[Clinical assessment of uneven ventilation by factor analysis of Xe-133 washout scintigram].
Factor analysis (FA) was applied to 50 consecutive Xe-133 washout lung scintigrams, and its findings were compared with dynamic scintigrams of Xe-133 washout (DSW). Mean transit time (MTT) of radioactive xenon measured by FA also was compared with that measured by height/area (H/A) or two-compartment analysis (2CA). In 12 patients with normal DSW, FA separated and located two factors: one represented background activity, and the other uniform washout from the lung. In 31 out of 38 patients (82%) with abnormal DSW, FA separated the same areas where the washout was delayed on DSW. In 5 (13%) patients, FA diagnosed more areas of delayed washout than DSW. FA failed in 2 (5%) patients, but this failure was due to small number of counts of pixels. Diagnosis by FA was seemed easier than diagnosis by DSW in 95% of all patients by the authors' impression. MTT by FA (y) correlated with MTT by 2CA (x) in small groups of patients: in 9 patients in whom only one MTT was obtainable by FA (r = 0.75, p = 0.02, y = 4.2x + 1.9), and in 8 patients of normal DSW in whom two MTT's were obtainable by FA (r = 0.77, p = 0.02, y = 0.69x + 6.2, y; shorter MTT by FA between the two). MTT by FA did not correlate with MTT by H/A. In conclusion, FA is useful for diagnosing uneven Xe-133 washout from the lung.
N
N
Honda
K
K
Machida
T
T
Mamiya
T
T
Takahashi
T
T
Takishima
N
N
Hasegawa
T
T
Kamano
K
K
Ohno
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging* / Q000378:metabolism; D008171:Lung Diseases / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D012119:Respiration; D014980:Xenon Radioisotopes / Q000493:pharmacokinetics
D014980:Xenon Radioisotopes