Acute and subacute ischemic stroke at high-field-strength (3.0-T) diffusion-weighted MR imaging: Intraindividual comparative study
Acute and subacute ischemic stroke at high-field-strength (3.0-T) diffusion-weighted MR imaging: Intraindividual comparative study
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DOI：
10.1148/radiol.2342031323
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发表时间：
2005-02-01
期刊：
影响因子：
19.7
通讯作者：
Schild, HH
中科院分区：
文献类型：
--
作者：
Kuhl, CK;Textor, J;Schild, HH
目得：比较1.5 T和3.0 T弥散加权（DW）磁共振（MR）成像诊断缺血性卒中病变的信噪比（SNR）、对比噪声比（CNRs）、图像质量和置信度。材料和方法：研究设计经机构审查委员会批准，所有患者均知情同意。在一项前瞻性个体内研究中，25例具有与缺血性卒中一致的临床症状的患者在1.5 T和3.0 T下接受了DW MR成像。3.0-或1.5-T检查以随机顺序依次进行。两个.一致的阅片者记录缺血性病变的存在和数量，并评定图像质量和病变的显著性。量化缺血病灶的图像SNR和CNR。配对Student t和Wilcoxon配对符号秩检验用于检验统计显著性。结果：由于图像失真较大，3.0 T DW MR成像的图像质量始终低于1.5 T DW MR成像（P <0.05）。然而，在3.0 T时，总体SNR和病变CNR显著增加;平均增加分别为48.8%（P < .001）和96.3%（P < .01）。较高的总体SNR和病变CNR t转化为3.0 T时检测缺血性病变的灵敏度显著高于1.5 T时。在25名患者中的19名患者共识别出48处病变，其中47处（98%）在3.0 T下诊断，36处（75%）在1.5 T下诊断。此外，在3.0 T时，两种系统可见病变的显著性显著更高（P < .001）。结论：尽管3.0 T DW MR成像产生更大的图像失真，但与1.5 T DW MR成像相比，它产生更高的SNR和CNR。在3.0 T时CNR的增加转化为诊断置信度的显著提高。在亚急性和急性缺血性卒中中检测局灶表观弥散系数变化。(C)RSNA，2004年。
PURPOSE: To compare signal-to-noise ratios (SNRs), contrast-to-noise ratios (CNRs), image quality, and confidence in diagnosis between 1.5- and 3.0-T diffusion-weighted (DW) magnetic resonance (MR) imaging of ischemic stroke lesions.MATERIALS AND METHODS: The study design was approved by the institutional review board, and all patients gave informed consent. In a prospective intraindividual study, 25 patients who had clinical symptoms consistent with ischemic stroke underwent DW MR imaging at both 1.5 T and 3.0 T. The 3.0- or 1.5-T examination was performed immediately one after the other, in random order. Two. readers in consensus recorded the presence and number of ischemic lesions and rated image quality and lesion conspicuity. The image SNR and the CNR of the ischemic lesions were quantified. Paired Student t and Wilcoxon matched-pairs signed rank tests were used to test for statistical significance.RESULTS: Image quality at 3.0-T DW MR imaging was consistently lower than that at 1.5-T DW MR imaging owing to greater image distortions (P < .05). Yet, overall SNR and lesion CNR at 3.0 T increased,significantly; mean increases were 48.8% (P < .001) and 96.3% (P < .01), respectively. The higher overall SNR and lesion CNR t translated into a significantly higher sensitivity in the detection of ischemic lesions a 3.0 T than at 1.5 T. Of the total of 48 lesions that were identified in 19 of the 25 patients, 47 (98%) were diagnosed at 3.0 T and 36 (75%) were diagnosed at 1.5 T. In addition, the conspicuity of the lesions that were visible with both systems was significantly higher at 3.0 T (P < .001).CONCLUSION: Although 3.0-T DW MR imaging, generates greater image distortions, it yields increased SNR and CNR compared with DW MR imaging at 1.5 T. The increased CNR at 3.0 T translates into a significantly improved diagnostic confidence. in the detection of focal apparent diffusion coefficient changes in the setting of subacute and acute ischemic stroke. (C) RSNA, 2004.