Learning objectives
1.
To briefly describe the technique of delayed enhancement cardiac magnetic resonance (CMR) imaging.
2.
To discuss pathophysiology and patterns of late gadolinium enhancement (LGE) in a myriad of uncommon non-ischemic cardiomyopathies,
congenital cardiac conditions,
as well as inflammatory and infiltrative myocardial disease.
These include endocardial fibroelastosis,
non-compaction cardiomyopathy,
collagen vascular diseases such as scleroderma,
muscular dystrophy,
Fabry’s disease,
as well as conditions causing pulmonary arterial hypertension,
both idiopathic and those related to congenital heart disease.
Background
CMR permits optimal differentiation between normal and diseased myocardium with the use of gadolinium-based contrast agents and specific pulse sequences.
First described more than 10 years ago [1],
delayed enhancement CMR has now become the standard of reference for evaluation of myocardial scar due to infarction.
Delayed myocardial enhancement is,
however,
not specific for myocardial infarction (MI) and can occur in a variety of non-ischemic cardiac conditions.
Differential myocardial contrast enhancement forms the basis of tissue characterization and is seen in many pathophysiologic scenarios other...
Imaging findings OR Procedure details
The technique for LGE-CMR involves intravenous administration of gadolinium chelate contrast material (0.05-0.2 mmol/kg) followed 8-30 minutes later by a cardiac-gated T1-weighted pulse sequence.
The typical LGE pulse sequence is a cardiac-gated segmented inversion-recovery-prepared fast gradient-echo sequence: an inversion recovery preparatory pulse nulls normal myocardium,
followed by a segmented k-space gradient-echo acquisition.
Retention of contrast material results in T1 shortening and thus increased signal intensity on T1-weighted images relative to that of the normal myocardium.
Typical values for inversion time (TI) are 150-400 milliseconds (ms),...
Conclusion
Due to its superior spatial resolution as well as its capabilities for cardiac anatomical and physiological assessment,
LGE-CMR imaging has become the preferred tool to determine the presence and extent of myocardial disease.
While LGE CMR has become fairly well established for imaging of acute and chronic MI and relatively more common non-ischemic cardiomyopathies such as HCM and DCM,
delayed myocardial enhancement can be seen in many other lesser known cardiac pathologic conditions.
Hence,
it behoves the cardiac imager to be aware of appearance and...
References
Dulce MC,
Duerinckx AJ,
Hartiala J,
et al.
MR imaging of the myocardium using non-ionic contrast medium: signal-intensity changes in patients with subacute myocardial infarction.
AJR Am J Roentgenol 1993; 160:963–970.
Kellman P,
Arai AE,
McVeigh ER,
et al.
Phase-sensitive inversion recovery for detecting myocardial infarction using gadolinium-delayed hyperenhancement.
Magn Reson Med 2002; 47:372-383.
Vogel-Claussen J,
Rochitte CE,
Wu KC,
et al.
Delayed Enhancement MR Imaging: Utility in Myocardial Assessment.
Radiographics 2006; 26:795-810.
Vohringer M,
Mahrholdt H,
Yilmaz A,
et al.
Significance of Late Gadolinium...