NIHR Leeds Biomedical Research Centre, Chapel Allerton Hospital, Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom.
NIHR Leeds Biomedical Research Centre, Chapel Allerton Hospital, Leeds Teaching Hospitals NHS Trust, Leeds, United Kingdom; Leeds Institute of Rheumatic and Musculoskeletal Medicine, Chapel Allerton Hospital, University of Leeds, Leeds, United Kingdom.
Radiography (Lond). 2022 Aug;28(3):831-837. doi: 10.1016/j.radi.2022.01.004. Epub 2022 Feb 15.
Rheumatoid arthritis (RA) affects 1% of the population and is principally associated with joint inflammation. It is suggested however that muscle involvement may be one of the earliest clinical features of RA. It is therefore important that techniques exist to accurately assess muscle health in those with RA to enable successful treatment. This study assesses the inter-rater and intra-rater repeatability of Diffusion Tensor MRI (DTI), 2-Point Dixon fat fraction, and T2 relaxation of the thigh muscle in patients with RA using manual regions of interest (ROI).
Nineteen patients (10/19 males; mean age 59; range 18-85) diagnosed with RA had an MRI scan of their hamstrings and quadriceps muscles to obtain fat fraction (FF), mean diffusivity (MD), fractional anisotropy (FA), and T2 quantitative measurements. Two raters DB & MF independently contoured ROIs for each patient. DB repeated the ROI for the same 19 patients after a 6-month hiatus to assess intra-rater repeatability. Inter-rater and intra-rater repeatability for the ROI measurements were compared using Inter Class Correlation (ICC) and Bland-Altman plots.
There was excellent agreement for both inter-rater and intra-rater repeatability. ICC results ranged from 0.900 to 0.998 (P < 0.001), and intra-rater ICC results ranged from 0.977 to 0.999 (P < 0.001). Bland-Altman plots also showed excellent agreement.
ICC measurements and Bland-Altman plots showed excellent repeatability and agreement with no statistically significant differences when assessing the inter-rater and intra-rater repeatability of FF, MD, FA, and T2 relaxation of the thigh muscle using manual regions of interest in patients with RA.
Manual ROI drawing does not introduce significant errors obtaining FF, MD, FA, and T2 MRI measurements in an RA population.
类风湿关节炎（RA）影响 1%的人口，主要与关节炎症有关。然而，有人认为肌肉受累可能是 RA 的最早临床特征之一。因此，存在能够准确评估 RA 患者肌肉健康的技术非常重要，以便进行成功的治疗。本研究使用手动感兴趣区域（ROI）评估 RA 患者大腿肌肉的弥散张量 MRI（DTI）、2 点 Dixon 脂肪分数和 T2 弛豫的组内和组间可重复性。
19 名诊断为 RA 的患者（10/19 名男性；平均年龄 59 岁；范围 18-85 岁）接受了他们的腘绳肌和股四头肌肌肉的 MRI 扫描，以获得脂肪分数（FF）、平均扩散系数（MD）、分数各向异性（FA）和 T2 定量测量值。两位评估者 DB 和 MF 分别为每位患者勾画 ROI。DB 在 6 个月的间隔后重复了相同的 19 位患者的 ROI，以评估组内可重复性。使用组内相关系数（ICC）和 Bland-Altman 图比较 ROI 测量的组内和组间可重复性。
组内和组间的重复性都有很好的一致性。ICC 结果范围为 0.900 到 0.998（P<0.001），组内 ICC 结果范围为 0.977 到 0.999（P<0.001）。Bland-Altman 图也显示了很好的一致性。
ICC 测量值和 Bland-Altman 图显示，在使用手动 ROI 评估 RA 患者大腿肌肉的 FF、MD、FA 和 T2 弛豫的组内和组间可重复性时，具有极好的可重复性和一致性，没有统计学上的显著差异。
在 RA 人群中，手动 ROI 绘图不会在获得 FF、MD、FA 和 T2 MRI 测量值时引入显著误差。
