title: [Evaluation of interstitial shadows by thin slice computed tomography].
abstract: We developed a method for evaluation of interstitial shadows by thin slice computed tomography (CT). We studied thirty-seven cases with interstitial shadows confirmed by thin slice CT, and 13 normal cases. Thin slice CT was scanned on 3 levels: 1) at the aortic arch, 2) about 2 cm below the carina, and 3) about 1 cm above the right diaphragm. Each level was scanned bilaterally to produce 6 regions of interest (ROI); CT numbers were recorded from each ROI. CT numbers ranging from -1000 to 100 Hounsfield units (H.U.) were classified into 4 different bands, -1000 - (-900) H.U. (low band), -900 - (-750) H.U. (medium low band), -750 - (-500) H.U. (medium high band), and -500 - 100 H.U. (high band), for cases with interstitial shadows and for normal cases. We calculated the prevalence of CT numbers in each band for both normals and subjects with interstitial shadows. Compared to the normals, subjects with interstitial shadows showed fewer pixels in the medium low band and more pixels in the medium high and high bands. Furthermore, the prevalence of CT numbers in each band correlated with %TLC, %VC, and pulmonary diffusing capacity. We conclude that thin slice CT is a useful method for evaluation of the extent and characteristics of interstitial shadows.
authors.affiliation: Department of Internal Medicine, School of Medicine, Kitasato University, Kanagawa, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Yamamoto
authors.forename: T
authors.initials: T
authors.lastname: Abe
authors.forename: K
authors.initials: K
authors.lastname: Tadokoro
authors.forename: N
authors.initials: N
authors.lastname: Yanase
authors.forename: T
authors.initials: T
authors.lastname: Tomita
mesh_terms: D000542:Alveolitis, Extrinsic Allergic / Q000000981:diagnostic imaging* / Q000473:pathology; D003095:Collagen Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D011658:Pulmonary Fibrosis / Q000000981:diagnostic imaging* / Q000473:pathology; D012129:Respiratory Function Tests; D014057:Tomography, X-Ray Computed / Q000379:methods*