Publications by authors named "Sebastian McWilliams"

A pulmonary arteriovenous malformation (PAVM) is a fistulous connection between a pulmonary artery and a pulmonary vein that bypasses the normal pulmonary capillary bed resulting in a right-to-left shunt. Because of the potential for paradoxical emboli, PAVMs are treated when their feeding arteries exceed 3 mm or patients are symptomatic. PAVMs are often encountered in patients with suspected hereditary hemorrhagic telangiectasia (HHT).

View Article and Find Full Text PDF

Background And Purpose: Healthcare systems are challenged to provide access to thrombectomy in acute stroke patients. Either the "drip and ship" or "mothership" models result in increased numbers of patients in the endovascular stroke centre (ESC). We describe our approach for a "drip, ship, retrieve and leave" model repatriating patients immediately or within 24 hours of thrombectomy.

View Article and Find Full Text PDF

Purpose: To report the anatomical associations and radiological characteristics of Scimitar syndrome on CT and MR.

Materials And Methods: Retrospective review of the medical records between February 2001 and February 2016 was performed. To identify patients, radiological reports were queried for "Scimitar" or "partial anomalous pulmonary venous return.

View Article and Find Full Text PDF

Rationale And Objectives: The purpose of this study is to quantify the clinical impact of resident-attending discrepancies at a tertiary referral academic radiology residency program by assessing rates of intervention, discrepancy confirmation, recall rate, and management change rate; furthermore, a discrepancy categorization system will be assessed.

Materials And Methods: Retrospective review of the records was performed for n = 1482 discrepancies that occurred in the 17-month study period to assess the clinical impact of discrepancies. Discrepancies were grouped according to a previously published classification system.

View Article and Find Full Text PDF

Radiologists in any practice setting should be prepared to use thoracic magnetic resonance (MR) imaging for noncardiac and nonangiographic applications. This begins with understanding the sequence building blocks that can be used to design effective thoracic MR imaging protocols. In most instances, the sequences used in thoracic MR imaging are adapted from protocols used elsewhere in the body.

View Article and Find Full Text PDF

Objectives: We designed a prospective study to investigate the in-vivo relationship between abdominal body composition and radiation exposure to determine the strongest body composition predictor of dose length product (DLP) at CT.

Methods: Following institutional review board approval, quantitative analysis was performed prospectively on 239 consecutive patients who underwent abdominopelvic CT. DLP, BMI, volumes of abdominal adipose tissue, muscle, bone and solid organs were recorded.

View Article and Find Full Text PDF

Purpose Of Review: The study aimed to illustrate the cardiopulmonary findings of the following collagen vascular diseases on cross-sectional imaging: rheumatoid arthritis, scleroderma (progressive systemic sclerosis), systemic lupus erythematosus, the inflammatory myopathies (polymyositis/dermatomyositis), and Sjögren's syndrome.

Recent Findings: Although collagen vascular diseases can affect any part of the body, interstitial lung disease and pulmonary hypertension are the two most important cardiopulmonary complications and are responsible for the majority of morbidity and mortality in this patient population. Interstitial pneumonia with autoimmune features (IPAF) is a newly described entity that encompasses interstitial lung disease in patients with clinical, serologic, or morphologic features suggestive of but not diagnostic of collagen vascular disease; these patients are thought to have better outcomes than idiopathic interstitial pneumonias.

View Article and Find Full Text PDF

Invasive fungal and fungal-like infections contribute to substantial morbidity and mortality in immunocompromised individuals. The incidence of these infections is increasing-largely because of rising numbers of immunocompromised patients, including those with neutropenia, human immunodeficiency virus, chronic immunosuppression, indwelling prostheses, burns, and diabetes mellitus, and those taking broad-spectrum antibiotics. Invasive fungal pathogens include primary mycotic organisms such as Histoplasma capsulatum, Coccidioides immitis, Blastomyces dermatitidis, and Paracoccidioides brasiliensis, which are true pathogens and inherently virulent.

View Article and Find Full Text PDF

Purpose: To evaluate the safety and effectiveness of cryoablation of musculoskeletal metastases in terms of achieving pain palliation and local tumor control.

Materials And Methods: A retrospective review was performed of 92 musculoskeletal metastases in 56 patients treated with percutaneous image-guided cryoablation. Mean age of the cohort was 53.

View Article and Find Full Text PDF

The purpose of this study was to evaluate the safety, technical success rate, and diagnostic efficacy of drill-assisted axial and appendicular bone biopsies. During a 3-y period, 703 drill-assisted biopsies were performed. The cohort included 54.

View Article and Find Full Text PDF

A tailgut cyst is a rare developmental lesion and usually is located in the retrorectal or presacral space. Extrahepatic hydatid disease has been reported in several locations including the pelvis and it often poses a diagnostic challenge. There are very few reported cases of primary perineal hydatid cysts.

