Intravascular Ultrasound in the Creation of Transhepatic Portosystemic Shunts Reduces Needle Passes, Radiation Dose, and Procedure Time: A Retrospective Study of a Single-Institution Experience.

PURPOSE: To assess whether intravascular ultrasound (US) guidance impacts number of needle passes, contrast usage, radiation dose, and procedure time during creation of transjugular intrahepatic portosystemic shunts (TIPS). MATERIALS AND METHODS: Intravascular US-guided creation of TIPS in 40 patients was retrospectively compared with conventional TIPS in 49 patients between February 2010 and November 2015 at a single tertiary care institution. Patient sex and age, etiology of liver disease (hepatitis C virus, alcohol abuse, nonalcoholic steatohepatitis), severity of liver disease (mean Model for End-Stage Liver Disease score), and indications for TIPS (variceal bleeding, refractory ascites, refractory hydrothorax) in conventional and intravascular US-guided cases were recorded. RESULTS: The two groups were well matched by sex, age, etiology of liver disease, Child-Pugh class, Model for End-Stage Liver Disease scores, and indication for TIPS (P range = .19-.94). Fewer intrahepatic needle passes were required in intravascular US-guided TIPS creation compared with conventional TIPS (2 passes vs 6 passes, P < .01). Less iodinated contrast material was used in intravascular US cases (57 mL vs 140 mL, P < .01). Radiation exposure, as measured by cumulative dose, dose area product, and fluoroscopy time, was reduced with intravascular US (174 mGy vs 981 mGy, P < .01; 3,793 µGy * m(2) vs 21,414 µGy * m(2), P < .01; 19 min vs 34 min, P < .01). Procedure time was shortened with intravascular US (86 min vs 125 min, P < .01). CONCLUSIONS: Intravascular US guidance resulted in fewer intrahepatic needle passes, decreased contrast medium usage, decreased radiation dosage, and shortened procedure time in TIPS creation.

Radiation Protection for the Fluoroscopy Operator and Staff.

OBJECTIVE: The purposes of this article are to review available data regarding the range of protection devices and garments with a focus on eye protection and to summarize techniques for reducing scatter radiation exposure. CONCLUSION: Fluoroscopy operators and staff can greatly reduce their radiation exposure by wearing properly fitted protective garments, positioning protective devices to block scatter radiation, and adhering to good radiation practices. By understanding the essentials of radiation physics, protective equipment, and the features of each imaging system, operators and staff can capitalize on opportunities for radiation protection while minimizing ergonomic strain. Practicing and promoting a culture of radiation safety can help fluoroscopy operators and staff enjoy long, productive careers helping patients.

Radiation Risk to the Fluoroscopy Operator and Staff.

OBJECTIVE: Recent articles discussing cases of brain cancer in interventionalists have raised concerns regarding the hazards of occupational exposure to ionizing radiation. We review the basics of radiation dose and the potential radiation effects, particularly as they pertain to the operator. Then we present the data regarding the risk of each type of radiation effect to the fluoroscopy operator and staff, with special attention on cancer induction, radiation-induced cataracts, and the pregnant operator. CONCLUSION: Although the evidence overwhelmingly shows that exposure to higher doses of radiation carries a risk of cancer and tissue reactions, the risks of chronic exposure to low-level radiation are less clear. Many studies examining occupational exposure to radiation fail to show an increased risk of stochastic effects of radiation, but the positive results raise concern that the studies are underpowered to consistently detect the small risk. The lack of information in these studies about radiation doses and adherence to radiation protection further confound their interpretation. Large prospective studies of populations with occupational exposure to low-level radiation might clarify this issue. More clearly established are the risks of radiation to the fetus and the risk of cataracts in interventional cardiologists and interventional radiologists. Interventionalists can mitigate these risks by following established radiation safety practices.

Nickel hypersensitivity in patients with inferior vena cava filters: case report and literature and MAUDE database review.

