Hong Kong Imaging and Diagnostic Centre

Computerized Tomography Scan (CT Scan)

What is a CT Scan

CT stands for computerised tomography. This is a diagnostic imaging technique that produces a sequence of detailed cross-sectional images of the body. A CT scan utilizes a rotating X-ray gantry coupled with sophisticated computers to generate multiple images or pictures of the inside of the body. It is used to analyse the internal organs, bones, soft tissue and blood vessels with great clarity and reveal more detailed images than those produced by regular X-ray examination. A CT scan can diagnose cancers, cardiovascular disease, infectious disease, trauma and musculoskeletal disorders. CT scans are reported by in-house radiologists with many years of training and practical experience in interpreting CT examinations.

At Hong Kong Imaging, our new CT scanner is an Ultra-Low Dose CT that employs the latest CT technology to reduce patient dose to only 1/6 of that of a standard CT, along with optimization of image quality and reduction in any metallic artifacts.

How is a CT done

A technician will position you lying on a CT table with either your head or your feet closest to the CT gantry, depending on which part of your body is being scanned.

You may be required to drink an oral 'contrast' solution 1 hour prior to your exam, particularly if you are having scans of your abdomen and/or pelvis. The contrast helps provide a clearer outline of the stomach and intestines.

Some CT scans require intravenous (IV) injection of contrast medium into a vein, usually administered into the back of the hand. You may notice a hot flush feeling, and experience an unusual metallic taste or smell after the IV injection. These sensations are normal and usually only last between 10 and 60 seconds. The table is slowly moved through the scanner. You will be asked to remain motionless for the length of the examination. Some studies will require you to hold your breath. The technician will be in the room and will help instruct you.

Depending on the area(s) to be examined, the CT procedure normally takes between 10 – 45 minutes.

What to expect afterwards

Your radiologist will examine your scans and send the film and report to your referring doctor.

After your procedure you will be able to resume all normal activities. If you notice any pain, redness, and/or swelling at the IV site after you return home following your procedure, you should notify your physician straight away.

Click Here for   "Cardiac Computed Tomography (Cardiac CT) Scan"

What you Must Tell us

Please tell the technician if you are pregnant, or suspect you might be pregnant, or are breast-feeding.

If you have had an adverse reaction to a previous contrast injection or any other drugs.

Please inform our staff if you have any allergies, a history of asthma, heart disease, renal impairment, thyroid disease, or diabetes mellitus

If you are diabetic, you should not take insulin or anti-diabetic drug before the examination. Please let the technician know if you take any diabetic medication that contains metformin - examples are diabex, diaformin, avandament, glucomet, novamet, genex, glucophage, insulin, or blood thinner (warfrin or aspirin products).

How to Prepare

You will be shown to a private changing area and be given a gown to change into. You may be asked to remove jewellery, eyeglasses, underwired brassieres, and metal objects that could interfere with the x-ray images.

No preparation is required for a non-contrast examination.

Contrast examination:
  • Fast for 4 hours prior to the scheduled examination. Plain water is allowed.
  • Do not drink coffee, tea or soft drinks on the date of examination. Do not take diet pills, Viagra or similar medication for 24 hours before the examination.
  • Do not take diabetes mellitus medication , e.g. Metformin 24 hours prior to examination. Resume intake of DM medication 48 hours after the examination.
  • Oral contrast (provided by our centre) may be required for certain examination.
  • Please inform our staff if there are any allergy history.
  • Please bring any previous CT films and results on the examination date in case they are needed for comparison.