Computed Tomography and Magnetic Resonance Imaging of the Female Pelvis

Abstract

Computed tomography (CT) of the pelvis requires good contrasting of the gastrointestinal tract; this is achieved by oral application of about 1000 ml of an appropriate contrast medium solution, which the patient starts drinking about 1 hour before the examination. Retrograde contrasting of the rectosigmoid is normally not required, but is recommended for evaluating a possible infiltration of the colon in patients with suspicion of an advanced ovarian carcinoma (in such cases about 250 ml of the contrast solution are sufficient). The bladder should be well filled with urine. Since a precontrast examination is not required, CT starts directly with the intravenous bolus enhanced contrast study. It is important to ensure adequate contrast enhancement of both the arteries and the veins in order to facilitate the differentiation of suspicious lymph nodes from vascular structures. A digital radiogram for adjustment of the first scanning plane is not required. When conventional CT is used (i. e., without spiral technique), scanning should proceed from the floor of the pelvis in a cranial direction to make optimal use of the strong contrast enhancement of the uterus and ova ries in the early phase after application of the contrast agent. For staging or follow-up of ovarian carcinomas, the entire abdomen should be scanned to identify possible lymphomas, liver metastases or subdiaphragmatic metastases. In such cases, however, scannin g should start at the diaphragm and continue caudad, since the reversed order (i. e., from the floor of the pelvis in a cranial direction) might lead to obscuring of potential liver metastases in the late phase of contrast enhancement.