CT VENOGRAM

A CT scan is a type of imaging procedure that involves the use of x-rays as well as interventional radiology to visualize a person's venous system. Additionally, a CT scan employs a computer for image reconstruction. The CT scanner captures cross-sectional images of the body, which are then reconstructed into detailed images of the veins, which facilitates the diagnosis of blood clots in limbs as well as observing the general health of the venous system throughout the body. 

What is a CT Venogram? 

For better visualization during the operation, a doctor will first inject contrast dye into the patient's veins, more precisely into the upper limb. The locally injected contrast agent travels through the veins and illuminates the target tissues during the CT scan, providing clearer images of the veins and helping the medical professionals to see any pathologies, blockages or thrombosis that are occurring. 

Depending on the area being scanned, a CT venogram can be split into two categories: lower limb CT venogram and upper limb CT venogram.  

Types of CT Venogram 

As with any other diagnostic procedure, there are various types of CT venograms. Those considered most important are listed as follows:  

• CT venogram with contrast: This is the most common type of CT venogram, which uses a contrast dye to visualize the veins.  
• CT venogram without contrast: This type of test is performed on patients allergic to contrast dye or suffering from kidney disease.  
• Spiral CT venogram: This type of test uses a spiral motion to capture images of the veins, which can be more detailed than standard CT venograms.  

Professionals will look at the following factors during the examination:  

• The pattern of blood flow within the veins.  
• Blood clots or other obstructions, if any. 
• The veins' contours and dimensions. 
• Presence of other lesions: varicose veins and blood vessel damage. 

Check for clots in the legs or other body parts. 

• Assess general health status of the venous system. 
• To evaluate the effectiveness of treatment administered to blood clots. 
• To assess other lesions of the veins.

When and Who Needs to Take a CT Venogram? 

A CT venogram or venography is suggested to patients who are suspected of having a blood clot in their legs or elsewhere in the body. Some of the reasons for conducting this test include: 

• Pain in the leg accompanied with swelling 
• Leg becoming warm or red 
• Chest Pain or breathlessness 
• Coughing blood 

The test is often suggested for patients who are more susceptible to getting blood clots like: 

• People aged above 60 
• People with a family tree showing consistently blood clot cases 
• Bedridden or sedentary individuals 
• Patients suffering from specific diseases like cancer and inflammatory bowel syndrome. 

Benefits of Taking the Test

• High detection rate of blood clots. 
• The procedure is non-invasive and causes little discomfort. 
• Helps identify other lesions such as varicose veins and blood vessel damage. 

Illnesses Diagnosed with CT Venogram

• Deep vein thrombosis (DVT). 
• Pulmonary embolism. 
• Varicose veins. 
• Blood vessel damage or blockage. 
• Post-thrombotic syndrome. 

To best prepare for a CT venogram, one should: 

• Arrive at least 30 minutes early to finalize the paperwork needed for the test. 
• Dress in loose, comfortable clothing. 
• Take off any metalliferous appendages such as jewellery and spectacles as these may impede with the test. 
• State all the medical conditions, allergies, and medication to the technician. 

Pre-requisites 

• Do not eat or drink anything for 4 hours prior to having this test done. 
• Refrain from taking all medications that could alter the outcome of the test, blood thinners for example. 
• Say to the person operating the machine if you have any kidney disease or if you suffer from an allergy to iodine. 

Best Time to Take the CT Venogram 

A CT venogram can be done any time of the day but it is preferable to do it in the morning so that there are no queues. 

Eligibility 

Most adults can have a CT venogram but there are some who should not have it done such as: 

• Chronic kidney disease 
• Iodine allergy 
• Expecting or nursing mothers 

Procedure for Taking a CT Venogram 

The procedure for a CT venogram generally includes the steps outlined below: 

1. Preparation: The patient is required to undress and put on a hospital gown and remove any metallic objects. 
2. Contrast injection: A contrast agent will be administered into the vein located in the arm or hand.  
3. CT scan: The person will be positioned on the CT scanner table and the procedure will commence. 
4. Image capture: A CT scanner will take pictures of the veins along with other tissues in the region. 
5. Reconstruction: The images will then be reconstructed into specific detailed images of the veins. 

Caution Before Taking the Test 

Before proceeding with a CT venogram, participants must inform the technician regarding any of the following: 

• Medical history like existing kidney problems or suffering from an iodine allergy, 
• Use of blood thinning medication, 
• Any adverse effects to contrast dye in the past.