Validation and initial clinical use of automatic peak skin dose localization with fluoroscopic and interventional procedures.

PURPOSE: To assess the accuracy and initial clinical use of a software tool that automatically maps and records values of skin dose, including peak skin dose (PSD), administered to patients undergoing fluoroscopically guided interventional procedures. MATERIALS AND METHODS: In this retrospective study, the institutional review board determined that this HIPAA-compliant study met the criteria as a quality assurance investigation. Informed consent was waived. After the initial validation and accuracy tests, distributed skin dose and PSD estimates were obtained for fluoroscopically guided interventional procedures performed in the radiology, cardiology, and gastroenterology practice areas between January and October 2011. A total of 605 procedures were performed in 520 patients (64% men; age range, 20-95 years). The accuracy of a skin dose tool to estimate patient dose distribution was verified with phantom studies by using an external dosimeter and direct exposure film. PSD distribution, PSD according to procedure type, and PSD for individual physician operators were assessed. RESULTS: Calculated PSD values agreed within ±9% of that measured by using film dosimetry under the condition of matched-phantom geometry. The area receiving the highest dose (greater than 95% of peak) agreed within ±17%. Of 605 patient procedures, 15 demonstrated PSD greater than 2 Gy, with a maximum PSD of 5.6 Gy. CONCLUSION: Knowledge of the patient skin dose can help direct treatment of patients who were administered relatively high skin dose and may be used to plan future procedures. SUPPLEMENTAL MATERIAL: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12112295/-/DC1.

Primary percutaneous treatment of transplant ureteral strictures using tandem stents.

PURPOSE: To evaluate outcomes of primary (first-occurrence) treatment of renal transplant ureteral strictures using tandem parallel internal double-pigtail stents. MATERIALS AND METHODS: A retrospective electronic chart review, including demographics, medical history, stricture intervention, and outcomes, was performed of patients with renal transplants with first-occurrence ureteral obstructions or leaks reported in a transplant nephrology database over a 4-year period, with a focus on patients treated primarily with tandem stents. RESULTS: Of 27 patients with first-occurrence ureteral obstruction or ureteral leak, 18 (67%) were treated primarily using tandem internal stents, with 15 (83%) of 18 stent-free for a minimum 90 days of follow-up. There was no significant difference between outcomes for male versus female patients (P>.99) or early versus late strictures (P = .53). Urinary tract infections (UTIs) occurred in 14 (78%) of 18 patients with tandem stents in place. Four patients were hospitalized<48 hours with UTI and sepsis; there were no other major complications. CONCLUSIONS: Patients with renal transplants can be successfully managed nonsurgically using tandem ureteral stents for the primary treatment of first-occurrence ureteral stricture. These patients may require more intensive monitoring for UTIs.

Developing Interventional Radiology Anticoagulation Guidelines: Process and Benefits †.

We created, posted, and updated radiology department anticoagulation guidelines and identified various steps in the process, including triggering events, consensus building, legal analysis, education, and distribution of the guidelines to nurses and clinicians. Supporting data collected retrospectively, before and after implementation, included nursing satisfaction survey results and the number of procedure cancellations. After the guidelines were developed and posted, significantly fewer procedures were cancelled, nursing satisfaction was higher, and radiologists performed procedures with less variability. Anecdotally, radiologists had fewer queries about anticoagulation. The development and dissemination of radiologic procedure anticoagulation guidelines should be considered as a departmental quality improvement project.

The accordion sign in the transplant ureter: ramifications during balloon dilation of strictures.

PURPOSE: This study was designed to demonstrate the accordion sign within the transplant ureter and evaluate its ramifications during balloon dilation of strictures. METHODS: A retrospective electronic chart and imaging review included demographic characteristics, procedure reports, and complications of 28 renal transplant patients having ureteral strictures treated with percutaneous balloon dilation reported in our transplant nephrology database during an 8-year period. The accordion sign was deemed present or absent on the basis of an imaging review and was defined as present when a tortuous ureter became kinked and irregular when foreshortened after placement of a wire or a catheter. Procedure-related urine leaks were categorized as occurring at the stricture if within 2 cm; otherwise, they were considered away from the stricture. RESULTS: The accordion sign was associated with a significantly greater occurrence of leaks away from the stricture (P = 0.001) but not at the stricture (P = 0.34). CONCLUSIONS: The accordion sign is an important consideration when performing balloon dilation procedures on transplant ureteral strictures, given the increased risk of leak away from the stricture. Its presence should prompt additional care during wire and catheter manipulations.

Quadrilateral space syndrome: the Mayo Clinic experience with a new classification system and case series.

