Author + information
- Received August 23, 2017
- Revision received January 17, 2018
- Accepted January 18, 2018
- Published online April 1, 2019.
- Guan Wang, MDa,b,
- Hsin-Jung Yang, PhDb,
- Avinash Kali, PhDb,
- Ivan Cokic, MDb,
- Richard Tang, MDb,
- Guoxi Xie, PhDc,
- Qi Yang, MDb,
- Joseph Francis, PhDd,
- Songbai Li, MDa,∗∗ ( and )
- Rohan Dharmakumar, PhDb,c,e,∗ ()
- aDepartment of Radiology, The First Affiliated Hospital of China Medical University, Shenyang, China
- bBiomedical Imaging Research Institute, Cedars-Sinai Medical Center, Los Angeles, California
- cDepartment of Biomedical Engineering, Guangzhou Medical University, Guangzhou, China
- dDepartment of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana
- eDavid Geffen School of Medicine, University of California, Los Angeles, California
- ↵∗Address for correspondence:
Dr. Rohan Dharmakumar, Biomedical Imaging Research Institute, Department of Biomedical Sciences, Cedars-Sinai Medical Center, PACT Building–Suite 400, 8700 Beverly Boulevard, Los Angeles, California 90048.
- ↵∗∗Dr. Songbai Li, Department of Radiology, The First Affiliated Hospital of China Medical University, No.155 North Nanjing Street, Shenyang, Liaoning, China 110001.
Objectives This study sought to determine whether T2 cardiac magnetic resonance (CMR) can stage both hemorrhagic and nonhemorrhagic myocardial infarctions (MIs).
Background CMR-based staging of MI with or without contrast agents relies on the resolution of T2 elevations in the chronic phase, but whether this approach can be used to stage both hemorrhagic and nonhemorrhagic MIs is unclear.
Methods Hemorrhagic (n = 15) and nonhemorrhagic (n = 9) MIs were created in dogs. Multiparametric noncontrast mapping (T1, T2, and T2*) and late gadolinium enhancement (LGE) were performed at 1.5- and 3.0-T at 5 days (acute) and 8 weeks (chronic) post-MI. CMR relaxation values and LGE intensities of hemorrhagic, peri-hemorrhagic, nonhemorrhagic, and remote territories were measured. Histopathology was performed to elucidate CMR findings.
Results T2 of nonhemorrhagic MIs was significantly elevated in the acute phase relative to remote territories (1.5-T: 39.8 ± 12.8%; 3.0-T: 27.9 ± 16.5%; p < 0.0001 for both) but resolved to remote values by week 8 (1.5-T: −0.0 ± 3.2%; p = 0.678; 3.0-T: −0.5 ± 5.9%; p = 0.601). In hemorrhagic MI, T2 of hemorrhage core was significantly elevated in the acute phase (1.5-T: 17.7 ± 10.0%; 3.0-T: 8.6 ± 8.2%; p < 0.0001 for both) but decreased below remote values by week 8 (1.5-T: −8.2 ± 3.9%; 3.0-T: −5.6 ± 6.0%; p < 0.0001 for both). In contrast, T2 of the periphery of hemorrhage within the MI zone was significantly elevated in the acute phase relative to remote territories (1.5-T: 35.0 ± 16.1%; 3.0-T: 24.2 ± 10.4%; p < 0.0001 for both) and remained elevated at 8 weeks post-MI (1.5-T: 8.6 ± 5.1%; 3.0-T: 6.0 ± 3.3%; p < 0.0001 for both). The observed elevation of T2 in the peri-hemorrhagic zone of MIs and the absence of T2 elevation in nonhemorrhagic MIs were consistent with ongoing or absence of histological evidence of inflammation, respectively.
Conclusions Hemorrhagic MIs are associated with persisting myocardial inflammation and edema, which can confound staging of hemorrhagic MIs when T2 elevations alone are used to discriminate between acute and chronic MI. Moreover, given the poor prognosis in patients with hemorrhagic MI, CMR evidence for myocardial hemorrhage with persistent edema may evolve as a risk marker in patients after acute MI.
This work was supported in part by grants HL136578 and HL133407 from the National Heart, Lung, and Blood Institute to Dr. Dharmakumar. All authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Received August 23, 2017.
- Revision received January 17, 2018.
- Accepted January 18, 2018.
- 2019 The Authors