A CT scan is an X-ray procedure that uses a computer to produce 3-D cross-sectional images of inside the body. Unlike conventional X-rays, CT scans provide exceptionally detailed images of the bones, organs and tissues. X-rays are taken from many angles and combined to create a cross-sectional image.
During a CT scan, a patient rests on a table that slides into a large, tunnel-shaped scanner. Some exams require that a contrast dye be injected into a vein before the procedure. This helps certain areas show up better on the images. The procedure is painless and typically takes a few minutes.
A CT scan may be used to pinpoint the location of a tumor, evaluate the extent of cancer in the body and assess whether the disease is responding to treatment. In some cases, CT technology is used to accurately guide cancer treatment during a procedure.
Some types of CT scans include:
3-D CT angiography
CT angiography (CTA) is a diagnostic tool used to locate tumors in the body, determine whether cancer has spread, and detect abnormal blood vessels that may indicate a health risk.
CTA produces multiple X-rays of cross sections of the body, which are reconstructed through a computer to form a 3-D image. CTA may help determine the location of a tumor, and where to administer cancer therapies. The test also may serve as an alternative to a standard angiogram, which involves placing a catheter through a large artery.
The potential advantages of CTA include:
- More detailed images than those provided by MRI or ultrasound
- A less time-consuming process than a standard angiogram
- A more thorough examination, including images of almost every blood vessel in the body, as well as the brain, heart, lungs, pelvis, abdomen and extremities
- A painless and relatively short (typically 30 to 60 minutes) procedure
CT-guided biopsy
During a CT-guided biopsy, our doctors insert a biopsy needle into the body under the guidance of images generated by a CT scanner.
Large bore CT scanner / RT with simulation
This test produces detailed images of areas inside the body for diagnosing cancer and planning radiation therapy. This sophisticated imaging technology combines simulation, fluoroscopy and respiratory gating to plan and deliver radiation.
The potential advantages of the large bore CT scanner include:
- Pinpoints tumor location while monitoring tumor motion to guide a variety of interventional procedures
- Allows radiologists to plan treatment in accordance with patients’ breathing patterns
- Has a large opening that allows for accurate scanning of patients of all sizes and in various positions
- Typically makes for a more comfortable, less claustrophobic experience for patients
Multi-detector CT scanner
Because multi-detector CT scanners obtain multiple image slices in a single rotation, radiologists are able to view high-quality images of the body in micro-level detail. This technology also allows doctors to obtain data faster than they would during a typical scan. And, the increased width of the scanning space generally allows for a more comfortable, less claustrophobic experience for patients.
PET/CT
This nuclear imaging technique combines position emission tomography (PET) and computed tomography (CT) into one machine. A PET/CT scan reveals information about both the structure and function of cells and tissues in the body during a single imaging session.
During a PET/CT scan, the patient is first injected with a glucose (sugar) solution that contains a very small amount of radioactive material. The substance is absorbed by the organs or tissues being examined. The patient rests on a table that slides into a large tunnel-shaped scanner. The PET/CT scanner is then able to “see” damaged or cancerous cells where the glucose is being absorbed (cancer cells often use more glucose than normal cells) and the rate at which the tumor is using the glucose, which may help determine the tumor grade. The procedure is painless and varies in length, depending on the part of the body being evaluated.
By combining information about the body’s anatomy and metabolic function, a PET/CT scan provides a more detailed picture of cancerous tissues than either test does on its own. The images are captured in a single scan.
Most oncologists perform a CT scan and/or a bone scan prior to ordering a PET/CT scan.