Comparison of quantitative angiographic image quality using high kV and low kV technique, a retrospective and phantom study.

Previous studies have shown that high kilovoltage (kV) angiographic imaging techniques can reduce radiation doses to patients more effectively than using low kV techniques. While radiologists often accept the resulting image quality, a detailed quantitative comparison between these techniques remains limited. This study aimed to evaluate and compare the quality of cerebral angiographic images acquired using high kV (79-90 kV) and low kV (68-82 kV) techniques on a biplane digital subtraction angiography (DSA) system. Images were analyzed from patients with cerebral aneurysms as well as a quality assurance phantom (TO DSA), focusing on 2-dimensional angiography (2D-DSA). The contrast-to-noise ratio (CNR) and signal-to-noise ratio (SNR) were measured at various vascular locations in posteroanterior (PA) axial and lateral views. While demographic data did not differ between groups, CNR for PA axial view and PA phantom images produced with high kV was significantly lower than that with low kV. In contrast, the high kV technique demonstrated higher SNR values in both PA and lateral views compared to the low kV technique. Radiation dose per frame confirmed a reduction in dose for the high kV protocol. Conversely, TO DSA images acquired using high kV had a lower SNR than those from low kV. The low kV technique achieved better vessel contrast, as evidenced by its higher CNR compared to the high kV technique. However, it also resulted in a lower SNR in patient images and a higher radiation dose. Protocol selection should, therefore, aim to optimize the trade-off between image quality and radiation exposure.