Medical workforce in the United States.

This section focuses on the professional workforce comprised of the primary medical specialties that utilize ionizing radiation in their practices. Those discussed include the specialties of radiology and radiation oncology, as well as the subspecialties of radiology, namely diagnostic radiology, interventional radiology, nuclear radiology, and nuclear medicine. These professionals provide essential health care services, for example, the interpretation of imaging studies, the provision of interventional procedures, radionuclide therapeutic treatments, and radiation therapy. In addition, they may be called on to function as part of a radiologic emergency response team to care for potentially exposed persons following radiation events, for example, detonation of a nuclear weapon, nuclear power plant accidents, and transportation incidents. For these reasons, maintenance of an adequate workforce in each of these professions is essential to meeting the nation's future needs. Currently, there is a shortage for all physicians in the medical radiology workforce.

North American Practice-Based Recommendations for Transjugular Intrahepatic Portosystemic Shunts in Portal Hypertension.

Complications of portal hypertension, including ascites, gastrointestinal bleeding, hepatic hydrothorax, and hepatic encephalopathy, are associated with significant morbidity and mortality. Despite few high-quality randomized controlled trials to guide therapeutic decisions, transjugular intrahepatic portosystemic shunt (TIPS) creation has emerged as a crucial therapeutic option to treat complications of portal hypertension. In North America, the decision to perform TIPS involves gastroenterologists, hepatologists, and interventional radiologists, but TIPS creation is performed by interventional radiologists. This is in contrast to other parts of the world where TIPS creation is performed primarily by hepatologists. Thus, the successful use of TIPS in North America is dependent on a multidisciplinary approach and technical expertise, so as to optimize outcomes. Recently, new procedural techniques, TIPS stent technology, and indications for TIPS have emerged. As a result, practices and outcomes vary greatly across institutions and significant knowledge gaps exist. In this consensus statement, the Advancing Liver Therapeutic Approaches group critically reviews the application of TIPS in the management of portal hypertension. Advancing Liver Therapeutic Approaches convened a multidisciplinary group of North American experts from hepatology, interventional radiology, transplant surgery, nephrology, cardiology, pulmonology, and hematology to critically review existing literature and develop practice-based recommendations for the use of TIPS in patients with any cause of portal hypertension in terms of candidate selection, procedural best practices and, post-TIPS management; and to develop areas of consensus for TIPS indications and the prevention of complications. Finally, future research directions are identified related to TIPS for the management of portal hypertension.

Intermediate to Long-Term Clinical Outcomes of Percutaneous Cryoablation for Renal Masses.

PURPOSE: The purpose of this study was to evaluate the effectiveness and adverse outcomes of percutaneous cryoablation (CA) for treatment of renal masses in a large cohort of patients. MATERIALS AND METHODS: This retrospective analysis included 299 CA procedures (297 masses in 277 patients) performed between July 2007 and May 2018 at a single institution. The mean patient age was 66.1 years (range, 30-93 years) with 65.8% being male. A total of 234 (78.8%) masses were biopsy-proven renal cell carcinoma (RCC). The mean maximal tumor diameter was 2.5 cm (range, 0.7-6.6 cm). Efficacy was assessed only for ablations of biopsy-proven RCC, whereas the evaluation of adverse events and renal function included all masses. Complications were graded according to the Society of International Radiology classification. RESULTS: Major complications occurred in 3.0% of procedures (n = 9), none of which resulted in death or permanent disability. The mean imaging follow-up period was 27.4 months (range, 1-115) for the 199 RCC patients (204 ablated tumors) with follow-up imaging available. Complete response on initial follow-up imaging at mean 4.2 months (range, 0.3-75.6) was achieved in 195 of 204 tumors (95.6%) after a single session and in 200 of 204 tumors (98.0%) after 1 or 2 sessions. Of the RCC patients achieving complete response initially, local recurrence during the follow-up period occurred in 3 of 200 tumors (1.5%). Metastatic progression occurred in 10 of 193 (5.2%) RCC patients without prior metastatic disease during follow-up. CONCLUSIONS: CA for renal masses is safe and remains efficacious through intermediate- and long-term follow-up.

Safety and Efficacy of Transjugular Liver Biopsy in Patients with Left Lobe-Only Liver Transplants.

PURPOSE: To evaluate efficacy and safety of transjugular liver biopsy (TJLB) via the left hepatic vein in patients with left lobe-only liver transplants (LLOTs). MATERIALS AND METHODS: Retrospective review revealed 43 TJLBs performed in 26 patients with LLOTs (mean age 51.3 y; range, 18-73 y) between January 2009 and June 2016 at a single institution. A comparison group of 44 randomly selected TJLBs performed in 37 orthotopic whole liver transplant (OWLT) recipients (mean age 57.6 y; range, 35-74 y) during the same time period was evaluated. Patient demographics, type and age of transplant, technical success, adequacy of samples, number of portal tracts obtained, pathologic diagnosis, and complication rate were reviewed. RESULTS: Technical success was achieved in 98% (42/43) of LLOT procedures. TJLB failed in 1 patient with LLOT, in whom no patent hepatic veins were identified. Technical success was achieved in 100% (44/44) in the OWLT group. Mean (SD) number of needle passes was 4.12 (1.25) in the LLOT group vs 3.95 (1.28) in the OWLT group (P = .54). Mean (SD) specimen length was 1.16 (0.75) cm in the LLOT group vs 1.19 (0.58) cm in the OWLT group (P = .78). Mean (SD) number of portal tracts obtained in the LLOT group was 10.7 (5.26) vs 12.3 (4.68) in the OWLT group (P = .17). No major complications were observed in either group. CONCLUSIONS: TJLB in adult patients with LLOTs appears safe and feasible, with favorable rates of technical success and adequacy of sampling.

