Li Chia-Wei, Hsu Ai-Ling, Huang Chi-Wen C, Yang Shih-Hung, Lin Chien-Yuan, Shieh Charng-Chyi, Chan Wing P
Department of Radiology, Wan Fang Hospital, Taipei Medical University, Taipei 116, Taiwan.
Department of Radiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan.
J Clin Med. 2020 Jun 14;9(6):1857. doi: 10.3390/jcm9061857.
The reliability of relaxation time measures in synthetic magnetic resonance images (MRIs) of homemade phantoms were validated, and the diagnostic suitability of synthetic imaging was compared to that of conventional MRIs for detecting ischemic lesions. Phantoms filled with aqueous cupric-sulfate (CuSO) were designed to mimic spin-lattice (T) and spin-spin (T) relaxation properties and were used to compare their accuracies and stabilities between synthetic and conventional scans of various brain tissues. To validate the accuracy of synthetic imaging in ischemic stroke diagnoses, the synthetic and clinical scans of 18 patients with ischemic stroke were compared, and the quantitative contrast-to-noise ratios (CNRs) were measured, using the Friedman test to determine significance in differences. Results using the phantoms showed no significant differences in the interday and intersession synthetic quantitative T and T values. However, between synthetic and referenced T and T values, differences were larger for longer relaxation times, showing that image intensities in synthetic scans are relatively inaccurate in the cerebrospinal fluid (CSF). Similarly, CNRs in CSF regions of stroke patients were significantly different on synthetic T-weighted and T-fluid-attenuated inversion recovery images. In contrast, differences in stroke lesions were insignificant between the two. Therefore, interday and intersession synthetic T and T values are highly reliable, and discrepancies in synthetic T and T relaxation times and image contrasts in CSF regions do not affect stroke lesion diagnoses. Additionally, quantitative relaxation times from synthetic images allow better estimations of ischemic stroke onset time, consequently increasing confidence in synthetic MRIs as diagnostic tools for ischemic stroke.
对自制体模的合成磁共振图像（MRI）中弛豫时间测量的可靠性进行了验证，并将合成成像与传统MRI在检测缺血性病变方面的诊断适用性进行了比较。设计了填充硫酸铜水溶液（CuSO）的体模，以模拟自旋晶格（T）和自旋 - 自旋（T）弛豫特性，并用于比较各种脑组织在合成扫描和传统扫描之间的准确性和稳定性。为了验证合成成像在缺血性中风诊断中的准确性，比较了18例缺血性中风患者的合成扫描和临床扫描，并测量了定量对比噪声比（CNR），使用Friedman检验确定差异的显著性。使用体模的结果显示，日间和不同时间段的合成定量T和T值没有显著差异。然而，在合成T和T值与参考值之间，弛豫时间越长差异越大，表明合成扫描中的图像强度在脑脊液（CSF）中相对不准确。同样，中风患者脑脊液区域在合成T加权和T液体衰减反转恢复图像上的CNR显著不同。相比之下，两者在中风病变方面的差异不显著。因此，日间和不同时间段的合成T和T值高度可靠，脑脊液区域合成T和T弛豫时间及图像对比度的差异不影响中风病变的诊断。此外，合成图像的定量弛豫时间可以更好地估计缺血性中风的发病时间，从而增加对合成MRI作为缺血性中风诊断工具的信心。
