Procedure of Chest CT scan

CT scans are generally painless, quick, and simple. The amount of time the patient must lie still is reduced with multidetector CT.

Inform your doctor if you think you are pregnant and discuss any recent illnesses, medical conditions, medications you are taking, and allergies you have. You may be told not to eat or drink anything for a few hours before the procedure. Your doctor may prescribe medications to reduce the risk of an allergic reaction if you have a known allergy to contrast material. These medications must be started 12-13 hours before your exam. Wear loose, comfortable clothing and leave your jewellery at home. For the exam, you may need to change into a gown.

Remove all metallic objects and medication devices from your body before undergoing a CT scan. This includes the following:

• watches and glasses jewellery and piercings
• hairpins, hearing aids, dentures, underwire bras, "antimicrobial" clothing with silver technology
• Patches for nicotine
• additional medication patches

The technologist starts by placing you on the CT exam table, usually on your back. Straps and pillows may be used to help you maintain the correct position and remain still during the exam.

Many scanners are fast enough that children can be scanned without sedation. Sedation may be required in some cases for children who cannot sit still. Motion can cause image blurring and degrade image quality in the same way that it does in photographs.

On a CT table, you will lie flat on your back.

A pillow will be placed under your head, and the CT table will be lowered beneath the scanner.

The scanner will circle your chest, between your neck and your abdomen.

To obtain high-quality images of the structures in your chest, the radiographer will ask you to breathe in, breathe out, or hold your breath.

If a contrast material is used in your exam, the nurse or technologist will inject it into a vein shortly before scanning begins.

During the scanning, the technologist may ask you to hold your breath. Artifacts on images can be caused by any motion, including breathing and body movements. This loss of image quality can be compared to the blurring seen in photographs of moving objects.

A CT scan has many applications, but it is especially useful for diagnosing diseases and evaluating injuries. The imaging technique can assist your doctor in the following ways:

• determine infections, muscle problems, and bone fractures
• find the exact location of masses and tumours, including cancer
• investigation of blood vessels and other internal structures
• guide procedures such as surgeries and biopsies by assessing the extent of internal injuries and bleeding
• monitor the efficacy of treatments for specific medical conditions such as cancer and heart disease

When the exam is finished, the technologist will ask you to wait until the images are of sufficient quality for accurate interpretation by the radiologist.

The CT scan itself takes less than 30 seconds. The entire process, including exam preparation, takes about 30 minutes on average.