Computed tomography (CT) is a radiological test that can obtain excellent images of most parts of the body. These images are obtained in cross sections and then analyzed by a computer into 3 dimensional images. The detailed images and improved resolution of most pathology in the body can be effectively seen with this technique. Many a times, a mass/fluid is seen in an unusual position. CT scan is increasingly being used to confirm the identity of these abnormal masses. CT guided needle biopsy is widely used all over North America and is an excellent tool in preventing unnecessary surgery for many individuals.

Which part of the body can biopsied?

Ct guided biopsy can done almost anywhere in the body, as long as there is a radiologist trained in the technique. CT scans of the relevant part of the body are done and a needle is used to obtain a biopsy. The precise location of the needle is guided by the CT scan. The organs which are common biopsied using Ct scan are the liver, lungs, kidneys, pelvis, pancreas, pleura, lymph nodes, bone.

What type of pathology can CT scan needle biopsy be used for?

CT needle guided biopsy can be used to make a diagnosis of:

• lung cancer
• kidney cancers
• liver masses
• pancreatic masses
• retroperitoneal masses
• bone
• aspirate fluid in the lung or abdomen
• remove blood (hematoma) from abdomen
• biopsy pleural
• biopsy lymph nodes in neck or groin
• biopsy collections or masse sin extremities
• aspirate fluid from cysts

what are precautions for CT scan?

The patient that suffers from claustrophobia will want to discuss this with their physician. This procedure involves the patient being placed into the CT scanner, typically a small, enclosed area. Depending on the specific type of biopsies being performed, certain anesthetics will be used, so discuss drug allergies with your physician.

What preparations are required?

Before a CT guided biopsy can be done, the individual must get some blood work to ensure that the kidney function is okay and the coagulation profile (bleeding parameters) are okay. One is asked not eat for several hours before the procedure. The individual should always bring old CT scans or x rays to the radiology suite. These are general preparations for a CT guided biopsy and more details are always available from the radiologist prior to the procedure.

How is the procedure done?

Once the individual arrives at the radiology site, he or she is asked to lie down on a flat table. The appropriate part of the body is exposed and the table is moved into the CT scanner where images are obtained. Once the location of the mass is identified, the body site is cleaned with an antibiotic solution and draped in a sterile fashion. A small amount of local anesthetic is injected into the skin. Using a special needle, under x ray guidance the biopsy of the pathology is obtained. The tissue samples or fluid are then sent to the pathology department for histological analysis. Once the needle is removed, a small sterile dressing is applied and the individual is observed for a few hours. The individual can go home if there are no complications.

What are risks of CT guided biopsy?

Unlike surgery, the risks of CT guided biopsy are infinitely less. However, certain complications can and do occur and include the following:

• allergy reaction to dye
• renal failure from the use of the contrast dye
• bleeding at the site
• pain
• other complications are based on what site is being biopsied

What happens after the procedure?

The CT guided biopsy generally takes anywhere from 30-60 minutes. Once the procedure is done, the individual is always observed for at least 2-4 hours. Only in some minor cases is the individual admitted if there is suspicion of a possible problem. Most individuals are asked to rest for the next 24 hrs. Following this, all patients can resume their normal activities?

When can I get the results

In most cases the tissue biopsied is sent to the pathologist. The tissue analysis usually takes anywhere from 2-5 days and the final results are available from the physicians in about a week.

Disadvantages

With any technique where needles are inserted in the body, risks can be expected and these include:

• Bleeding
• Pain
• Other complications depend on where the biopsy is performed

What are the limitations of CT guided Needle Biopsy?

In some cases where the lesion is very small, the needle may not be able to obtain a decent sample size. In such cases, either a second attempt may be done or surgery.

Needle biopsy is not cost effective when the lesions are less than 1-2 mm

For those individual who have blood disorders, CT guided biopsy may be very risky.

For those individuals with congestive heart failure, CT needle biopsy is not recommended.

Alternatives to biopsy may include continued follow-up with imaging and surgical removal of the abnormality.

Assistant Professor Clinical Radiology