Quantitative Assessment of Myocardial Edema by MR T2 Mapping in Children With Kawasaki Disease

Abstract

Background: Few studies assessed myocardial inflammation using Cardiovascular Magnetic Resonance Imaging in Kawasaki disease (KD) patients.

Purpose: To quantify myocardial edema in KD patients using T2 mapping and explore the independent predictors of T2 values.

Study type: Prospective.

Subjects: Ninety KD patients including 40 in acute phase (26 males, 65.0%) and 50 in chronic phase (34 males, 68.0%). Thirty-one healthy volunteers (21 males, 70.0%).

Field strength/sequence: 3.0 T T2-weighted Turbo Spin Echo-Short Time of Inversion Recovery sequence, True fast imaging with steady precession flash sequence and fast low-angle shot 3D spoiled gradient echo sequence.

Assessment: T2 values were compared among KD groups and controls.

Statistical test: Student's t test and Fisher's exact test; One-way analysis of variance; Pearson correlation analysis; Receiver operating curve analysis; Multivariable linear regression.

Results: Global T2 value of KD patients in acute phase was the highest, followed by those of chronic-phase patients and controls (38.83 ± 2.41 msec vs. 37.55 ± 2.28 msec vs. 36.05 ± 1.64 msec). Regional T2 values showed a same trend. There were no significant differences in global and regional T2 values between KD patients with and without coronary artery (CA) dilation, no matter in acute or chronic phase (all KD patients: P = 0.51, 0.51, 0.53, 0.72; acute KD: P = 0.61, 0.37, 0.33, 0.83; chronic KD: P = 0.65, 0.79, 0.62, 0.79). No significant difference was observed in global T2 values between KD patients with Z score > 5.0 and 2.0 < Z score ≤ 5.0 (P = 0.65). Multivariate analysis demonstrated that stage of disease (β = -0.123) and heart rate (β = 0.280) were independently associated with global T2 values.

Data conclusion: The degree of myocardial edema was more severe in acute-phase than in chronic-phase KD patients. Myocardial edema persists in patients regardless of the existence or degree of CA dilation.

Evidence level: 2 TECHNICAL EFFICACY: Stage 2.

Keywords: Cardiovascular Magnetic Resonance Imaging; Kawasaki disease; T2 mapping; myocardial edema.