MRI for the diagnosis of ultrasonographically indeterminate pelvic masses.

OBJECTIVE To determine the diagnostic accuracy of magnetic resonance imaging in ultrasonographically indeterminate masses of female pelvis against histopathological findings. METHODS The comparative cross sectional, analytical study was conducted at Liaquat National Medical College and Hospital, Karachi, from January to December 2006. Female patients with pelvic masses in whom the definite diagnosis of the mass could not be determined by ultrasonogaraphy were further evaluated with magnetic resonance imaging of the pelvis. All patients subsequently underwent a surgical procedure for a definite histopathological diagnosis. The imaging results were then compared with the pathological results to determine the sensitivity and specificity of magnetic resonance imaging for the determination of the nature of mass and anatomical site of the origin of mass. RESULTS The age of the 63 patients in the study ranged between 14 and 84 years. The sensitivity and specificity of the imaging procedure for the assessment of benign lesion was 95.8% and 93.3% respectively, and for malignant lesion, 93.3% and 95.8% respectively. In diagnosing uterine mass, the values were 100% and 97.5% respectively, for ovarian mass, 97.3% and 96% respectively, and extra uterine/extra ovarian mass, 66.6% and 100% respectively. CONCLUSION Magnetic resonance imaging was highly accurate in characterising the pelvic masses as benign and malignant and in determining their site of origin.