What is it?
A computerised tomography (CT) scan is made from combining multiple X-ray images into a computer system which generates cross-sectional images of your body. In a CT Abdomen/Pelvis (CT AP), the scan focuses on the lower half of your torso to create a series of detailed images to visualise the organs, bones, blood vessels and soft tissues in your abdomen and pelvic regions. This scan can be used to diagnose various conditions involving the intestines, liver, gallbladder, pancreas, kidneys, bladder, uterus and prostate.
What conditions does a CT Abdomen/Pelvis test for?
Your Gastroenterologist will usually recommend a CT abdomen/pelvis if you experience pain in the abdomen or pelvic area. It is commonly used to diagnose diseases related to the solid organs as well as the hollow organs such as the small bowel and colon:
- Inflammatory bowel diseases like ulcerative colitis or Crohn’s disease
- Liver cirrhosis
- Pancreatitis
- Abdominal aortic aneurysms
- Appendicitis
Sometimes, a CT abdomen/pelvis also helps guide biopsies, and plan and assess for surgery.
How do I prepare for a CT Abdomen/Pelvis?
You may be asked to abstain from food and drinks 4 hours before the exam if contrast material is used. Do remember to let your Gastroenterologist know if you have any allergies.
On the day of the test, wear comfortable, loose-fitting clothing. Metal objects, including piercings, jewellery, glasses, hearing aids and dentures should be removed.
What to expect
The scan may be done with or without contrast, depending on your history/presentation and whether you have any allergies. Contrast enables enhancement of the blood vessels or structures supplied by these blood vessels, allowing better visualisation of any disruptions in the blood flow or masses that have an unusual blood supply. In CT scans, iodinated contrast is often used, and it will be given intravenously.
The CT machine is shaped like a large doughnut, and you will be required to lie still on the scan table throughout the duration of the examination. The radiographer may occasionally require you to hold your breath. The table will gradually move you through the central ring of the CT machine, with the machine taking various X-ray images. The scan generally lasts from 15-30 minutes, or longer if additional body parts need to be imaged.
How long does a CT Abdomen/Pelvis take?
Generally, the test can take up to 30 minutes.
Do I need to take my clothes off for a CT Abdomen/Pelvis test?
You may be asked to change into a gown before taking the test.
Do I get my CT Abdomen/Pelvis scan results immediately?
No, a radiologist will first have to interpret the information from your scan. This is then relayed to your Gastroenterologist, who will then discuss the results with you during your next appointment.
Is a CT Abdomen/Pelvis scan better than an Ultrasound test?
Ultrasounds are helpful in other conditions, such as gallbladder stones. CT scans are more useful in detecting cancer or other structural abnormalities within the abdomen and pelvis.
What happens after a CT Abdomen/Pelvis?
You may resume your usual diet and activities unless your Gastroenterologist advises you differently.
Limitations
CT scans are efficient and provide a series of high-quality images. However, it is not without its limitations:
- This scan involves radiation exposure, and is not recommended in pregnancy.
- Most CT scans are performed with contrast, but for patients with iodine/dye allergies or pre-existing kidney disease, a CT scan without contrast or alternative imaging modalities may be recommended instead.
References
- “Abdominal and Pelvic CT.” RadiologyInfo.org, https://www.radiologyinfo.org/en/info/abdominct. Accessed 9 January 2023.
- “CT of the Abdomen or Pelvis - Los Angeles, CA.” Cedars-Sinai, https://www.cedars-sinai.org/programs/imaging-center/exams/ct-scans/abdomen-pelvis.html. Accessed 9 January 2023.
