Garetier Marc, Rousset Jean, Makki Karim, Brochard Sylvain, Rousseau François, Salem Douraïed Ben, Borotikar Bhushan
Department of Radiology, Military Teaching Hospital Clermont-Tonnerre, Brest, France.
Department of Radiology, University Hospital Morvan, Brest, France.
Acta Radiol. 2023 Mar;64(3):1093-1102. doi: 10.1177/02841851221101889. Epub 2022 May 26.
Real-time sequences allow functional evaluation of various joint structures during a continuous motion and help understand the pathomechanics of underlying musculoskeletal diseases.
To assess and compare the image quality of the two most frequently used real-time sequences for joint dynamic magnetic resonance imaging (MRI), acquired during finger and ankle joint motion.
A real-time dynamic acquisition protocol, including radiofrequency (RF)-spoiled and balanced steady-state free precession (bSSFP) sequences, optimized for temporal resolution with similar spatial resolution, was performed using a 3.0-T MRI scanner on 10 fingers and 12 ankles from healthy individuals during active motion. Image quality criteria were evaluated on each time frame and compared between these two sequences. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were determined and compared from regions of interest placed on cortical bone, tendon, fat, and muscle. Visualization of anatomical structures and overall image quality appreciation were rated by two radiologists using a 0-10 grading scale.
Mean CNR was significantly higher with bSSFP sequence compared to RF-spoiled sequence. The grading score was in the range of 5-9.3 and was significantly higher with RF-spoiled sequence for bone and joint evaluation and overall image appreciation on the two joints. The standard deviation for SNR, CNR, and grading score during motion was smaller with RF-spoiled sequence for both the joints. The inter-reader reliability was excellent (>0.75) for evaluating anatomical structures in both sequences.
A RF-spoiled real-time sequence is recommended for the in vivo clinical evaluation of distal joints on a 3.0-T MRI scanner.
实时序列能够在连续运动过程中对各种关节结构进行功能评估，有助于理解潜在肌肉骨骼疾病的病理力学机制。
评估并比较在手指和踝关节运动过程中采集的两种最常用的关节动态磁共振成像（MRI）实时序列的图像质量。
使用3.0-T MRI扫描仪，对健康个体的10根手指和12个踝关节在主动运动时执行一个实时动态采集方案，该方案包括针对时间分辨率进行优化且具有相似空间分辨率的射频（RF）扰相和稳态自由进动平衡（bSSFP）序列。在每个时间帧上评估图像质量标准，并比较这两种序列。从置于皮质骨、肌腱、脂肪和肌肉上的感兴趣区域确定并比较信噪比（SNR）和对比噪声比（CNR）。两名放射科医生使用0-10分级量表对解剖结构的可视化和整体图像质量评价进行评分。
与RF扰相序列相比，bSSFP序列的平均CNR显著更高。分级分数在5-9.3范围内，对于两个关节的骨骼和关节评估以及整体图像评价，RF扰相序列的分级分数显著更高。两个关节在运动期间SNR、CNR和分级分数的标准差，RF扰相序列更小。两种序列在评估解剖结构方面的阅片者间可靠性均极佳（>0.75）。
对于3.0-T MRI扫描仪上远端关节的体内临床评估，推荐使用RF扰相实时序列。
