October 27, 2020 – Magnetic resonance imaging (MRI) examinations can be safely performed in...
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.
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.
This is Figure 2 from the article in Radiology: Acute encephalopathy. A 60 year-old-man without history of seizures presenting with convulsion. (A-B) Multifocal areas of FLAIR hyperintensity in the right cerebellum (arrows in A), left anterior cingular cortex and superior frontal gyrus (arrows in B). (C-D) Restricted diffusion in the left anterior cingulate cortex, superior frontal and middle temporal gyrus (arrows in D) and right cerebellum (arrows in E), consistent with cerebellar diaschisis. F) No hemosiderin deposits in gradient echo sequences.
Figure 4 for the study. Images of a 65-year-old man (patient 6). (a) Cardiac MRI perfusion shows perfusion deficit of anterior/anterolateral wall attributed to left anterior descending artery/left circumflex artery (*). (b) CT coronary angiography. (c) Coronary angiography, left anterior oblique projection with caudal angulation. (d) Three-dimensional image fusion helped refine diagnosis: perfusion deficits (*) were most likely caused by narrow first diagonal branch and its first, stented side branch (arrowhead). Retrospectively, denoted lesion could also be found at CT coronary angiography and coronary angiography (arrowheads in b and c, respectively). CT FFR = CT-derived fractional flow reserve, LGE = late gadolinium enhancement. Image courtesy of RSNA, Radiology.
GE Healthcare partnered with the AI developer Dia to provide an artificial intelligence algorithm to auto contour and calculate cardiac ejection fraction (EF). The app is now available on the GE Vscan pocket, point-of-care ultrasound (POCUS) system, as seen here displayed at RSNA 2019. Watch a VIDEO demo from RSNA.