Computer tomography scan or more popularly known as CT scans are a non-invasive diagnostic imaging procedure utilizing a combination of computer and X-ray technology to generate accurate and detailed images of body structures including organs, blood vessels, tissues, and bones. Widely regarded as one of the most important medical developments of the past century, it is a valuable medical diagnostic tool that allows specialists to more easily and accurately diagnose diseases.
Compared to the standard X-ray technology which generates two-dimensional views of bodily structures, CT scans can create detailed and 360-degree images. This is made possible by an X-ray machine rotating around the body and taking various images in thin and horizontal slices. A computer, in turn, draws together these cross-section images to create a three-dimensional model of the bodily structure.
What To Expect: CT Scans
More information and instructions for this procedure.
CT Scans are typically utilized in the workup of abdominal or chest pain. During cases when cancer is suspected, a CT scan is relied upon by physicians in visualizing the tumor and assessing its size and location as well as the potential involvement with other tissues.
CT scanning is also widely used for the early detection of cancer. Low-dose CT scans, wherein the radiation emitted is significantly lower and which can take less than a minute to complete, is highly recommended for adults considered to be at high-risk of lung cancer due to their history of smoking. It may also be used in detecting vascular diseases, osteoporosis, infections, finding injuries, clots, hemorrhages, and other issues.
How It Works
During a CT scan procedure, a patient lies on a motorized table that goes through the CT scanner, a large machine with a hole in the center. This advanced machine emits a series of radiation beams through the patient’s body which is held in position with straps and pillows.
As the table moves the patient into the scanner, an X-ray source rotates around the circular opening. Each rotation yields different images of internal organs and tissues. All data coming from the X-ray source is digitally transmitted to a computer that reconstructs the individual shots of internal organs and tissues.
In some instances, a patient may need to be administered with a contrast agent to visualize organs, blood vessels, and certain structures that are hard to see. A contrast agent may be administered intravenously, orally, or both; depending on how your doctor prescribes it.
During The Test
During the test, the patient will lie on the motorized table which then goes through the CT scanner. The specialist leaves the exam room and goes into a control room. The patient can communicate with the technologist through an intercom.
The table then slowly goes into the scanner and moves a few millimeters at a time. Buzzing and whirring sounds may be heard. However, the patient won’t feel anything throughout the entire procedure.
The patient needs to stay still while the CT images are being captured. Movement can result in blurred images. In some instances, the patient may be asked to hold his or her breath for a few seconds to prevent the chest and abdomen from moving.
Once the procedure is over, the captured images are processed and transmitted to a radiologist for review. A report will be generated and sent electronically to your chart and to your ordering physician.
CT scans are a painless procedure that normally takes 15-20 minutes to complete including the interview and administration of contrast material. But there are instances when additional scanning may be needed depending on the diagnostic requirements.
Regardless of the type of scan a patient may receive, it is very important that the patient avoids clothing with any metal zippers, underwire bras, metal clasps, or jewelry. Also, please notify the ordering physician if there is any chance that you may be pregnant.
For Patients Drinking Oral Contrast:
Three hours of fasting prior to the exam (clear liquids are acceptable).
Please inform your physician if you have any allergy to any contrast agent or had an allergic reaction in the past.
On the day of your CT Scan, please do the following:
Pour the 30mL bottle of Gastroview into the 500mL bottle of water (shake well before drinking).
Start drinking the mixture 1.5 hours prior to your appointment time, but do not finish it.
Bring the bottle with you to the appointment and finish drinking it in the waiting room.
For Patients Receiving An IV Contrast:
Three hours of fasting prior to the exam (clear liquids are acceptable).
If you are receiving IV contrast for a CT scan, you must have a CREATININE blood test drawn and the results forwarded to us or in your chart prior to the CT scan. Please inform your physician if you have any allergy to any IV contrast agent or had an allergic reaction in the past.
Kidney function blood work is required for all contrast patients within 30 days.
You will be asked to fill out a questionnaire and consent form for injection.
For All Diabetic Patients:
This is a list of diabetic medications – excluding insulin – that should be discussed with your physician if your CT exam is ordered with IV contrast medium:
The patient must have a recent normal BUN/CREATININE within 4 weeks.
The ordering physician determines whether or not to stop the medications listed below prior to receiving IV contrast.
If instructed by the ordering physician, these medications should be withheld 48 hours after the IV contrast. A repeat BUN and CREATININE should be drawn before the patient goes back on their diabetic medications.
The patient’s renal functions should be normal before starting these following medications:
Types Of CT Scans
CT Head or Brain. CT scan of the brain is used to assess injury or abnormality including tumors, bleeding, blood clots, or any sign of stroke.
CT Orbits. This is a procedure that scans the eyes, its sockets or orbits, as well as the surrounding nerves, muscles, and bones. It is used to detect infection of the eye area, foreign object in the eye socket or a damaged eye socket bone.
CT Soft Tissue Neck. This type of CT scan examines the neck starting from above the ears and below the collarbone. It can accurately diagnose conditions affecting areas like the mouth, throat, nasal passages, and thyroid glands.
CT Maxillofacial. This is a key diagnostic procedure for evaluating face trauma. It is used to assess parts of the face like the jaw, orbits, sinuses, and cheekbone.
CT Sinus. A procedure aimed at capturing images of the sinuses, CT sinus is useful in diagnosing sinusitis and examining tumors of the sinuses and the nasal cavity.
CT Chest. This procedure helps uncover the cause of unexplained chest pain, cough, difficulty in breathing, and other chest-related symptoms.
CT Abdomen. This examination helps in detecting diseases of the colon, small bowel, and other internal organs.
CT Pelvis. CT pelvis examines structures inside and near the pelvis such as bladder, prostate and reproductive organs as well as pelvic bones and lymph nodes.
Cervical Spine. This procedure is often performed in patients who recently were in an accident as well as those who are complaining of neck pain. It examines the portion of the spine running through the neck.
Thoracic This type of CT scan can diagnose abnormalities in the mid back area from the bottom of the neck to the upper abdominal area.
Lumbar Spine. This type of CT scan can diagnose conditions affecting the lumbar portion of the spine.
CT Upper Extremity. This procedure can evaluate pain, swelling, trauma, and fracture in any area of the upper extremity including the hand, shoulder, and arms.
CT Lower Extremity. By obtaining multiple images of the hip, ankle, knees, and foot, this procedure can help determine the cause of swelling, pain, or trauma involving the lower extremities.
Low-Dose Lung Cancer Screening. This type of CT scan is recommended for people with no history or symptoms of the disease but are considered high-risk because of a history of heavy smoking or advanced age (55 to 80 years old).