John M. Racadio

Inferior vena cava filters in children: our experience and suggested guidelines.

Although use of inferior vena cava (IVC) filters for prophylaxis against pulmonary embolism (PE) is well reported in adults, long-term studies in children are lacking. We performed retrospective review of imaging and clinical database of IVC filters for the last 12 years. Thirty-five patients (mean age: 15.5 y) underwent filter placement and/or retrieval. Indications for placement were contraindication to anticoagulation with known deep venous thrombosis (DVT) (18) or high risk of venous thromboembolism (5), recurrent DVT despite anticoagulation (1), and prophylaxis before endovascular thrombolysis (8). All filter placements were technically successful without any complications. Filter retrieval was successful in 15 of 19 attempted (79%) at a mean of 42 days. Two complications occurred during retrieval: IVC stenosis successfully treated with angioplasty and contained IVC perforation. Endothelialization of filter prevented retrieval in 4 patients. Mean follow-up was 29.3 months. No patients had IVC thrombosis, breakthrough pulmonary embolism, filter fracture, or embolism. Two patients had recurrent DVT. Our results indicate that IVC filters can be successfully placed and retrieved in children with minimal procedural complications; follow-up demonstrates acceptable complication rate owing to presence of filters. Prophylactic IVC filter placement may be considered before endovascular thrombolysis for lower extremity DVT. Retrievable filters should be used in children for appropriate indications.

Post‐biopsy renal arteriovenous fistula

Abstract:

Is Hand Injection of Central Venous Catheters for Contrast-Enhanced CT Safe in Children?

OBJECTIVE Our objective is to review our safety experience with hand injection of central venous catheters for administration of i.v. contrast material for CT in children. CONCLUSION Administration of i.v. contrast material by means of hand injection led to damage of four central venous catheters during a 6-year period at our institution (0.3% of central venous catheters hand injected during that time). In addition to the growing evidence of the safety of power injection of i.v. contrast material in central venous catheters, the potential danger of hand injection of central venous catheters should be considered when policies are made concerning the delivery of i.v. contrast material via central venous catheters.

Imaging and Radiological Interventional Techniques for Gastrointestinal Bleeding in Children

Causes of pediatric gastrointestinal (GI) bleeding in children are numerous. The role of radiology in defining associated pathology, pinpointing the bleeding site, and intervening to control hemorrhage is discussed here. Barium studies, computed tomography (CT), and magnetic resonance imaging (MRI) each may play a role in identifying the underlying pathology associated with the bleeding. The exact source of bleeding may be localized by means of nuclear scintigraphy as well as selective angiography. In cases of life-threatening or persistent hemorrhage, once a bleeding source is identified, the interventional radiologist may offer percutaneous transcatheter therapy with selective intraarterial vasopressin infusion or embolotherapy.

Surgical Navigation Technology Based on Augmented Reality and Integrated 3D Intraoperative Imaging: A Spine Cadaveric Feasibility and Accuracy Study.

Study Design. A cadaveric laboratory study. Objective. The aim of this study was to assess the feasibility and accuracy of thoracic pedicle screw placement using augmented reality surgical navigation (ARSN). Summary of Background Data. Recent advances in spinal navigation have shown improved accuracy in lumbosacral pedicle screw placement but limited benefits in the thoracic spine. 3D intraoperative imaging and instrument navigation may allow improved accuracy in pedicle screw placement, without the use of x-ray fluoroscopy, and thus opens the route to image-guided minimally invasive therapy in the thoracic spine. Methods. ARSN encompasses a surgical table, a motorized flat detector C-arm with intraoperative 2D/3D capabilities, integrated optical cameras for augmented reality navigation, and noninvasive patient motion tracking. Two neurosurgeons placed 94 pedicle screws in the thoracic spine of four cadavers using ARSN on one side of the spine (47 screws) and free-hand technique on the contralateral side. X-ray fluoroscopy was not used for either technique. Four independent reviewers assessed the postoperative scans, using the Gertzbein grading. Morphometric measurements of the pedicles axial and sagittal widths and angles, as well as the vertebrae axial and sagittal rotations were performed to identify risk factors for breaches. Results. ARSN was feasible and superior to free-hand technique with respect to overall accuracy (85% vs. 64%, P < 0.05), specifically significant increases of perfectly placed screws (51% vs. 30%, P < 0.05) and reductions in breaches beyond 4 mm (2% vs. 25%, P < 0.05). All morphometric dimensions, except for vertebral body axial rotation, were risk factors for larger breaches when performed with the free-hand method. Conclusion. ARSN without fluoroscopy was feasible and demonstrated higher accuracy than free-hand technique for thoracic pedicle screw placement. Level of Evidence: N/A

Estimates of Diagnostic Reference Levels for Pediatric Peripheral and Abdominal Fluoroscopically Guided Procedures

