Improved CTA imaging for stroke evaluation - deep learning and iterative reconstruction comparative study.

Purpose: This study compares a novel reconstruction algorithm deep learning-based image reconstruction (DLIR) and adaptive statistical iterative reconstruction-Veo (ASIR-V) for CTA in acute ischemic stroke (AIS) patients, emphasizing DLIR's potential to improve diagnostic accuracy and visualization of large vessel occlusion.

Methods: This study retrospectively assessed 108 consecutive AIS-suspected emergency department patients (mean age 72.3 years +/- 17) who underwent head and neck CTA with DLIR and ASIR-V reconstructions. The analysis compared the impact of DLIR versus ASIR-V on image quality, assessing signal-to-noise (SNR), contrast-to-noise ratios (CNR), and contrast-enhanced arteries homogeneity computed on mean HU values and SD in six regions of interest located in head and neck including three arteries.

Results: The DLIR reconstruction allowed for significant SNR and CNR improvement, with the largest SNR distinction obtained in the common carotid artery (52.29% increased SNR) and white matter of the pons (63.98% increased SNR). Among the three regions subject to CNR evaluation DLIR yielded superiority in the neck and posterior cerebral fossa while ASIR-V accounted for higher CNR in the medial cerebral fossa (MCF). Additionally, DLIR-reconstructed images achieved a 21.10% improvement in arterial homogeneity, enhancing the visualization of potential occlusion.

Conclusion: DLIR yields superior image quality of the contrast-enhanced head and neck structures in CTA, providing artery images with increased homogeneity and potentially allowing for more proficient occlusion evaluation specifically in the area of the posterior cerebral fossa. However, this technique faces challenges in the visualization of MCF.