Placement of a prophylactic retrievable inferior vena cava (IVC) filter was requested in a 73-year-old woman with nickel hypersensitivity resulting in a clinical dilemma. Given that all retrievable filters contain nickel, the published literature and the Manufacturer and User Facility Device Experience (MAUDE) database were reviewed; no documented case of IVC filter placement in a patient with nickel hypersensitivity or reported hypersensitivity reaction in a patient after IVC filter placement could be identified. This article presents the uneventful course of the case described and a review of the literature and recommendations on use of nickel-containing devices in patients with nickel hypersensitivity.

Comparative efficacy of new interfaces for intra-procedural imaging review: the Microsoft Kinect, Hillcrest Labs Loop Pointer, and the Apple iPad.

We adapted and evaluated the Microsoft Kinect (touchless interface), Hillcrest Labs Loop Pointer (gyroscopic mouse), and the Apple iPad (multi-touch tablet) for intra-procedural imaging review efficacy in a simulation using MIM Software DICOM viewers. Using each device, 29 radiologists executed five basic interactions to complete the overall task of measuring an 8.1-cm hepatic lesion: scroll, window, zoom, pan, and measure. For each interaction, participants assessed the devices on a 3-point subjective scale (3 = highest usability score). The five individual scores were summed to calculate a subjective composite usability score (max 15 points). Overall task time to completion was recorded. Each user also assessed each device for its potential to jeopardize a sterile field. The composite usability scores were as follows: Kinect 9.9 (out of 15.0; SD = 2.8), Loop Pointer 12.9 (SD = 13.5), and iPad 13.5 (SD = 1.8). Mean task completion times were as follows: Kinect 156.7 s (SD = 86.5), Loop Pointer 51.5 s (SD = 30.6), and iPad 41.1 s (SD = 25.3). The mean hepatic lesion measurements were as follows: Kinect was 7.3 cm (SD = 0.9), Loop Pointer 7.8 cm (SD = 1.1), and iPad 8.2 cm (SD = 1.2). The mean deviations from true hepatic lesion measurement were as follows: Kinect 1.0 cm and for both the Loop Pointer and iPad, 0.9 cm (SD = 0.7). The Kinect had the least and iPad had the most subjective concern for compromising the sterile field. A new intra-operative imaging review interface may be near. Most surveyed foresee these devices as useful in procedures, and most do not anticipate problems with a sterile field. An ideal device would combine iPad's usability and accuracy with the Kinect's touchless aspect.

Informatics in Radiology: developing a touchless user interface for intraoperative image control during interventional radiology procedures.

Review of prior and real-time patient images is critical during an interventional radiology procedure; however, it often poses the challenge of efficiently reviewing images while maintaining a sterile field. Although interventional radiologists can "scrub out" of the procedure, use sterile console covers, or verbally relay directions to an assistant, the ability of the interventionalist to directly control the images without having to touch the console could offer potential gains in terms of sterility, procedure efficiency, and radiation reduction. The authors investigated a potential solution with a low-cost, touch-free motion-tracking device that was originally designed as a video game controller. The device tracks a person's skeletal frame and its motions, a capacity that was adapted to allow manipulation of medical images by means of hand gestures. A custom software program called the Touchless Radiology Imaging Control System translates motion information obtained with the motion-tracking device into commands to review images on a workstation. To evaluate this system, 29 radiologists at the authors' institution were asked to perform a set of standardized tasks during a routine abdominal computed tomographic study. Participants evaluated the device for its efficacy as well as its possible advantages and disadvantages. The majority (69%) of those surveyed believed that the device could be useful in an interventional radiology practice and did not foresee problems with maintaining a sterile field. This proof-of-concept prototype and study demonstrate the potential utility of the motion-tracking device for enhancing imaging-guided treatment in the interventional radiology suite while maintaining a sterile field. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.332125101/-/DC1.

