利用低kVp和锐利卷积核提升超高清光子计数探测器CT脑血管造影的潜力
该研究回顾性分析了141例脑CTA超高清光子计数探测器CT图像，比较了不同kVp和重建卷积核对图像质量的影响。结果表明，采用90 kVp采集并结合（非常）锐利卷积核重建可改善血管衰减、信噪比、对比噪声比及血管锐利度，主观图像质量也更优。
要点
- 90 kVp采集可提高血管衰减和对比噪声比，优于140 kVp。
- 非常锐利卷积核（Hv72）在90 kVp下显著改善血管锐利度，但整体噪声增加。
- 小口径血管中，90 kVp联合非常锐利核可保持信噪比和对比噪声比稳定。
关键影像表现/征象
- 90 kVp采集较140 kVp提高血管衰减、信噪比和对比噪声比（0.2 mm多能图像及0.4 mm虚拟单能图像均改善，后者改善程度较小）。
- 0.2 mm多能图像中，90 kVp联合非常锐利核（Hv72）因噪声增加导致信噪比和对比噪声比下降，但小口径血管中信噪比和对比噪声比保持稳定。
- 90 kVp/非常锐利核协议显著改善血管锐利度，主观图像质量评估也优于其他协议。
诊断标准与关键数值
- 血管衰减、信噪比、对比噪声比在前循环4个位置测量。
- 血管锐利度通过边缘上升距离和边缘上升斜率量化。
- 主观评估采用5点Likert量表，由2名读者对图像噪声、血管衰减和血管锐利度评分。
临床应用与阅片要点
- 日常脑CTA阅片可采用90 kVp采集联合锐利卷积核重建，以提升小血管显示和血管锐利度。
- 使用非常锐利核时需注意整体噪声增加，但小口径血管的信噪比和对比噪声比仍稳定。
- 0.4 mm虚拟单能图像（55 keV）也可从90 kVp采集和锐利核重建中获益。
局限性
- 回顾性单中心研究。
- 排除协议偏差、严重运动伪影或脑循环停止的病例，可能存在选择偏倚。
以上解读依据论文摘要（全文未开放获取或许可不允许翻译转载）。
英文原文（摘要）· 点击展开
OBJECTIVES: To assess quality improvements in ultra-high resolution (UHR) photon counting detector (PCD) CT angiography (CTA) of the cerebral vasculature using image acquisition at lower kVp and image reconstruction with sharper kernels.
MATERIALS AND METHODS: All cerebral CTA imaging on PCD-CT performed over a period of 25 months was evaluated retrospectively. Records were excluded in case of protocol deviations, severe motion artifacts, or cerebral circulatory arrest. Using UHR resolution data acquisition (120×0.2 mm collimation) and reconstruction of polyenergetic (T3D) images at 0.2 mm, 3 subsequent protocols were evaluated: (1) 140 kVp/medium-sharp kernel (Hv40); (2) 90 kVp/Hv40; and (3) 90 kVp/very sharp kernel (Hv72). Virtual monoenergetic 0.4 mm reconstructions were derived at 55 keV using a medium-sharp kernel (Hv40) in protocols 1 and 2 and a sharp kernel (Hv60) in protocol 3. Vessel attenuation, signal-to-noise ratios (SNRs), and contrast-to-noise ratios (CNRs) were derived at 4 locations in the anterior circulation. Vessel sharpness was quantified using the edge rise distance and edge rise slope. Subjective assessments of image noise, vessel attenuation, and vessel sharpness were performed by 2 readers on a 5-point Likert scale.
RESULTS: Out of 154 screened patient records, 141 were included. Vessel attenuation, SNR, and CNR improved with image acquisition at 90 kVp compared with 140 kVp for both 0.2 mm T3D images and, to a lesser extent, for 0.4 mm virtual monoenergetic images (VMI) in the protocols using a medium-sharp reconstruction kernel. In the 0.2 mm T3D images, SNR and CNR decreased when applying very sharp kernels at 90 kVp due to an increase in noise. However, SNR and CNR remained stable in small-caliber vessels, whereas both parameters decreased with medium-sharp kernels. Vessel sharpness was markedly improved in the 90 kVp/very sharp kernel protocol. Subjective assessment of image quality also favored the 90 kVp/very sharp kernel protocol. In the 0.4 mm VMI, similar improvements in quantitative and qualitative image quality were observed with image acquisition at 90 kVp (compared with 140 kVp) and image reconstruction using a sharp kernel (compared with a medium-sharp kernel).
CONCLUSIONS: Image quality of UHR PCD-CTA of the cerebral vasculature is improved with image acquisition at 90 kVp and image reconstruction with (very) sharp kernels.
引用
- Pinckaers FME, Wagemans BAJM, Huijberts I, et al. Leveraging the Potential of Ultra-High Resolution Photon Counting Detector CT Angiography of the Cerebral Vasculature by Using Low kVp and Sharp Kernels. Invest Radiol. 2026. PMID: 41982097. doi:10.1097/RLI.0000000000001285
供执业医师工作参考，不替代临床判断；数值与分级以指南原文为准。