Using imaging techniques, such as CT scan and ultrasound, it is possible to perform precise needle punctures into different organs of the abdomen, obtaining samples for analysis. This procedure is called percutaneous biopsy. Relatively small needles are used for that purpose, but the sample is big enough for a reliable diagnosis in the large majority of the cases. This has been a major advance over an open surgical biopsy.
Percutaneous biopsies are basically of two types. Fine needle aspiration, where the cells are used for the diagnosis, is a less invasive modality. Core biopsies are punctures made with slightly larger needles to obtain a larger sample which is usually more reliable.
CT-guided or US-guided biopsies are performed in the CT scan or US suite, by an interventional radiologist trained in the procedure. The precision of the needle placement is very high, but in a small number of cases, the diagnosis is insufficient by fragmentation of the sample or inadequacy of the tissue.
Possible complications are most frequently related to bleeding following the puncture. A much less frequent complication is seeding of cancer cells along the needle tract. Fortunately, these complications are relatively rare and do not cause major problems.