Percutaneous CT-Guided Abdominal and Pelvic Biopsies: Comparison of an Electromagnetic Navigation System and CT Fluoroscopy.

PURPOSE: To compare electromagnetic navigation (EMN) with computed tomography (CT) fluoroscopy for guiding percutaneous biopsies in the abdomen and pelvis. MATERIALS AND METHODS: A retrospective matched-cohort design was used to compare biopsies in the abdomen and pelvis performed with EMN (consecutive cases, n = 50; CT-Navigation; Imactis, Saint-Martin-d'Hères, France) with those performed with CT fluoroscopy (n = 100). Cases were matched 1:2 (EMN:CT fluoroscopy) for target organ and lesion size (±10 mm). RESULTS: The population was well-matched (age, 65 vs 65 years; target size, 2.0 vs 2.1 cm; skin-to-target distance, 11.4 vs 10.7 cm; P > .05, EMN vs CT fluoroscopy, respectively). Technical success (98% vs 100%), diagnostic yield (98% vs 95%), adverse events (2% vs 5%), and procedure time (33 minutes vs 31 minutes) were not statistically different (P > .05). Operator radiation dose was less with EMN than with CT fluoroscopy (0.04 vs 1.2 µGy; P < .001), but patient dose was greater (30.1 vs 9.6 mSv; P < .001) owing to more helical scans during EMN guidance (3.9 vs 2.1; P < .001). CT fluoroscopy was performed with a mean of 29.7 tap scans per case. In 3 (3%) cases, CT fluoroscopy was performed with gantry tilt, and the mean angle out of plane for EMN cases was 13.4°. CONCLUSIONS: Percutaneous biopsies guided by EMN and CT fluoroscopy were closely matched for technical success, diagnostic yield, procedure time, and adverse events in a matched cohort of patients. EMN cases were more likely to be performed outside of the gantry plane. Radiation dose to the operator was higher with CT fluoroscopy, and patient radiation dose was higher with EMN. Further study with a wider array of procedures and anatomic locations is warranted.

A Comparison of Histotripsy and Percutaneous Cryoablation in a Chronic Healthy Swine Kidney Model.

PURPOSE: To compare the safety and efficacy of histotripsy with cryoablation in a chronic human-scale normal porcine kidney model. MATERIALS AND METHODS: Eighteen female domestic swine were divided evenly into histotripsy and cryoablation treatment arms. A planned 2-3 cm diameter treatment was performed under ultrasound (histotripsy) or ultrasound and computed tomography (CT) guidance (cryoablation). Contrast-enhanced CT and serum blood analysis were performed immediately postprocedure and on day 7, with either immediate killing (n = 3) or continued survival to day 30 (n = 6), at which time contrast-enhanced CT, serum blood analysis, and necropsy were performed. Animal welfare, treatment zone appearance, procedure-related adverse events, and histopathology of the treatment zones and surrounding tissues were assessed. RESULTS: Histotripsy treatment zones (mean ±standard deviation diameters, 2.7 ± 0.12 × 2.4 ± 0.19 × 2.4 ± 0.26 cm; volume, 8.3 ± 1.9 cm3) were larger than cryoablation zones (mean diameters, 2.2 ± 0.19 × 1.9 ± 0.13 × 1.7 ± 0.19 cm; volume, 3.9 ± 0.8 cm3; P < .001). At 30 days, histotripsy and cryoablation treatment zone volumes decreased by 96% and 83% on CT, respectively (P < .001). Perirenal hematomas were present after 8 of 9 (89%) cryoablation (mean volume, 22.2 cm3) and 1 of 9 (11%, P < .001) histotripsy (volume, 0.4 cm3) procedures, with active arterial extravasation in 4 of 9 (44%) cryoablation and no histotripsy animals (P = .206). All 9 histotripsy animals and 5 of 9 (56%) cryoablation animals had collecting system debris (P = .042). Changes in serum creatinine were similar between the groups (P = .321). CONCLUSIONS: Other than a higher rate of bleeding after cryoablation, the safety and early efficacy of histotripsy and cryoablation were comparable for creating treatment zones in a chronic normal porcine kidney model.

