When compared with contrast enhanced magnetic resonance angiography (MRA), the strength of CTA lies in its ability to better distinguish a severe stenosis from total occlusion due to its superior spatial resolution. Although conventional angiography has very high spatial resolution, its usefulness is limited by its invasive nature and inability to evaluate plaque morphology.

Identifying plaque morphology plays an important role in deciding on the most appropriate treatment option. Duplex ultrasound is adequate as a screening method but it lacks the precision necessary to provide a definitive, pre-operative assessment regarding the severity of the stenosis (blockage).

At Renaissance Radiology, our new 64-slice CT scans the carotid arteries in a few seconds. This new capability allows for an extremely fast and accurate, non-invasive method of evaluating patients for significant carotid vascular disease.

Renal and Peripheral Arteries
Just as for the carotid arteries, CTA offers a non-invasive method for evaluation of renal artery stenosis. High resolution and the ability to assess plaque morphology help distinguish the exact type of stenosis, as well as assessing the degree of lesion calcification.

CTA can better visualize tiny accessory arteries and evaluate the ureters on a delayed phase. Patients with abrupt onset or worsening hypertension, hypertension refractory to treatment, severe hypertension in a smoker, diabetic, or patients with known chronic kidney disease and vascular arterial disease elsewhere are candidates for a renal CTA study. Identifying the presence of renal artery stenosis early in its course is important to prevent progression of disease.

Our new 64-slice CT can assess the entire peripheral arterial circulation with extremely high three-dimensional resolution. Small collateral branches are readily seen. Soft plaque and lesion calcification can also be evaluated. The 64-slice CT scanner can easily image from the iliac arteries to the feet with high resolution that is optimal for the evaluation of small distal arteries and collateral branches.

Coronary Arteries
Though coronary angiography is the gold standard for evaluating coronary artery stenosis, its shortcomings, above and beyond the risk inherent with this invasive procedure to the patient, include the high cost and patient inconvenience associated with a hospital-based intervention.

A less invasive and more convenient method of evaluating the coronary arteries is desirable, particularly if it identifies the presence of coronary atherosclerosis earlier in the asymptomatic phase of the disease in at-risk patients.

An advantage would also be to identify patients with ambiguous symptoms who have no significant history of coronary artery disease to reduce the need for them to have an in-hospital coronary angiogram.

Recent advances in computerized tomography have made possible a non-invasive method of evaluating coronary artery disease. Studies using new 64-slice CT scanners to perform Computed Tomography Coronary Angiography (CTCA) show sensitivities and specificities near 90% with a negative predictive value in the high 90% range.

CT Coronary Angiography (CTCA) can be a valuable asset during the non-invasive work-up because it is the only non-invasive method that allows for direct visualization of the coronary artery lumen and wall. CTCA not only determines the severity of obstructive coronary disease, but also determines the presence of calcified and “soft” non-calcified plaque in the wall of the coronary artery before the disease results in significant obstruction and symptoms.

The high negative predictive value of CTCA is extremely useful for identifying those without significant obstructive disease in their coronary arteries. When properly utilized during the non-invasive work-up of a cardiology patient, CTCA may rule out the need for conventional coronary angiography.

Pulmonary Embolism
With the evolution of multi-detector CT scanners, CT is rapidly becoming the initial study of choice for detecting pulmonary embolism (PE). Sensitivities above 95% have been achieved with multi-slice CT using 3mm slices.

In addition, subsegmental arteries can be imaged allowing for identification of even smaller PE's with reduced intravenous contrast loads. Furthermore, CT offers other information concerning associated pathology that is not available with conventional angiography or nuclear ventilation perfusion scans.

In addition to CTA, we offer CT, MRI, MRA, ultrasound, digital mammography, X-ray, fluoroscopy and bone densitometry. For more information, call 951-687-5755.