurogram CT and MRI of the abdomen and pelvis are usually not appropriate, and neither is radiographic intravenous urography, Tc-99m whole body bone scan, nor bladder ultrasound for pretreatment staging of MIBC. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Post-treatment Follow-up Prostate Cancer.

Diagnosis and management of prostate cancer post treatment is a large and complex problem, and care of these patients requires multidisciplinary involvement of imaging, medical, and surgical specialties. Imaging capabilities for evaluation of men with recurrent prostate cancer are rapidly evolving, particularly with PET and MRI. At the same time, treatment options and capabilities are expanding and improving. These recommendations separate patients into three broad categories: (1) patients status post-radical prostatectomy, (2) clinical concern for residual or recurrent disease after nonsurgical local and pelvic treatments, and (3) metastatic prostate. This article is a review of the current literature regarding imaging in these settings and the resulting recommendations for imaging. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

High postprostatectomy prostate-specific antigen level prior to salvage radiation therapy is not always a bad sign.

Although radical prostatectomy is a popular treatment modality for clinically localized prostate cancer, 10-year biochemical recurrence can reach 28%. Before salvage radiation therapy (SRT), prostate-specific antigen (PSA) values alone should be used cautiously in predicting SRT eligibility. A long, slow PSA rise may suggest locally confined disease still amenable to SRT; corresponding imaging to identify potential gross recurrence is useful. Patients with local disease may safely benefit from higher doses of radiation.