Ultrasound Elastographic Measurement of Rigor Mortis in an Animal Model: A Feasibility Study for Improved Time-of-Death Estimates in Forensic Investigations.

OBJECTIVE. The purpose of our study was to assess the feasibility of 2D shear wave ultrasound elastography to quantitatively measure changes of rigor mortis. SUBJECTS AND METHODS. Muscle stiffness of two live pigs and nine sacrificed pigs was measured in kilopascals using ultrasound elastography. The nine sacrificed pigs were divided into three groups of three pigs each and placed in one of three environments at 90°F (32°C), 70°F (21°C), or 34°F (1°C). Ultrasound elastography of five muscles was performed at 1- to 2-hour intervals for up to 50 hours postmortem. For each pig and muscle location, the time to start, peak intensity, duration of peak, and time to decline of rigor mortis were identified from the graphs of muscle stiffness values over time. These outcome variables were then compared across ambient temperature, body weight, and age groups using the Wilcoxon rank sum test. RESULTS. Postmortem measurements show a rise, peak, and decline of muscle stiffness after death. Rigor mortis was highly significantly affected by ambient temperature (p < .001), was significantly affected by body weight (p = .04), and was not significantly affected by animal age or muscle location (facial vs truncal vs limb) (p > .50). Peak intensity of rigor mortis developed more quickly but attained lower levels of muscle stiffness at 90°F (80-100 kPa) compared with 70°F and 34°F (280-300 kPa) (p < .001). The duration of peak rigor mortis and the time to decline of rigor mortis were significantly longer for the lower temperatures (p < .001). CONCLUSION. Two-dimensional shear wave ultrasound elastography can quantifi-ably measure the trajectory of rigor mortis in an animal model. This new approach may have direct implications for human forensic investigations.

RadioGraphics Update: Venous Thrombosis and Hypercoagulability in the Abdomen and Pelvis-Findings in COVID-19.

Editor's Note.-Articles in the RadioGraphics Update section provide current knowledge to supplement or update information found in full-length articles previously published in RadioGraphics. Authors of the previously published article provide a brief synopsis that emphasizes important new information such as technological advances, revised imaging protocols, new clinical guidelines involving imaging, or updated classification schemes. Articles in this section are published solely online and are linked to the original article.

Risk Factors for Complications and Nondiagnostic Results following 1,155 Consecutive Percutaneous Core Renal Mass Biopsies.

PURPOSE: The purpose of this study was to evaluate patient, tumor and technical factors associated with procedural complications and nondiagnostic findings following percutaneous core renal mass biopsy. MATERIALS AND METHODS: We reviewed core renal mass biopsies from 2000 to 2017. Complications at 30 days or less were graded using the Clavien-Dindo system. Univariate and multivariable analyses were done to evaluate associations between clinical characteristics and the risk of complications or nondiagnostic findings. RESULTS: Of the 1,155 biopsies performed in a total of 965 patients procedural complications were identified in 24 patients (2.2%), including 5 (0.4%) with major complications (Clavien 3a or greater). No patients were identified with tumor seeding of the biopsy tract. Patient age, body mass index, gender, Charlson comorbidity index, smoking, mass diameter, nephrometry score, number of cores and prior biopsy were not associated with complication risk (p = 0.06 to 0.53). Complications were not increased for patients on aspirin or those with low platelets (25,000 to 160,000/µl blood) or a mildly elevated INR (international normalized ratio) (1.2 to 2.0, p = 0.16, 0.07 and 0.50, respectively). The complication risk was not increased during the initial 50 cases of a radiologist or when a trainee was present (p = 0.35 and 0.12, respectively). Nondiagnostic findings were present in 14.6% of biopsies. Independent predictors included cystic features, contrast enhancement, mass diameter and skin-to-mass distance (p <0.001, 0.002, 0.02 and 0.049, respectively). Radiologist experience was not associated with the nondiagnostic rate (p = 0.23). Prior nondiagnostic biopsy was not associated with an increased nondiagnostic rate on subsequent attempts (19.2% vs 14.2%, p = 0.23). CONCLUSIONS: Procedural complications following biopsy are rare even with low serum platelets, a mildly elevated INR or when the patient remains on aspirin. Cystic features, hypo-enhancement on imaging, a smaller mass diameter and a longer skin-to-tumor distance increase the risk of nondiagnostic findings.

