A Novel Polymer-Encapsulated Multi-Imaging Modality Fiducial Marker with Positive Signal Contrast for Image-Guided Radiation Therapy.

BACKGROUND: Current fiducial markers (FMs) in external-beam radiotherapy (EBRT) for prostate cancer (PCa) cannot be positively visualized on magnetic resonance imaging (MRI) and create dose perturbation and significant imaging artifacts on computed tomography (CT) and MRI. We report our initial experience with clinical imaging of a novel multimodality FM, NOVA. METHODS: We tested Gold Anchor [G-FM], BiomarC [carbon, C-FM], and NOVA FMs in phantoms imaged with kilovoltage (kV) X-rays, transrectal ultrasound (TRUS), CT, and MRI. Artifacts of the FMs on CT were quantified by the relative streak artifacts level (rSAL) metric. Proton dose perturbations (PDPs) were measured with Gafchromic EBT3 film, with FMs oriented either perpendicular to or parallel with the beam axis. We also tested the performance of NOVA-FMs in a patient. RESULTS: NOVA-FMs were positively visualized on all 4 imaging modalities tested. The rSAL on CT was 0.750 ± 0.335 for 2-mm reconstructed slices. In F-tests, PDP was associated with marker type and depth of measurement (p < 10-6); at 5-mm depth, PDP was significantly greater for the G-FM (12.9%, p = 10-6) and C-FM (6.0%, p = 0.011) than NOVA (4.5%). EBRT planning with MRI/CT image co-registration and daily alignments using NOVA-FMs in a patient was feasible and reproducible. CONCLUSIONS: NOVA-FMs were positively visible and produced less PDP than G-FMs or C-FMs. NOVA-FMs facilitated MRI/CT fusion and identification of regions of interest.

Utilization of Endovascular and Surgical Treatments for Symptomatic Uterine Leiomyomas: A Population Health Perspective.

PURPOSE: To conduct a population-level analysis of surgical and endovascular interventions for symptomatic uterine leiomyomata by using administrative data from outpatient medical encounters. MATERIALS AND METHODS: By using administrative data from all outpatient hospital encounters in California (2005-2011) and Florida (2005-2014), all patients in the outpatient setting with symptomatic uterine leiomyomata were identified. Patients were categorized as undergoing hysterectomy, myomectomy, uterine artery embolization (UAE), or no intervention. Hospital stay durations and costs were recorded for each encounter. RESULTS: A total of 227,489 patients with uterine leiomyomata were included, among whom 39.9% (n = 90,800) underwent an intervention, including hysterectomy (73%), myomectomy (19%), or UAE (8%). The proportion of patients undergoing hysterectomy increased over time (2005, hysterectomy, 53.2%; myomectomy, 26.9%; UAE, 18.0%; vs 2013, hysterectomy, 80.1%; myomectomy, 14.4%; UAE, 4.0%). Hysterectomy was eventually performed in 3.5% of patients who underwent UAE and 4.1% who underwent myomectomy. Mean length of stay following hysterectomy was significantly longer (0.5 d) vs myomectomy (0.2 d) and UAE (0.3 d; P < .001 for both). The mean encounter cost for UAE ($3,772) was significantly less than those for hysterectomy ($5,409; P < .001) and myomectomy ($6,318; P < .001). Of the 7,189 patients who underwent UAE during the study period, 3.5% underwent subsequent hysterectomy. CONCLUSIONS: The proportion of women treated with hysterectomy in the outpatient setting has increased since 2005. As a lower-cost alternative with a low rate of conversion to hysterectomy, UAE may be an underutilized treatment option for patients with uterine leiomyomata.

Transjugular Intrahepatic Portosystemic Shunts Reduce Variceal Bleeding and Improve Survival in Patients with Cirrhosis: A Population-Based Analysis.

