Table 1.
CMR techniques to assess myocardial features of CKD
| CMR sequence | Assessment | Utility | Comments |
|---|---|---|---|
| Cine imaging | LV mass | Reference standard | No geometrical assumptions with CMR. |
| LV function, RV function | Reference standard | Volumes, EF are dependent on heart rate, bloodpressure, inotropic state. | |
| Atrial size | No geometrical assumptions if short axis stack used. | ||
| Cine-strain | Strain is theoretically more tightly linked with pump-function than LVEF. | Cine-strain segmental analysis is not accurate enough for clinical use. | |
| Contrast-enhanced MR | Late gadolinium enhancement (scar/fibrosis) | Standard in clinical CMR practice to identify focal or diffuse scar | Gadolinium-based contrast agents contraindicated in patients with eGFR < 30 ml/min/1.73 m2 |
| T1 mapping (pre- and post- contrast) | Diffuse fibrosis, chronic scar, inflammation | Longitudinal relaxation (T1, ms). Pre and post gadolinium contrast T1 mapping and hematocrit can calculate segmental Extra-cellular volume fraction. Can be used to identify diffuse fibrosis, edema. | Gadolinium-based contrast agents contraindicated in patients with eGFR < 30 ml/min/1.73 m2 |
| T2 mapping | Oedema | Transverse decay (T2, ms). Standard in clinical CMR or identifying myocardial edema. | |
| T2* mapping | Iron overload | Gold standard in non-invasive assessment of iron overload. | Can only be reliably used at 1.5T. Higher artifact rate at 3.0T. |
| Bespoke strain techniques (tagging, phase-contrast imaging) | Peak systolic strain, strain rate, early diastolic strain rate | Tagging is the gold standard for strain assessment. | Time consuming analysis. Bespoke strain techniques prolong imaging time. |
| Phase-contrast imaging | Aortic pulse wave velocity, flow | Standard CMR assessment of aortic flow. | |
| Adenosine-stress perfusion imaging | Inducible perfusion defect | Typically requires clinician supervision | Gadolinium-based contrast agents contraindicated in patients with eGFR < 30 ml/min/1.73 m2 |
| Dobutamine stress imaging | Inducible wall-motion abnormality | Typically requires clinician supervision | Theoretical risk of inducing ventricular arrhythmias, angina. |
| Blood oxygen level dependent imaging | T2* signal reduction with reduction in myocardial oxygenation | Non- invasive assessment of myocardial microcirculation | Still a research tool, not routinely available in clinical practice. |
LV left ventricle, EF ejection fraction, eGFR electronic glomerular filtration rate