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Correlation of lung parenchymal MR signal intensity with pulmonary function tests and quantitative computed tomography (CT) evaluation: A pilot study
Author(s) -
Iwasawa Tae,
Takahashi Hiroshi,
Ogura Takashi,
Asakura Akira,
Gotoh Toshiyuki,
Kagei Seiichiro,
Nishimura Junichi,
Obara Makoto,
Inoue Tomio
Publication year - 2007
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.21183
Subject(s) - medicine , hounsfield scale , copd , expiration , lung , lung volumes , nuclear medicine , coronal plane , intensity (physics) , radiology , parenchyma , computed tomography , linear regression , respiratory system , pathology , mathematics , statistics , physics , quantum mechanics
Purpose To evaluate the effect of ventilatory impairment on MR signal intensity of the lung parenchyma. Materials and 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. Conclusion In COPD patients, lung signal change measured by MRI correlates with airflow obstruction, but not with volume of the emphysema measured by lung CT. J. Magn. Reson. Imaging 2007. © 2007 Wiley‐Liss, Inc.