Computed Tomography (CT) scans use specialized X-ray equipment and computer processing to create detailed cross-sectional images of the body’s internal structures. This imaging technology offers a much greater level of detail for organs, bones, and soft tissues than a standard X-ray. CT scanners do generate sounds, but they are generally mild and significantly quieter than the loud, repetitive sounds associated with a Magnetic Resonance Imaging (MRI) machine.
The Specific Sounds of the Scanner
Inside the large, doughnut-shaped gantry, an X-ray tube and a set of detectors are mounted directly opposite each other on a rotating ring. As the table moves the patient through the gantry, this ring rapidly spins around the patient to capture images from multiple angles. This rapid rotation is the primary source of the noise, often described as a soft whirring, humming, or brief mechanical buzzing sound.
You may also hear intermittent clicking noises, particularly at the beginning or end of a scan sequence. These sounds are not constant, but instead occur in short bursts as the X-ray tube activates and rotates. The sounds are typically brief and not loud enough to require ear protection.
The Complete Sensory Experience
The patient lies on a motorized examination table that slides smoothly into and out of the center opening of the scanner. Patients are often asked to remain completely still during the short imaging sequences, and sometimes to hold their breath for a few seconds. Any movement can blur the images, which would compromise the diagnostic quality of the scan.
Although the technologist operates the machine from a separate control room, they maintain constant visual and auditory contact with the patient. Communication is managed through an intercom system, allowing the technologist to provide instructions about when to hold still or hold your breath. The CT scanner has a much wider, open-ended gantry compared to an MRI, which helps reduce feelings of confinement.
Preparing for Your CT Scan
Preparation focuses on ensuring a clear path for the X-rays. Because metal can interfere with the X-ray beam, you will be asked to remove all metallic objects, including jewelry, glasses, and any clothing with zippers or metal snaps. You may also be asked to change into a hospital gown.
The duration of the actual scanning time is often very fast, with many modern machines completing the imaging sequence in just a few minutes. The entire process, from preparation to completion, typically takes about 30 minutes. In some cases, a contrast dye may be administered orally or through an intravenous (IV) line to enhance the visibility of certain tissues. If contrast is injected, you may experience a temporary warm or flushing sensation.