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Advanced Cardiac MR Imaging for Myocardial Characterization and Quantification: T1 Mapping.

Hwang SH, Choi BW - Korean Circ J (2013)

Bottom Line: Although late gadolinium enhancement after injection of the gadolinium extracellular contrast agent has further extended our ability to characterize the myocardial tissue, it also has limitations in the quantification of enhanced myocardial tissue pathology, and the detection of diffuse myocardial disease, which is not easily recognized by enhancement contrast.Recently, the remarkable advances in CMR technique, such as T1 mapping, which can quantitatively evaluate myocardial status, showed potentials to overcome limitations of existing CMR sequences and to expand the application of CMR.This article will review the technical and clinical points to be considered in the practical use of pre- and post-contrast T1 mapping.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Yonsei University College of Medicine, Seoul, Korea.

ABSTRACT
Magnetic resonance as an imaging modality provides an excellent soft tissue differentiation, which is an ideal choice for cardiac imaging. Cardiac magnetic resonance (CMR) allows myocardial tissue characterization, as well as comprehensive evaluation of the structures. Although late gadolinium enhancement after injection of the gadolinium extracellular contrast agent has further extended our ability to characterize the myocardial tissue, it also has limitations in the quantification of enhanced myocardial tissue pathology, and the detection of diffuse myocardial disease, which is not easily recognized by enhancement contrast. Recently, the remarkable advances in CMR technique, such as T1 mapping, which can quantitatively evaluate myocardial status, showed potentials to overcome limitations of existing CMR sequences and to expand the application of CMR. This article will review the technical and clinical points to be considered in the practical use of pre- and post-contrast T1 mapping.

No MeSH data available.


Related in: MedlinePlus

Late gadolinium enhancement (LGE) (A), pre- and post-contrast (B and C) T1 map images using 3-T MR system in a patient with secondary myocardial amyloidosis from multiple myeloma. LGE-MR image shows diffuse subendocardial gadolinium enhancement, which is a typical finding of myocardial amyloidosis deposition. Post-contrast T1 map image shows decrease of T1 value in the myocardium which enables quantification of extracellular volume fraction.
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Figure 2: Late gadolinium enhancement (LGE) (A), pre- and post-contrast (B and C) T1 map images using 3-T MR system in a patient with secondary myocardial amyloidosis from multiple myeloma. LGE-MR image shows diffuse subendocardial gadolinium enhancement, which is a typical finding of myocardial amyloidosis deposition. Post-contrast T1 map image shows decrease of T1 value in the myocardium which enables quantification of extracellular volume fraction.

Mentions: Post-contrast T1 values in myocardial fibrosis are much smaller than those of normal myocardium due to the retention of more gadolinium in the expanded extracellular space in the fibrotic tissue. Messroghli et al.40) reported that post-contrast T1 values were approximately 390 msec in chronic infarction scar and 483 msec in normal myocardium by T1 mapping with MOLLI sequence at 1.5T. Kehr et al.41) also showed that post-contrast T1 values for both diffuse and replacement fibrosis were significantly shorter than those for normal myocardium. In addition, myocardial ECV obtained by combining pre- and post-contrast T1 mapping may be useful to detect mild or diffuse abnormalities. Ugander et al.10) reported that the ECV obtained by T1 mapping at 1.5T of "normal appearing" myocardium without LGE was 26±3%, and increased with age. Mild ECV abnormalities were consistent with fibrosis according to age in the remote myocardium from infarction. A recent study reported that extracellular volume expansion measured by CMR might predict both mortality and other composite end points, including death, cardiac transplantation, and left ventricular assist device implantation.42) The investigators enrolled 793 patients and 9 volunteers, and measured ECV in non-infarcted myocardium. The ECV in patients ranged from 21.0% to 45.8%, while that in volunteers ranged from 21.7% to 26.2%. After the cohort was followed for 0.8 year, ECV was related to all-cause mortality and the other composite end points (hazard ratio, 1.5 and 1.48 for every 3% increase in ECV, respectively). Myocardial infiltrative diseases, such as amyloidosis and sarcoidosis usually reveal LGE at the diseased myocardium. Cardiac amyloidosis is characterized by a deposition of amyloid fibrils mainly in the endocardial myocardium, where LGE can be seen with an expanded extracellular space.23) Diffuse subendocardial enhancement is a hallmark of cardiac amyloidosis. T1 mapping can be a useful method to detect and quantify diffuse infiltrative pathology in the myocardium (Fig. 2).


