Abdominal CT Scan: Purpose, Preparation & Procedure

An abdominal CT scan is a medical test used to capture the internal images of the belly by employing X-rays and computers to evaluate abdominal organs.

During the test, a patient lies on a table that can move through a machine shaped like a doughnut that takes multiple X-ray images from different angles. The computer combines these images to create detailed 3D pictures of the organs and tissues in the abdomen.

This test helps doctors diagnose various health issues in the body, including tumours, infections, injuries, and other abnormalities.

Why do you need an Abdominal CT Scan?

The abdomen can be scanned to assess various health conditions:

• Abdominal CT scans are used by doctors to diagnose abdominal or pelvic pain and diseases of the internal organs, small bowel, and colon.
• A CT scan of the abdomen can be used to diagnose different health problems like infections, swelling in the bowel, cancer, stones in the kidney or bladder, and ballooning in the main blood vessel that runs through the belly.
• This test can also be used by doctors to guide biopsies and other procedures. It also helps plan and assess the results of surgery, stage tumours, administer radiation treatments, and monitor response to chemotherapy.

Preparation

In case you have any queries about the preparation for an abdominal CT scan procedure, it is always better to talk with your doctor. However, below are some general preparation tips that can be beneficial before going through the scan:

• Observe what your health advisor says and carefully follow their instructions.
• If you are allergic to any medications, contrast dyes, or iodine, inform your doctor before the test.
• In some cases, the patient may need to fast for a few hours before the test. Your doctor will inform you if it is required.
• You may be asked to change into a hospital gown for the test. Wear comfortable and loose-fitting clothing to make changing easy.
• To avoid problems during the scan, it’s important to remove any metal objects like jewellery or hairpins.
• Women may need to remove undergarments that have metal adornments.
• During an abdominal scan, you may need to remove any piercings you have.
• You may also have to remove your hearing aids and removable dental work.
• If you have diabetes or kidney problems, tell your doctor before taking an abdominal scan.
• Doctors recommend having ample water in many abdominal CT scan cases for better visualisation of the organs.

Procedure

The CT scan of the abdomen takes around 30 minutes to complete. During the procedure, one can expect the following to happen.

• Before the procedure, you may need to change into a hospital gown and take off any jewellery or metal objects.
• A contrast dye is used during the process, which helps assess the organs and tissues better.
• You will lie down on a table that slides into the CT scanner, which is a large machine shaped like a doughnut.
• The CT scanner takes multiple X-ray images from different angles around your body. You may need to hold your breath briefly during some of the scans to reduce any blurring of the images.
• In some cases, you may also receive an injection of contrast dye into a vein in your arm during the scan, which can help highlight certain structures in your abdomen.
• Once the scan abdomen is complete, you can leave the hospital or imaging centre and resume normal activities. Your doctor will typically review the images and discuss the results with you at a later appointment.

How does the test feel?

During an abdominal scan, lying on a hard table may make you feel uncomfortable. If you are injected with the contrast dye through your vein, you could feel a metallic taste in the mouth or a sensation of burning, but these feelings are common and generally disappear within a short period.

During the Procedure

During this CT scan, you might see the lines of light projected towards your body to make sure you’re in the right position on the table. The CT scanner may make buzzing, clicking, or whirring sounds as it takes pictures of your abdomen. You won’t see the scanner’s internal parts, but you may hear the noise they make during the scan.

After the Procedure

Post abdominal CT scan; the technologist will remove the intravenous line and cover the small needle hole with a dressing. You can then resume your usual activities without any delay.

What should you do after the scan?

If you receive a contrast injection during the CT scan, drink 1.5 to 2 litres of water within 24 hours to remove the contrast from your body. On the other hand, if you are a diabetic who received a contrast injection with iodine, you may need to stop consuming certain medicines for 48 hours (a list of medicine names will be provided by the technologist). There are no dietary or physical restrictions that need to be followed after the CT scan.
A radiologist will diagnose the scan images and send the results to your regular doctor, who will discuss the results with you.

Result

An abdominal test can provide detailed images of the organs and tissues inside the belly area. Doctors can use these images to find any problems or diseases that might be there. CT scans can help diagnose conditions like infections, tumours, injuries, or other health problems. After getting the results, your healthcare expert will talk to you about what they found and discuss the treatment options or any further tests if they are needed.

Risk Factors

Before getting an abdominal CT scan, talk to your doctor about any concerns and queries you may have about the advantages and drawbacks of the procedure. Although the abdominal or pelvic CT scan is safe, there can be some possible risks, including:

• Exposure to ionising radiation may increase the risk of cancer in the long term.
• Allergic reaction to the contrast dye, which can cause hives, itching, swelling, or difficulty breathing, can be seen in rare cases.
• Kidney damage or failure can be observed in patients with pre-existing kidney disease or those taking certain medications that affect kidney function.
• Rarely, the perforation of the bowel or other internal organs can be seen due to the pressure from the gas used to inflate the colon during a CT colonography.
• Women who are expecting may be asked not to undergo a CT scan unless it is necessary for medical reasons. This is because a CT scan exposes you to high doses of radiation that can potentially harm the unborn baby. If there is any chance of pregnancy, women should inform their doctor and the CT technologist.

Limitations

Pelvic or CT abdomen scan has some limitations, such as:

• Very large people may not fit into the CT scanner or be over the limit specified for the weight allowed for the instrument.
• A CT scan might not be comparable to ultrasound in terms of accuracy in detecting gallstones.
• Doctors may prefer other imaging techniques like plain films, ultrasound, and GI contrast exams for assessing acute abdominal ailments in babies.
• For certain conditions, MRI is considered a better option than a CT scan for diagnosis and evaluation.