Scintigraphy of Gastrointestinal Motility: Best Practices in Assessment of Gastric and Bowel Transit in Adults.

Various radiologic examinations and other diagnostic tools exist for evaluating gastrointestinal diseases. When symptoms of gastrointestinal disease persist and no underlying anatomic or structural abnormality is identified, the diagnosis of functional gastrointestinal disorder is frequently applied. Given its physiologic and quantitative nature, scintigraphy often plays a central role in the diagnosis and treatment of patients with suspected functional gastrointestinal disorder. Most frequently, after functional gallbladder disease is excluded, gastric emptying scintigraphy (GES) is considered the next step in evaluating patients with suspected gastric motility disorder who present with upper gastrointestinal symptoms such as dyspepsia or bloating. GES is the standard modality for detecting delayed gastric emptying (gastroparesis) and the less commonly encountered clinical entity, gastric dumping syndrome. Additionally, GES can be used to assess abnormalities of intragastric distribution, suggesting specific disorders such as impaired fundal accommodation or antral dysfunction, as well as to evaluate gastric emptying of liquid. More recently, scintigraphic examinations for evaluating small bowel and large bowel transit have been developed and validated for routine diagnostic use. These can be performed individually or as part of a comprehensive whole-gut transit evaluation. Such scintigraphic examinations are of particular importance because clinical assessment of suspected functional gastrointestinal disorder frequently fails to accurately localize the site of disease, and those patients may have motility disorders involving multiple portions of the gastrointestinal tract. The authors comprehensively review the current practice of gastrointestinal transit scintigraphy, with diseases and best imaging practices illustrated by means of case review. ©RSNA, 2024 See the invited commentary by Maurer and Parkman in this issue.

Prostate-specific membrane antigen-positron emission tomography (PSMA-PET) of prostate cancer: current and emerging applications.

Prostate-specific membrane antigen-positron emission tomography (PSMA-PET) is transforming the management of patients with prostate cancer. In appropriately selected patients, PSMA-PET offers superior sensitivity and specificity compared to conventional imaging (e.g., computed tomography and bone scintigraphy) as well as choline and fluciclovine PET, with the added benefit of consolidating bone and soft tissue evaluation into a single study. Despite being a newly available imaging tool, PSMA-PET has established indications, interpretation guidelines, and reporting criteria, which will be reviewed. The prostate cancer care team, from imaging specialists to those delivering treatment, should have knowledge of physiologic PSMA radiotracer uptake, patterns of disease spread, and the strengths and limitations of PSMA-PET. In this review, current and emerging applications of PSMA-PET, including appropriateness use criteria as well as image interpretation and pitfalls, will be provided with an emphasis on clinical implications.

MR Defecating Proctography with Emphasis on Posterior Compartment Disorders.

MR defecating proctography (MRDP) is a noninvasive examination that can be used for evaluating posterior compartment disorders. MRDP has several advantages over conventional fluoroscopic defecography. These benefits include high-contrast resolution evaluation of the deep pelvic organs, simultaneous multicompartmental assessment that is performed statically and dynamically during defecation, and lack of ionizing radiation. MRDP also provides a highly detailed anatomic evaluation of the pelvic floor supportive structures, including direct assessment of the pelvic floor musculature and indirect assessment of the endopelvic fascia. As the breadth of knowledge regarding anatomic and functional posterior compartment disorders expands, so too does the advancement of noninvasive and surgical treatment options for these conditions. High-quality MRDP examinations, with key anatomic and functional features reported, guide treatment planning. Reporting of MRDP examination findings with use of standardized terminology that emphasizes objective measurements rather than subjective grading aids consistent communication among radiologists, clinicians, and surgeons. Familiarity with commonly encountered posterior compartment pelvic floor pathologic entities that contribute to posterior compartment disorders and awareness of the essential information needed by surgeons are key to providing an optimal multidisciplinary discussion for planning pelvic floor dysfunction treatment. The authors provide an overview of the basic concepts of the MRDP acquisition technique, the anatomic abnormalities of posterior compartment pelvic floor pathologic entities associated with defecatory disorders, and recently developed interdisciplinary MRDP reporting templates and lexicons. In addition, the associated imaging findings that are key for surgical treatment guidance are highlighted. © RSNA, 2022 Online supplemental material is available for this article.