Advanced Cardiac MR Imaging for Myocardial Characterization and Quantification: T1 Mapping.

Hwang SH, Choi BW - Korean Circ J (2013)

Late gadolinium enhancement (LGE) (A), pre- and post-contrast (B and C) T1 map images using 3-T MR system in a patient with secondary myocardial amyloidosis from multiple myeloma. LGE-MR image shows diffuse subendocardial gadolinium enhancement, which is a typical finding of myocardial amyloidosis deposition. Post-contrast T1 map image shows decrease of T1 value in the myocardium which enables quantification of extracellular volume fraction.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3569561&req=5

Figure 2: Late gadolinium enhancement (LGE) (A), pre- and post-contrast (B and C) T1 map images using 3-T MR system in a patient with secondary myocardial amyloidosis from multiple myeloma. LGE-MR image shows diffuse subendocardial gadolinium enhancement, which is a typical finding of myocardial amyloidosis deposition. Post-contrast T1 map image shows decrease of T1 value in the myocardium which enables quantification of extracellular volume fraction.
Mentions: Post-contrast T1 values in myocardial fibrosis are much smaller than those of normal myocardium due to the retention of more gadolinium in the expanded extracellular space in the fibrotic tissue. Messroghli et al.40) reported that post-contrast T1 values were approximately 390 msec in chronic infarction scar and 483 msec in normal myocardium by T1 mapping with MOLLI sequence at 1.5T. Kehr et al.41) also showed that post-contrast T1 values for both diffuse and replacement fibrosis were significantly shorter than those for normal myocardium. In addition, myocardial ECV obtained by combining pre- and post-contrast T1 mapping may be useful to detect mild or diffuse abnormalities. Ugander et al.10) reported that the ECV obtained by T1 mapping at 1.5T of "normal appearing" myocardium without LGE was 26±3%, and increased with age. Mild ECV abnormalities were consistent with fibrosis according to age in the remote myocardium from infarction. A recent study reported that extracellular volume expansion measured by CMR might predict both mortality and other composite end points, including death, cardiac transplantation, and left ventricular assist device implantation.42) The investigators enrolled 793 patients and 9 volunteers, and measured ECV in non-infarcted myocardium. The ECV in patients ranged from 21.0% to 45.8%, while that in volunteers ranged from 21.7% to 26.2%. After the cohort was followed for 0.8 year, ECV was related to all-cause mortality and the other composite end points (hazard ratio, 1.5 and 1.48 for every 3% increase in ECV, respectively). Myocardial infiltrative diseases, such as amyloidosis and sarcoidosis usually reveal LGE at the diseased myocardium. Cardiac amyloidosis is characterized by a deposition of amyloid fibrils mainly in the endocardial myocardium, where LGE can be seen with an expanded extracellular space.23) Diffuse subendocardial enhancement is a hallmark of cardiac amyloidosis. T1 mapping can be a useful method to detect and quantify diffuse infiltrative pathology in the myocardium (Fig. 2).

Bottom Line: Although late gadolinium enhancement after injection of the gadolinium extracellular contrast agent has further extended our ability to characterize the myocardial tissue, it also has limitations in the quantification of enhanced myocardial tissue pathology, and the detection of diffuse myocardial disease, which is not easily recognized by enhancement contrast.Recently, the remarkable advances in CMR technique, such as T1 mapping, which can quantitatively evaluate myocardial status, showed potentials to overcome limitations of existing CMR sequences and to expand the application of CMR.This article will review the technical and clinical points to be considered in the practical use of pre- and post-contrast T1 mapping.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Yonsei University College of Medicine, Seoul, Korea.

ABSTRACT
Magnetic resonance as an imaging modality provides an excellent soft tissue differentiation, which is an ideal choice for cardiac imaging. Cardiac magnetic resonance (CMR) allows myocardial tissue characterization, as well as comprehensive evaluation of the structures. Although late gadolinium enhancement after injection of the gadolinium extracellular contrast agent has further extended our ability to characterize the myocardial tissue, it also has limitations in the quantification of enhanced myocardial tissue pathology, and the detection of diffuse myocardial disease, which is not easily recognized by enhancement contrast. Recently, the remarkable advances in CMR technique, such as T1 mapping, which can quantitatively evaluate myocardial status, showed potentials to overcome limitations of existing CMR sequences and to expand the application of CMR. This article will review the technical and clinical points to be considered in the practical use of pre- and post-contrast T1 mapping.

No MeSH data available.


Related in: MedlinePlus