A5028311559- Bone health and osteoporosis research
- Medical Imaging Techniques and Applications
- Advanced X-ray and CT Imaging
- Hip and Femur Fractures
- Hip disorders and treatments
- Radiation Dose and Imaging
- Bone and Joint Diseases
- Advanced MRI Techniques and Applications
- Orthopaedic implants and arthroplasty
- Cardiac Imaging and Diagnostics
- Bone health and treatments
- Radiomics and Machine Learning in Medical Imaging
- Liver Disease Diagnosis and Treatment
- Radiation Detection and Scintillator Technologies
- Hepatocellular Carcinoma Treatment and Prognosis
- Advanced Semiconductor Detectors and Materials
- Orthopedic Infections and Treatments
- Liver Disease and Transplantation
- Body Composition Measurement Techniques
- Parathyroid Disorders and Treatments
- Pelvic and Acetabular Injuries
- Bone fractures and treatments
- Vasculitis and related conditions
- Colorectal Cancer Screening and Detection
- Meta-analysis and systematic reviews
Healthways (United States)
2008-2020
Beijing Jishuitan Hospital
2019
Peking University
2019
Software (Spain)
2015
University of California, San Francisco
1994-2003
University of California, Berkeley
1997-2002
United States Department of Health and Human Services
2002
National Institutes of Health
2002
National University of Singapore
1993
Major alterations in body composition, such as with obesity and weight loss, have complex effects on the measurement of bone mineral density (BMD) by dual-energy X-ray absorptiometry (DXA). The altered fat quantitative computed tomography (QCT) measurements are unknown. We scanned a spine phantom DXA QCT before after surrounding sequential layers (up to 12 kg). In addition, we measured lumbar proximal femur BMD trabecular 13 adult volunteers simulated 7.5 kg increase fat. With phantom,...
Abstract The anatomic distribution of cortical and cancellous bone in the femoral neck may be critical determining resistance to fracture. We investigated effects aging on women. In this cross-sectional study, we used clinical multidetector computed tomography (MDCT) hips investigate 100 female volunteers aged 20 90 years. developed a clinically efficient protocol measure thickness (C.Th) cortical, trabecular, integral mineral density (CtBMD, TrBMD, iBMD mg/cm3) quadrants neck. nested ANOVA...
Background Although chemical shift-encoded (CSE) MRI proton density fat fraction (PDFF) is the current noninvasive reference standard for liver quantification, more frequently imaged with CT. Purpose To validate quantitative CT measurements of against PDFF standard. Materials and Methods In this prospective study, 400 healthy participants were recruited between August 2015 July 2016. Each participant underwent same-day abdominal unenhanced a calibration phantom CSE 3.0-T MRI. used to...
The authors present experimental results for attenuation correction of emission tomography through use an map derived from X-ray CT data. and gamma-ray data were obtained a third-generation scanner single-headed SPECT Scanner juxtaposed to enable systematic registration Images. measurements known materials at given technique, then related coefficients 140 keV. resulting calibration used generate maps the coregistered In addition, phantom studies provided recovery as function object size...
This study investigates the general use of single-beam X-ray computed tomography (CT) images for generating attenuation maps compensation photon in SPECT images. A 3D mathematical thorax phantom is used to simulate both emission and transmission projection data monoenergetic (radionuclide) polyenergetic (X-ray) sources. Polyenergetic are simulated a standard spectrum fan-beam geometry. The reconstructed using filtered backprojection form an CT image which then scaled produce estimate map at...
To test the performance of dual-energy computed tomography (CT) in assessment marrow adipose tissue (MAT) content lumbar spine by using proton (hydrogen 1 [(1)H]) magnetic resonance (MR) spectroscopy as a reference standard and to determine influence MAT on bone mineral density (BMD).This study was institutional review board approved complied with HIPAA guidelines. Written informed consent obtained. Twelve obese osteopenic but otherwise healthy subjects (mean age ± deviation, 43 years 13)...
Bone mineral density (BMD) estimates for the proximal femur using Dual Energy X-ray Absorptiometry (DXA) are currently considered standard making a diagnosis of osteoporosis in an individual patient BMD alone. We have compared results from commercial Quantitative CT (QCT) analysis system, "CTXA Hip", which provides clinical data femur, to DXA. also used CTXA Hip determine cortical and trabecular contributions total BMD. Sixty-nine patients were scanned 3D QCT measurements Total Femoral Neck...
ABSTRACT For patients undergoing routine contrast-enhanced CT examinations, an opportunity exists for concurrent osteoporosis screening without additional radiation exposure or patient time using proximal femur X-ray absorptiometry (CTXA). We investigated the effect of i.v. contrast enhancement on femoral neck CTXA T-score measurement compared with DXA. This cohort included 355 adults (277 female; mean age, 59.7 ± 13.3 years; range, 21 to 90 years) who underwent standard assessment at 120...
We have developed a prototype emission-transmission computed tomographic (ETCT) system, which can acquire both radionuclide-emission and dual-energy X-ray transmission data. The data are used to synthesize an object- energy-specific attenuation map is incorporated into ML-EM algorithm reconstruct attenuationcorrected SPECT image. technique was applied thoraxlike phantom with regions simulating lung, background cardiac regions, bone. images reconstructed no correction, or uniform...
For patients undergoing contrast-enhanced CT examinations that include the proximal femur, an opportunity exists for concurrent screening bone mineral density (BMD) measurement. We investigated effect of IV contrast enhancement on CT-derived x-ray absorptiometry areal BMD measurement.Our cohort included 410 adults (mean age, 65.3 ± 10.0 years; range, 49-95 years) who underwent split-bolus urography at 120 kVp. Areal femoral neck in g/cm(2) was measured both unenhanced and series with...
ABSTRACT Pediatric Crohn's Disease (CD) is associated with low trabecular bone mineral density (BMD), cortical area, and muscle mass. Low-magnitude mechanical stimulation (LMMS) may be anabolic. We conducted a 12-month randomized double-blind placebo-controlled trial of 10 minutes daily exposure to LMMS (30 Hz frequency, 0.3 g peak-to-peak acceleration). The primary outcomes were tibia BMD area by peripheral quantitative CT (pQCT) vertebral QCT; additional included dual-energy X-ray...
We have developed and demonstrated an imaging system that couples X-ray CT scanner to a scintillation camera for the localization absolute measurement of radionuclide uptake. use registered images provide physical information overcome quantitative errors in nuclear due attenuation, scattering limited spatial resolution. The registration accuracy precision phantom experiments was 0.0/spl plusmn/0.4 mm. Preliminary patient scans suggest techniques studies can be used. Conversion image data...
The effects of photon noise in the emission projection data and uncertainty attenuation map on image attenuation-corrected SPECT images reconstructed using a maximum-likelihood expectation-maximization algorithm were investigated. Emission physical Hoffman brain phantom thorax-like acquired from prototype emission-transmission computed tomography (ETCT) scanner being developed at UCSF. Computer-simulated head-like also obtained fan-beam geometry consistent with ETCT system. simulation...