When using endorectal coils, local radiofrequency (RF) heating may occur in the surrounding tissue. Furthermore, most endorectal coils create a susceptibility artifact detrimental to both anatomical magnetic resonance imaging (MRI) and spectroscopy (MRS) acquisitions. We aimed at assessing the safety and MRS performance of a susceptibility‐matched endorectal coil for further rectal wall analysis. Experiments were performed on a General Electric MR750 3 T scanner. A variable number of miniaturized passive RF traps were incorporated in the reception cable. The assessment of RF heating and coil sensitivity was conducted on a 1.5% agar‐agar phantom doped with NaCl. Several susceptibility‐matched materials such as Ultem, perfluorocarbon and barium sulfate were then compared with an external coil. Finally, Ultem was used as a solid support for an endorectal coil and compared with a reference coil. Phantom experiments exhibited a complete suppression of both the RF heating phenomenon and the coil sensitivity artifact. Ultem was the material that produced the smallest image distortion. The full width at half maximum of MR spectra acquired using the susceptibility‐matched endorectal coil showed at least 30% narrowing compared with a reference endorectal coil. A susceptibility‐matched endorectal coil with RF traps incorporated was validated on phantoms. This coil appears to be a promising device for future in vivo experiments.

中文翻译：

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用于磁共振波谱的安全磁化率匹配直肠内线圈的可行性和表征。

使用直肠内线圈时，周围组织可能会发生局部射频 (RF) 加热。此外，大多数直肠内线圈会产生不利于解剖磁共振成像 (MRI) 和光谱 (MRS) 采集的磁化率伪影。我们旨在评估磁敏度匹配的直肠内线圈的安全性和 MRS 性能，以进行进一步的直肠壁分析。实验在通用电气 MR750 3 T 扫描仪上进行。接收电缆中包含数量可变的小型无源射频陷阱。RF 加热和线圈灵敏度的评估是在掺杂有 NaCl 的 1.5% 琼脂模型上进行的。然后将几种磁化率匹配的材料（如 Ultem、全氟化碳和硫酸钡）与外部线圈进行比较。最后，Ultem 用作直肠内线圈的固体支持物，并与参考线圈进行比较。体模实验表现出对 RF 加热现象和线圈灵敏度伪影的完全抑制。Ultem 是产生最小图像失真的材料。与参考直肠内线圈相比，使用磁化率匹配的直肠内线圈获得的 MR 波谱半峰全宽显示至少 30% 变窄。在体模上验证了磁化率匹配的直肠内线圈，并结合了 RF 陷阱。该线圈似乎是未来体内实验的有前途的装置。Ultem 是产生最小图像失真的材料。与参考直肠内线圈相比，使用磁化率匹配的直肠内线圈获得的 MR 波谱半峰全宽显示至少 30% 变窄。在体模上验证了磁化率匹配的直肠内线圈，并结合了 RF 陷阱。该线圈似乎是未来体内实验的有前途的装置。Ultem 是产生最小图像失真的材料。与参考直肠内线圈相比，使用磁化率匹配的直肠内线圈获得的 MR 波谱半峰全宽显示至少 30% 变窄。在体模上验证了磁化率匹配的直肠内线圈，并结合了 RF 陷阱。该线圈似乎是未来体内实验的有前途的装置。