Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA.
Grinnell College, Grinnell, Iowa, USA.
Magn Reson Med. 2025 Feb;93(2):850-863. doi: 10.1002/mrm.30289. Epub 2024 Sep 25.
To study if adaptive image receive (AIR) receiver coil elements can be configured into a 2D array with high (>45% by diameter) element-to-element overlap, allowing improved SNR at depth (0.7-1.5× element diameter) versus conventional (20%) overlap.
An anterior array composed of twenty 10-cm diameter elements with 45% overlap arranged into a 4 × 5 grid and a similar 3 × 7 twenty-one-element posterior array were constructed. SNR and g-factor were measured in a pelvic phantom using the new high-density (HD) arrays (41 total elements) and compared to vendor AIR-based arrays (30 total elements) with conventional overlap. T-weighted fast-spin-echo (T2SE) images acquired using both arrays were compared in 20 subjects. SNR was estimated in vivo. Results were compared blindly by three uroradiologists using a five-point scale. Images using the HD arrays were also compared to a set of images acquired over a range of acceleration factors (R = 2.0, 2.5, 3.0) with the conventional arrays.
SNR within the phantom was on average 15% higher for R = 1.0, 1.5, and 2.0 using the HD arrays. Across the 20 subjects SNR within the prostate was 11% higher and assessed radiologically as significantly higher (p < 0.001) for the HD versus conventional arrays. At all acceleration factors the new HD arrays outperformed the conventional arrays (p ≤ 0.01), allowing increased R for similar SNR.
AIR elements can be configured into 2D arrays with high (45%) element-to-element overlap, consistently providing increased SNR at depth versus arrays with conventional (20%) overlap. The SNR improvement allows increased acceleration in T2SE prostate MRI.
研究自适应图像接收（AIR）接收线圈元件是否可以配置成具有高（直径的> 45％）元件到元件重叠的 2D 阵列，从而在深度（0.7-1.5×元件直径）处相对于常规（20％）重叠提高 SNR。
构建了一个由二十个 10cm 直径的元件组成的前侧阵列，元件之间的重叠度为 45％，排列成 4×5 栅格，以及类似的后侧 3×7 二十一个元件的二十一个元件的后侧阵列。使用新的高密度（HD）阵列（共 41 个元件）测量了骨盆体模中的 SNR 和 g 因子，并与具有常规重叠的基于供应商的 AIR 阵列（共 30 个元件）进行了比较。在 20 名受试者中比较了使用这两种阵列采集的 T2 加权快速自旋回波（T2SE）图像。三位泌尿科医生使用五分制进行了盲法比较。还将使用 HD 阵列获得的图像与使用常规阵列在一系列加速因子（R=2.0、2.5、3.0）下获得的一组图像进行了比较。
在使用 HD 阵列时，R=1.0、1.5 和 2.0 时，体模内的 SNR 平均高 15％。在 20 名受试者中，前列腺内的 SNR 高 11％，并且 HD 与常规阵列相比，影像学评估显着更高（p<0.001）。在所有加速因子下，新的 HD 阵列均优于常规阵列（p≤0.01），从而允许在保持相似 SNR 的情况下增加 R。
可以将 AIR 元件配置成具有高（45％）元件到元件重叠的 2D 阵列，与具有常规（20％）重叠的阵列相比，始终可以在深度处提供更高的 SNR。SNR 的提高允许在 T2SE 前列腺 MRI 中增加加速。
