What Is a Helical CT Scan?

The spiral CT scan is a continuous rotating scan of the X-ray tube around the human body, and the scan bed automatically enters the bed horizontally at a uniform speed. Therefore, the scan line is spiral on the patient's body surface. Different from conventional CT scans, spiral scans obtain continuous layer information and information of all tissues within the scan range, so they are also called volume data, which avoids the small lesions that are easily missed due to respiratory movement during tomographic CT scan Disadvantages. Spiral CT is divided into single-layer spiral CT and multi-layer spiral CT according to the different detectors. Digital flat-panel detectors, thanks to the use of special detectors and new technologies, have significantly increased scanning speeds, enabling fast, high-resolution thin-layer scanning with large coverage.

Basic Information

Chinese name

Spiral CT

Come out

year 1987

Classification

Single layer, double layer, multilayer

Advantages

Save contrast agent

Preparation before spiral CT examination

1. Fast for 4 to 8 hours. No barium meal in the digestive tract or barium in the abdomen has been excreted recently.

2. Drink water or take 1.5% to 2% of Mesoglucamine 500-800ml 15 to 30 minutes before scanning, and drink water or take 1.5% to 2% Mesoglucamine 200ml before taking the scan. Do an iodine allergy test.

Clinical significance of spiral CT

Spiral CT scans can generally be performed within 5 to 10 seconds, or data collection can be completed in a patient's breath-holding state, which is convenient for examination of critically ill patients and infants and young children. It can also image when the contrast agent reaches its peak, saving the amount of contrast agent . Can improve the detection rate of lesions and the accuracy of CT measurement, eliminate respiratory motion artifacts; avoid missing small lesions, and can be reconstructed in any position or direction. It can be guaranteed to focus on the lesion; avoid partial volume effects; spiral CT can reconstruct high-quality 3D images and angiographic images, obtain simulated endoscopic images in certain parts, have CT perspective function, and guide interventional surgery.