Medical Services > Radiology Services > Diagnostic Radiology > CT Scan

CT Scan

What is a CT scan?
A computed tomography (CT) scan uses x-rays and a sophisticated computer to view specific parts of the body's anatomy in great detail. It is a very common imaging exam.

Unlike a traditional x-ray, where the radiation beam comes from a stationary or non-moving source, a CT scan is created by moving the x-ray beam around the patient to obtain horizontal and vertical cross-sectional views. Spiral or helical CT scans can capture three-dimensional images.

Types of CT scans include:

• CTA for detailed images of blood vessels as an alternative to a traditional angiogram
• CT lung cancer screening for early detection*
• Dentascan to view the upper and lower jaw
• 64-slice volume CT scan – a new technology that is more than twice as fast as conventional scanners, offers advanced diagnostic imaging. The 64-slice volume scanner captures images of a beating heart in five heartbeats, an organ in one second and performs whole body scans in ten seconds. The 64-slice scanner identifies cardiac disease that less advanced scanners miss and aids physicians in diagnosing disease, viewing internal abnormalities and assessing the extent of trauma damage.

Why would I need a CT scan?
A CT scan allows the physician to see various angles of a particular structure such as the brain, the heart or joints inside the body. It is sometimes used to diagnose coronary artery disease.

What to Expect
The CT scanner is a large doughnut shaped machine. The patient lies on a table with the part of the body to be examined positioned within the scanner opening. The table moves slowly and periodically during the procedure. A whirring or whooshing sound may be heard as the scan is performed.

It's important for the patient to lie still during the exam to make the images as clear as possible. The patient will be able to speak to the technologist performing the exam through a built-in intercom system at all times.

Depending on the part of the body being scanned, a contrast medium, administered orally or by injection into a vein, may be required. For other organs, fasting may be required.

A CT scan usually takes about 20-30 minutes.

Female patients who may be pregnant or are breastfeeding should discuss this with the physician prior to scheduling and with the technologist prior to the scan.

CT scans are among Greenwich Hospital's broad range of diagnostic and interventional radiology services.

Radiology services are generally pain-free, non-invasive and available to both outpatients and inpatients.

Lung Cancer Screening – I-ELCAP
Greenwich Hospital is participating in the International Early Lung Cancer Action Program, I-ELCAP, a lung cancer study. The main objective of the study is to learn whether the identification and early diagnosis of lung cancer leads to improvement in survival. Lung cancer screening requires a low dose CT lung scan, a 3-dimensional X-ray of the chest reconstructed by computer. The scan has the radiation equivalent of 2-3 chest X-rays or 2-3 transcontinental flights. To learn more about lung cancer screening at Greenwich Hospital, call 203-863-3698. For more information regarding the I-ELCAP study, visit www.IELCAP.org.

Health Library: