Spectral aortoiliac photon-counting CT angiography with minimal quantity of contrast agent.

The incidence of vascular and especially aortic pathologies is increasing, which leads to a higher frequency of vascular imaging. As renal pathologies also become more frequent, especially in an aging population, the need for effective preventative scan protocols with reduced contrast material is pressing. An 81-year-old female patient in our institution required a follow-up imaging of an incidental, asymptomatic abdominal aortic aneurysm. Although the patient was suffering from incipient chronic renal failure, a contrast-enhanced aortoiliac computed tomography angiography was performed using a first generation, clinical photon-counting detector computed tomography scanner. This scanner allows a modified scan protocol with a significant reduction of contrast agent while preserving diagnostic confidence. Technically, this is feasible by dual-source spectral image acquisition and dynamic monochromatic reconstruction near the K-edge of Iodine without loss of temporal or spatial resolution. The results are promising, allowing vascular imaging with significantly less risk of renal damage. In this regard, further research into optimal scan-protocols and post-processing is needed.