ACR Appropriateness Criteria® Pretreatment Detection, Surveillance, and Staging of Prostate Cancer: 2022 Update.

Prostate cancer is second leading cause of death from malignancy after lung cancer in American men. The primary goal during pretreatment evaluation of prostate cancer is disease detection, localization, establishing disease extent (both local and distant), and evaluating aggressiveness, which are the driving factors of patient outcomes such as recurrence and survival. Prostate cancer is typically diagnosed after the recognizing elevated serum prostate-specific antigen level or abnormal digital rectal examination. Tissue diagnosis is obtained by transrectal ultrasound-guided biopsy or MRI-targeted biopsy, commonly with multiparametric MRI without or with intravenous contrast, which has recently been established as standard of care for detecting, localizing, and assessing local extent of prostate cancer. Although bone scintigraphy and CT are still typically used to detect bone and nodal metastases in patients with intermediate- or high-risk prostate cancer, novel advanced imaging modalities including prostatespecific membrane antigen PET/CT and whole-body MRI are being more frequently utilized for this purpose with improved detection rates. The ACR 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.

Rates of Detecting Thyroid Nodules Recommended for Biopsy with Ultrasound: Are All Indications Equal?

Background: The use of thyroid ultrasound increases yearly, adding to costs and overdetection of clinically irrelevant nodules. We investigated which indications most commonly prompt referral for thyroid ultrasound and the diagnostic utility by indication. Methods: We performed a retrospective observational cohort study of adults (≥18 years) undergoing an initial dedicated thyroid ultrasound between 2017 and 2019 at a tertiary academic center. Indicated reasons for referral were categorized into suspected palpable nodule (SPN), compressive symptoms (CS), metabolic symptoms (MS), screening due to high-risk factors, follow-up of incidental finding on other imaging, and combination of factors. Percentage of ultrasounds with an identifiable nodule and with a nodule recommended for biopsy was compared by indication. Separate logistic regression models were used to identify factors associated with finding any nodule and a biopsy-recommended nodule. Results: Among the 1739 patients included, the most common indication for thyroid ultrasound was SPN (40%), followed by incidental imaging (28%), CS (13%), combination (11%), MS (6%), and high-risk factors (2%). Overall, 62% of ultrasounds identified a nodule. Ultrasounds performed for incidental findings had the highest rate of nodule identification (94%), compared with 55%, 39%, and 43%, for SPN, CS, and MS, respectively (p < 0.05). Only 27% of ultrasounds identified a biopsy-recommended nodule. Nodules found incidentally had the highest rate of biopsy-recommended nodules at 55%. Rates of biopsy-recommended nodules for SPN, CS, and MS were 21%, 6%, and 10%, respectively. Logistic regression demonstrated that compared with patients referred for an SPN, those with incidental nodules were 10 times more likely to have a nodule found on ultrasound (odds ratio [OR] = 10.6 [CI 7.0-16.0]), while those referred for CS were half as likely to have a nodule (OR = 0.5 [CI 0.4-0.7]). Similar factors were associated with identification of biopsy-recommended nodules. Conclusions: Of all new dedicated thyroid ultrasounds, only a quarter find biopsy-recommended nodules, and nearly 40% do not identify a nodule at all. Notably, only 55% of ultrasounds done for SPN found a nodule. Ultrasound for CS and MS had the lowest rates of detecting nodules. Providing clear guidance on when to order thyroid ultrasounds can help reduce unnecessary health care utilization and potential overtreatment.