Managing Refractory Postoperative Fistulas as Chronic Wounds Using Video-Assisted Hydrodebridement (VAHD).

Postoperative fistula formation remains a serious complication following abdominal surgical procedures. Refractory fistulas requiring further surgical intervention delay adjuvant chemotherapy and functional recovery. Here, we present six cases of refractory fistulas and describe a new management technique, which we call video-assisted hydrodebridement. We postulate that refractory fistulas are a type of chronic wound, for which hydrodebridement may be used to hasten wound healing. In all cases, patients had undergone a prolonged period of conservative management and surgical intervention was not considered appropriate. Here, we describe the steps of the procedure in detail. We achieved timely closure of the refractory fistula in five of six cases. The median duration of attempted conservative management was 122 days (63-346 days) and median time to fistula closure after the procedure was 35 days (22-64 days) in the five successful cases. The findings during each procedure are discussed. We suspect that this procedure applies the same benefits to refractory fistulas that hydrodebridement provides to chronic wounds. The combination of endoscopic exploration and hydrodebridement can elucidate barriers to fistula resolution while creating a clean base for wound healing. This technique may be a useful tool to reduce the morbidity of refractory fistula management.

Radiation Dose Reduction during Uterine Fibroid Embolization Using an Optimized Imaging Platform.

PURPOSE: To assess radiation dose reduction during uterine fibroid embolization (UFE) using an optimized angiographic processing and acquisition platform. MATERIALS AND METHODS: Radiation dose data for 70 women (mean age, 46 y; range, 34-67 y) who underwent UFE were retrospectively analyzed. Twenty-one patients underwent UFE using the baseline fluoroscopic and angiographic image acquisition platform, and 49 underwent UFE after implementing an optimized imaging platform in otherwise identical angiography suites. Cumulative kerma-area product (CKAP), cumulative air kerma (CAK), total fluoroscopy time, and image exposure number were collected for each procedure. Image quality was assessed by 3 interventional radiologists blinded to the platform used for image acquisition and processing. RESULTS: Patients undergoing UFE using the new x-ray fluoroscopy platform had significantly lower CKAP and CAK indicators than patients for whom baseline settings were used. Mean CKAP decreased by 60% from 438.5 Gy · cm2 (range, 180.3-1,081.1 Gy · cm2) to 175.2 Gy · cm2 (range, 47.1-757.0 Gy · cm2; P < .0001). Mean CAK decreased by 45% from 2,034.2 mGy (range, 699.3-5,056.0 mGy) to 1,109.8 mGy (range, 256.6-4,513.6 mGy; P = .001). No degradation of image quality was identified through qualitative evaluation. CONCLUSIONS: Significant reduction in patient radiation dose indicators can be achieved with use of an optimized image acquisition and processing platform.

Interventional Management of Nonvascular Renal Transplant Complications.

Nonvascular complications represent a significant source of morbidity following renal transplantation and can be seen in up to 20% of patients. Postoperative problems include urinary tract obstruction or leakage and the development of peritransplant fluid collections. Interventional radiologists play a key role in the management of these patients. Image-guided interventions are used to identify the underlying anatomical problem, relieve immediate symptoms, and allow planning for long-term resolution. In this article, we review the urinary tract anatomy relevant to renal transplantation, procedural techniques for image-guided urinary tract interventions and interventions on peritransplant fluid collections, and expected outcomes following image-guided interventions.

Interventional Management of Vascular Renal Transplant Complications.

Renal transplantation is the therapy of choice in patients with end stage renal disease. Although transplant rejection remains the most common complication after renal transplantation, vascular anatomical complications occur in 1%-23% of renal transplant recipients. Interventional radiologists play an important role in the management of these complications. This review discusses the role of image-guided interventions within the context of multidisciplinary patient management. Particular emphasis is given to anatomical considerations unique to this patient population, techniques used for image-guided interventions, and outcomes of image-guided interventions.

Imaging Predictors of Elevated Lung Shunt Fraction in Patients Being Considered for Yttrium-90 Radioembolization.

