三段论形式：
1 病例入选原则，情况
2 研究的目的
3 MRI诊断方法标准

Following IRB approval, female patients diagnosed with urethral diverticulum from 1999 to 2004 were identified by a retrospective chart review using electronic medical records and paper charts. Information about presenting symptoms, urological history, diagnosis method, imaging studies, and outcomes at last followup was documented. Surgical operative reports and pathology reports were also reviewed for final diagnosis.

Cases were reviewed to assess the method of initial diagnosis (physical exam, MRI, VCUG, cystoscopy, or urethrography). Our goal was to determine how the diverticula were diagnosed and to determine what studies were most sensitive at making the diagnosis. Therefore, any additional studies, as well as their contribution to diagnosis and surgical planning, were recorded. Outcomes at last followup were correlated with the type of imaging modality used for diagnosis and/or surgical planning.

MRI studies (if obtained) were performed at this institution using a 1.5 Tessla magnet with a phase-array pelvic coil. Axial, coronal, and sagittal T2 weighted sequences were obtained using fast spin echo technique. Axial and sagittal T1 weighted sequences were obtained before and after intravenous gadolinium contrast. Computer tomographic (CT) scans were used in four cases due to clinical contraindications for MRI.