Micro-CT Used to Assess Pulmonary Arteries

The team has combined engineering, physiology, and mathematics to create quantitative models of the pulmonary arterial tree architecture to evaluate blood vessel alterations occurring in a rat model of pulmonary hypertension.

According to Robert C. Molthen, Ph.D., assistant professor of medicine in the division of pulmonary and critical care at the Medical College, these new imaging technologies could offer a foundation for developing strategies in clinical diagnosis, treatment options, or even screening for patients susceptible of pulmonary hypertension and pulmonary artery disease.

"Our broad focus is on the structure/function relationship in the pulmonary circulation, with a goal of better understanding the causes, progression, and hemodynamic impact of the vascular remodeling process,” Dr. Molten said. "In rats, various stimuli, such as exposure to lower than normal oxygen levels, as experienced when living at higher altitudes or with chronic obstructive pulmonary disorders [COPD], or exposure to certain toxins/drugs or blood-borne metabolic wastes, can lead to progressive pulmonary vascular remodeling, heart failure, and ultimately death.”

In the study, the investigators specifically assessed the impact of rats living in a 10% oxygen environment (the normal level is approximately 21%) on changes in the function and structure of lung arteries, and the role these alterations play in pulmonary hypertension. The results demonstrated that after 21 days, there was a reduction in the total length and number of branches identified in the pulmonary arterial tree of the rats who received less oxygen when compared to those assessed on control rates receiving a normal amount of oxygen. In addition, the pulmonary arteries in the rats bred in a low oxygen environment were much stiffer than those receiving normal levels of oxygen, a change that would considerably increase arterial blood pressure in the lungs.

The study was published in the December 2004 issue of the Journal of Applied Physiology.