Correlation of lung parenchymal MR signal intensity with pulmonary function tests and quantitative computed tomography (CT) evaluation: a pilot study.
OBJECTIVE
To evaluate the effect of ventilatory impairment on MR signal intensity of the lung parenchyma.


METHODS
Subjects were five normal volunteers (age = 30 +/- 7.9 years, mean +/- SD) and 19 male patients with chronic obstructive lung disease (COPD) (mean age = 70.4 +/- 6.5 years). Coronal MR images were obtained over entire lung fields at full inspiration and full expiration with cardiac triggering on a 1.5T system. Changes in the mean lung intensity between the two respiratory states were normalized by each intercept of the linear regression lines of the signal changes, and the slope of the relationship was calculated. Computed tomography (CT) images were also obtained in COPD patients at full inspiration using a multidetector row CT scanner. Attenuation values less than -950 Hounsfield units (HU) (RA-950) represented the percentage of relative lung area on the CT.


RESULTS
The mean slope of COPD patients (0.365 +/- 0.074) was less steep than that of the normal subjects (0.570 +/- 0.124, P < 0.001). In COPD patients, the slope correlated significantly with forced expiratory volume in one second (FEV1, r = 0.508, P = 0.026), but not with RA-950.


CONCLUSIONS
In COPD patients, lung signal change measured by MRI correlates with airflow obstruction, but not with volume of the emphysema measured by lung CT.
Iwasawa
Tae
T
Department of Radiology, Kanagawa Cardiovascular and Respiratory Center, Yokohama, Japan. tae_i_md@wb3.so-net.ne.jp
Takahashi
Hiroshi
H
Ogura
Takashi
T
Asakura
Akira
A
Gotoh
Toshiyuki
T
Kagei
Seiichiro
S
Nishimura
Jun-ichi
J
Obara
Makoto
M
Inoue
Tomio
T
D000328:Adult; D000368:Aged; D006801:Humans; D016014:Linear Models; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D010865:Pilot Projects; D029424:Pulmonary Disease, Chronic Obstructive / Q000000981:diagnostic imaging / Q000503:physiopathology*; D011656:Pulmonary Emphysema / Q000000981:diagnostic imaging / Q000503:physiopathology*; D012129:Respiratory Function Tests; D015656:Respiratory Mechanics; D014057:Tomography, X-Ray Computed