1. Purpose:
A comprehensive routine CT scan of the abdomen, whether with or without contrast, is used to evaluate abdominal organs, detect abnormalities, and diagnose conditions such as tumors, infections, or internal injuries. The use of contrast enhances the visibility of blood vessels and tissues, providing more detailed images.

2. Non-Contrast CT Scan:
In a non-contrast CT scan, images are captured without the use of contrast material. This approach is useful for assessing certain conditions, such as kidney stones or basic structural abnormalities, where contrast might not be necessary.

3. Contrast-Enhanced CT Scan:
For a contrast-enhanced CT scan, a contrast material is injected into the bloodstream through an intravenous line. This contrast highlights blood vessels, organs, and tissues, allowing for a more detailed examination of the abdominal structures and better differentiation between various tissue types.

4. Preparation:
Preparation for the scan may involve fasting for a few hours before the procedure. For contrast-enhanced scans, patients may also need to drink a contrast solution orally before the scan, in addition to the intravenous contrast.

5. Imaging Procedure:
The patient lies on a motorized table, which moves through the CT scanner. During the scan, multiple cross-sectional images of the abdomen are taken from different angles. For a contrast-enhanced scan, the contrast material is administered during the imaging process to enhance the clarity of the images.

6. Radiologist Analysis:
The resulting images are analyzed by a radiologist to identify any abnormalities or conditions. The contrast-enhanced images provide detailed views of vascular structures, tumors, and other lesions, aiding in a more accurate diagnosis.

7. Post-Procedure Care:
After the scan, particularly if contrast material was used, patients are advised to drink plenty of fluids to help flush the contrast from their system. Monitoring for any potential allergic reactions to the contrast dye is also important.

This approach ensures that comprehensive and clear imaging of the abdomen is achieved, supporting effective diagnosis and treatment planning.