Pulmonary small vessels alteration is significantly correlated with pulmonary perfusion, according to a study published in the April issue of the American Journal of Roentgenology.

Pulmonary vascular alterations are vital to the understanding of pathophysiologic manifestations of lung disorders. To quantitatively evaluate these alterations in vivo, many are suggesting the use of cross-sectional area (CSA) measurements of pulmonary small vessels. Lead author Shin Matsuoka, MD, PhD, of the St. Marianna University School of Medicine in Kanagawa, Japan, and colleagues examined the relationship between the pulmonary small vessels alteration, as measured by CSA on CT images, and pulmonary perfusion measured using lung perfusion scintigraphy.

The researchers’ study included 46 patients who underwent CT and lung perfusion scintigraphy. The CSA of pulmonary small vessels less than five millimeters² and between five and ten millimeters²were measured using CT. The percentage of the right lung to whole lung in each CSA group, measured as CSA_<5,R/W and CSA_5–10,R/W, were ascertained.

Additionally, Matsuoka and colleagues used ^99mTc–macroaggregated albumin (MAA) lung perfusion scintigraphy to gather the right and total lung counts, and calculated the percentage of the right-to-whole lung counts, known as MAA_R/W. They also evaluated the correlations of CSA_<5,R/W and CSA_5–10,R/W with MAA_R/W, the correlation between the percentage of each lung zone to whole-lung CSA_<5 and the percentage of each corresponding lung zone to whole-lung MAA.

Results indicated that the mean CSA_<5,R/W was 58.1 percent and the mean MAA_R/W was 59.3 percent. While CSA_<5,R/W was significantly correlated with MAA_R/W, a significant but weak correlation was found between CSA_5–10,R/W and MAA_R/W. Lastly, the percentage of each lung zone to whole-lung CSA_<5 had significant correlations with the percentage of each corresponding lung zone to whole-lung MAA.

“Data from the current study suggest that reduction in CSA of subsubsegmental vessels might be related to a decrease in pulmonary perfusion,” wrote Matsuoka and colleagues. “This is a first report to establish a relationship between quantitative measurements of pulmonary small vessels alteration and pulmonary perfusion in vivo. CSA measurements may represent an alternative imaging technique for the evaluation of pulmonary perfusion.”