Endovascular treatment of a congenital thoracic aortic aneurysm in a premature newborn.

Congenital aortic aneurysms are a rare, life-threatening disorder that present complex treatment challenges. The authors describe a congenital thoracic aortic aneurysm treated by endovascular means with stent-assisted coil deployment. Because of rapid in utero aneurysm growth and cardiac dysfunction, a 2.6-kg male was delivered expeditiously by Cesarean section at 35(2)/(7) weeks' gestation. On day of life 1, bilateral femoral arterial access was used to deliver a balloon-expandable stent across the wide-necked aneurysm. Microcoil embolization of the aneurysm via a prepositioned microcatheter was then performed. The child had an uncomplicated hospital course and is asymptomatic 5 months later, with complete aneurysm thrombosis.

Improving the tracking and removal of retrievable inferior vena cava filters.

Therapeutic and prophylactic inferior vena cava (IVC) filters should be placed based on currently accepted indications to prevent a fatal pulmonary embolism (PE). The protective effect of filters is offset by the potential for lower extremity deep venous thrombosis (DVT), caval thrombosis, and possible otherwise unnecessary life-long anticoagulation (AC). The duration of treatment for most DVTs or PEs is 3 to 6 months of AC/filter. Filters should be retrieved when duration of treatment for a DVT/PE has been met, the risk of a PE is no longer high, and/or there is no longer a contraindication to AC. An effective system that leads to improving the retrieval rate of filters must include education of the patient, a tracking system to minimize patient lost to follow-up, and dedicated personnel to oversee the process. If these goals are accomplished, interventionalists can help decrease the incidence of a fatal PE during the high-risk period, and also decrease the risk of a DVT or the use of otherwise unnecessary life-long AC in subsequent years. Currently, there is much room for improvement in the frequency that IVCF patients are systematically followed and filters are retrieved. The principles discussed in this report will be helpful in this process.

Optional inferior vena cava filters in the trauma patient.

Trauma patients are at exceedingly high risk of development of venous thromboembolism (VTE) including deep venous thrombosis and pulmonary embolism (PE). The epidemiology of VTE in trauma patients is reviewed. PE is thought to be the third major cause of death after trauma in those patients who survive longer than 24 hours after onset of injury. In fact, patients recovering from trauma have the highest rate of VTE among all subgroups of hospitalized patients. Various prophylactic and surveillance methods have been evaluated and found helpful in certain situations, but VTE complications can occur despite such measures. Therapeutic and prophylactic uses of inferior vena cava (IVC) filters in trauma patients are reviewed. Prophylactic IVC filter use is revealed to be a controversial subject with valid arguments on both sides of the issue. With the lack of prospective randomized trials of IVC filter use in trauma, it is impossible to make evidence-based recommendations. Unfortunately, two sets of guidelines are available for insertion of filters in trauma patients, with conflicting recommendations. The introduction of retrievable IVC filters seems to offer a unique solution for VTE protection in the trauma patient population, which often consists of younger members of our population. Lastly, current generations of FDA-approved retrieval filters are discussed.

Role of interventional radiology in the management of acute gastrointestinal bleeding.

Acute gastrointestinal bleeding (GIB) can lead to significant morbidity and mortality without appropriate treatment. There are numerous causes of acute GIB including but not limited to infection, vascular anomalies, inflammatory diseases, trauma, and malignancy. The diagnostic and therapeutic approach of GIB depends on its location, severity, and etiology. The role of interventional radiology becomes vital in patients whose GIB remains resistant to medical and endoscopic treatment. Radiology offers diagnostic imaging studies and endovascular therapeutic interventions that can be performed promptly and effectively with successful outcomes. Computed tomography angiography and nuclear scintigraphy can localize the source of bleeding and provide essential information for the interventional radiologist to guide therapeutic management with endovascular angiography and transcatheter embolization. This review article provides insight into the essential role of Interventional Radiology in the management of acute GIB.