Review of hepatic imaging and a problem-oriented approach to liver masses.

We believe that imaging of the liver is complicated. The sporadic appearance of incidental benign lesions and variability in scanning techniques, equipment and artifacts add difficulties to the evaluation of liver masses. Therefore we emphasize the need to define the problem for which the patient is being imaged. This information helps in choosing the procedure of choice and the technique needed to give the most expedient, accurate answer. This will also help apply the lowest risk and most cost-efficient care. Imaging algorithms vary depending on the suspected pathological conditions. Dynamic bolus-enhanced CT is the modality of choice in most situations. Tc99m sulfur-colloid liver-spleen scans are helpful in patients with suspected FNH, and Tc99m-tagged-RBC-SPECT scans are recommended to confirm cavernous hemangiomas. Cysts are easily confirmed by US. Although MRI is competitive with CT, it has not become a primary modality because of cost, availability, patient selection and variability of scanner capabilities among the many manufacturers and models. It is hard to predict what future development of imaging techniques will bring. Many feel that significant advances have plateaued. Time and money will more likely be concentrated on improving image resolution, speed of scanning and ability to transfer this information to sites outside of the radiology department. In addition to faster scanning, we expect to soon have available safe intravenous and enteric contrast agents for MRI. Certainly this will lead to a new round of investigations to compare MRI with CT scanning.