CT Scan

What is CT?

Computed Tomography, or CT (also known as Computerized Axial Tomography or CAT scan) is one of the most versatile diagnostic imaging test available today. The CT test provides the fastest and one of the most accurate means to look into the internal organs of the entire body.

The CT scanner is made up of a sophisticated combination of x-ray source, detectors, and computers to produce high resolution cross sectional images of the body. The patient lies on a table that moves through a doughnut hole like gantry containing the x-ray tube and multiple detectors. The walls of the opening into the gantry are wedge-shaped so that claustrophobia is not a significant problem. A series of cross sectional images are taken of the area of interest in a matter of seconds. The raw data from the multiple detectors are then reconstructed by computers to present images of the internal structures of the area scanned.

Equipment

Yeoh & Muranaka Radiology is equipped with Toshiba Aquilion 16 CT scanners at our Ala Moana and Kaheka offices. Our multi-detector CT scanners are capable of performing cross sectional slices as thin as 0.5 mm with sub second rotations of the gantry at 0.5 second providing high resolution studies. From a single data acquisition or scan, our CT units are capable of volumetric imaging that produces multiple 2D and 3D reconstructed imaging projections.

Toshiba’s commitment to patient centered imaging has led to continuous development of technologies that enhance patient safety. Their most recent enhancement is the SUREExposure dose reduction capability of the Aquilion CT. SUREExposure is a powerful dose reduction tool that incorporates the imaging task, patient size and shape, and the imaging parameters, to dramatically reduce radiation dose while ensuring excellent image quality.

Procedure

The examination is much like having a routine x-ray test. Prior to the test, depending on the area of the body being imaged, various preparations may be necessary. For example, for abdomen and pelvic CT studies, patients are given three to four cups of oral contrast to drink 45-60 minutes prior to beginning the CT study. The contrast is important for visualization and differentiation of bowel from adjacent abdomen and pelvic organs and diseases. For kidney examinations, patients are given water to drink in order to enhance the images of the test.

You will change into a gown and be led to the CT scanner room.
You will be positioned on the scanner table and special lights will be used to ensure that you are properly positioned.  Although you will be alone in the exam room during the scan, the technologist will be able to see, hear and speak with you at all times.

Some exams may require an intravenous (IV) contrast. If this is necessary, a temporary intravenous (IV) catheter will be placed in one of your arm veins.  It is very important that you report any food allergies or previous reactions to contrast you may have had in the past. If you have a significant allergy history, it may be necessary to give you some medication to reduce the risk of an allergic reaction to the intravenous contrast.

During the CT test, you may be asked to hold your breath for 8-12 seconds so that there is no motion and the clearest possible images are obtained. 

Preparation

All contrast or combined exams require BUN, Cr, and GFR.

*We use non-ionic contrast exclusively. Nonionic contrast is the safest intravenous contrast currently available.

Please alert our staff if you have any allergies, asthma or any kidney problems at the time of scheduling and again upon arrival at the office.

CT Abdomen / Pelvis with Contrast or Combined

  • Do not eat or drink anything 4 hours prior to the exam.
  • Studies of the abdomen and pelvis with or without contrast require patients to drink oral contrast after they arrive at the office for their appointment.  Allow an additional 1 hour to drink the oral contrast.

CT IVP

  • Do not eat anything 4 hours prior to the exam.
  • Allow an additional 30 minutes to drink water prior to exam time.

CT with contrast (CTA examinations (CT Angiography studies), Brain CT with contrast, Neck CT with contrast, Chest CT with contrast, Spine CT with contrast, other CT with contrast)

  • Do not eat anything 2 hours prior to the exam.

CT Non-Contrast (Head, Sinus, Chest, Spine & KUB)

  • No preparation necessary.