CT Scan

OUR NEW SCANNER!

Diagnosticare has just taken ownership of the worlds best CT scanner.

Siemens Force is the industries leading scanner for radiation dose and detail.

Don’t be fooled by the labels “Low Dose CT Scanning”.

This is the lowest dose CT scanner available. Diagnosticare is always willing to put patient welfare before cost saving!

Definition

A computed tomography (CT) scan is an imaging study that uses x-rays to create cross-sectional images of the body.

Other names/synonyms

CAT scan; Computed tomography scan.

How the test is performed

You will be escorted into the CT room and asked to lie on a narrow table that slides into the aperture of the CT scanner. Depending on the study being done, you may need to lie on your stomach, or back.

In most scans your head is positioned outside of the scanner aperture.

Once you are in position and unbeknown to you, the machine’s x-ray tube rotates around you.

Small detectors inside the scanner measure the amount of x-rays that make it through the part of the body being studied. A computer takes this information and uses it to create several individual images, called slices. These images can be stored, viewed on a monitor, or printed on film. Three-dimensional images of organs can be created by stacking the individual slices together.

You must keep still during the exam, because movement causes blurring of the images. You may be told to hold your breath for short periods of time.

Generally, complete scans take only a few minutes. The newest multidetector scanners can image your entire body, head to toe, in less than 30 seconds.

How to prepare for the test

Certain tests require a special fluid,calledcontrast, to be delivered into a vein before the test starts. Contrast can highlight specific areas inside the body, which creates a clearer image.

Some people have allergies to IV contrast and may need to take medications before their test in order to safely receive this substance.

You will be asked about any allergies you may have prior to commencement of the scan.

Contrast can be given several ways, and depends on the type of CT being performed.

It may be delivered through a vein (IV) in the back of your hand or your forearm.
It may be given through the rectum using an enema.
You might drink the contrast before your scan. Whether you actually drink the contrast depends on the type of exam being done. The contrast liquid is clear and tasteless. The contrast eventually passes out of your body through your stools.
If contrast is used, you may also be asked not to eat or drink anything for 4-6 hours before the test.

If you weigh more than 150 kilograms, have your doctor contact the radiographer before the exam. CT scanners have a weight limit. Too much weight can cause damage to the scanner’s working parts.

Since x-rays have difficulty passing through metal, you will be asked to remove jewellery and wear a hospital gown during the study.

How the test will feel

Some people may have minor discomfort from lying on the hard table.

Contrast given through an IV may cause a slight warm or hot sensation, a metallic taste in the mouth, and a warm flushing of the body. These sensations are normal and usually go away within a few seconds

Why the test is performed

CT creates high quality pictures of the body, including the brain, chest, spine, and abdomen. CT may be used to:

Guide the radiologist to the right area during a biopsy or injection
Identify masses and tumours, including cancer
Study blood vessels

What the risks are

CT scans and other x-rays are strictly monitored and controlled to make sure they use the least amount of ionising radiation. CT scans do create low levels of ionising radiation, which has the potential to cause cancer and other defects. However, the risk associated with any individual scan is very small. The risk increases as numerous additional studies are performed.

In some cases, a CT scan may still be done if the benefits substantially outweigh the risks. For example, it can be more risky not to have the exam, especially if your doctor thinks you might have cancer.

An abdominal CT is usually not recommended for pregnant women, because it may harm the unborn child. Women who are or may be pregnant should speak with their doctor to determine if ultrasound can be used instead.

The most common type of contrast given into a vein contains iodine. If a person with an iodine allergy is given this type of contrast, nausea, sneezing, vomiting, itching, or hives may occur.

If you absolutely must be given such contrast, your doctor may choose to treat you with antihistamines (such as Benadryl) or steroids before the test.

The kidneys help filter the iodine out of the body. Therefore, if you have kidney disease or diabetes you should receive plenty of fluids after the test and be closely monitored for kidney problems. If you have diabetes or are on kidney dialysis, talk to your radiographer before the test about your risks.

Rarely, the contrast may cause a life-threatening allergic response called anaphylaxis. If you have any trouble breathing during the test, you should notify the radiographer immediately. Scanners come with an intercom and speakers, so the radiographer can hear you at all times.

CT Colonography

CT colonography, also known as virtual colonoscopy is as effective, less invasive and quicker to perform then endoscopic (fibreoptic) colonoscopy in detection of colon cancer in screening programmes. Unlike endoscopic colonoscopy, no sedation is required which allows you to drive and or go back to work after the procedure.

DiagnostiCare offers you access to latest generation CT technology — the 64-slice CT scanner — for this screening. Centers offering CT colonoscopy have specialised software programmes and specially certified radiologists to read the results.

