PET evaluation of pulmonary vascular permeability: a structure-function correlation.
We compared regional measurements of the pulmonary transcapillary escape rate (rPTCER) for 68Ga-transferrin, obtained by positron emission tomography (PET), with morphometric data obtained from corresponding tissue samples in six anesthetized mechanically ventilated dogs, 1 h after oleic acid administration to either the left caudal lobe (0.015 ml/kg; Lobar group, n = 3) or the right atrium (0.08 ml/kg; Diffuse group, n = 3). Data were obtained from 48 regions in both injured and control lobes (right caudal lobes from the Lobar group). The volume density of edematous or hemorrhagic alveoli at the light-microscopic level was directly related to rPTCER (r = 0.82 for regions with rPTCER values less than 700 x 10(-4) min-1). Likewise, the relative surface of abnormal capillary endothelium and alveolar epithelium at the electron-microscopic level correlated well with rPTCER (r = 0.87 for regions with rPTCER less than 1,200 X 10(-4) min-1). We conclude that the rPTCER measurements obtained with PET reflect the morphological heterogeneity present in oleic acid-damaged lung tissue. Thus rPTCER measurements should be useful as a noninvasive quantitative index of lung injury. Furthermore, the tomographic image display of rPTCER may allow PET to be used as a "physiological probe" to guide tissue excision for later histological evaluation when lung injury is heterogeneous.
Velazquez
M
M
Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110.
Weibel
E R
ER
Kuhn
C
C
Schuster
D P
DP
D000818:Animals; D002199:Capillary Permeability / Q000502:physiology*; D004285:Dogs; D004730:Endothelium, Vascular / Q000293:injuries / Q000378:metabolism / Q000473:pathology; D005260:Female; D008168:Lung / Q000098:blood supply / Q000473:pathology; D055370:Lung Injury; D008297:Male; D008854:Microscopy, Electron; D019301:Oleic Acid; D009829:Oleic Acids; D011506:Proteins / Q000378:metabolism; D011652:Pulmonary Circulation / Q000502:physiology*; D014055:Tomography, Emission-Computed
D009829:Oleic Acids; D011506:Proteins; D019301:Oleic Acid