PURPOSE: To investigate from a population health perspective the effects of transjugular intrahepatic portosystemic shunt (TIPS) creation on recurrent variceal bleeding and survival in patients with cirrhosis. MATERIALS AND METHODS: Patients with cirrhosis who presented to outpatient and acute-care hospitals in California (2005-2011) and Florida (2005-2014) with variceal bleeding comprised the study cohort. Patients entered the study cohort at their first presentation for variceal bleeding; all subsequent hospital encounters were then evaluated to determine subsequent interventions, complications, and mortality data. RESULTS: A total of 655,577 patients with cirrhosis were identified, of whom 42,708 (6.5%) had at least 1 episode of variceal bleeding and comprised the study cohort. The median follow-up time was 2.61 years. A TIPS was created in 4,201 (9.8%) of these patients. There were significantly greater incidences of coagulopathy (83.9% vs 72.8%; P < .001), diabetes (45.5% vs 38.8%; P < .001), and hepatorenal syndrome (15.3% vs 12.5%; P < .001) in TIPS recipients vs those without a TIPS. Following propensity-score matching, TIPS recipients were found to have improved overall survival (82% vs 77% at 12 mo; P < .001) and a lower rate of recurrent variceal bleeding (88% vs 83% recurrent bleeding-free survival at 12 months,; P < .001) than patients without a TIPS. Patients with a TIPS had a significant increase in encounters for hepatic encephalopathy vs those without (1.01 vs 0.49 per year; P < .001). CONCLUSIONS: TIPS improves recurrent variceal bleeding rates and survival in patients with cirrhosis complicated by variceal bleeding. However, TIPS creation is also associated with a significant increase in hepatic encephalopathy.

Changes in inferior vena cava filter placement and retrieval practice patterns from a population health perspective.

PURPOSE: Inferior vena cava (IVC) filters are placed to reduce venous thromboembolism (VTE)-related morbidity and mortality, though the evidence supporting this practice is limited. In 2010, the Food and Drug Administration (FDA) released a device safety advisory due to the risk of filter migration, fracture, and thrombosis with long-term use. The purpose of this study was to evaluate trends and predictors for IVCF placement and retrieval over a 10-year time period from a population health perspective. MATERIALS AND METHODS: De-identified patient information from the State Inpatient Databases (SID) and the States Ambulatory Surgery and Services Databases (SASD) for Florida and California were used to identify all patients who underwent IVC filter placement from 2005 to 2014 and 2005 to 2011, respectively. Hospital practice patterns were assessed as a function of time as well as IVC filter placement and retrieval volume. Temporal trends were evaluated for statistical significance using the Cochran-Armitage test. RESULTS: A total of 181,260 IVC filters were placed in 178,327 patients over the study period. IVC filter placements peaked in 2010; following the FDA advisory in 2010, however, IVC filter placements monotonically decreased each subsequent year. The proportion of IVCF placement patients with both acute DVT and PE (17.6% vs 11.8%, P < 0.001) at the time of hospitalization increased; likewise, the proportion of IVCF patients with acute DVT or PE with a concomitant acute contraindication to anticoagulation at the time of hospitalization increased as well following 2010 (17.0% vs 11.9%, P < 0.001). From 2005 to 2014, there was a continual increase in both filter retrieval procedures as well overall percentage of filters retrieved. However, estimated retrieval rates remained low, with a retrieval rate of less than 6% in 2014. CONCLUSION: Following the FDA warning in 2010, there was a significant decrease in IVC filter placements, with filter placements more frequently performed in patients with poorer health. While retrieval rates increased over time, they remained low.

Interventional oncology: pictorial review of post-ablation imaging of liver and renal tumors.

Percutaneous image-guided ablation is now commonly performed in many institutions for the treatment of hepatocellular carcinoma, liver metastases, and renal cell carcinoma in select patients. Accurate interpretation of post-ablation imaging is of supreme importance because treatment algorithms for these diseases rely heavily on imaging to guide management decisions. The purpose of this pictorial essay is to provide abdominal imagers with a review of the indications for percutaneous ablation in the abdomen, a basic overview of ablation modalities in clinical use today, the expected post-ablation imaging findings in the liver and kidney, and potential complications of hepatic and renal ablation procedures.

Variability in evolution and course of gunshot injuries to the neck and impact on management. A case report.

This study reports the differences in evolution and course of multiple pseudoaneurysms (PAs) and an axillary arteriovenous fistula (AVF) after penetrating vascular trauma due to shotgun injury to the head and neck. We describe the unusual case of a young man who, following penetrating shotgun injuries to the head and neck, developed multiple PAs of the common carotid, vertebral and superficial temporal arteries as well as an axillary AVF. Serial angiographic follow-up studies documented differences in time of occurrence, evolution and course of these lesions. This allowed for tailored management using endovascular (AVF, superficial temporal artery PAs) and conservative (carotid and vertebral PAs) treatment. No complication occurred and complete cure of all lesions was achieved and documented after seven months. Time of occurrence, evolution and regression of penetrating vascular injuries can differ significantly even in the same patient. Close angiographic follow-up helps not only detect a lesion with delayed occurrence, but also provides a practical basis for decision-making for optimal therapeutic management.

