Radiology and biopsy:

What is biopsy?

Biopsy is a medical procedure, whereas tissue from a diseased organ in the body is removed by doctors which is then subjected to assessment by pathologist under microscope. It is one of the final and confirmatory step in making a diagnosis. In cancer treatment, biopsy is corner stone in deciding the treatment plan.

How is biopsy done?

To obtain tissue sample form the body the doctor needs to reach that organ and take a small sample. This can be done by various ways, like open surgery, key hole surgical technique like laparoscopy, by entering a cavity like endoscopy (putting a scope in the stomach) or putting a needle in body part without surgery. 

What is the role of radiology in biopsy?

Some of the tissues are directly accessible like a growth on the skin and do not need guidance (eg. Punch biopsy of a skin lesion). However, when an internal organ need to be biopsied, guidance is required to visualize the structure and biopsy it with minimal invasion and precision to minimize injury to normal structures. This is where radiology plays an important role to guide the needle at its target using imaging technology.

How do radiologist perform a biopsy?

A radiologist who performs a biopsy is called as “interventional radiologist” (as he or she intervenes). Radiologist use their knowledge and skill of imaging techniques to visualize the abnormal area or diseased organ. It is done with help of X-Ray fluoroscopy, ultrasound, CT scan, MRI or even PET CT. First the organ is imaged and exact target for biopsy is identified. 

Coordinates such as the depth and the angle of the needle to enter are planned based on the scan images. The needle entry, its depth and tip is monitored by one of the imaging technique. For eg. Ultrasound or CT scan. Once the desired target is reached, the biopsy is performed and the sample is removed and sent to the pathologist. The entire procedure is done under sterile conditions and when required under some kind of local anesthesia. Using such approach, it is minimally invasive and patients are able to go home same day after being in observation for some time. 

The image provided below is a representative and not of an actual biopsy. The blue arrow is representative of a needle tract (depth, angle etc.). The abnormal area (mass) is the target for biopsy. CT scan is able to differentiate between healthy organ and diseased organ.