ACR Appropriateness Criteria® Post-Treatment Follow-up of Prostate Cancer: 2022 Update.

Prostate cancer has a wide spectrum ranging between low-grade localized disease and castrate-resistant metastatic disease. Although whole gland and systematic therapies result in cure in the majority of patients, recurrent and metastatic prostate cancer can still occur. Imaging approaches including anatomic, functional, and molecular modalities are continuously expanding. Currently, recurrent and metastatic prostate cancer is grouped in three major categories: 1) Clinical concern for residual or recurrent disease after radical prostatectomy, 2) Clinical concern for residual or recurrent disease after nonsurgical local and pelvic treatments, and 3) Metastatic prostate cancer treated by systemic therapy (androgen deprivation therapy, chemotherapy, immunotherapy). This document 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.

ACR Appropriateness Criteria® Staging and Surveillance of Testicular Cancer: 2021 Update.

The staging and surveillance of testicular cancer is a complex topic, which integrates clinical, biochemical, and imaging components. The use of imaging for staging and surveillance of testicular cancer is individually tailored to each patient by considering tumor histology and prognosis. This document discusses the rationale for use of imaging by imaging modality during the initial staging of testicular seminoma and nonseminoma tumors and during the planned surveillance of stage IA and IB testicular cancer by histological subtype integrating clinical suspicion for disease recurrence in surveillance protocols. 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.

Incidental discovery of a rare right ventricular aneurysm.

Three types of cardiac outpouchings are encountered on cardiovascular imaging: diverticula, aneurysms and pseudoaneurysms. The underlying physiology, imaging findings, risk of rupture, and optimal treatment varies for each and a correct diagnosis is critical. We report a case of a rare, incidentally discovered right ventricular aneurysm that was characterized by transthoracic echocardiogram, computed tomography, and cardiac MRI. The types of cardiac outpouchings are reviewed, and we discuss the selection of imaging modality, keys to distinguishing the outpouchings, and management strategies.

Social Media in Radiology: Overview and Usefulness of Online Professional #SoMe Profiles.

Social media is a ubiquitous part of society and used by many healthcare professionals, including radiologists. This article prepared by the 2019-2020 Radiology Research Alliance Social Media Task Force presents different uses and benefits of an online professional social media profile. Physician and healthcare-specific issues along with popular platforms such as LinkedIn, Facebook, Twitter, Instagram, and YouTube are used to explore topics including education, branding, research, mentorship, promotion, and leadership.

ACR Appropriateness Criteria® Post-Treatment Surveillance of Bladder Cancer: 2021 Update.

Urothelial cancer is the second most common cancer, and cause of cancer death, related to the genitourinary tract. The goals of surveillance imaging after the treatment of urothelial cancer of the urinary bladder are to detect new or previously undetected urothelial tumors, to identify metastatic disease, and to evaluate for complications of therapy. For surveillance, patients can be stratified into one of three groups: 1) nonmuscle invasive bladder cancer with no symptoms or additional risk factors; 2) nonmuscle invasive bladder cancer with symptoms or additional risk factors; and 3) muscle invasive bladder cancer. This document is a review of the current literature for urothelial cancer and resulting recommendations for surveillance 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.

Innovations in Vascular Ultrasound.

