CT Angiography (CTA) is an advanced, non-invasive imaging technique that combines computed tomography (CT) scanning with contrast material to visualize blood vessels throughout the body. This diagnostic tool provides detailed 3D images of vascular structures, helping physicians evaluate circulation and detect abnormalities with exceptional precision.
CT Angiography (CTA)
CTA Procedure and Applications
About CTA
How CTA Works
- Uses X-rays and computer processing to create cross-sectional images
- Intravenous contrast dye highlights blood vessels
- Advanced software reconstructs 3D vascular images
- Typically completed in 10-30 minutes
Key Advantages
- Non-invasive alternative to conventional angiography
- Faster than MRI angiography
- Provides both vascular and tissue information
- High resolution for small vessels
- Minimal recovery time
Common Vascular Systems Evaluated
- Cerebrovascular: Carotid/vertebral arteries, Circle of Willis
- Cardiac: Coronary arteries, pulmonary veins
- Peripheral: Aorta, renal arteries, leg vessels
- Visceral: Mesenteric, hepatic, splenic circulation
Technical Specifications
- Uses multidetector CT scanners (64-320 slice)
- Contrast injection rate: 3-5 mL/sec
- Slice thickness: 0.5-1.25 mm
- ECG-gating for cardiac studies
Clinical Applications
Diagnostic Uses
- Aneurysm detection: Measuring size/location
- Atherosclerosis evaluation: Plaque characterization
- Vascular malformations: AVMs, fistulas
- Stenosis/occlusion: Degree of vessel narrowing
- Dissection identification: Arterial wall tears
- Pre-surgical planning: Vascular mapping
Specific Clinical Scenarios
- Stroke evaluation: Detect large vessel occlusion
- Pulmonary embolism: CT pulmonary angiography
- Coronary artery disease: Coronary CTA
- Peripheral artery disease: Runoff studies
- Renovascular hypertension: Renal artery stenosis
- Trauma assessment: Active bleeding detection
Comparison with Other Modalities
| Modality | Advantages | Limitations |
|---|---|---|
| CTA | Fast, high resolution, widely available | Radiation exposure, contrast needed |
| MRA | No radiation, good soft tissue contrast | Longer scan time, claustrophobia |
| DSA | Gold standard, therapeutic options | Invasive, higher complication risk |
Patient Information
Preparation Guidelines
- Fasting for 4-6 hours (varies by institution)
- Continue medications unless instructed otherwise
- Hydration before/after contrast administration
- Lab tests (creatinine, GFR) for kidney function
- Allergy premedication if needed
During the Procedure
- IV placement for contrast injection
- Lie still on CT table (may need breath-holding)
- Warm sensation during contrast injection
- Machine noises but no pain
After the Procedure
- Drink plenty of fluids to flush contrast
- Monitor IV site for swelling/redness
- Resume normal activities immediately
- Rare side effects: nausea, rash, delayed allergy
Safety Considerations
- Contrast allergy: Risk of reaction (report history)
- Kidney function: Contrast may affect renal function
- Radiation exposure: Minimal but considered
- Pregnancy: Generally avoided unless emergency
Interpreting Results
- Reviewed by radiologist (report within 24-48 hours)
- Normal: No stenosis, aneurysms, or malformations
- Abnormal: May show blockages, dilations, or anomalies
- Follow-up with referring physician for clinical correlation