Department of Radiology, Inje University Busan Paik Hospital, Republic of Korea.
Department of Neurosurgery, Inje University Haeundae Paik Hospital, Republic of Korea.
Neuroradiol J. 2021 Jun;34(3):213-221. doi: 10.1177/1971400920988099. Epub 2021 Jan 18.
Compressed sensing is used for accelerated acquisitions with incoherently under-sampled k-space data, and intracranial time-of-flight magnetic resonance angiography is suitable for compressed sensing. Compressed sensing time-of-flight is beneficial in decreasing acquisition time and increasing spatial resolution while maintaining acquisition time. In this retrospective study, we aimed to evaluate the image quality and diagnostic performance of compressed sensing time-of-flight with high spatial resolution and compare with parallel imaging time-of-flight using digital subtraction angiography as a reference.
In total, 39 patients with 46 intracranial aneurysms underwent parallel imaging and compressed sensing time-of-flight in the same imaging session and digital subtraction angiography before or after magnetic resonance angiography. The overall image quality, artefacts and diagnostic confidence were assessed by two observers. The contrast ratio, maximal aneurysm diameters and diagnostic performance were evaluated.
Compressed sensing time-of-flight showed significantly better overall image quality, degree of artefacts and diagnostic confidence in both observers, with better inter-observer agreement. The contrast ratio was significantly higher for compressed sensing time-of-flight than for parallel imaging time-of-flight in both observers (source images, 0.001; maximum intensity projection images, < 0.05 for both observers); however, the measured maximal diameters of aneurysms were not significantly different. Compressed sensing time-of-flight showed higher sensitivity, specificity, accuracy and positive and negative predictive values for detecting aneurysms than parallel imaging time-of-flight in both observers, with better inter-observer agreement. Compressed sensing time-of-flight was preferred over parallel imaging time-of-flight by both observers; however, parallel imaging time-of-flight was preferred in cases of giant and large aneurysms.
Compressed sensing-time-of-flight provides better image quality and diagnostic performance than parallel imaging time-of-flight. However, neuroradiologists should be aware of under-sampling artefacts caused by compressed sensing.
压缩感知用于对非相干欠采样 k 空间数据进行加速采集，颅内时间飞越磁共振血管成像适合压缩感知。压缩感知时间飞越可在保持采集时间的同时，减少采集时间和提高空间分辨率。在这项回顾性研究中，我们旨在评估高空间分辨率的压缩感知时间飞越的图像质量和诊断性能，并与平行成像时间飞越进行比较，以数字减影血管造影作为参考。
共有 39 例 46 个颅内动脉瘤患者在同一次成像过程中进行了平行成像和压缩感知时间飞越，并在磁共振血管成像前后进行了数字减影血管造影。两名观察者评估了总体图像质量、伪影和诊断信心。评估了对比度比、最大动脉瘤直径和诊断性能。
在两名观察者中，压缩感知时间飞越均显示出更好的整体图像质量、伪影程度和诊断信心，观察者间的一致性更好。在两名观察者中，压缩感知时间飞越的对比度比均显著高于平行成像时间飞越（源图像，0.001；最大强度投影图像，0.05）；然而，测量的动脉瘤最大直径没有显著差异。在两名观察者中，压缩感知时间飞越检测动脉瘤的敏感性、特异性、准确性、阳性预测值和阴性预测值均高于平行成像时间飞越，观察者间的一致性更好。两名观察者均更喜欢压缩感知时间飞越，而平行成像时间飞越在巨型和大型动脉瘤中更受欢迎。
压缩感知时间飞越比平行成像时间飞越提供更好的图像质量和诊断性能。然而，神经放射科医生应该注意压缩感知引起的欠采样伪影。
