Biomedical subjects

Randy D Ernst

Publications and source records attributed to Randy D Ernst.

3 recordsLinked to original sources

PubMed2003

Computerized tomographic colonography: performance evaluation in a retrospective multicenter setting.

BACKGROUND & AIMS: No multicenter study has been reported evaluating the performance and interobserver variability of computerized tomographic colonography. The aim of this study was to assess the accuracy of computerized tomographic colonography for detecting clinically important colorectal neoplasia (polyps >or=10 mm in diameter) in a multi-institutional study. METHODS: A retrospective study was developed from 341 patients who had computerized tomographic colonography and colonoscopy among 8 medical centers. Colonoscopy and pathology reports provided the standard. A random sample of 117 patients, stratified by criterion standard, was requested. Ninety-three patients were included (47% with polyps >or=10 mm; mean age, 62 years; 56% men; 84% white; 40% reported colorectal symptoms; 74% at increased risk for colorectal cancer). Eighteen radiologists blinded to the criterion standard interpreted computerized tomography colonography examinations, each using 2 of 3 different software display platforms. RESULTS: The average area under the receiver operating characteristic curve for identifying patients with at least 1 lesion >or=10 mm was 0.80 (95% lower confidence bound, 0.74). The average sensitivity and specificity were 75% (95% lower confidence bound, 68%) and 73% (95% lower confidence bound, 66%), respectively. Per-polyp sensitivity was 75%. A trend was observed for better performance with more observer experience. There was no difference in performance across software display platforms. CONCLUSIONS: Computerized tomographic colonography performance compared favorably with reported performance of fecal occult blood testing, flexible sigmoidoscopy, and barium enema. A prospective study evaluating the performance of computerized tomography colonography in a screening population is indicated.

Colonic Neoplasms↗

PubMedDate not supplied

Development of a teaching file by using a DICOM database.

A teaching file of Digital Imaging and Communications in Medicine (DICOM) images was developed. Selected computed tomographic, magnetic resonance, angiographic, nuclear medicine, and ultrasonographic images were transferred to a personal computer (PC) with a 75-GB hard drive. The database created from the DICOM header information was modified to include American College of Radiology (ACR) Learning File categories. Database modification allowed cases to be searched by diagnosis, by findings, and by patient age, sex, and demographics. Technologists inputted ACR codes into the DICOM headers before the images were acquired, thereby reducing database maintenance time. Images were manipulated and reviewed and were used for case presentations, board review, and conferences. Selected images were transferred via a hospital network to workstations for consultation, saving time for referring clinicians. The teaching file is reliable, cost-effective, and easy to install and takes advantage of recent technologic advances in computer hardware and software. Rapid cost reductions and increases in PC storage capacity allow maintenance of the teaching file in DICOM format without intermediate steps involving automation or manual conversion. This setup rivals any of the proprietary software currently available from other vendors.

Computer Communication Networks↗

PubMedDate not supplied

Paleoradiology: advanced CT in the evaluation of nine Egyptian mummies.

Axial thin-collimation state-of-the-art spiral computed tomography (CT) was combined with sagittal and coronal reformatting, three-dimensional (3D) reconstruction, and virtual "fly-through" techniques to nondestructively study nine Egyptian mummies. These techniques provided important paleopathologic and historical information about mummification techniques, depicted anatomy in the most informative imaging plane, illustrated the soft-tissue preservation and physical appearance of mummies in superb detail, and generated an intriguing virtual tour through hollow mummified remains without harming the specimens themselves. Images generated with these methods can help archaeologists and Egyptologists understand these fascinating members of mankind and can serve as adjunct visual aids for laypersons who are interested in mummies. CT has emerged as the imaging modality of choice for the examination of Egyptian mummies due to its noninvasive cross-sectional nature and inherently superior contrast and spatial resolution. As multi-detector row CT and postprocessing tools evolve, the capabilities and applications of CT will continue to proliferate, attesting to the expanded versatility and utility of CT as a noninvasive research tool in the multidisciplinary study of Egyptian mummies.

History, Ancient↗