View Article and Find Full Text PDF

Fistulae between the aorta and adjacent structures are a rare, emergent, and potentially life-threatening process. Most commonly, aortic fistulae arise secondarily as a complication of prior aortic surgery with fistulization to adjacent structures. Rarely, a primary fistula may arise from the aorta in the setting of a pre-existing aneurysm or from a mass, inflammation, or infection.

View Article and Find Full Text PDF

Hydatid disease is a zoonotic parasitic disease. The liver is the most commonly affected organ, and hepatic hydatid disease complications are not uncommon. Hydatid cyst superinfection, intrabiliary rupture, and direct rupture into the thoracic or abdominal cavities are the frequently encountered complications.

View Article and Find Full Text PDF

Purpose: To report discrepancy rates for examinations interpreted by on-call residents overall and by resident training level, and to describe a novel discrepancy classification system based on patient location and severity that facilitates recording of discrepancy data, helps ensure proper communication of report changes, and allows our radiology department to assume responsibility for contacting discharged patients with non-time-dependent results.

Methods: A HIPAA-compliant, institutional review board-exempt review of two years (January 2013 to December 2014) of discrepancy data was retrospectively performed for total number of examination interpreted, discrepancy rates, resident training level, and discrepancy categories. Most common diagnoses and means of results communication for discharged patients were also recorded.

View Article and Find Full Text PDF

Rationale And Objectives: The American Alliance of Academic Chief Residents in Radiology conducts an annual survey of chief residents in Diagnostic Radiology programs in North America. The survey serves as a resource for observing trends and disseminating ideas among radiology training programs.

Materials And Methods: An online survey was distributed to chief residents at 181 residency programs, with questions on a broad range of topics including resident benefits, program and call structure, American Board of Radiology Core exam preparation, fellowships, and the job market.

View Article and Find Full Text PDF

Purpose: Computed tomography (CT)-guided core needle biopsy (CNB) can be affected by streak artifact obscuring the needle tip. This study investigates factors that influence the occurrence and severity of streak artifact during CNB.

Materials And Methods: Eight coaxial guide needles of two sizes from two manufacturers with and without stylets were imaged in a CT phantom, with CT reconstructed with adaptive statistical iterative reconstruction and filtered back projection.

View Article and Find Full Text PDF

Objectives: The term functional gastrointestinal disorders (FGID) describes various aggregations of chronic gastrointestinal (GI) symptoms not explained by identifiable organic pathology; accordingly, their diagnosis rests on symptom-based criteria and a process of exclusion. Evidence is lacking on the appropriate use of abdominal imaging studies (AIS) in FGIDs.

Methods: We investigated the utilisation of AIS (site, modality, diagnostic yield/significance) at a tertiary FGID clinic over an 11-year period.

View Article and Find Full Text PDF

Purpose: Preoperative pulmonary assessment is undertaken in patients with resectable lung cancer to identify those at increased risk of perioperative complications. Guidelines from the American College of Chest Physicians indicate that if the FEV(1) and DLCO are ≥60% of predicted, patients are suitable for resection without further evaluation. The aim of our study is to determine if quantitative measures of lung volume and density obtained from pre-operative CT scans correlate with pulmonary function tests.

View Article and Find Full Text PDF

Introduction: This study investigated the optimal Hounsfield unit (HU) threshold range when using threshold-based segmentation to estimate volumes of contained gas (i.e. intestinal gas) on CT.

View Article and Find Full Text PDF

Background & Aims: Magnetic resonance and ultrasonography have increasing roles in the initial diagnosis of Crohn's disease, but computed tomography (CT) with positive oral contrast agents is most frequently used to identify those with acute extramural complications. However, CT involves exposure of patients to radiation. We prospectively compared the diagnostic accuracy of low-dose CT (at a dose comparable to that used to obtain an abdominal radiograph) with conventional-dose CT in patients with active Crohn's disease.

View Article and Find Full Text PDF

Background: Results of previous studies have shown that repeated abdominopelvic computed tomography (CT) examinations can lead to substantial cumulative diagnostic radiation exposure in patients with Crohn's disease (CD). Improved selection of patients referred for CT will reduce unnecessary radiation exposure. This study examines if serum C-reactive protein (CRP) concentration predicts which symptomatic patients with CD are likely to have significant disease activity or disease complications (such as abscess) detected on abdominopelvic CT.

View Article and Find Full Text PDF

Objective: With the increasing life expectancy for patients with cystic fibrosis (CF), and a known predisposition to certain cancers, cumulative radiation exposure from radiologic imaging is of increasing significance. This study explores the estimated cumulative effective radiation dose over a 17-year period from radiologic procedures and changing trends of imaging modalities over this period.

Methods: Estimated cumulative effective dose (CED) from all thoracic and extrathoracic imaging modalities and interventional radiology procedures for both adult and pediatric patients with CF, exclusively attending a nationally designated CF center between 1992-2009 for > 1 year, was determined.

View Article and Find Full Text PDF