Fluoroscopic Evaluation of Duodenal Diseases.

The duodenum can be affected by a variety of abnormalities because of its development during embryogenesis and its dual intra- and retroperitoneal location. If small bowel embryogenesis is disturbed, congenital errors occur. Although some congenital variants may be asymptomatic and inconsequential to the patient, other anomalies can result in life-threatening emergencies such as malrotation, leading to midgut volvulus. Many infectious processes affect the duodenum, including duodenal ulcers and opportunistic infection in patients with HIV/AIDS or Crohn disease. Small bowel malignancies are uncommon but important to recognize, because the duodenum can be involved in polyposis syndromes or the development of primary adenocarcinoma, neuroendocrine tumors, lymphoma, and metastasis. Although endoscopy is currently the most used diagnostic method to assess the lumen of the upper gastrointestinal tract, fluoroscopy is a valuable adjunct technique and the study of choice for many diseases, specifically those for which anatomic and functional information is required. Fluoroscopy is also commonly used postoperatively to assess for complications such as obstruction and extraluminal leaks. Compared with endoscopy, fluoroscopy is an inexpensive and noninvasive technique that provides salient anatomic information and allows delineation of the duodenal mucosa and assessment of real-time duodenal motility. The authors examine the broad spectrum of conditions that can involve the duodenum, including congenital, infectious, inflammatory, and neoplastic abnormalities, and review their typical appearances at fluoroscopy. Online supplemental material is available for this article. ©RSNA, 2022.

Should Radiology Residency Interviews Remain Virtual? Results of a Multi-institutional Survey Inform the Debate.

RATIONALE AND OBJECTIVES: The recent completion of the inaugural virtual interview season has triggered calls for the permanency of virtual interviews in the radiology resident selection process. We designed a study to assess the inaugural 2020-2021 virtual interview season and inform the anticipated debate on the future of radiology residency interviews. MATERIALS AND METHODS: Forty-four and 39-question survey instruments developed for program directors (PDs) and applicants, respectively, were distributed through the Radiology Residency Education Research Alliance to measure the demographics, experiences with technology, attitudes toward the virtual interview season and attitudes about proposed changes to the interview process. Comparisons were made between demographics and survey queries. RESULTS: PD and applicant response rates were 74% (25/34) and 45% (84/186), respectively. Eighty percent (20/25) of PDs and 76% (64/84) of applicants described the virtual interview season as excellent or very good. Sixty percent of PDs agreed or strongly agreed with the statement "The benefits of the virtual interview season outweighed the drawbacks," while 24% disagreed or strongly disagreed, and 16% were neutral. Among applicants, 80% agreed or strongly agreed, 10% disagreed or strongly disagreed, and 10% were neutral toward the same statement. Ninety-two percent of PDs noted that their rank order list performed the same or better than in years prior. Both PDs and applicants identified applicant equity and wellness as major benefits of virtual interviews, while identifying over-application and interview hoarding as significant detriments. CONCLUSION: The virtual interview provides an adequate substitute for the conventional in-person residency interview, with real and perceived benefits to applicant wellness, equity, and financial well-being. The downsides of virtual interviews, namely over-application and interview hoarding, have workable solutions.

From Beginning to End: A Single Radiology Residency Program's Experience with Web-Based Resident Recruitment during COVID-19 and a Review of the Literature.

