T2-weighted cardiac magnetic resonance imaging of edema in myocardial diseases

Abstract

The purpose of this paper is to describe imaging techniques and findings of T2-weighted magnetic resonance imaging (MRI) of edema in myocardial diseases. T2-weighted cardiac MRI is acquired by combining acceleration techniques with motion and signal suppression techniques. The MRI findings should be interpreted based on coronary artery supply, intramural distribution, and comparison with delayed-enhancement MRI. In acute myocardial diseases, such as acute myocardial infarction and myocarditis, the edema is larger than myocardial scarring, whereas the edema can be smaller than the scarring in some types of nonischemic cardiomyopathy, including hypertrophic cardiomyopathy. T2-weighted MRI of edema identifies myocardial edema associated with ischemia, inflammation, vasculitis, or intervention in the myocardium and provides information complementary to delayed-enhancement MRI.

Figure 1

Myocardial T2 mapping generated from multiecho T2-weighted imaging.

Figure 2

63-year-old female with myocardial infarction. Short-axis delayed-enhancement MRI (a) shows myocardial infarction at the inferior myocardium (arrows) and the anterior myocardium (arrowhead). Short-axis T2-weighted cardiac MRI (b) shows only myocardial edema associated with acute myocardial infarction in the inferior myocardium and right ventricular myocardium (arrows) that are consistent with blood supply from the right coronary artery.

Figure 3

25-year-old male with acute myocarditis. T2-weighted MRI shows myocardial edema associated with acute myocarditis (arrows). The edema predominantly involves the epicardial or transmural myocardium in the lateral wall.

Figure 4

50-year-old female with Churg-Strauss syndrome. Short-axis T2-weighted MRI shows patchy myocardial edema of the papillary muscle (arrow) in the eosinophilic myocarditis associated with this syndrome.

Figure 5

73-year-old female with cardiac sarcoidosis presenting with lower ejection fraction and conduction disturbance. Short-axis delayed-enhancement MRI (a) shows abnormal enhancement consistent with the edema (arrow) as well as the septal mesocardial myocardial scarring (arrowhead). T2-weighted cardiac MRI (b) shows myocardial edema at the transmural myocardium of the inferior region (arrow).

Figure 6

41-year-old male with cardiac sarcoidosis presenting with premature ventricular contraction. Short-axis T2-weighted MRI (a) shows a small myocardial edema at the inferior septal myocardium (arrow). ¹⁸FDG-PET (b) shows the focal inflammation (arrow), consistent with the edema on MRI.

Figure 7

77-year-old female with hypertrophic cardiomyopathy presenting with chest pain. Delayed-enhancement MRI (a) shows patchy enhancement at the anterior and inferior septal myocardium (arrows). T2-weighted cardiac MRI (b) shows myocardial edema at the inferior and inferior septal myocardium (arrow).

Figure 8

Comparison between myocardial edema (white) and scarring (dotted) in the myocardium. (a) At the acute stage of ischemic or inflammatory cardiomyopathy, myocardial edema is associated with smaller myocardial scarring or its absence. (b) In some types of nonischemic cardiomyopathy, myocardial edema is smaller than the scarring, indicating relapsed ischemia.

Figure 9

55-year-old female with takotsubo cardiomyopathy. Long-axis delayed enhancement (a) shows no myocardial scarring of the apical myocardium, whereas the T2-weighted MRI (b) shows circumferential myocardial edema at the apical and midventricular regions (arrows). The T2-weighted MRI at its remission (c) shows no myocardial edema. The flow artifact is seen in the apical cavity (arrow), due to the insufficient blood signal suppression by black-blood prepulse.

Figure 10

66-year-old male who has undergone cryoablation for ventricular tachycardia associated with chronic myocardial infarction. Delayed-enhancement MRI (a) visualizes apical myocardial scarring with various transmurality (arrows). T2-weighted MRI (b) shows myocardial edema after ablation (arrow), where nontransmural scarring has been seen in the delayed-enhancement MRI.