High-resolution magnetic resonance angiography of the lower extremities with a dedicated 36-element matrix coil at 3 Tesla
High-resolution magnetic resonance angiography of the lower extremities with a dedicated 36-element matrix coil at 3 Tesla
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DOI：
10.1097/01.rli.0000263183.66407.69
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发表时间：
2007-06-01
影响因子：
6.7
通讯作者：
Schoenberg, Stefan O.
中科院分区：
文献类型：
--
作者：
Kramer, Harald;Michaely, Henrik J.;Schoenberg, Stefan O.
简介：硬件和软件的最新发展有助于显着提高磁共振血管造影（MRA）的图像质量。并行采集技术（PAT）有助于提高空间分辨率和减少采集时间，但也会降低信噪比（SNR）。向更高场强的移动和专用血管造影线圈的使用可以进一步提高空间分辨率，同时在与现代检查相同的SNR下减少采集时间。我们研究的目的是比较的图像质量的MRA数据集采集与标准矩阵线圈相比，MRA数据集采集与专用的外围血管造影矩阵线圈和更高的因素的并行imaging.Materials和Methods：在第一志愿者检查，unaccelerated幻影测量进行了不同的线圈。在机构审查委员会批准后，15名健康志愿者在32通道3.0特斯拉MR系统上接受了下肢MRA。其中5例采用PAT加速因子为2，并在腿部放置标准体矩阵表面线圈进行小牛MRA。10名志愿者使用专用的36-elennent血管造影矩阵线圈对小牛进行了MRA：5名志愿者的PAT加速度为3，5名志愿者的PAT加速度因子为4。所有检查的采集体积和采集时间大致相同，只有空间分辨率随加速因子增加。计算每个体素的采集时间。图像质量由2名阅片师根据血管清晰度、静脉覆盖和伪影发生率独立评定。通过K-统计量计算阅片者间一致性。结果：15名志愿者均完成了检查，无不良事件发生。所有检查均未显示静脉覆盖; 70%的检查显示血管清晰度极佳，而50%的检查出现伪影。所有这些伪影均被判定为无干扰。阅片者之间的一致性良好，K值范围在0.65和0.74之间。SNR和对比噪声比没有表现出显着difficulties.Conclusion：在3.0特斯拉的外围MRA的专用线圈的实施有助于提高空间分辨率和减少采集时间，而图像质量可以保持平等。尽管使用高分辨率扫描，但可以有效避免静脉覆盖。
Introduction: Recent developments in hard- and software help to significantly increase image quality of magnetic resonance angiography (MRA). Parallel acquisition techniques (PAT) help to increase spatial resolution and to decrease acquisition time but also suffer from a decrease in signal-to-noise ratio (SNR). The movement to higher field strength and the use of dedicated angiography coils can further increase spatial resolution while decreasing acquisition times at the same SNR as it is known from contemporary exams. The goal of our study was to compare the image quality of MRA datasets acquired with a standard matrix coil in comparison to MRA datasets acquired with a dedicated peripheral angio matrix coil and higher factors of parallel imaging.Materials and Methods: Before the first volunteer examination, unaccelerated phantom measurements were performed with the different coils. After institutional review board approval, 15 healthy volunteers underwent MRA of the lower extremity on a 32 channel 3.0 Tesla MR System. In 5 of them MRA of the calves was performed with a PAT acceleration factor of 2 and a standard body-matrix surface coil placed at the legs. Ten volunteers underwent MRA of the calves with a dedicated 36-elernent angiography matrix coil: 5 with a PAT acceleration of 3 and 5 with a PAT acceleration factor of 4, respectively. The acquired volume and acquisition time was approximately the same in all examinations, only the spatial resolution was increased with the acceleration factor. The acquisition time per voxel was calculated. Image quality was rated independently by 2 readers in terms of vessel conspicuity, venous overlay, and occurrence of artifacts. The inter-reader agreement was calculated by the K-statistics. SNR and contrast-to-noise ratios from the different examinations were evaluated.Results: All 15 volunteers completed the examination, no adverse events occurred. None of the examinations showed venous overlay; 70% of the examinations showed an excellent vessel conspicuity, whereas in 50% of the examinations artifacts occurred. All of these artifacts were judged as none disturbing. Inter-reader agreement was good with K values ranging between 0.65 and 0.74. SNR and contrast-to-noise ratios did not show significant differences.Conclusion: Implementation of a dedicated coil for peripheral MRA at 3.0 Tesla helps to increase spatial resolution and to decrease acquisition time while the image quality could be kept equal. Venous overlay can be effectively avoided despite the use of high-resolution scans.