From the Department of Radiology and Radiological Science (A.T., J.A.C., M.Y., M.G.M., J.O., S.V.T., M.V.S.), Medical University of South Carolina, Charleston, South Carolina.
Siemens Medical Solutions (J.O.), Malvern, Pennsylvania.
AJNR Am J Neuroradiol. 2024 Oct 3;45(10):1450-1457. doi: 10.3174/ajnr.A8350.
The first-generation photon-counting detector CT was recently introduced into clinical practice and represents a promising innovation in high-resolution CT imaging. The purpose of this study was to assess the image quality of ultra-high-resolution photon-counting detector CT compared with energy-integrating detector CT and to explore different reconstruction kernel sharpness levels for the evaluation of intracranial aneurysms.
Ten patients with intracranial saccular aneurysms who had previously undergone conventional energy-integrating detector CT were prospectively enrolled. CT angiograms were acquired on a clinical dual-source photon-counting detector CT in ultra-high-resolution mode and reconstructed with 4 vascular kernels (Bv36, Bv40, Bv44, Bv48). Quantitative and qualitative image-quality parameters of the intracranial arteries were evaluated. For the quantitative analysis (image noise, SNR, contrast-to-noise ratio), ROIs were manually placed at standard anatomic intracranial and extracranial locations by 1 author. In addition, vessel border sharpness was evaluated quantitatively. For the qualitative analysis, 3 blinded neuroradiologists rated photon-counting detector CT and energy-integrating detector CT image quality for the evaluation of the intracranial vessels (ie, the aneurysms and 9 standard vascular branching locations) on a 5-point Likert-type scale. Additionally, readers independently selected their preferred kernel among the 4 kernels evaluated on photon-counting detector CT.
In terms of quantitative image quality, Bv48, the sharpest kernel, yielded increased image noise and decreased SNR and contrast-to-noise ratio parameters compared with Bv36, the smoothest kernel. Compared with energy-integrating detector CT, the Bv48 kernel offered better quantitative image quality for the evaluation of small intracranial vessels ( < .001). Image-quality ratings of the Bv48 were superior to those of the energy-integrating detector CT and not significantly different from ratings of the B44 reconstruction kernel. When comparing side by side all 4 photon-counting detector reconstruction kernels, readers selected the B48 kernel as the best to visualize the aneurysms in 80% of cases.
Ultra-high-resolution photon-counting detector CT provides improved image quality for neurovascular imaging. Although the less sharp kernels provided superior SNR and contrast-to-noise ratio, the sharpest kernels delivered the best subjective image quality on photon-counting detector CT for the evaluation of intracranial aneurysms.
第一代光子计数探测器 CT 最近已应用于临床实践，它是高分辨率 CT 成像领域的一项很有前途的创新。本研究旨在评估超高分辨率光子计数探测器 CT 的图像质量，并探讨不同的重建核锐利度水平在颅内动脉瘤评估中的应用。
前瞻性纳入 10 例经传统能量积分探测器 CT 检查的颅内囊状动脉瘤患者。采用临床双源光子计数探测器 CT 行超高分辨率 CT 血管造影检查，并采用 4 种血管重建核（Bv36、Bv40、Bv44、Bv48）进行重建。评估颅内动脉的定量和定性图像质量参数。对于定量分析（图像噪声、SNR、对比噪声比），由 1 名作者手动在标准的颅内和颅外解剖部位放置 ROI。此外，还对血管边界锐利度进行了定量评估。定性分析中，3 名神经放射科医师对光子计数探测器 CT 和能量积分探测器 CT 图像质量进行评分，评估颅内血管（即动脉瘤和 9 个标准血管分支部位），评分采用 5 分 Likert 量表。此外，读者还在光子计数探测器 CT 上评估的 4 种重建核中独立选择了他们偏爱的核。
在定量图像质量方面，与最平滑的核 Bv36 相比，最锐利的核 Bv48 增加了图像噪声，并降低了 SNR 和对比噪声比参数。与能量积分探测器 CT 相比，Bv48 核在评估小颅内血管时具有更好的定量图像质量（<.001）。Bv48 的图像质量评分优于能量积分探测器 CT，与 B44 重建核的评分无显著差异。当并排比较光子计数探测器的 4 种重建核时，80%的读者选择 Bv48 核作为最佳核以显示动脉瘤。
超高分辨率光子计数探测器 CT 可为神经血管成像提供更好的图像质量。虽然较不锐利的核提供了更高的 SNR 和对比噪声比，但在光子计数探测器 CT 上评估颅内动脉瘤时，最锐利的核提供了最佳的主观图像质量。
