Measurement of pulmonary parenchymal attenuation: use of spirometric gating with quantitative CT.
A new approach to reproducible measurement of lung attenuation and structure by means of respiratory-gated computed tomography (CT) was developed. The patient breathes through a microcomputer-controlled pocket spirometer during the complete CT examination, starting with a measurement of the vital capacity. At a user-selected respiratory level, the CT scan is triggered and air flow is inhibited mechanically. To exclude operator-related reproducibility errors, evaluation is based on semiautomated algorithms that isolate lung parenchyma by fast contour tracing. In a study on one volunteer, measurement of lung attenuation changed by a factor of about 2.6 (-895 to -730 HU) as a function of inspirational status. Reproducibility on the order of 5% or better can be achieved only with tight spirometric control of respiration.
Kalender
W A
WA
Siemens Medical Systems, Erlangen, Federal Republic of Germany.
Rienmüller
R
R
Seissler
W
W
Behr
J
J
Welke
M
M
Fichte
H
H
D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D008838:Microcomputers; D013147:Spirometry / Q000295:instrumentation*; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods*