title: Evaluation of the distribution of air and blood in emphysema patients using radioisotopic tracers.
abstract: Continuous recording of the respiratory cycle with the simultaneous or sequential radionucleic exploration (gamma camera) of ventilation (133Xe) and perfusion (MAT-99) was performed to determine the V/Q index in regional areas (Polaroid photography, mini-computer, memory visualization system, Benson incremental tracer, etc.) from the level of 1,024 points. An average ratio per sector was calculated and only three median sectors were retained. The wash-in and wash-out curves were traced by computer, and the calculation of the average T 1/2 for the different compartments of each median sector (apex--middle and base) was done in about 22 observations: in 18 diffuse emphysema, 11 of which were associated with giant cystic emphysema (spirometric, plethysmographic and radiographic data), T 1/2 values were greater than those of normal subjects (compartments C1 and C2) in diffuse emphysema and can become indefinable in zones of cystic emphysema. The values of the index V/Q approach the normal in diffuse emphysema with a tendency toward equalization of the ratios from the apex to the base. Extremely large divergence is observed in the elevated V/Q ratios in cystic emphysema.
mesh_terms: D000328:Adult; D000368:Aged; D003201:Computers; D004646:Emphysema / Q000503:physiopathology*; D006801:Humans; D008433:Mathematics; D008875:Middle Aged; D011652:Pulmonary Circulation; D012119:Respiration; D014692:Ventilation-Perfusion Ratio