Section of Neuroradiology, Department of Radiology (Institut de Diagnòstic per la Imatge), Vall d'Hebron Hospital Universitari, Vall d'Hebron Institut de Recerca (VHIR), Universitat Autònoma de Barcelona, Pg Vall d'Hebron 119-129, 08035, Barcelona, Spain.
Department of Automatic Control (ESAII), Universitat Politècnica de Catalunya, Barcelona, Spain.
Neuroradiology. 2022 Dec;64(12):2315-2322. doi: 10.1007/s00234-022-02973-2. Epub 2022 May 18.
To qualitatively and quantitatively compare synthetic and conventional MRI sequences acquired on a 1.5-T system for patients with multiple sclerosis (MS).
Prospective study that involved twenty-seven consecutive relapsing-remitting MS patients scanned on a 1.5-T MRI scanner. The MRI protocol included 2D transverse conventional spin-echo sequences: proton density-weighted (PD), T2-weighted, T2-FLAIR, and T1-weighted. Synthetic images were generated using 2D transverse QRAPMASTER and SyMRI software with the same voxel size, repetition, echo, and inversion times as the conventional sequences. Four raters performed a crosstab qualitative analysis that involved evaluating global image quality, contrast, flow artefacts, and confidence in lesion assessment introducing the concepts of predominance, agreement, and disagreement. A quantitative analysis was also performed and included evaluating the number of lesions (periventricular, juxtacortical, brainstem, and cerebellum) and the contrast-to-noise ratio between regions (CSF, white matter, grey matter, lesions).
The global image quality assessment showed predominance for better scores for conventional sequences over synthetic sequences, whereas contrast, confidence in lesion assessment, and flow artefacts showed predominance for agreement between sequences. There was predominance for disagreement between all pairs of raters in most of the evaluated qualitative parameters. Synthetic PD and T2-FLAIR images showed higher contrast-to-noise ratios than the corresponding conventional images for most comparison between regions. There were no significant differences in the number of lesions detected for most of the study regions between conventional and synthetic images.
Synthetic MRI can be potentially used as an alternative to conventional brain MRI sequences in the assessment of MS.
定性和定量比较在 1.5-T 系统上为多发性硬化症 (MS) 患者获取的合成和常规 MRI 序列。
这是一项前瞻性研究，涉及 27 例连续的复发缓解型 MS 患者在 1.5-T MRI 扫描仪上进行扫描。MRI 方案包括二维横向常规自旋回波序列：质子密度加权（PD）、T2 加权、T2-FLAIR 和 T1 加权。使用二维横向 QRAPMASTER 和 SyMRI 软件生成合成图像，其体素大小、重复、回波和反转时间与常规序列相同。四位评估者进行了交叉表定性分析，包括评估整体图像质量、对比度、流动伪影和对病变评估的信心，引入了优势、一致性和不一致性的概念。还进行了定量分析，包括评估病变数量（脑室周围、皮质下、脑干和小脑）和区域之间的对比噪声比（CSF、白质、灰质、病变）。
整体图像质量评估显示，常规序列的得分优于合成序列，而对比度、对病变评估的信心和流动伪影则显示出序列之间的一致性优势。在大多数评估的定性参数中，所有评估者之间都存在优势不一致。与相应的常规图像相比，合成 PD 和 T2-FLAIR 图像在大多数区域之间的对比度噪声比更高。在大多数研究区域中，常规和合成图像之间检测到的病变数量没有显著差异。
合成 MRI 可以作为 MS 评估中常规脑 MRI 序列的替代方法。
