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tomography and magnetic resonance (MR) im-300/16/0.75–1 (repetition time/echo time/excitations),aging (1–7). Since these pathologic conditions in the orbit usually enhance after injection of contrast material and exhibit a high signal in-tensity similar to that of fat, a fat-suppression technique is useful for emphasizing the enhanc-ing pathologic tissues bordered by the orbital fat tissue (4, 5, 8). The purpose of this study was to assess contrast enhancement of normal ex-traocular muscles in the orbit using fat-sup-pressed T1-weighted MR imaging. Subjects and Methods We obtained MR images of normal orbits of eight sub-jects (three men and five women) ranging in age from 25 to 66 years (average, 50 years). This group consisted of three patients with cerebral infarctions, three patients with postoperative brain tumors (Rathke’s cyst, glioblastoma 256 3 192–256 matrix, a 21- to 24-cm field of view, and a 5-mm section thickness with a 2.5-mm gap. The acqui-sition time was 1 minute, 4 seconds. Fat suppression was obtained by using the chemical-shift selective saturation method developed by Haase et al (9). Contrast-enhanced MR images were obtained immediately after administra-tion of 0.2 mL/kg gadopentetate dimeglumine. The imag-ing setting—such as sequence parameters, transmit and receive attenuation, pixel size, section position, scale fac-tor, and window width and level—were all identical before and after administration of contrast material. Contrast enhancement of extraocular muscles in the orbit was assessed by two reviewers, and agreement was reached by consensus. Since noncontrast, fat-suppressed T1-weighted images failed to delineate the accurate mar-gins of the extraocular muscles, the signal intensity quan-titation of these muscles was not available for this study. Instead, a three-step grading system was used to evaluate contrast enhancement of extraocular muscles: grade 0, muscle showed no definite enhancement; grade 1, be-tween grades 0 and 2; grade 2, muscle enhanced as mark-edly as nasal mucosa. Noncontrast and contrast-en