Quadrilateral space syndrome (QSS) arises from compression or mechanical injury to the axillary nerve or the posterior circumflex humeral artery (PCHA) as they pass through the quadrilateral space (QS). Quadrilateral space syndrome is an uncommon cause of paresthesia and an underdiagnosed cause of digital ischemia in overhead athletes. Quadrilateral space syndrome can present with neurogenic symptoms (pain and weakness) secondary to axillary nerve compression. In addition, repeated abduction and external rotation of the arm is felt to lead to injury of the PCHA within the QSS. This often results in PCHA thrombosis and aneurysm formation, with distal emboli. Because of relative infrequency, QSS is rarely diagnosed on evaluation of athletes with such symptoms. We report on 9 patients who presented at Mayo Clinic with QSS. Differential diagnosis, a new classification system, and the management of QSS are discussed, with a comprehensive literature review. The following search terms were used on PubMed: axillary nerve, posterior circumflex humeral artery, quadrilateral space, and quadrangular space. Articles were selected if they described patients with symptoms from axillary nerve entrapment or PCHA thrombosis, or if related screening or imaging methods were assessed. References available within the obtained articles were also pursued. There was no date or language restriction for article inclusion; 5 studies in languages besides English were reported in German, French, Spanish, Turkish, and Chinese.

Successful coil embolization of circumflex iliac artery pseudoaneurysms following paracentesis.

Abdominal paracentesis complicated by perforation of a penetrating arterial branch is an extremely rare complication. We report 2 patients who presented with abdominal wall pseudoaneurysms following abdominal paracentesis for the evaluation and treatment of their hepatic dysfunction. We subsequently review the treatment modalities and interventions performed in each case.

Direct percutaneous embolization of bleeding stomal varices.

Stomal variceal bleeding can develop in patients with underlying cirrhosis and portal hypertension. Most patients are best treated with transjugular intrahepatic portosystemic shunt (TIPS) creation because this addresses the underlying problem of portal hypertension. However, some patients are not good candidates for TIPS creation because they have end-stage liver disease or encephalopathy. We describe such a patient who presented with recurrent bleeding stomal varices, which was successfully treated with percutaneous coil embolization. The patient had bleeding-free survival for 1 month before death from unrelated causes.

Percutaneous embolization of a lumbar pseudoaneurysm in a patient with type IV Ehlers-Danlos syndrome.

Ehlers-Danlos syndrome (EDS) is a rare hereditary connective tissue disorder. Patients with type IV EDS are prone to develop visceral pseudoaneurysms and aortic aneurysms. Surgical and endovascular interventions are fraught with complications and high morbidity. We present a case of a patient with type IV EDS who presented with a new psoas pseudoaneurysm arising from a hypertrophied lumbar artery which was treated with percutaneous embolization by using n-butyl cyanoacrylate glue and coils.

Percutaneous Thrombin Injection for Treatment of a Splenic Artery Aneurysm.

Splenic artery aneurysms are an uncommon entity and are usually asymptomatic when diagnosed. Treatment is based on size, with aneurysms greater than 2 cm usually undergoing surgical repair. We present a case in which percutaneous thrombin injection was used for treatment of a splenic artery aneurysm.

Popliteal vascular entrapment syndrome caused by a rare anomalous slip of the lateral head of the gastrocnemius muscle.

Popliteal vascular entrapment syndrome can result in calf claudication, aneurysm formation, distal arterial emboli, or popliteal vessel thrombosis. The most commonly reported causes of this syndrome have been anomalies of the medial head of the gastrocnemius muscle as it relates to the course of the popliteal artery. We report two cases of rare anomalous slips of the lateral head of the gastrocnemius muscle causing popliteal vascular entrapment syndrome.

Percutaneous retrieval of a Wallstent from the pulmonary artery following stent migration from the iliac vein.

Wallstents are being used increasingly in conjunction with balloon dilatation for treatment of iliac vein stenosis. Stent misplacement or migration is a complication of the procedure, and may be symptomatic and warrant repositioning or removal. We report the case of a patient whose iliac vein stenosis was managed with two overlapping Wallstents and was complicated by embolization of one stent into the right ventricle (RV) and the other to the pulmonary artery (PA). This article illustrates percutaneous endovascular removal of a migrated stent from the PA using a jugular and femoral approach.

Chemoembolization followed by orthotopic liver transplant for epithelioid hemangioendothelioma.

Hepatic epithelioid hemangioendothelioma (HEHE) is a rare liver tumor with an indolent course relative to other hepatic malignancies. Over the past two decades, primary treatment for these lesions has been defined as resection for localized disease, or transplantation for diffuse and multifocal tumors. No published report to date has described effective pre- or post-operative adjuvant treatment for this disease. In this report, we present the first case of HEHE effectively managed with chemoembolization followed by transplantation, documenting objective tumor response to embolization. Furthermore, diagnosis for this lesion can easily be mistaken, directing management in erroneous directions. This case illustrates diagnostic pitfalls affiliated with the work-up of this tumor.