Kondo Shota, Nakamura Yuko, Higaki Toru, Nishihara Takashi, Takizawa Masahiro, Shirai Toru, Fujimori Motoshi, Bito Yoshitaka, Narita Keigo, Fonseca Dara, Maeda Shogo, Kawashita Ikuo, Honda Yukiko, Awai Kazuo
Diagnostic Radiology, Hiroshima University, 1-2-3 Kasumi, Minami-Ku, Hiroshima City, Hiroshima, 734-8551, Japan.
Graduate School of Advanced Science and Engineering, Hiroshima University, 1-4-1 Kagamiyama, Higashi-Hiroshima City, Hiroshima, 739-8527, Japan.
Jpn J Radiol. 2025 Mar;43(3):463-471. doi: 10.1007/s11604-024-01688-z. Epub 2024 Nov 5.
Under-sampled scans with iterative reconstruction and high-frequency preserving transform (Us-IRHF) can increase the acquisition speed without degrading the image quality by recovering image information from under-sampled data. We investigate the clinical applicability of high spatial resolution magnetic resonance cholangiopancreatography (MRCP) images without extending the scanning time using Us-IRHF.
A slit phantom was scanned with conventional- (without Us-IRHF), Us-IR- (without HF), and Us-IRHF scanning. The matrix size was 320 × 320 for Us-IR- and Us-IRHF- and 288 × 208 for conventional scanning. Modulation transfer function (MTF) focused on the 1.0 lp/cm gauge for each scanning was calculated. For clinical study we acquired respiratory-triggered 3D MRCP scans with and without Us-IRHF (U-, UMRCP) in 41 patients. The matrix size was 320 × 320 for U- and 288 × 208 for UMRCP. The acquisition time and the relative duct-to-periductal contrast ratios (RCs) for the right- and left intrahepatic bile-, the common bile-, and the main pancreatic duct were recorded. Visualization of each duct and overall image quality was scored on 5-point confidence scales. For visualization of each duct the score ranged from 1 (not visible) to 5 (visible with excellent details), for the image quality, it ranged from 1 (undiagnostic) to 5 (excellent). Superiority for the qualitative visualization score and non-inferiority for the RC values with prespecified margins were assessed.
Phantom study showed that compared to the conventional- and Us-IR (without HF) images, the MTF for the Us-IRHF image revealed the highest response. For clinical study, the mean acquisition time was 161 s for U- and 165 s for UMRCP. For all ducts, the RC value of UMRCP was non-inferior to UMRCP and the qualitative visualization score assigned to UMRCP was superior to UMRCP.
Us-IRHF improved the image quality of high spatial resolution MRCP without extending the scanning time.
采用迭代重建和高频保留变换的欠采样扫描（Us-IRHF）能够通过从欠采样数据中恢复图像信息来提高采集速度，同时不降低图像质量。我们研究了使用Us-IRHF在不延长扫描时间的情况下，高空间分辨率磁共振胰胆管造影（MRCP）图像的临床适用性。
使用传统扫描（不使用Us-IRHF）、Us-IR（不使用HF）和Us-IRHF扫描对狭缝模体进行扫描。Us-IR和Us-IRHF扫描的矩阵大小为320×320，传统扫描的矩阵大小为288×208。计算每种扫描在1.0 lp/cm规格下的调制传递函数（MTF）。在临床研究中，我们对41例患者进行了有和没有Us-IRHF（U-、UMRCP）的呼吸触发3D MRCP扫描。U-的矩阵大小为320×320，UMRCP的矩阵大小为288×208。记录采集时间以及肝内左右胆管、胆总管和主胰管的相对胆管与胆管周围对比率（RC）。每个胆管的可视化和整体图像质量采用5分置信度量表评分。每个胆管可视化的评分范围为1（不可见）至5（可见且细节极佳），图像质量的评分范围为1（无法诊断）至5（极佳）。评估定性可视化评分的优越性以及RC值在预设边界内的非劣效性。
模体研究表明，与传统图像和Us-IR（不使用HF）图像相比，Us-IRHF图像的MTF显示出最高响应。在临床研究中，U-的平均采集时间为161秒，UMRCP的平均采集时间为165秒。对于所有胆管，UMRCP的RC值不劣于U-，并且赋予UMRCP的定性可视化评分优于U-。
Us-IRHF在不延长扫描时间的情况下提高了高空间分辨率MRCP的图像质量。