PURPOSE: To identify imaging findings associated with elevated lung shunt fraction (LSF) in patients being considered for yttrium-90 ((90)Y) radioembolization. MATERIALS AND METHODS: During the period 2009-2014, 152 consecutive patients underwent planning hepatic arteriography with technetium-99m ((99m)Tc) macroaggregated albumin (MAA) injection. Computed tomography (CT) or magnetic resonance imaging performed before the procedure for each patient was assessed for hepatic vein (HV) tumor thrombus or occlusion from external compression by tumor. When imaging was a multiphase CT scan (117 patients), the arterial phase was evaluated for evidence of early HV opacification (relative to unaffected HVs), indicating hepatic venous shunting. These factors were correlated with LSF determined by (99m)Tc-MAA imaging. RESULTS: Median LSF was 6.7% (range, < 0.1%-71%), significantly higher for HCC (8.0% vs 6.3% for other tumors, P = .048). Larger tumor size was associated with higher LSF in univariate analysis (P = .001). There was high interobserver agreement for determining hepatic venous shunting (97%, κ = 0.847), which was associated with higher LSF (P < .001; 78% sensitivity, 93% specificity). Of 5 cases of HV tumor thrombus, all had high (> 20%) LSF (P < .001). HV occlusion was also associated with higher LSF (P = .039). Multivariate analysis confirmed that early HV opacification and either HV tumor thrombus or occlusion were associated with higher LSF. CONCLUSIONS: Early HV opacification and HV tumor thrombus or occlusion on cross-sectional imaging performed before radioembolization are associated with elevated LSF, which may contraindicate or limit the dose delivered in (90)Y radioembolization. This information could be helpful during patient counseling for anticipating the most appropriate mode of liver-directed therapy.

Patient Radiation Dose Reduction during Transarterial Chemoembolization Using a Novel X-Ray Imaging Platform.

PURPOSE: To evaluate radiation dose reduction in patients undergoing transarterial chemoembolization with the use of a new image acquisition and processing platform. MATERIALS AND METHODS: Radiation-dose data were obtained from 176 consecutive chemoembolization procedures in 135 patients performed in a single angiography suite. From January 2013 through October 2013, 85 procedures were performed by using our institution's standard fluoroscopic settings. After upgrading the x-ray fluoroscopy system with an image acquisition and processing platform designed to reduce image noise and reduce skin entrance dose, 91 chemoembolization procedures were performed from November 2013 through December 2014. Cumulative dose-area product (CDAP), cumulative air kerma (CAK), and total fluoroscopy time were recorded for each procedure. Image quality was assessed by three interventional radiologists blinded to the x-ray acquisition platform used. RESULTS: Patient radiation dose indicators were significantly lower for chemoembolization procedures performed with the novel imaging platform. Mean CDAP decreased from 3,033.2 dGy·cm(2) (range, 600.3-9,404.1 dGy·cm(2)) to 1,640.1 dGy·cm(2) (range, 278.6-6,779.9 dGy·cm(2); 45.9% reduction; P < .00001). Mean CAK decreased from 1,445.4 mGy (range, 303.6-5,233.7 mGy) to 971.7 mGy (range, 144.2-3,512.0 mGy; 32.8% reduction; P < .0001). A 20.3% increase in mean total fluoroscopy time was noted after upgrading the imaging platform, but blinded analysis of the image quality revealed no significant degradation. CONCLUSIONS: Although a small increase in fluoroscopy time was observed, a significant reduction in patient radiation dose was achieved by using the optimized imaging platform, without image quality degradation.

A guide to the Interventional Radiology residency program requirements.

The program requirements for the new Interventional Radiology (IR) Residency were approved by the ACGME in September 2014. Soon, training institutions will be able to apply for accreditation and begin enrolling residents. The IR program requirements are long (44 pages) and a bit complex. In addition, some concepts in the program requirements, such as options for integrated or independent formats, may be unfamiliar to the radiology community. In this article, we summarize key concepts and explain important provisions in the IR program requirements. We hope to provide the reader with a firm foundation for understanding the full program requirement document and the application process.

The inferior emissary vein: a reliable landmark for right adrenal vein sampling.

BACKGROUND: Right adrenal vein (RAV) catheterization can be a very challenging step in adrenal venous sampling (AVS). Visualization of the inferior emissary vein (IEV) may be an indication of successful RAV catheterization. PURPOSE: To compare the rate of successful RAV sampling in the presence of the IEV. MATERIAL AND METHODS: Retrospective review of all consecutive patients with PA who underwent AVS between April 2009 and April 2012 was performed. A total of 30 patients were identified. Procedural images, cortisol, and aldosterone values obtained from sampling of the RAV and inferior vena cava (IVC) were reviewed. Cortisol measurements obtained from RAV samples were divided by measurements from the infra-renal IVC blood samples in order to calculate the selectivity index (SI). An SI >3 was considered indicative of technically successful RAV sampling. RESULTS: RAV sampling was considered technically successful in 29 out of 30 cases (97%). In cases of successful RAV sampling (29 patients), the IEV was identified in 25 patients (86%). The IEV was visualized in isolation in 16 patients (64%), and in conjunction with visualization of the RAV or right adrenal gland stain in nine patients (36%). The IEV was not visualized in the one case of unsuccessful RAV sampling. Visualizing the IEV had a sensitivity of 86.2% for successful RAV sampling. CONCLUSION: The IEV may serve as a reliable landmark for the RAV during RAV sampling.