CT scan

Also found in: Dictionary, Thesaurus, Legal, Encyclopedia, Wikipedia.


1. to examine or map the body, or one or more organs or regions of it, by gathering information with a sensing device, such as a moving detector or a sweeping beam of radiation.
2. the data or image so obtained, often designated according to the organ under examination, such as a brain scan, kidney scan, or thyroid scan.
3. shortened form of scintiscan.
A-scan display on a cathode ray tube of ultrasonic echoes, in which one axis represents the time required for return of the echo and the other corresponds to the strength of the echo.
B-scan display on a cathode ray tube of ultrasonic echoes, in which the position of a bright dot on the tube corresponds to the time elapsed and the brightness of the spot to the strength of the echo; movement of the transducer across the skin surface yields a two-dimensional cross-sectional display.
CAT scan (CT scan) the image generated by computerized axial tomography.
HIDA scan a type of scan using a technetium 99m complex to assess hepatobiliary function.
thallium scan a scintiscan involving use of thallium 201; see also thallium scan.
ventilation-perfusion scan (V/Q scan) a scintigraphic technique for demonstrating perfusion defects in normally ventilated areas of the lung in the diagnosis of pulmonary embolism, consisting of the imaging of the distribution of an inhaled radionuclide followed by the imaging of the perfusion of the lungs by an injected radionuclide.


Making of a radiographic image of a selected plane by means of reciprocal linear or curved motion of the x-ray tube and film cassette; images of all other planes are blurred ("out of focus") by being relatively displaced on the film.

CT scan

1. An image produced by a CT scanner.
2. The act or process of producing such an image.

CT scan

Computed tomography, see there.

CT scan (computed tomography scan)

The abbreviated term for computed or computerized axial tomography. The test may involve injecting a radioactive contrast into the body. Computers are used to scan for radiation and create cross-sectional images of internal organs.

Patient discussion about CT scan

Q. I get bad headaches had ct scans and m.r.i. even sinus surgery, suffering 2yrs now, dizzness occurs too..

A. If all prior medical investigations turned out normal, and sinus surgery didn't help relieve your symptoms, I would suggest the reason for your headaches is probably migraine attacks, that can cause severe headaches, and no CT scan or MRI can diagnose them. The diagnosis is made clinically, by your doctor. Migraine headaches can be eased by proper medications, before and during an attack. You should consult a neurologist.

More discussions about CT scan
References in periodicals archive ?
Because of patients' high expectations of having top imagistic procedures, of financial incentives for doctors (in case the CT scan was requested) and of practicing a defensive medicine style, this imagistic method is highly used.
Radiation doses from contemporary CT scans are likely to be lower than those in 1985-2005, but some increase in cancer risk is still likely from current scans.
Evidence shows that radiation doses from CT scans could be halved without affecting diagnostic accuracy.
But they said that CT scans are lifesaving and the absolute risk of developing cancer is very small.
C HILDREN undergoing life-saving CT scans could triple the risk of developing leukaemia and brain tumours, North East scientists have warned.
As far as the indications for a CT scan, 52% were for abdominal pain, followed by bleeding (7%), weight loss (4%), C.
Amy Berrington de Gonzalez of the National Cancer Institute projected that the 72 million CT scans conducted yearly in the U.
Since the advent of computed tomography (CT) scans in the early 1970s, the demand from emergency room physicians for CT scans for minor head injury patients is a routine practice, although most of these investigations are normal and fewer than 1% of patients require neurosurgery.
This researcher told USA Today that "Virtually anyone who presents in the emergency room with pain in the belly or a chronic headache will automatically get a CT scan.
By that time, a CT scan taken a couple of months before (June) as part of preoperative clearance for knee surgery showed that the irregular mass had grown significantly since the CT scan in May of the previous year.
I have never seen a meaningful positive CT scan in a patient who was awake and conversant.
Researchers say that an abdominal CT scan exposes patients to 50 times more radiation than an x-ray of the same region.