Diastolic Cardiac Function by MRI—Imaging Capabilities and Clinical Applications

Figures

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  Figure 1. Mitral flow analysis in (a) normal case and (b) diastolic dysfunction, showing early (E) and atrial (A) filling peaks. E/A ratio shows normal (>1) and abnormal (<1) diastolic function in normal and pathological cases, respectively. Four-dimensional (4D) flow images are shown at three timepoints in the cardiac cycle (early systole, early diastole, and late diastole), confirming the analysis findings (E & A filling peaks). White dotted line shows mitral valve plane and red arrow shows flow direction. LV, left ventricle; MV, mitral valve.

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  Figure 2. Reduced left ventricle myocardial contractility in a rat model of lung cancer radiation therapy (experimental). Segmental circumferential strain curves in six segments (color code shown on top left) in a mid-ventricular short-axis slice in a normal rat (a) and an experimental rat (b) that received localized heart irradiation of 24 Gy. Note reduced peak systolic strain (solid arrows) and diastolic strain rate (dotted arrows) post radiation.

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  Figure 3. Grades of diastolic dysfunction (I–IV) based on trans-mitral flow pattern. E, early-diastolic flow; A, atrial/late-diastolic flow; DT, deceleration time.

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  Figure 4. Myocardial strain in heart failure with normal ejection fraction (HFNEF) and normals. (A) Representative color-coded myocardial strain maps at end-systole from a volunteer (up) and HFNEF patient (down). Left, middle, and right panels show circumferential, longitudinal, and radial strains, respectively. Representative circumferential (B), longitudinal (C) and radial (D) strain curves are shown from normal (dashed line) and HFNEF (solid line) cases during the cardiac cycle. The results show higher dynamic strain range (difference between end-systolic and end-diastolic strains) in normal compared to HFNEF, which explains the less relaxation experienced in HFNEF during diastole. Figure reproduced with permission from [67]. Copyright 2011 Elsevier.

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  Figure 5. Myocardial perfusion imaging. Short-axis (top) and long-axis (bottom) series of T1-weighted saturation-recovery perfusion images acquired before contrast injection (pre), and at times of bolus arrival in the right-ventricular (RV) blood pool, left-ventricular (LV) blood pool, and myocardium, as denoted by the red asterisks. The images show normal perfusion without any defects.

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  Figure 6. Left-ward septal wall bowing in pulmonary hypertension. Tagged images acquired in a normal case (top) and in pulmonary hypertension (bottom) during diastole (left) and systole (right). Note abnormal left-ward septal wall bowing (white arrows), especially during systole, in pulmonary hypertension due to increased pressure in the right ventricle. Displacement vectors calculated from the tagged images are represented by red arrows, which show reduced myocardial contractility in pulmonary hypertension.

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  Figure 7. Tissue-tracking strain analysis in the right ventricle (RV) in tetralogy of Fallot (ToF). (a) RV circumferential strain map showing reduced strain at the RV insertion points. (b) Global circumferential strain curve in the RV.

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  Figure 8. Myocardial hypertrophy in a rat model of lung cancer radiation therapy (experimental). Four-chamber cine images acquired during diastole (left) and systole (right) in a normal rat (top) and an experimental rat (bottom) that received localized heart irradiation of 24Gy. Note developed hypertrophy (solid arrows) and pleural effusion (dotted arrows) post radiation.

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  Figure 9. T1 mapping. (a) Pre-contrast T1 map, (b) post-contrast T1 map, and (c) generated extracellular volume (ECV) map. Higher ECV values reflect increased fibrosis or collagen formation.

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  Figure 10. T2 mapping. T2 map in a mid-ventricular short-axis slice, showing increased T2 values in the anteroseptal wall (arrows). Increased T2 values could reflect edema.