MRI T1 mapping、T2 mapping心肌分段在诊断急性心肌炎中的应用

Myocardial Segmentation of MRI T1 Mapping and T2 Mapping in Diagnosis of Acute Myocarditis

目的比较急性心肌炎患者与健康志愿者的心肌T2值、NativeT1值及细胞外容积(ECV)值,探讨MRIT2mapping、T1mapping在急性心肌炎中的诊断价值。资料与方法回顾性分析17例临床确诊的急性心肌炎患者(研究组)的心脏磁共振(CMR)图像,根据“路易斯湖标准”观察1~16节段心肌是否存在心肌水肿及延迟强化;选取年龄与急性心肌炎患者相匹配的健康志愿者14例(对照组),分别测量两组受检者各心肌节段的T2值、NativeT1值及ECV值,比较每组内各节段间、两组间各节段的差异。结果研究组心肌水肿节段数(45个)多于延迟强化的节段数(27个),但分布范围大体一致,最多累及第5节段;其中5例未能达到“路易斯湖标准”;研究组内与对照组内各心肌节段的T2值、NativeT1值及ECV值比较,差异均有统计学意义(均P<0.001);研究组患者的T2值(5、10、11段)、NativeT1值(5、6、8、12段)、ECV值(5段)高于对照组,差异均有统计学意义(均P<0.05)。结论急性心肌炎患者T2值、NativeT1值及ECV值升高,能发现传统“路易斯湖标准”不能检出的急性心肌炎病例,建议将MRIT2mapping、T1mapping纳入常规扫描序列,并通过分节段评估法,提高本病的检出率。

Purpose To compare myocardial T2 value,Native T1 value and extracellular volume (ECV) between patients with acute myocarditis and healthy volunteers,and to explore the value of MRI T2 mapping and T1 mapping in diagnosing acute myocarditis. Materials and Methods Cardiac magnetic resonance (CMR) images of 17 patients clinically diagnosed as acute myocarditis (study group) was retrospectively analyzed.Myocardial edema and delayed reinforcement of 1-16 segment myocardium were observed as per “Lake Louis Standard”;14 healthy volunteers (control group) matched with acute myocarditis patients in age were selected.The T2 value, Native T1 value and ECV value of each myocardial segment of the two groups were measured respectively to compared between the segments within the group and that between the two groups.Results The number of myocardial edema segments (45) in the study group was more than that of delayed reinforcement segments (27),but the distribution range was generally consistent,implicating the 5th segment at most;5 of them failed to meet the “Lake Louis Standard”;the difference concerning the T2 value,Native T1 value and ECV value of the myocardial segments between the study group and the control group was statistically significant (P<0.001);the T2 value (5th,10th,and 11th segment),Native T1 value (5th,6th,8th,and 12th segment) and ECV value (5th segment) of patients in the study group were higher than that in the control group,the difference of which was statistically significant (P<0.05).Conclusion The rise of T2 value,Native T1 value and ECV value in patients with acute myocarditis can help spot acute myocarditis that cannot be detected by the traditional "Lake Louis Standard".It is recommended to include MRI T2 mapping and T1 mapping into the routine scanning sequence and improve the detection rate of the disease by segmental evaluation.