title: Periodic analysis of urethane-induced pulmonary tumors in living A/J mice by respiration-gated X-ray microcomputed tomography.
abstract: X-ray microcomputed tomography (micro-CT) with a respiratory gating system is a useful non-invasive approach to evaluate lung tumor development in living animal models. Here micro-CT was applied for the detection of lung lesions induced by a single intraperitoneal injection (250 mg/kg) of urethane in male A/J mice, at 2-week intervals from 10 to 30 weeks after carcinogen exposure. In micro-CT cross sections, lung tumor images were easily distinguished from surrounding non-tumorous tissues, the smallest detected tumor being approximately 0.5 mm in diameter. All of the urethane-treated mice (n = 15) developed lung tumors and the number of tumors developed in each mouse was 8.6 +/- 3.9. Six tumors, determined histopathologically to be adenocarcinomas, were detected, growing at different rates during the experimental period. The most aggressive carcinoma, increasing in diameter from 0.9 to 3.5 mm within 8 weeks, was a solid-type nodule with a clear tumor margin on the micro-CT imaging. Other tumors, histopathologically adenomas, grew slowly or moderately. The results provide evidence that micro-CT is a useful non-invasive imaging approach for evaluating the characteristics and growth of lung tumors in mice.
authors.affiliation: Cancer Prevention Basic Research Project, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan.
authors.forename: Yusaku
authors.initials: Y
authors.lastname: Hori
authors.forename: Nobuo
authors.initials: N
authors.lastname: Takasuka
authors.forename: Michihiro
authors.initials: M
authors.lastname: Mutoh
authors.forename: Tsukasa
authors.initials: T
authors.lastname: Kitahashi
authors.forename: Shuji
authors.initials: S
authors.lastname: Kojima
authors.forename: Katsumi
authors.initials: K
authors.lastname: Imaida
authors.forename: Masahiro
authors.initials: M
authors.lastname: Suzuki
authors.forename: Kazushi
authors.initials: K
authors.lastname: Kohara
authors.forename: Shuji
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Moriyama
authors.forename: Takashi
authors.initials: T
authors.lastname: Sugimura
authors.forename: Keiji
authors.initials: K
authors.lastname: Wakabayashi
mesh_terms: D000818:Animals; D002273:Carcinogens / Q000494:pharmacology; D004195:Disease Models, Animal; D008175:Lung Neoplasms / Q000139:chemically induced / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D012119:Respiration; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014520:Urethane / Q000494:pharmacology
chemical_list: D002273:Carcinogens; D014520:Urethane