PDF version of this entire document

Strain-encoded Cardiac Magnetic Imaging

Strain-encoded (SENC) cardiac magnetic imaging is used by numerous groups (e.g. [23,24]) to detect myocardial dysfunction.

Garot et al. [22] performed experiments on five healthy volunteers and nine patients with infarction. They assess performance without tags and to quote the abstract, ``Local contractile performance was decreased in infracted myocardium versus that in remote and adjacent myocardium (P < .01) and in adjacent versus remote myocardium (P < .05).''

The paper says that ``[i]n contrast to conventional tagging, strain-encoded MR imaging is a technique that uses tag surfaces that are parallel, not orthogonal, to the image plane, combined with out-of-plane phase-encoding gradients in the perpendicular section-select direction (14). Because local frequency of the tag pattern is related to myocardial strain (15,16), we hypothesized that strain-encoded MR imaging might provide direct myocardial longitudinal strain (Ell) imaging embedded on short-axis images of the LV. This technique may have potential in the online assessment of intrinsic myocardial contractility and may therefore represent a powerful addition to the assessment of myocardial viability by quantifying local function automatically. Thus, the purpose of our study was to prospectively evaluate strain-encoded MR imaging as a method for direct imaging of regional LV function that precludes the need for post-processing and can be used in combination with contrast material-enhanced MR imaging in the assessment of local myocardial viability.''

Mirja Neizel [25,26,27] published a series of studies with a group whose study ``evaluated the value of systolic and diastolic deformation indexes determined by strain-encoded imaging to predict persistent severe dysfunction at follow-up in patients after reperfused acute myocardial infarction (AMI) in comparison with late gadolinium enhancement (LGE).''

This body of work constitutes a surrogate or replacement for tagging.