COVID-19 disrupted the practice of in-person visits for the 2020-2021 recruitment cycle. This past year, Graduate Medical Education (GME) programs converted to online interviews and virtual visits for all applicants. Given the unpredictable nature of this pandemic, it remains unclear when or if conventional travel for residency interviews will resume. Therefore, it is important to reflect on this past season and look ahead to our next recruitment and interview cycle. Here, we review prior publications studying faculty and applicant experiences with web-based interviewing strategies, and we describe our own residency program's recruitment strategy for a virtual interview season, including survey results of reactions by both interviewers and candidates following our first season in this new era of virtual meetings and interviews. Web-based recruitment and interviews are feasible and can be done well with careful planning and preparation of those involved. Concerns persist primarily among applicants that virtual visits to a training program are inadequate for providing sufficient information prior to ranking. Regardless of future travel restrictions, GME programs will likely benefit all stakeholders by offering web-based recruitment and interviews, while also providing opportunities for optional in-person visits.

ACR Appropriateness Criteria Facilitate Judicious Use of CT Angiography for Stroke Workup in the Emergency Department.

PURPOSE: CT angiography (CTA) of the head and neck plays a key role in the evaluation of patients with stroke in the emergency department, particularly to evaluate for large-vessel occlusion and consider patients for mechanical thrombectomy. However, CTA is not always indicated and has various costs. The aim of this study was to examine the correlation between ACR imaging appropriateness recommendations and findings explanatory for stroke on CTA of the head and neck. METHODS: CTA head and neck examinations of emergency department patients performed to evaluate for stroke between January 1, 2019, and June 30, 2019, were retrospectively reviewed. Patients with previously known acute infarct, with primary concern for or discovered hemorrhage, or being evaluated for trauma were excluded. Presenting symptoms were classified on the basis of the most recent ACR Appropriateness Criteria, into three categories: "usually appropriate" (UA), "may be appropriate" (MBA), or "usually not appropriate" (UNA). The percentage of examinations with findings explanatory for stroke were compared among the three groups using the Fisher exact test. RESULTS: A total of 707 cases were reviewed, of which 317 were included; 199 fell into the UA category, 38 MBA, and 80 UNA. For UA, 57 of 199 CTAs (29%) had findings explanatory for stroke, compared with 1 of 38 (3%) in the MBA group (difference, 26%; 95% confidence interval, 13%-34%; P < .001) and 1 of 80 (1%) in the UNA group (difference, 27%; 95% confidence interval, 19%-35%; P < .001). CONCLUSIONS: ACR Appropriateness Criteria recommendations correlate with imaging findings explanatory for stroke and may guide the judicious use of CTA for suspected stroke workup.

Can Activities of Daily Living Predict Complications following Percutaneous Nephrolithotomy?

PURPOSE: Activities of daily living provide information about the functional status of an individual and can predict postoperative complications after general and oncological surgery. However, they have rarely been applied to urology. We evaluated whether deficits in activities of daily living could predict complications after percutaneous nephrolithotomy and how this compares with the Charlson comorbidity index and the ASA(®) (American Society of Anesthesiologists(®)) classification. MATERIALS AND METHODS: We retrospectively reviewed the records of all patients who underwent percutaneous nephrolithotomy between March 2013 and March 2014. Those with complete assessment of activities of daily living were included in analysis. Perioperative outcomes, complications and hospital length of stay were examined according to the degree of deficits in daily living activities. RESULTS: Overall 176 patients underwent a total of 192 percutaneous nephrolithotomies. Deficits in activities of daily living were seen in 16% of patients, including minor in 9% and major in 7%. Complications developed more frequently in those with vs without deficits in daily living activities (53% vs 31%, p = 0.029) and length of stay was longer (2.0 vs 4.5 days, p = 0.005). On multivariate logistic regression activities of daily living were an independent predictor of complications (OR 1.11, p = 0.01) but ASA classification and Charlson comorbidity index were not. CONCLUSIONS: Activities of daily living are easily evaluated prior to surgery. They independently predict complications following percutaneous nephrolithotomy better than the Charlson comorbidity index or the ASA classification. Preoperative assessment of daily living activities can help risk stratify patients and may inform treatment decisions.

