Engineering Commons^™

Mitigation Of Radiation Induced Pulmonary Vascular Injury By Delayed Treatment With Captopril, Robert C. Molthen, Qingping Wu, Brian L. Fish, John E. Moulder, Elizabeth R. Jacobs, Meetha M. Medhora

Biomedical Engineering Faculty Research and Publications

Background and Objective: A single dose of 10 Gy radiation to the thorax of rats results in decreased total lung angiotensin-converting enzyme (ACE) activity, pulmonary artery distensibility and distal vascular density while increasing pulmonary vascular resistance (PVR) at 2 months post-exposure. In this study, we evaluate the potential of a renin-angiotensin system (RAS) modulator, the ACE inhibitor captopril, to mitigate this pulmonary vascular damage.

Methods: Rats exposed to 10 Gy thorax only irradiation and age-matched controls were studied 2 months after exposure, during the development of radiation pneumonitis. Rats were treated, either immediately or 2 weeks after radiation exposure, with …

Reducing The Radiation Dose To Women Receiving Cardiac Ct Scans, Michael Hoppe

Master's Theses (2009 -)

This thesis aims to quantify the reduction in radiation dose deposited in glandular breast tissue achieved by using tilted gantry acquisition during cardiac CT scans. Previous work by Halpern et al. suggested using tilted acquisition parallel to the long axis of the patient’s heart. However, for a larger portion of the population this is not feasible due to the design of current scanners (which are limited to maximum tilt angles of 30 degrees). This study investigated the potential dose reduction and image quality effects at commercially available tilt angles between 0-30 degrees through simulation and experimental studies.

Upon IRB approval, …

Vascular Injury After Whole Thoracic X-Ray Irradiation In The Rat, S. N. Ghosh, Q. Wu, M. Mäder, B. L. Fish, John E. Moulder, Elizabeth R. Jacobs, Meetha Medhora, Robert C. Molthen

Biomedical Engineering Faculty Research and Publications

Purpose

To study vascular injury after whole thoracic irradiation with single sublethal doses of X-rays in the rat and to develop markers that might predict the severity of injury.

Methods and Materials

Rats that received 5- or 10-Gy thorax-only irradiation and age-matched controls were studied at 3 days, 2 weeks, and 1, 2, 5, and 12 months. Several pulmonary vascular parameters were evaluated, including hemodynamics, vessel density, total lung angiotensin-converting enzyme activity, and right ventricular hypertrophy.

Results

By 1 month, the rats in the 10-Gy group had pulmonary vascular dropout, right ventricular hypertrophy, increased pulmonary vascular resistance, increased dry lung …

Imaging Radiation Pneumonitis In A Rat Model Of A Radiological Terrorism Incident, Robert C. Molthen, Qingping Wu, Gary S. Krenz, Meetha Medhora, Elizabeth R. Jacobs, John E. Moulder

Biomedical Engineering Faculty Research and Publications

We have developed a rat model of single, sub-lethal thoracic irradiation. Our irradiation protocol is considered representative of exposures near the detonation site of a dirty bomb or small nuclear device. The model is being used to investigate techniques for identifying, triaging and treating possible victims. In addition to physiological markers of right ventricular hypertrophy, pulmonary vascular resistance, and arterial distensibility, we present two methods for quantifying microvascular density. We used methods including microfocal X-ray imaging to investigate changes in lung structure/function resulting from radiation exposure. Radiation pneumonitis is a complication in subjects receiving thoracic irradiation. A radiographic hallmark of …