title: [Distinction between adrenal adenomas and metastases using 0.5 Telsa MR imaging: diagnosis with out-of-phase T2*-weighted gradient-field-echo image].
abstract: The purpose of this study was to investigate the ability of MR imaging with a 0.5-T apparatus to distinguish adrenal adenomas from adrenal metastases. The series included 23 adrenal adenomas (18 non-hyperfunctioning adenomas, 5 hyperfunctioning) and 23 adrenal metastases (14 from lung, 5 liver, 3 colon, and 1 stomach cancer). The signal intensity (SI) ratio (adrenal tumor/liver) on T1-, T2-, and T2*-weighted MR images was calculated for adrenal tissue characterization. Adrenal adenomas were more precisely distinguished from adrenal metastases on T2*-weighted images (21/23, 91%) than on T2-weighted images (15/23, 65%). In conclusion, T2*-weighted images were better than routine T2-weighted images in distinguishing adrenal adenomas from adrenal metastases. The reason could be that the total signal intensity of adrenal adenomas which contained some fat components decreased on T2*-weighted images due to an out-of-phase effect.
authors.affiliation: Department of Radiology, Yamanashi Medical College.
authors.forename: T
authors.initials: T
authors.lastname: Ichikawa
authors.forename: H
authors.initials: H
authors.lastname: Fujimoto
authors.forename: G
authors.initials: G
authors.lastname: Uchiyama
authors.forename: K
authors.initials: K
authors.lastname: Murakami
authors.forename: K
authors.initials: K
authors.lastname: Ohtomo
mesh_terms: D000236:Adenoma / Q000175:diagnosis*; D000310:Adrenal Gland Neoplasms / Q000175:diagnosis / Q000556:secondary*; D000328:Adult; D000368:Aged; D003937:Diagnosis, Differential; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D007089:Image Enhancement; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods; D008297:Male; D008875:Middle Aged