DIAGNOSIS OF PELVIC ENDOMETRIOSIS BY MAGNETIC-RESONANCE-IMAGING USINGFAT-SATURATION TECHNIQUE

Objective: To assess the usefulness of fat-saturated magnetic resonanc e (MR) imaging for detecting small endometrial implants. Design: Prosp ective evaluation by conventional and fat-saturated MR imaging. Settin g: Shimane Medical University Hospital, Izumo, Japan. Patients: Fifty- one consecutive patients with clinically suspected pelvic endometriosi s. Interventions: Magnetic resonance images <2 weeks before laparoscop y or laparotomy. Main Outcome Measure: The location, number, and size of lesions. Results: Surgery revealed a normal pelvis in 5 patients, e ndometriosis in 44 (42 with pigmented lesions and 2 with nonpigmented lesions and adhesions), and other cystic lesions in 2. With fat-satura ted MR imaging, overall sensitivity, specificity, positive predictive value, and negative predictive Value were 89%, 71%, 95%, and 50%, resp ectively. At surgery, 122 pigmented lesions of endometriosis were dete cted. Conventional MR images indicated lesions of endometriosis in 74. When fat-saturated images were used, 103 lesions were detected. With conventional MR images, only one of 34 small endometrial implants (2 t o 3 mm in diameter) was detected. However, the addition of fat-saturat ed images increased the detection rate to 15 of 34, and all lesions >4 mm in diameter. Conclusion: Conventional MR imaging for detecting sma ll endometrial implants was improved by addition of the fat-saturation technique. Therefore, fat-saturation MR imaging is an acceptable for detecting small endometriomas.