title: [Attempt of helical CT densitometry for assessing regional pulmonary ventilation].
abstract: Pulmonary dynamic CT densitometry during steady-state breathing was recorded and analyzed using helical CT scan in 14 patients with obstructive disorders involving small and large airways, and 2 with restrictive lung disease. The data set of 7-second, continuous helical scan at constant table position were reconstructed as 35 one-second temporarily overlapping images at 0.2- second intervals over 2-3 respiratory cycles, and regional CT densitometry was displayed. Normal lungs (5 volunteers) showed a regular sinusoidal curve, and maximal lung density change (LDC) was greater independent lungs than in independent lungs, with an average difference of 29.5 HU, indicating the gravitational effect In contrast, a regular sinusoidal curve was not shown in obstructive disorders, and a significant reduction in maximal LDC (33.7 +/- 22.6 HU) compared with the normal lungs (60.8 +/- 25.9 HU) (P < 0.001) was indicated. In contrast, no marked reduction in maximal LDC (53.7 +/- 28.6 HU) was shown in restrictive disorders. This method is fast and easy, and appears useful for the detection of ventilation abnormalities in obstructive lung disorders.
authors.affiliation: Department of Radiology, Yamaguchi University, School of Medicine, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Kume
authors.forename: K
authors.initials: K
authors.lastname: Suga
authors.forename: K
authors.initials: K
authors.lastname: Nishigauchi
authors.forename: K
authors.initials: K
authors.lastname: Takano
authors.forename: S
authors.initials: S
authors.lastname: Koike
authors.forename: T
authors.initials: T
authors.lastname: Matsumoto
authors.forename: N
authors.initials: N
authors.lastname: Matsunaga
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008171:Lung Diseases / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011659:Pulmonary Gas Exchange; D015898:Tomography Scanners, X-Ray Computed; D014057:Tomography, X-Ray Computed