Publications by authors named "Alex Wallace"

Purpose: To assess the safety and effectiveness of percutaneous transsplenic access (PTSA) for portal vein (PV) interventions among patients with PV disease.

Materials And Methods: Adult patients with PV disease were enrolled if they required percutaneous catheterization for PV angioplasty, embolization, thrombectomy, variceal embolization, or transjugular intrahepatic portosystemic shunt (TIPS) placement for a difficult TIPS or recanalization of a chronically occluded PV. The procedures were performed between January 2018 and January 2023.

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Purpose: Percutaneous thermal ablation is an effective treatment for primary and metastatic liver tumors and is a recommended local therapy for early-stage hepatocellular carcinoma (HCC). Reported evidence shows an increase in the ablation zone volume over the first 24-h post-liver ablation. This report compares ablation zone volumes immediately at the completion (T = 0) of 26 microwave ablations of liver tumors to 24-h post-procedure (T = 24) volumes.

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Purpose: To demonstrate the safety and effectiveness of percutaneous transesophageal gastrostomy (PTEG) as a palliative option in patients with malignant bowel obstructions (MBOs), and provide a comprehensive review of PTEG indications, placement technique, and short- and long-term outcomes.

Materials And Methods: Thirty-eight consecutive patients who underwent a PTEG procedure attempt from 2014 to 2022 were included in this analysis. Clinical indications, method of placement, technical and clinical success, adverse events, including procedure-related mortality, and effectiveness were assessed.

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Liver transplant remains the definitive therapy for patients with end-stage liver disease. Outcomes have continued to improve, in part owing to interventions used to treat posttransplant complications involving the hepatic arteries, portal vein, hepatic veins or inferior vena cava (IVC), and biliary system. Significant hepatic artery stenosis can be treated with angioplasty or stent placement to prevent thrombosis and biliary ischemic complications.

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Background: The Adolescent Brain Cognitive Development ™ Study (ABCD Study®) is an open-science, multi-site, prospective, longitudinal study following over 11,800 9- and 10-year-old youth into early adulthood. The ABCD Study aims to prospectively examine the impact of substance use (SU) on neurocognitive and health outcomes. Although SU initiation typically occurs during teen years, relatively little is known about patterns of SU in children younger than 12.

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Purpose: Island blocking occurs in single-isocenter multiple-target (SIMT) stereotactic radiotherapy (SRS) whenever targets share multi-leaf collimator (MLC) leaf pairs. This study investigated the effect on plan quality and delivery, of reducing island blocking through collimator angle optimization (CAO). In addition, the effect of jaw tracking in this context was also investigated.

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Ergonomic research in the field of interventional radiology remains limited. Existing literature suggests that operators are at increased risk for work-related musculoskeletal disorders related to the use of lead garments and incomplete knowledge of ergonomic principles. Data from existing surgical literature suggest that musculoskeletal disorders may contribute to physician burnout and female operators are at a higher risk of developing musculoskeletal disorders.

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Introduction: Acute hypoxaemic respiratory failure (AHRF) in children is the most frequent reason for non-elective hospital admission. During the initial phase, AHRF is a clinical syndrome defined for the purpose of this study by an oxygen requirement and caused by pneumonia, lower respiratory tract infections, asthma or bronchiolitis. Up to 20% of these children with AHRF can rapidly deteriorate requiring non-invasive or invasive ventilation.

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Hepatocellular carcinoma (HCC) is the most common form of primary liver cancer and affects millions worldwide. Due to the lack of effective systemic therapies for HCC, researchers have been investigating the use of locoregional tumor control with Yttrium-90 (Y90) radioembolization since the 1960s. Following the development of glass and resin Y90 microspheres in the early 1990s, Y90 radioembolization has been shown to be a safe and efficacious treatment for patients with HCC across Barcelona Clinic Liver Cancer (BCLC) stages.

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Lower extremity peripheral arterial disease (PAD) is a chronic, debilitating disease with a significant global burden. A number of diagnostic imaging techniques exist, including computed tomography angiography (CTA) and contrast-enhanced magnetic resonance angiography (CEMRA), to aid in PAD diagnosis and subsequent treatment planning. Due to concerns of renal toxicity or nephrogenic systemic fibrosis (NSF) for iodinated and gadolinium-based contrasts, respectively, a number of non-enhanced MRA (NEMRA) protocols are being increasingly used in PAD diagnosis.