CT colonoscopy is indicated if:

  1.  You require colon cancer screening because you’re age 50 or older or because you have family history of cancers. (not Medicare rebatable)
  2. If you have vague symptoms, suggesting that a polyp may be present (anaemia from blood loss in the stool) (Not currently Medicare rebatable)
  3. You have had a failed endoscopic colonoscopy (Medicare rebatable)

Benefits of Virtual Colonoscopy

Benefits of virtual colonoscopy include:

Low risk: Unlike colonoscopy, CT colonoscopy lacks the risks associated with sedation and with bowel perforation.
Faster: CT colonoscopy takes about an hour to perform, as opposed to the majority of the day required for endoscopic colonoscopy. Patients can return to work and normal daily activities on the same day and do not need someone to take them home.
Quick diagnosis: At Diagnosticare, reports are returned to your doctor within 48 hours or sooner.
We can see what is in, and outside the bowel wall: Unlike endoscopic colonoscopy, CT colonoscopy can detect the cancers and growths in and outside the colon because it images the entire abdominal cavity and pelvis.
CT colonoscopy is approved by the American Cancer Society (ACS) and leading gastrointestinal societies as an alternative to endoscopic colonoscopy.

What Happens During the Procedure

Virtual colonoscopy requires the same preparation as standard colonoscopy. You must receive laxative bowel cleansing and a liquid only diet for 24 hours prior to the scan. You will also be asked to swallow a mouthful of Barium the night before the study. Detailed preparation instructions are available on booking.

The procedure involves placing a small rubber tube (compared to a 2 meter scope used in endoscopic colonoscopy) into the rectum to inflate the colon. The radiologist inserts some carbon dioxide into the colon to expand it. Carbon dioxide, provides better visualisation, is more rapidly absorbed and causes much less cramping and discomfort compared with room air. You are given an antispasmodic (Buscopan) immediately prior to insufflation of the Carbon Dioxide.

The scan takes 10 to 12 seconds on your back and the same time when lying on your stomach. The whole procedure takes about one hour.

If a polyp or polyps are found, then endoscopic colonoscopy must be performed to remove them. You’ll have to complete another bowel preparation, usually on a different day. Polyps are detected in about 10 to 20 percent of patients at colonoscopy.

Cardiac CT

Definition

CT Coronary Angiography is the x-ray examination of the blood vessels of the heart after contrast has been injected into the bloodstream.

(Contrast is a water-soluble substance that improves the visibility of internal structures and is usually harmless to the body).

Accurate information is obtained without the need to position a catheter in the coronary arteries. Information is also obtained about the heart muscle and heart valves.

CT Coronary Angiography allows for detection of calcified and soft, non-calcified narrowing and blockage of the coronary arteries.

It is also useful in following progress of coronary artery stents.

How to prepare for the test

No special preparation is required, but we do require you to arrive one hour and fifteen minutes before the scheduled study, so you can fill in an important questionnaire.
An hour before the scan you will be given a Beta-blocker tablet to lower your heart rate.

Procedure

A plastic IV access cannula will be placed in a vein and you will be positioned on the scanner. ECG leads will be attached to your chest.
You may receive an under the tongue spray just before the scan. The intravenous contrast will then be injected. This is the same contrast used for all CT scans. We then proceed with the scan.

How the test will feel

You will feel a warm flush sensation when the intravenous contrast is injected, which is normal.

Recovery

After the scan is completed, you are free to go within a few minutes.

What the risks are

The vast majority of examinations proceed smoothly. There may be a reaction to contrast medium such as wheezing and skin rash. Severe reactions however are extremely rare.

Contraindications

These are conditions or factors that serve as a reason to withhold treatment.

  • Severe Asthma
  • Allergy to contrast medium
  • Poor renal function
  • Inability to lie still

About the Referral

CT Coronary Angiography is Medicare rebatable if a physician or cardiologist makes the referral.

Calcium Scoring is an out of pocket procedure.

The radiation dose is anywhere from 1.6 millisieverts. (Annual environmental background radiation is approximately 2 millisieverts).

Most studies are performed on the low dose step-and-shoot mode with dose of 1.8 to 2.5 millisieverts.

Heart disease and stroke

Heart disease and stroke is the cause of death in about half of all Australians who die each year. Many people have no warning signs of the disease when their first attack happens. Nearly half of first attack patients die from that event.

What is Artery Calcium Scoring?

The Coronary Calcium Score is a measurement of the amount of calcium in the walls of the arteries that supply the heart muscle. Calcification of the artery occurs secondary to a disease called atherosclerosis. This calcification is a reliable indicator of the overall load of atherosclerosis in a person’s arteries. The calcium score measures your risk of having a heart attack or stroke in the next five years.

A valuable preventative measure

Your doctor will use the Calcium Score to decide whether you are at low or high risk of a heart attack and use this information to reduce your risk. This may be by changes in diet, exercise, blood pressure control, stopping smoking and reducing cholesterol.