While many of us are preoccupied with wires and balloons ,( coronary myopia ! ) , our radiology colleagues are making rapid strides . Let us spend some time to understand how the myocardial segments are inflicted the final insult . We need to realize , there is a pattern to this myocardial end game of scarring and fibrosis.
MRI is the gold standard to assess the myocardial architecture . It has a role in both assessing the anatomy , function , perfusion and viability .
- LV function is assessed by cine MRI
- Viability stud by delayed enhancement MRI (DEMRI , also called as LGE- Late Gadolinum enhancement )
- Myocardial scar best assessed by DEMRI*
- Mid myocardial scar
- Epicardial scars
- Global sub-endocardial scars
- No scar(Ironically if no delayed hyper-enhancement is noted it is likely to be non Ischemic DCM )
- Regional transmural scars
- Localised sub-endocardial scars
- Amyloidosis (Can be restrictive as well )
Why is scar localisation and Quantification important ?
Apart from differentiating various cardiomyopathies it has few clinical implication .
- Since scar indicates irreversible damage , if extensive it will argue against any re-vascularisation .
- Scar location becomes vital if we plan CRT .It will be futile to place a CRT lead over a scar.
- Scars are often form a macro re-entrant circuits for VT .Help us localize or zeroing in VT focus.
- Scar quantification is helpful risk stratification of patients with HOCM .and their family.