What Is a Bone CT Scan?

A bone CT scan is a medical imaging test used to diagnose injuries, diseases, or disorders of the bones. Scans are also used to monitor medical conditions such as bone infections. A bone CT scan is typically performed by a nuclear radiology technologist and interpreted by a radiologist. The results are sent to the ordering physician to aid in the diagnosis and treatment of the patient.

The patient is provided instructions in how to prepare for the scan. In most cases, the patient will have a small amount of radioactive dye injected through a vein on the day of the scan. Such scans typically require waiting a few hours between the injection and the actual imaging test; therefore, patients are advised to bring some reading material or a project they can work on while they wait. The dye causes problem areas, commonly called hotspots, to become illuminated on the scan.

Patients who breastfeed children should formula feed for a couple of days following their bone CT scan. Pregnant patients should alert the ordering physician about their condition. In addition, if a patient has had any imaging test using a contrast material within the four days leading to the scan, the scan should be rescheduled, because the contrast dye can interfere with bone CT scan results.

Once the contrast dye has had time to disperse throughout the body, the patient is asked to lie on his or her back on an examination table. A large scanning camera moves around the patient to capture images. Sometimes patients are asked to move into several different positions to enhance the scanning results. Remaining still during the scan is important because moving around causes blurry images.

A bone CT scan takes approximately an hour to complete once the dye has moved throughout the body. Scans are typically painless, though if the patient is in pain already, it may continue or be exacerbated during the scan. Staying still during the scan can be difficult. Patients should request pillows and blankets to be more comfortable.

Risks from having a bone CT scan include injury at the dye injection site or an allergic reaction to the dye. Such reactions are rare, however. The dye will exit the body via the urine within a few days.

Results of the scan are usually sent to the ordering physician within 48 hours. Hotspots will be obvious, whether they are caused by a fracture, cancer, arthritis, or other conditions. Bone scan results are not conclusively accurate diagnostic tools. Instead, scan results are interpreted as they relate to the patient's symptoms and other medical test results. Once the diagnosis is made, treatment can begin.