Sampling tissue from throughout the body for evaluation
from the body for careful laboratory analysis.
Most such procedures performed are image-guided biopsy, an approach that has been used successfully for decades now. The radiologists can use various imaging modalities, including CT, ultrasound, and the various forms of angiography, to see the position of fine needles used to take a puncture sample, or to draw up (or aspirate, especially in cases of needing a sample of a fluid collection), small amounts of tissue. For some biopsies, they will use more than one imaging modality or they may use a special technique of intersecting coordinates from the imaging (called stereotactic biopsy) to pinpoint an area of tissue. The type of imaging used will depend on the type of abnormality that has been identified or suspected and which type of imaging reveals the mass most clearly.
Interventional radiologists can biopsy most areas of the body. Most commonly, though, they perform these biopsies on the:
• breast (or under the arm or near the chest wall);
• or thyroid.
Often patients undergo such biopsies to determine the cause of a lump or mass.
For example, most abnormalities seen on mammograms are not cancer. But to determine whether a patient's lesion is benign or malignant, specialists often must take a small sample of cells from the abnormal location and examine them under the microscope. Needle biopsy, often guided by ultrasound, makes this step much less invasive and much easier to undergo than in past eras when a biopsy required an incision and removal of significantly more tissue. And with image guidance, interventionalists can avoid other tissues or vital structures surrounding the targeted areas. The radiologist will sometimes use a vacuum-assisted needle to remove the entire lesion in question, if the lesion is small.
In addition, specialists have also begun using MR imaging to guide biopsies, especially for breast biopsy. Some lesions are only, or best, visible with MR imaging and, thus, their biopsy is best guided by this modality. The radiologist may also use MR imaging to place a marker clip or guide wire at the site of a small breast lump, to help surgeons locate and remove the lump.
Nodules or lesions in the lungs are also a common target of needle-guided biopsy. This procedure involves introducing a fine needle through the chest to the location of the abnormality.
Interventionalists may also take other types of needle samples, including (for example from the renal vein, to diagnose endocrine function) or fluid from the spine (with a lumbar puncture or "spinal tap," which can also measure or release pressure in the cerebrospinal fluid).
Biopsy (by needle) leaves no permanent mark. Patients normally need only a local anesthetic or sedation, or both, prior to these studies.
These procedures are almost always performed on an outpatient basis. Most patients can go home shortly after these procedures, although in some cases a brief recovery period at the hospital is needed.