July 2, 2021 — Philips has participated in an important research project to develop a magnetic resonance...
Magnetic Resonance Imaging (MRI)
Cardiac MRI creates images from the resonance of hydrogen atoms when they are polarized to face in one direction and then hit with an electromagnetic pulse to knock them off axis. The wobbling of the atoms is what is recorded by computers and used to reconstruct the images. Cardiac MR allows very detailed visualization of the myocardial tissue above the resolution found with cardiac CT. Using different protocol sequences, various contrast type images can be created with MRI to enhance various tissues or to provide physiological data on the function of the heart. This section includes MR analysis software, MRI scanners, gadolinium contrast agents, and related magnetic resonance accessories.
Cardiac Magnetic Resonance Imaging in Athletes With Clinical and Subclinical Myocarditis A-D, Athlete A with subclinical possible myocarditis was asymptomatic with normal electrocardiogram (ECG), echocardiogram, and high-sensitivity troponin findings. A, T2 mapping showing elevated T2 in basal-mid inferolateral wall in short axis view. B, late gadolinium enhancement (LGE) in the basal inferolateral wall in short axis view. C, Postcontrast steady state-free precession (SSFP) images showing contrast uptake in the basal-mid inferolateral wall in short axis view. D, LGE in the inferolateral wall in 3-chamber view. E-H, Athlete B with subclinical probable myocarditis was asymptomatic with normal ECG, normal echocardiogram, and elevated high-sensitivity troponin findings. E, T2 mapping showing elevated T2 in the anteroseptal wall in short axis view. F, LGE in the anteroseptal wall in 3-chamber view. G, T2 mapping showing elevated T2 in the anteroseptal wall in 3-chamber view. F, Postcontrast SSFP image showing pericardial effusion in short axis view. I-K, Athlete C with clinical myocarditis and chest pain, dyspnea, abnormal ECG, normal echocardiogram, and normal troponin findings. I, T2 mapping showing elevated T2 in the lateral wall short axis view. J, Postcontrast SSFP images showing contrast uptake in midlateral wall in short axis view. K, LGE in the epicardial midlateral wall in short axis view. L-N, Athlete D with clinical myocarditis, chest pain, abnormal ECG, echocardiogram, and troponin findings. L, T1 mapping showing elevated native T1 in midlateral wall in short axis view. M, T2 mapping showing elevated T2 in the midlateral wall in short axis view. N, LGE in the epicardial midlateral wall in short axis view. IR indicates inferior right view; IRP, inferior, right, posterior view; PLI, posterior, left, inferior view; SL, superior left view; SLA, superior, left, anterior view. Image courtesy of JAMA Cardiol. Published online May 27, 2021. doi:10.1001/jamacardio.2021.2065
MRI scan of a damaged heart. Blue means reduced blood flow, orange is good blood flow. In this figure the inferior part of the heart shows dark blue, so the myocardial blood flow is very reduced. The angiogram shows the coronary artery which supplies the blood to this part of the heart is occluded. The three colored MRI images show different slices of the heart — the basal mid and apical slices. Image courtesy of European Heart Journal
Chest X-ray from a patient included in the study. Posteroanterior view, of a 79-year-old man with history of a previous pacemaker, with abandoned right atrial and right ventricular pacing leads on the right side at time of new cardiac resynchronization therapy defibrillator implant on the left side. Arrows indicate a nodular opacity in the right midlung concerning for mass. Find more images of patients in this study in Radiology: Cardiothoracic Imaging.
Cardiac MRI for four children with clinical diagnosis of acute myocarditis in the setting of COVID-19–related Kawasaki-like symptoms of MIS-C. The top panel demonstrates minimal pericardial effusion on cine images. The second panel demonstrates increased T2-STIR signal intensity with average ratios between myocardium and muscle > 2 in patient 2 (12-year-old male), patient 3 (11-year-old female) and patient 4 (6-year-old female). The third panel demonstrates abnormal native-T1 mapping, which was > 1,100 ms in patients 2, 3 and 4 and normal in patient 1 (8-year-old female). The bottom panel demonstrates absence of late gadolinium enhancement (LGE) in patients 2 and 3. Myocardial null times were recognized as too short in patient 4 but could not be repeated due to lack of further patient cooperation; however review of Look Locker images and additional sequences revealed no LGE. Image courtesy of RSNA.