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Acute limb ischemia (ALI), a subclass of critical limb ischemia, is a medical emergency. The cause of ALI is usually thrombotic or embolic in nature, and the specific etiology often dictates the appropriate therapy. While the diagnosis is a clinical with common presenting symptoms, advances in ultrasound, computed tomography, and magnetic resonance technology have impacted the diagnosis and subsequent therapy.

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Deep vein thrombosis (DVT) is a major preventable cause of morbidity and mortality worldwide. Venous thromboembolism (VTE), which includes DVT and pulmonary embolism (PE), affects an estimated 1 per 1,000 people and contributes to 60,000-100,000 deaths annually. Normal blood physiology hinges on a delicate balance between pro- and anti-coagulant factors.

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Central venous catheters (CVCs) are ubiquitous in the healthcare industry and carry two common complications, catheter related infections and occlusion, particularly by thrombus. Catheter-related bloodstream infections (CRBSI) are an important cause of nosocomial infections that increase patient morbidity, mortality, and hospital cost. Innovative design strategies for intravenous catheters can help reduce these preventable infections.

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Deep venous thrombosis (DVT) is a significant medical problem with an incidence of 1 in 1,000 adults and greatly reduces quality of life through post-thrombotic syndrome. Treatment choice for DVT can be influenced by the age of the clot. While new endovascular catheter techniques treat venous clots to potentially prevent post-thrombotic syndrome, they require improved imaging techniques to accurately determine clot age.

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The anti-inflammatory effects of statins have likely not been used to their fullest extent, particularly in reducing venous thromboembolic events. Current therapy for thrombotic events hinges on anticoagulation via heparin, warfarin or new oral anticoagulants. Interventional procedures with thrombectomy may also play a critical role.

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Venous thrombosis (VT) is a prevalent clinical condition with significant adverse sequela or mortality. Anticoagulation and pharmacologic or pharmacomechanical thrombolytic therapies are the mainstays of VT treatment. An understanding of thrombosis biology will allow for more effective VT-tailored diagnosis and therapy.

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Background: Guidelines are lacking for isolated below-knee deep vein thrombosis (BKDVT). The American College of Chest Physicians (ACCP) suggests anticoagulation only if symptoms are severe, otherwise surveillance with follow-up ultrasound in 2 weeks is recommended. Yet clinical practice remains highly variable.

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Genotype, particularly Ras status, greatly affects prognosis and treatment of liver metastasis in colon cancer patients. This pilot aimed to apply word frequency analysis and a naive Bayes classifier on radiology reports to extract distinguishing imaging descriptors of wild-type colon cancer patients and those with v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations. In this institutional-review-board-approved study, we compiled a SNaPshot mutation analysis dataset from 457 colon adenocarcinoma patients.

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Venous thromboembolism (VTE), a disease that includes deep venous thrombosis (DVT) and pulmonary embolism (PE), is associated with high mortality, morbidity, and costs. It can result in long-term complications that include postthrombotic syndrome (PTS) adding to its morbidity. VTE affects 1/1000 patients, costs $13.

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A gas monitor detector was implemented and characterized at the Soft X-ray Research (SXR) instrument to measure the average, absolute and pulse-resolved photon flux of the LCLS beam in the energy range between 280 and 2000 eV. The detector is placed after the monochromator and addresses the need to provide reliable absolute pulse energy as well as pulse-resolved measurements for the various experiments at this instrument. This detector provides a reliable non-invasive measurement for determining flux levels on the samples in the downstream experimental chamber and for optimizing signal levels of secondary detectors and for the essential need of data normalization.

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The LCLS beam provides revolutionary capabilities for studying the transient behavior of matter in extreme conditions. The particular strength of the Matter in Extreme Conditions instrument is that it combines the unique LCLS beam with high-power optical laser beams, and a suite of dedicated diagnostics tailored for this field of science. In this paper an overview of the beamline, the capabilities of the instrumentation, and selected highlights of experiments and commissioning results are presented.

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Background: Illicit drug overdose deaths (IDD) relate to individual drug dose and context of use, including use with other drugs and alcohol. IDD peaked in British Columbia (BC) in 1998 with 417 deaths, and continues to be a public health problem. The objective of this study was to examine IDD in 2006 in BC by place of residence, injury and death, decedents' age and sex and substances identified.

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