OBJECTIVE The objective of our study was to survey radiation dose indexes of pediatric peripheral and abdominal fluoroscopically guided procedures from which estimates of diagnostic reference levels (DRLs) can be proposed for both a standard fluoroscope and a novel fluoroscope with advanced image processing and lower radiation dose rates. MATERIALS AND METHODS Radiation dose structured reports were retrospectively collected for 408 clinical pediatric cases: Half of the procedures were performed with a standard imaging technology and half with a novel x-ray technology. Dose-area product (DAP), air Kerma (AK), fluoroscopy time, number of digital subtraction angiography images, and patient mass were collected to calculate and normalize radiation dose indexes for procedures completed with the standard and novel fluoroscopes. RESULTS The study population was composed of 180 and 175 patients who underwent procedures with the standard and novel technology, respectively. The 21 different types of pediatric peripheral and abdominal interventional procedures produced 408 total studies. Median ages, mass and body mass index, fluoroscopy time per procedure, and total number of recorded images for the standard and novel technologies were not statistically different. The area of the x-ray beams was square at the level of the patient with a dimension of 10-13 cm. The dose reduction achieved with the novel fluoroscope ranged from 18% to 51% of the dose required with the standard fluoroscope. The median DAP and AK patient dose indexes were 0.38 Gy · cm(2) and 4.00 mGy, respectively, for the novel fluoroscope. CONCLUSION Estimates of dose indexes of pediatric peripheral and abdominal fluoroscopically guided, clinical procedures should assist in the development of DRLs to foster management of radiation doses of pediatric patients.

Computerized Provider Order Entry with Pager Notification Improves Efficiency in STAT Radiographic Studies and Respiratory Treatments

BACKGROUND The use of computerized provider order entry (CPOE) has been widely linked to improvements in patient safety. We hypothesized that electronic routing of CPOE-generated orders through individual pagers would improve the efficiency of STAT radiographic studies and respiratory treatments. METHODS The study was conducted in two periods before and after implementing pager notification of STAT orders. In the Baseline Period, CPOE-generated STAT orders were communicated to radiology technicians or respiratory therapists through the use of printed orders, manual paging and/or telephone communication. The time to process the order and deliver a radiology result or respiratory treatment was tracked. In the Intervention Period CPOE-generated STAT orders were electronically routed to the radiology technicians or respiratory therapists pager. During both time periods, clinicians completed user satisfaction surveys. RESULTS Using pager notification, there was a significant reduction in radiology technician arrival time (16.8±2.1 vs 7.9±0.7 mins, p<0.001). Similarly there was a significant reduction in the cumulative time required to capture the radiographic image, image availability in the picture archiving and communication system (PACS) and the verbal report from the radiologist (p<0.05). The time required in obtaining a preliminary or final radiographic written report and the total cycle times were not significantly reduced. For STAT respiratory therapy orders there was a significant reduction in the mean time from ordering to administration of respiratory therapy treatments (124.7±14.1 vs 49.8±11.4 minutes, p<0.01). Radiologists, respiratory therapists and ordering clinicians reported improved satisfaction after implementation of pager notification. CONCLUSION Computer-generated orders for STAT radiographic studies and respiratory treatments can be carried out significantly faster through the use of direct pager notification. The implementation of this process has resulted in improved care delivery and widespread clinician satisfaction.

WE‐E‐18A‐10: Comparison of Patient Dose and Vessel Visibility Between Antiscatter Grid Removal and Lower Angiographic Radiation Dose Settings for Pediatric Imaging: A Preclinical Investigation

PURPOSE To define an alternative to antiscatter grid (ASG) removal in angiographic systems which achieves similar patient dose reduction as ASG removal without degrading image quality during pediatric imaging. METHODS This study was approved by the local institution animal care and use committee (IACUC). Six different digital subtraction angiography settings were evaluated that altered the mAs, (100, 70, 50, 35, 25, 17.5% of reference mAs) with and without ASG. Three pigs of 5, 15, and 20 kg (9, 15, and 17 cm abdominal thickness; smaller than a newborn, average 3 yr old, and average 10 year old human abdomen respectively) were imaged using the six dose settings with and without ASG. Image quality was defined as the order of vessel branch that is visible relative to the injected vessel. Five interventional radiologists evaluated all images. Image quality and patient dose were statistically compared using analysis of variance and receiver operating curve (ROC) analysis to define the preferred dose level and use of ASG for a minimum visibility of 2nd or 3rd order branches of vessel visibility. RESULTS ASG grid removal reduces dose by 26% with reduced image quality. Only with the ASG present can 3rd order branches be visualized; 100% mAs is required for 9 cm pig while 70% mAs is adequate for the larger pigs. 2nd order branches can be visualized with ASG at 17.5% mAs for all three pig sizes. Without the ASG, 50%, 35% and 35% mAs is required for smallest to largest pig. CONCLUSION Removing ASG reduces patient dose and image quality. Image quality can be improved with the ASG present while further reducing patient dose if an optimized radiographic technique is used. Rami Nachabe is an employee of Philips Health Care; Keith Strauss is a paid consultant of Philips Health Care.