Computed Tomography

What is a CT?

A CT exam is a test using special X-ray equipment that takes clearer, more detailed pictures than traditional X-rays. A CT machine rotates to take X-ray images from different angles around your body. A computer puts these images together for a radiologist to read.

We perform many types of CT exams including cardiac CT, CTA, CT colonography, dental CT and low-dose CT for lung screening. Most exams take less than 15 minutes on the scanner. Some exams can take longer.

Cardiac CT

Mass General Imaging offers full cardiac CT services in Boston. A cardiac CT scan is designed to detect the buildup of plaque in the coronary arteries. The radiologists reading the scans partner with the Mass General Corrigan Minehan Heart Center to deliver the highest level of cardiac care.
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CTA

Mass General Imaging offers CTA services in Boston and other community locations. This type of exam uses CT technology to better examine blood vessels.
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CT Colonography

Mass General Imaging offers CT colonography in Boston and Waltham. This type of exam produces a 3D view of the colon to screen for abnormal growths of tissue, or polyps.
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Dental CT

Mass General Imaging offers dental CT imaging in Chelsea and Waltham. The 3D images help dentists and oral surgeons plan implant procedures.
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Low Dose CT

Mass General Imaging offers lung screening using low-dose CT scans (LDCT) in Boston, Chelsea, Danvers and Waltham. This exam is used to screen patients at high risk for lung cancer.
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CT and Radiation Dose

Learn about the many ways we minimize radiation dose at Mass General Imaging.

How to Prepare for a CT

You can use this information to prepare for most CT exams. You need to follow special instructions to prepare for a CT colonography, cardiac CT and CT angiography.

You can log into Patient Gateway for more details about your specific appointment.
  • CT Screening Form - You can print out and complete the CT Screening Form before your appointment. 
  • Eating & Drinking - Please do not eat solid food two hours before your appointment. Please drink plenty of fluids such as water or clear soup. Your doctor's office can tell you if you have any other restrictions.
  • Contrast - You may need contrast for your CT. There are two kinds: the kind you drink in the waiting room (oral contrast) and the kind you get through an IV (IV contrast). Contrast helps us see the images more clearly. We can usually tell you before your appointment if you need contrast. Sometimes we get information on the day of your exam that changes how we image you and if you need contrast.
  • Clothing - If you can, try to wear loose-fitting, comfortable clothing with no metal like zippers or underwire in bras. Metal can blur the images. We may ask you to change into hospital attire for clearer images. 
  • Valuables - We suggest you leave your valuables at home so you don’t have to worry about them. You can keep your things with you during your exam. 
  • Children - Children are not allowed in the exam room. If you need to bring kids, please bring someone to watch them in the waiting room.

Patient Resources

Use these patient resources to learn more about getting a CT at Mass General. You can contact us if you have any questions.

CT Screening Form
CT Screening Form

CT Screening Form

You can print this CT screening form and fill it out before your appointment.

checking in
Checking in

Checking in

Find out what happens when you check and why we keep asking for your date of birth.

ct and radiation
CT and Radiation

CT and Radiation

We pay special attention to minimizing radiation exposure. Find out how.

ct with anesthesia
CT with Anesthesia

CT with Anesthesia

Learn more about a CT exam with anesthesia.

order your exam
Order Your Images

Order Your Images

You can order your images online or in person.

get your results
Get Your Results

Get Your Results

Most imaging results are in Patient Gateway in about a week. Sign in or sign up now.