There are several vascular ultrasound technologies that are useful in challenging diagnostic situations. New vascular ultrasound applications include directional power Doppler ultrasound, contrast-enhanced ultrasound, B-flow imaging, microvascular imaging, 3-dimensional vascular ultrasound, intravascular ultrasound, photoacoustic imaging, and vascular elastography. All these techniques are complementary to Doppler ultrasound and provide greater ability to visualize small vessels, have higher sensitivity to detect slow flow, and better assess vascular wall and lumen while overcoming limitations color Doppler. The ultimate goal of these technologies is to make ultrasound competitive with computed tomography and magnetic resonance imaging for vascular imaging.

Collaborative Learning in Radiology: From Peer Review to Peer Learning and Peer Coaching.

BACKGROUND: A Radiology Research Alliance Task Force was assembled in 2018 to review the literature on peer review and report on best practices for peer learning and peer coaching. FINDINGS: This report provides a historical perspective on peer review and the transition to peer collaborative learning and peer coaching. Most forms of current peer review have fulfilled regulatory requirements but have failed to significantly impact quality improvement or learning opportunities. Peer learning involves joint intellectual efforts by two or more individuals to study best practices and review error collaboratively. Peer coaching is a process in which individuals in a trusted environment work to expand, refine, and build new skills in order to facilitate self-directed learning and professional growth. We discuss the value in creating opportunities for peer learning and peer coaching. CONCLUSION: Peer collaborative learning combined with peer coaching provides opportunities for teams to learn and grow together, benefit from each other's expertise and experience, improve faculty morale, and provide more opportunities for collaborations between faculty.

ACR Appropriateness Criteria® Recurrent Lower Urinary Tract Infections in Females.

Urinary tract infections (UTIs) in women are common, with an overall lifetime risk over >50%. UTIs are considered recurrent when they follow complete clinical resolution of a previous UTI and are usually defined as at least three episodes of infection within the preceding 12 months. An uncomplicated UTI is classified as a UTI without structural or functional abnormalities of the urinary tract and without relevant comorbidities. Complicated UTIs are those occurring in patients with underlying structural or medical problems. In women with recurrent uncomplicated UTIs, cystoscopy and imaging are not routinely used. In women suspected of having a recurrent complicated UTI, cystoscopy and imaging should be considered. CT urography or MR urography are usually appropriate for the evaluation of recurrent complicated lower urinary tract infections or for women who are nonresponders to conventional therapy, develop frequent reinfections or relapses, or have known underlying risk factors. 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.

The Science of Quality Improvement.

Scientific rigor should be consistently applied to quality improvement (QI) research to ensure that healthcare interventions improve quality and patient safety before widespread implementation. This article provides an overview of the various study designs that can be used for QI research depending on the stage of investigation, scope of the QI intervention, constraints on the researchers and intervention being studied, and evidence needed to support widespread implementation. The most commonly used designs in QI studies are quasi-experimental designs. Randomized controlled trials and cluster randomized trials are typically reserved for large-scale research projects evaluating the effectiveness of QI interventions that may be implemented broadly, have more than a minimal impact on patients, or are costly. Systematic reviews of QI studies will play an important role in providing overviews of evidence supporting particular QI interventions or methods of achieving change. We also review the general requirements for developing quality measures for reimbursement, public reporting, and pay-for-performance initiatives. A critical part of the testing process for quality measures includes assessment of feasibility, reliability, validity, and unintended consequences. Finally, publication and critical appraisal of QI work is discussed as an essential component to generating evidence supporting QI initiatives in radiology.

Conventional Medical Education and the History of Simulation in Radiology.

Simulation is a promising method for improving clinician performance, enhancing team training, increasing patient safety, and preventing errors. Training scenarios to enrich medical student and resident education, and apply toward competency assessment, recertification, and credentialing are important applications of simulation in radiology. This review will describe simulation training for procedural skills, interpretive and noninterpretive skills, team-based training and crisis management, professionalism and communication skills, as well as hybrid and in situ applications of simulation training. A brief overview of current simulation equipment and software and the barriers and strategies for implementation are described. Finally, methods of measuring competency and assessment are described, so that the interested reader can successfully implement simulation training into their practice.