Which imaging technique is primarily non-invasive?

CT angiography is primarily considered a non-invasive imaging technique because it utilizes computed tomography to visualize arteries and blood vessels without the need for surgical intervention. This method injects a contrast dye into the bloodstream, which allows for the detailed visualization of vascular structures on the CT images. Since CT angiography is performed externally and does not involve any direct insertion of instruments into the body, it minimizes patient risk and recovery time, making it an attractive option for evaluating vascular health.

In contrast, techniques such as CT-guided biopsy or ultrasound-guided aspirations involve a degree of invasiveness, as they necessitate the use of needles or other instruments that penetrate the skin and tissues to obtain samples. Traditional angiography also entails more invasive procedures since it often requires catheter insertion into the vascular system. Therefore, CT angiography stands out for its non-invasive nature while still providing valuable diagnostic information.