A5024221938- Radiation Dose and Imaging
- Advanced X-ray and CT Imaging
- Digital Radiography and Breast Imaging
- Medical Imaging Techniques and Applications
- Advanced Radiotherapy Techniques
- Radiology practices and education
- Radiomics and Machine Learning in Medical Imaging
- Pelvic and Acetabular Injuries
- Spinal Fractures and Fixation Techniques
- Ocular and Laser Science Research
- Kidney Stones and Urolithiasis Treatments
- Dental Implant Techniques and Outcomes
- Dynamics and Control of Mechanical Systems
- Pregnancy-related medical research
- Face recognition and analysis
- Advances in Oncology and Radiotherapy
- COVID-19 and healthcare impacts
- COVID-19 diagnosis using AI
- Advanced MRI Techniques and Applications
- Traumatic Brain Injury and Neurovascular Disturbances
- Eosinophilic Esophagitis
- Advanced machining processes and optimization
- Hip disorders and treatments
- Advanced Neuroimaging Techniques and Applications
- Automotive and Human Injury Biomechanics
University of Washington
2012-2024
University of Washington Medical Center
2019-2021
GE Global Research (United States)
2021
Hospital de Especialidades José Carrasco Arteaga
2020
University of Colorado Denver
2018
Seattle University
2011-2016
The University of Texas MD Anderson Cancer Center
2007-2011
Arizona State University
2004
Purpose To investigate performance in detectability of small (≤1 cm) low-contrast hypoattenuating focal lesions by using filtered back projection (FBP) and iterative reconstruction (IR) algorithms from two major CT vendors across a range 11 radiation exposures. Materials Methods A phantom consisting 21 objects (seven sizes between 2.4 10.0 mm, three contrast levels) embedded into liver-equivalent background was scanned at exposures (volume dose index range, 0.5–18.0 mGy; size-specific...
Objective: Postmortem computed tomography (PMCT) is a procedure fairly unfamiliar to many US radiologists. We embarked on collaboration between the department of radiology and medical examiner’s office (MEO) with purpose introducing PMCT into autopsy workflow goal assisting forensic pathologist decision-making regarding need for in determining cause death. Methods: Establishing this service involved coordination, education, extensive planning involving numerous professionals volunteering...
Background Virtual unenhanced (VUE) images obtained by using a dual-energy CT (DECT) multimaterial decomposition algorithm hold promise for diagnostic use in the abdomen lieu of true (TUE) images. Purpose To assess VUE from DECT patients undergoing renal mass and urinary stone evaluation. Materials Methods In this retrospective Health Insurance Portability Accountability Act–compliant study, was performed evaluation or stone. were compared quantitatively to TUE qualitatively assessed four...
Effective and organ specific doses of ionizing radiation during videourodynamics are unknown. We estimated exposure in children undergoing videourodynamics, identified patient examination factors that contribute to higher dosing.
Beginning with the advent of digital radiography systems in 1981, manufacturers these provided indicators detector exposure. These were manufacturer-specific, and users facilities equipment from multiple found it a challenge to monitor manage variations indicated exposure routine clinical use. In 2008, common definition index (EI) was realized International Electrotechnical Commission (IEC) Standard 62494-1 Ed. 1, which also introduced defined deviation (DI), number quantifying difference...
Purpose: Four‐dimensional computed tomography (4D‐CT) is commonly used to account for respiratory motion of target volumes in radiotherapy the thorax. From 4D‐CT acquisition, a maximum‐intensity projection (MIP) image set can be created and help define tumor envelope or internal gross volume (iGTV). The purpose this study was quantify differences automatically contoured usage delivery stereotactic body radiation therapy using MIP data sets generated from one four methods: (1) phase‐binned...
Iterative reconstruction (IR) techniques are susceptible to contrast-dependent spatial resolution, limiting overall radiation dose reduction potential. Deep learning image (DLIR) may mitigate this limitation.