Clinically oriented three-year medical physics curriculum: a new design for the future.

OBJECTIVE: Medical physics instruction for diagnostic radiology residency at our institution has been redesigned with an interactive and image-based approach that encourages clinical application. The new medical physics curriculum spans the first 3 years of radiology residency and is integrated with the core didactic curriculum. CONCLUSION: Salient features include clinical medical physics conferences, fundamentals of medical physics lectures, practicums, online modules, journal club, and a final review before the American Board of Radiology core examination.

III-nitride core­shell nanowire arrayed solar cells.

A solar cell based on a hybrid nanowire­film architecture consisting of a vertically aligned array of InGaN/GaN multi-quantum well core­shell nanowires which are electrically connected by a coalesced p-InGaN canopy layer is demonstrated. This unique hybrid structure allows for standard planar device processing, solving a key challenge with nanowire device integration, while enabling various advantages by the nanowire absorbing region such as higher indium composition InGaN layers by elastic strain relief, more efficient carrier collection in thinner layers, and enhanced light trapping from nano-scale optical index changes. This hybrid structure is fabricated into working solar cells exhibiting photoresponse out to 2.1 eV and short-circuit current densities of ~1 mA cm(-2) under 1 sun AM1.5G. This proof-of-concept nanowire-based device demonstrates a route forward for high-efficiency III-nitride solar cells.

Laparoscopic sleeve gastrectomy: a guide to postoperative anatomy and complications.

The purpose of this pictorial essay is to review the surgical technique, postoperative anatomy, and potential complications of the laparoscopic sleeve gastrectomy. As the laparoscopic sleeve gastrectomy becomes an increasingly popular bariatric surgery, it is important for radiologists to familiarize themselves with the procedure and possible complications.

Evaluation of a new, rapid test for detecting HCV infection, suitable for use with blood or oral fluid.

The availability of a highly accurate, rapid, point-of-care test for hepatitis C virus (HCV) may be useful in addressing the problem of under-diagnosis of HCV, by increasing opportunities for testing outside of traditional clinical settings. A new HCV rapid test device (OraQuick® HCV Rapid Antibody Test), approved recently in Europe for use with venous blood, fingerstick blood, serum, plasma, or oral fluid was evaluated in a multi-center study and performance compared to established laboratory-based tests for detection of HCV. The HCV rapid test was evaluated in prospective testing of subjects with signs and/or symptoms of hepatitis, or who were at risk for hepatitis C using all 5 specimen types. Performance was assessed relative to HCV serostatus established by laboratory methods (EIA, RIBA and PCR) approved in Europe for diagnosis of hepatitis C infection. Sensitivity to antibody in early infection was also compared to EIA in 27 seroconversion panels. In addition, the reliability of the oral fluid sample for accurate detection of anti-HCV was assessed by studying the impact of various potentially interfering conditions of oral health, use of oral care products and consumption of food and drink. In this large study of at-risk and symptomatic persons, the overall specificities of the OraQuick® HCV Rapid Antibody Test were equivalent (99.6-99.9%) for all 5 specimen types and the 95% CIs substantially overlapped. Overall sensitivities were virtually identical for venous blood, fingerstick blood, serum and plasma (99.7-99.9%). Observed sensitivity was slightly lower for oral fluid at 98.1% though the upper CI (99.0%) was equal to the lower CI for venous blood and fingerstick blood. Most of the HCV positive subjects which gave nonreactive results in oral fluid had serological and virological results consistent with resolved infection. Sensitivity for anti-HCV in early seroconversion was virtually identical between the HCV rapid test and EIA. Detection of anti-HCV in oral fluid appeared generally robust to conditions of oral health, consumption of food and drink and use of oral care products. The OraQuick® HCV Rapid Antibody Test demonstrated clinical performance that was equivalent to current laboratory-based EIA. This new, HCV rapid test appears suitable as an aid in the diagnosis of HCV infection and may increase testing opportunities due to its simplicity and flexibility to use multiple specimen types, including fingerstick blood and oral fluid.

Optical performance of top-down fabricated InGaN/GaN nanorod light emitting diode arrays.

