Diagnosing GI Conditions: CT Vs. MRI

Digestive symptoms can disrupt your everyday life and feel frustrating, scary, and even embarrassing to talk about.

Gastrointestinal issues such abdominal pain, a change in bowel habits, rectal bleeding, trouble swallowing, and unexplained weight loss are some of the most common GI symptoms we see at Rockford Gastroenterology Associates. That’s what our team of 14 Board-certified Gastroenterologists and seven Advanced Nurse Practitioners spend their days diagnosing, treating, and monitoring.

When patients come to RGA, they’re often referred by their primary care physician or they’ve reached out directly to us. Your first appointment – whether that’s in person or via telehealth – will be all about discussing and explaining your symptoms with your RGA provider to help determine what needs to happen next.

The next steps could include a procedure such as a colonoscopy or upper endoscopy to further diagnose symptoms or imaging such as a CT or MRI scan. In this blog, we’ll explain more about the imaging process related to GI conditions.

People might understand MRI to be a better test than CT scan because an MRI is more complex and can produce clearer and more detailed images than a CT scan. In truth, the decision to use one exam versus the other depends on the symptom being evaluated and the specific question being asked.

CT Scan

A CT scan provides excellent images when investigating abdominal pain. CT scans provide great detail about the liver, pancreas, and other solid organs in the abdomen, and can provide clues to other abnormalities such as diverticulitis and appendicitis of the intestinal organs or the abdominal blood vessels.

CT scans are very quick exams and can be completed in a matter of a few minutes, which can be very important in the emergency room setting. They use a small dose of radiation to obtain images and are better tolerated by patients who cannot hold still for extended periods of time, have difficulty with claustrophobia, or have certain kinds of metal implants in the body.

MRI

Meanwhile, MRI can provide detailed imaging for specific questions but may not be able to provide specific details when evaluating for a symptom such as abdominal pain. For example, depending on their composition, bile duct stones can be missed by CT scan but can be readily identified by MRI when specific bile duct images are obtained.

Additionally, MRI can provide highly detailed images of pancreatic cysts, which are especially helpful when looking for specific characteristics to understand cancer risk, including changes from one exam to the next.

Asking specific questions about these kinds of diseases allows the radiologist to arrange the exam to obtain the appropriate images and details. Not all exams are performed the same way, so an MRI of the spine will capture different images from an MRI of the abdomen.

MRI scans take longer to obtain, requiring the patient to remain still for the duration, and MRI is a loud machine in which patients can feel claustrophobic. MRI does not use radiation but uses a magnetic field and radio frequencies to image the body and is more expensive than a CT scan.

Symptom evaluation is key

The decision to order a CT scan or MRI will depend on the physician’s evaluation of your symptoms. Not all abdominal pain needs imaging evaluation. Upper abdominal pain might be better evaluated by upper endoscopy or ultrasound, sometimes in combination with lab work.

Imaging generally does not provide much information in evaluating diarrhea or GI bleeding, where upper endoscopy or colonoscopy would be more helpful.

On the other hand, imaging may be recommended first, depending on the symptom being evaluated, but is not always necessary. It’s just one of several tools that can be utilized in the evaluation of GI symptoms.

If you’re experiencing any type of GI symptom and have questions, please call us at 815-397-7340 or make an appointment online. A referral is not always needed.