Abstract Unstable pelvic ring fractures are severe and complex injuries, surgical fixation is challenging can be complicated by early failure due in part to difficulties with securely fixing screws low‐density bone. There limited information the literature about how density distribution across bones changes age sex. In this study, we used 60 sets of calibrated bone measurements obtained opportunistically from clinical computed tomography scans pelvis. Three‐dimensional models innominate were...
The displayed air kerma during a fluoroscopy-guided procedure often does not represent the entrance skin dose. purpose of this work is to develop system-specific kerma-to-entrance dose look-up table (LUT) for immediate reference and evaluate its clinical utility.Physicists are involved in retrospective dosimetry risk estimates. Conservative conversion factors, represented by total factor, prospectively estimate maximum potential from kerma. Air kerma-to-skin LUTs with corresponding tissue...
Contrast curve truncation in CTP protocols may introduce errors. We sought to identify risk factors and design a protocol avoid while limiting radiation.In an initial fixed-timing cohort, patients underwent 65-second with 2-second delay postcontrast injection. Multivariable analysis identified associated truncation. A later case-specific cohort either the original or low cardiac output 7-second 75-second scanning window, selection determined by CTA test-dose enhancement upswing delay....
BACKGROUND. Clinical use of the dual-energy CT (DECT) iodine quantification technique is hindered by between-platform (i.e., across different manufacturers) variability in concentration (IC) values, particularly at low levels. OBJECTIVE. The purpose this study was to develop an anthropomorphic phantom a method for reducing content levels using DECT and evaluate method's performance patients undergoing serial clinical examinations on platforms. METHODS. An three body sizes, incorporating...
Objective To investigate in an anthropomorphic phantom study the accuracy of dual-energy computed tomography (DECT) techniques for fat quantification comparison with magnetic resonance (MR) proton density fraction (PDFF) and single-energy (SECT), using known content as reference standard. Methods Between August 2018 November 2020, organic material-based cylinders, composed mixtures lean tissues mimics, iodine, iron, were constructed to simulate varying levels (0%, 10%, 15%, 25%, 50%, 75%,...
Purpose: We have implemented a commercially available Radiation Exposure Monitoring System (REMS) to enhance the processes of radiation dose data collection, analysis and alerting developed over past decade at our sites practice. REMS allows for consolidation multiple information sources quicker than previously processes. Methods: Thirty‐nine x‐ray producing imaging modalities were interfaced with REMS: thirteen computed tomography scanners, sixteen angiography/interventional systems, nine...
Characterizing changes in sacral bone density could help us to inform instrumentation choices for procedures involving the sacrum. The aim of this study is provide detailed maps across a series patients using opportunistic quantitative computed tomography (QCT). We hypothesized that there would be significant differences local cortical and trabecular associated with age sex. Fifty-four three-dimensional models were segmented from routine clinical scans, estimates derived each calibrated QCT...
The purpose of this article is to illustrate the use American College Radiology Dose Index Registry data with a novel measurement exposure guide quality improvement efforts.Using information from report covering July through December 2012, we examined our relative ranking compared national median CT dose for 20 most frequently performed examinations at institution. total variance, defined as difference between institutional and multiplied by local examination frequency expressed in units...
In Ecuador, there are no epidemiological data on inflammatory bowel disease (IBD). We seek to determine the epidemiology and behavior of IBD in Ecuadorian population. Methods. Descriptive observational study, using clinical records patients diagnosed with IBD, from three referral centers for social insurance, 1990 2018. Results. This study included a total 206 these, 148 ulcerative colitis (UC) 58 Crohn’s (CD). The average age diagnosis both UC CD was 42 years. time onset symptoms 7.5 months...
This study is an initial investigation into methods to harmonize quantitative imaging (QI) feature values across CT scanners based on image quality metrics. To assess the impact of harmonization QI features, we: (1) scanned assessment phantom three over a wide range acquisition and reconstruction conditions; (2) from those scans, assessed for each scanner at condition; (3) these assessments, identified set parameters that yielded similar ("harmonized condition"); (4) second with texture...