CT-guided biopsy: lung, abdomen and deep lesions explained

What a CT-guided biopsy is

CT shows the body in thin cross-sections, so it can guide a needle to a target that ultrasound cannot reach or see well. The doctor plans the safest path on the scan, numbs the skin, advances the needle in steps with repeat scans, and takes a sample once the tip is confirmed in the target.

The sample can be cells (FNAC) or a thin core of tissue (a core or Trucut biopsy), and the pathologist then identifies what the lesion is.

When CT guidance is used

CT is chosen when ultrasound cannot show the target safely.

• Lung nodules, masses and shadows, including those near the chest wall or the middle of the chest (mediastinum).
• Deep abdominal and retroperitoneal masses, the pancreas and adrenal glands.
• Enlarged deep glands in the chest or abdomen.
• Bone and soft-tissue lesions near the spine or pelvis.
• Lesions that need a very precise path, close to major vessels or other structures.

How it is done

Plan around 30 to 60 minutes for most CT-guided biopsies, including preparation and the scans.

• A scan is done first, and the doctor plans the safest route and marks the skin.
• You lie in the position that gives the best path, often on your back, side or front, and you are asked to keep still and breathe as instructed.
• The skin and tissue are numbed with local anaesthetic.
• The needle is advanced in stages with checking scans, and the sample is taken once the tip is confirmed in the target.
• A dressing is placed and you are observed. For lung biopsies, a chest X-ray is done after a few hours to check for a pneumothorax.

Risks: pneumothorax and bleeding

For lung biopsies, the main risk is pneumothorax, where a small amount of air leaks between the lung and the chest wall. A small one often settles by itself, and a larger one may need a thin tube to remove the air. A pooled analysis of 32 studies of core biopsy (8,133 procedures) and 17 studies of FNA (4,620 procedures) found overall complication rates of 38.8% for core biopsy and 24.0% for FNA, mostly minor, with major complication rates of 5.7% and 4.4% ^[2]. In that analysis, FNA complications were more likely with smaller lesions, larger needles and more lung traversed.

Bleeding is also planned for: deep biopsies fall in the higher bleeding risk group, so blood tests are checked and blood thinners are managed with your doctor beforehand ^[1].

Who may not be suitable, and radiation

A CT-guided biopsy needs you to lie still and follow breathing instructions. Severe lung disease, an uncontrolled bleeding tendency or a target in a very risky position may make the risk higher, and your doctor will discuss alternatives. Radiation from the scans is kept as low as reasonably possible, and in almost all cases the value of a firm diagnosis outweighs it. Tell the team if you may be pregnant.

Preparing and recovery

You may be asked to fast for a few hours. Bring your scans and blood tests, and do not stop blood thinners without instructions. After a lung biopsy you are asked to rest, avoid strenuous activity and flying for the period advised, and report breathlessness, worsening chest pain, coughing blood or fever straight away. Results of tissue samples take from a few days to a week or more when special stains are needed.

Cost and insurance

Health insurance can cover these procedures, subject to your policy terms. The exact cost is calculated after consultation, a complete evaluation of the problem, and a decision on the procedure that suits you. Cashless treatment can be arranged with major Indian health insurers and TPAs, and credit treatment is available for CGHS and Singareni beneficiaries. Eligibility is confirmed after a policy check.