Intra-articular injection of micronized dehydrated human amnion/chorion membrane attenuates osteoarthritis development.

INTRODUCTION: Micronized dehydrated human amnion/chorion membrane (µ-dHACM) is derived from donated human placentae and has anti-inflammatory, low immunogenic and anti-fibrotic properties. The objective of this study was to quantitatively assess the efficacy of µ-dHACM as a disease modifying intervention in a rat model of osteoarthritis (OA). It was hypothesized that intra-articular injection of µ-dHACM would attenuate OA progression. METHODS: Lewis rats underwent medial meniscal transection (MMT) surgery to induce OA. Twenty four hours post-surgery, µ-dHACM or saline was injected intra-articularly into the rat joint. Naïve rats also received µ-dHACM injections. Microstructural changes in the tibial articular cartilage were assessed using equilibrium partitioning of an ionic contrast agent (EPIC-µCT) at 21 days post-surgery. The joint was also evaluated histologically and synovial fluid was analyzed for inflammatory markers at 3 and 21 days post-surgery. RESULTS: There was no measured baseline effect of µ-dHACM on cartilage in naïve animals. Histological staining of treated joints showed presence of µ-dHACM in the synovium along with local hypercellularity at 3 and 21 days post-surgery. In MMT animals, development of cartilage lesions at 21 days was prevented and number of partial erosions was significantly reduced by treatment with µ-dHACM. EPIC-µCT analysis quantitatively showed that µ-dHACM reduced proteoglycan loss in MMT animals. CONCLUSIONS: µ-dHACM is rapidly sequestered in the synovial membrane following intra-articular injection and attenuates cartilage degradation in a rat OA model. These data suggest that intra-articular delivery of µ-dHACM may have a therapeutic effect on OA development.

Poly (l-lactide-co-caprolactone) scaffolds enhanced with poly (ß-hydroxybutyrate-co-ß-hydroxyvalerate) microspheres for cartilage regeneration.

Biodegradable polymers, either as porous scaffolds or microspheres, have been investigated broadly for cartilage tissue engineering. A combination of these two forms of materials could potentially maximize their benefits. In this study, porous poly (l-lactide-co-ε-caprolactone) (PLCL) scaffolds were integrated with poly (ß-hydroxybutyrate-co-ß-hydroxyvalerate) (PHBV) microspheres to enhance the mechanical properties of the scaffolds as well as to potentially regulate cell behavior through altering surface topography. PHBV microspheres fabricated with an emulsion solvent evaporation method were incorporated into PLCL scaffolds (0%, 20%, 40% and 50% W/W). Compressive modulus, surface topography and porosity of the composite scaffolds were evaluated, and in vitro and in vivo chondrogenesis within the chondrocyte-laden scaffolds was investigated by examining proliferation of chondrocytes and the deposition of glycosaminoglycan (GAG) and type II collagen. The results showed significant enhancement of the compressive modulus of the scaffolds incorporated with PHBV microspheres, while Young's modulus of the scaffolds with 50% PHBV incorporation was 3.3 times higher than PLCL scaffolds alone. The porosity of the composite scaffolds was kept constant for all levels of PHBV incorporation. Though the PLCL scaffolds incorporated with microspheres showed no significant effects on adhesion at 6 h as well as in vitro cartilage formation and proliferation of the chondrocytes at both 2 weeks and 4 weeks, total contents of GAG and type II collagen excreted increased significantly with time. The chondrocyte-laden scaffolds formed cartilage-like tissues at 4 and 8 weeks after implantation in nude mice, with increased staining density of type II collagen and GAG over time. In conclusion, incorporation of PHBV microspheres not only enhanced the compressive modulus of PLCL scaffolds, but could also serve as scaffolding structures for cartilaginous tissue formation.