title: Thoracic tissue thickness measured by transmission scintigraphy with 99Tcm.
abstract: A flood source containing 25 mCi of technetium-99m (99Tcm) was used to measure thoracic tissue thickness (Tt) in 20 healthy subjects, 14 patients with cardiogenic pulmonary oedema, 8 patients with biopsy proven cryptogenic fibrosing alveolitis (CFA) and 10 subjects with radiographic evidence of severe, widespread emphysema. Unattenuated counts from the flood source were acquired first, and then with the subject seated between the flood source and the gamma camera, a second scan of transmitted counts was acquired. Assuming a constant linear attenuation coefficient of 0.135 cm-1, we calculated Tt per pixel of the gamma camera image, thus creating a profile of Tt throughout the length of the thorax. In normal subjects mean (S.D.) Tt at the base of the right lung was 10.8 (2.4) cm. In patients with pulmonary oedema, CFA and emphysema, mean (S.D.) values for Tt, in cm, were 12.9 (2.7) p less than 0.05, 14.4 (1.9) p less than 0.001 and 6.0 (1.1) p less than 0.0001 respectively. This simple, quick and inexpensive technique could be used to give regional measurements of Tt.
authors.affiliation: Department of Medicine and Nuclear Medicine, Charing Cross Hospital, London, UK.
authors.forename: D J
authors.initials: DJ
authors.lastname: Seddon
authors.forename: P D
authors.initials: PD
authors.lastname: Snashall
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008171:Lung Diseases / Q000000981:diagnostic imaging*; D008297:Male; D008722:Methods; D008875:Middle Aged; D011654:Pulmonary Edema / Q000000981:diagnostic imaging; D011656:Pulmonary Emphysema / Q000000981:diagnostic imaging; D011658:Pulmonary Fibrosis / Q000000981:diagnostic imaging; D011877:Radionuclide Imaging; D013667:Technetium; D013909:Thorax / Q000000981:diagnostic imaging*
chemical_list: D013667:Technetium