Endsystolic versus enddiastolic scar imaging for transmurality assessment
© Schuster et al; licensee BioMed Central Ltd. 2011
Published: 2 February 2011
To investigate the influence of endsystolic scar imaging over routine enddiastolic scar imaging on transmurality.
The late gadolinium enhancement (LGE) technique has been an important achievement in cardiovascular magnetic resonance (CMR) and is widely used to precisely localize and determine the amount of necrosis and fibrosis. The percentage of transmurality of LGE is inversely related to the likelihood of functional recovery after revascularisation. LGE imaging is usually performed in enddiastole as recommended by current guidelines of the SCMR. Whether or not endsystolic imaging would significantly influence transmurality in patients with ischemic scarring remains unclear.
107 segments with moderate hypokinesia or more severe wall motion abnormalities were studied in 20 patients with established coronary artery disease referred for viability assessment (33% of all segments). We used a SSFP standard 4-chamber view to determine the endsystolic and enddiastolic position in the cardiac cycle. LGE imaging was performed with patient specific trigger delays to obtain enddiastolic (LGEed) and endsystolic (LGEes) images. Enddiastolic and endsystolic wall thickness (WTed and WTes), thickness of the remaining viable rim (RIMed and RIMes) and thickness of scar in enddiastole was measured manually.
Evidence of LGE was 84% in all dysfunctional segments with a mean scar of 3.4±2.5 mm. Total wall thickness and the thickness of the remaining viable myocardium increased from diastole to systole (WTed 7.9±1.9 versus WTes 8.4±2.2, p<0.001 ; RIMed 4.5±3.1 versus RIMes 5±3.4, p<0.001). There was a difference between the transmurality of scar measured in enddiastole and endsystole (LGEed 46±33% versus LGEes 44±33%, p<0.001). This difference was most pronounced in a subgroup of segments (n=50) between 25 and 75% transmurality of LGE (LGEed 57±18% versus LGEes 53±18%, p<0.001). Reduced transmurality was inversely correlated with increased thickness of the remaining viable rim between diastole and systole (r=-0.73).
Enddiastolic versus endsystolic LGE imaging and segmental transmurality
All segments (n=107)
LGEed 46±33% versus LGEes 44±33%,
Segments with up to 25% transmurality (n=25)
LGEed 25±9% versus LGEes 22±8%
Segments with 25% and 75% transmurality (n=50)
LGEed 57±18% versus LGEes 53±18%
Segments with transmural scar (n=15)
LGEed 99±1% versus LGEes 99±2%
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