Vertically aligned InGaN/GaN nanorod light emitting diode (LED) arrays were created from planar LED structures using a new top-down fabrication technique consisting of a plasma etch followed by an anisotropic wet etch. The wet etch results in straight, smooth, well-faceted nanorods with controllable diameters and removes the plasma etch damage. 94% of the nanorod LEDs are dislocation-free and a reduced quantum confined Stark effect is observed due to reduced piezoelectric fields. Despite these advantages, the IQE of the nanorod LEDs measured by photoluminescence is comparable to the planar LED, perhaps due to inefficient thermal transport and enhanced nonradiative surface recombination.

Evaluation of a new enzyme-linked immunosorbent assay for detection of Chagas antibody in US blood donors.

BACKGROUND: Chagas disease, caused by the parasite Trypanosoma cruzi, represents a serious blood safety problem due to increasing immigration from Latin America. The Food and Drug Administration recently recommended implementation of Chagas antibody screening for US donors as soon as a suitable assay is licensed. An anonymized preclinical study of a prototype T. cruzi lysate-based enzyme-linked immunosorbent assay (ELISA) developed by Ortho-Clinical Diagnostics was conducted. STUDY DESIGN AND METHODS: Two populations of specimens were evaluated: 1) 10,192 sequential donations from blood donors residing in the El Paso, Texas, area and 2) 178 specimens from South America which were presumptively positive for antibodies to T. cruzi and purchased from commercial vendors. RESULTS: A total of 10,189 (99.97%) of the 10,192 screened donor specimens did not react, whereas 3 (0.03%) tested initially reactive. The 3 initially reactive specimens tested repeat reactive and were confirmed by radioimmunoprecipitation analysis (RIPA). Based on antibody profile analysis, 2 of the 3 Chagas-positive specimens were from the same donor. Observed specificity of the test was therefore 100 percent. Of the specimens from South America, 173 of 178 were reactive by the prototype ELISA. Of the 5 nonreactive specimens, all did not react by indirect fluorescence assay, but 4 were positive by RIPA. Therefore, calculated sensitivity of the ELISA was 97.7 percent (173/177). CONCLUSIONS: These studies indicate that the prototype ELISA has excellent sensitivity and specificity for detection of antibodies to T. cruzi in donors. Moreover, among donations from a geographically selected collection region of the United States, observed seroprevalence was 0.03 percent.

Impact of HCV 3.0 EIA relative to HCV 2.0 EIA on blood-donor screening.

BACKGROUND: In 1996, the Ortho HCV Version 3.0 ELISA Test System (HCV 3.0 EIA) was licensed in the United States for donor screening but was neither mandated nor universally implemented. Data from two studies comparing the differential performance of HCV 3.0 EIA and HCV 2.0 EIA are presented. The first study evaluated the differential performance in a cross-section of screened whole-blood donors after implementation of HCV 3.0 EIA; the second study evaluated the differential performance of HCV 3.0 EIA in plasma donors acutely infected with HCV, identified during routine Abbott HCV 2.0 EIA and HCV NAT (using Roche Ampliscreen plate assay) donor screening. STUDY DESIGN AND METHODS: The first study evaluated HCV 3.0 EIA repeat-reactive donations from four US blood centers, identified during the first 5 months of HCV 3.0 EIA implementation. HCV EIA repeat-reactive donations confirmed by RIBA HCV 3.0 SIA were retested using both Ortho HCV Version 2.0 ELISA Test System and Abbott HCV 2.0 EIA. All EIA-discordant donations were tested by polymerase chain reaction (PCR). In the second study, Abbott HCV 2.0 EIA-nonreactive, HCV PCR-positive donors were enrolled in a follow-up study in which the index and follow-up samples were re-evaluated by HCV 3.0 EIA. RESULTS: In the first study, of 292,459 donations, 501 (0.17%) confirmed HCV 3.0 EIA-reactive donations were identified; 15 (0.005%) were nonreactive by Ortho HCV 2.0 EIA and were all HCV RNA negative. In the second study, Ortho HCV 3.0 EIA retesting of Abbott HCV 2.0 EIA-nonreactive, RNA-positive index donations identified 16 (23%) as 3.0 EIA reactive. In 42 panels with a discordant time of seroconversion, HCV 3.0 EIA sero-conversion preceded HCV 2.0 EIA in all cases (p < 0.001). Two donors with HCV 3.0 EIA-reactive index donations never seroconverted by HCV 2.0 EIA during 160 to 180 days of follow-up. CONCLUSION: These studies demonstrate that HCV 3.0 EIA compared to HCV 2.0 EIA can better detect 1) remote nonviremic HCV infections, 2) acute infection, and 3) HCV antibodies in cases of atypical seroconversion.