Biomedical subjects

James A Gehl

Publications and source records attributed to James A Gehl.

3 recordsLinked to original sources

PubMed2005

Comparison of X-ray fluoroscopy and interventional magnetic resonance imaging for the assessment of coronary artery stenoses in swine.

The accuracy of a two-step interventional MRI protocol to quantify coronary artery disease was compared to the clinical gold standard, X-ray angiography. Studies were conducted in nine swine with a surgically induced stenosis in the proximal left circumflex coronary artery. The two-step protocol consisted of catheter-directed magnetic resonance angiography (MRA), which was first used to localize the stenosis, followed by MRI cross-sectional images to quantify the degree of stenosis without the use of contrast agent. Line signal intensity profiles were drawn across the vessel diameter at the stenosis site and proximal to the stenosis for each data set to measure percentage stenosis for each animal. Catheter-directed MRA successfully detected eight of nine stenoses. Cross-sectional MRI accurately quantified each stenosis, with strong agreement to the measurements made using X-ray fluoroscopy (intraclass correlation coefficient = 0.955; P < 0.05). This study demonstrates that in the future interventional MRI may be an alternative to X-ray angiography for the detection and quantification of coronary artery disease.

Angiography↗

PubMed2005

Validating DICOM content in a remote storage model.

Verifying the integrity of DICOM files transmitted between separate archives (eg, storage service providers, network attached storage, or storage area networks) is of critical importance. The software application described in this article retrieves a specified number of DICOM studies from two different DICOM storage applications; the primary picture archiving and communication system (PACS) and an off-site long-term archive. The system includes a query/retrieve (Q/R) module, storage service class provider (SCP), a DICOM comparison module, and a graphical user interface. The system checks the two studies for DICOM 3.0 compliance and then verifies that the DICOM data elements and pixel data are identical. Discrepancies in the two data sets are recorded with the data elements (tag number, value representation, value length, and value field) and pixel data (pixel value and pixel location) in question. The system can be operated automatically, in batch mode, and manually to meet a wide variety of use cases. We ran this program on a 15% statistical sample of 50,000 studies (7500 studies examined). We found 2 pixel data mismatches (resolved on retransmission) and 831 header element mismatches. We subsequently ran the program against a smaller batch of 1000 studies, identifying no pixel data mismatches and 958 header element mismatches. Although we did not find significant issues in our limited study, given other incidents that we have experienced when moving images between systems, we conclude that it is vital to maintain an ongoing, automatic, systematic validation of DICOM transfers so as to be proactive in preventing possibly catastrophic data loss.

Computer Communication Networks↗

PubMedDate not supplied

Informatics in radiology (infoRAD): integrating MIRC-compliant semiautomated teaching files into PACS work flow.

A Medical Image Resource Center (MIRC)-compliant teaching file system was created that can be integrated into a picture archiving and communication system (PACS) environment. This system models the three-step process necessary for efficient teaching file creation in a PACS environment: (a) identifying and transferring a case quickly and easily during primary interpretation, (b) editing and authoring the case outside of primary interpretation time, and (c) publishing the case locally and via MIRC standard-based mechanisms. Images from interesting cases are e-mailed to the teaching file system from either the PACS workstation or the radiologist's personal computer. Notes and clinical information may be included in the e-mail text to prompt the recollection of case details. Images are automatically extracted from the e-mail and sent to an image repository, and text fields are captured in a database. The World Wide Web-based authoring component provides tools for final authoring of cases and for the manipulation of existing cases. Authors designate access levels for each case, which is then made available locally and, potentially, to the entire MIRC-compliant community. Although this application has not yet been implemented as a departmental solution, it promises to improve and streamline medical education and promote better patient care.

Radiology↗