Fig. 1. Selected CTAP image demonstrate a dominant mass i n the right lobe of the liver with two smaller adjacent masses anteromedially. There is a smaller fourth lesion seen anterior to the large lesion, in the periphery. There is also a wedge-shaped perfusion defect posterior to the large dominant lesion (curved black arrow). Fig. 1a. Adjacent caudal image.			Fig. 2. Selected delayed CT image again demonstrate the dominant right lobe mass and smaller lesions. The wedge-shaped perfusion defect posterior to the large mass is no longer apparent.   Fig. 2a. Adjacent caudal image.
Case Reference No. CC-0298-02 The patient is a 37-year-old woman who was found to have multiple lesions in the right lobe of the liver on an ultrasound examination performed at an outside institution. These lesions were found to be metastases from colon carcinoma. The patient was referred to our institution for CT arterial portography (CTAP) to assess the number, size, and locations of the metastatic lesions in preparation for surgical resection. We performed celiac and superior mesenteric arteriography prior to CTAP.   Questions: 1) Who is the appropriate candidate for CTAP? 2) Would a less invasive modality such as MR imaging of the liver have been equally sensitive and specific in detecting these lesions? 3) Should MR imaging be done in conjunction with CTAP to increase the specificity? 4) Should full superior mesenteric and celiac arteriography be performed before or after completion of the CTAP procedure? 5) Related to question 4, would the contrast material load from arteriography done prior to CTAP decrease the sensitivity of CTAP in detecting occult metastatic lesions?			Fig. 3. Celiac angiogram suggested hypovascular lesions within the right lobe. Fig. 4. The portal vein is patent. The dominant hypovascular lesion is seen (white arrows).