Mu Zeng1, Nan Zhang1, Yi He1, Jing An2, Andreas Greiser3, and Zhanming Fan1
1Radiology, Beijing Anzhen Hospital,Capital medical university, Beijing, China, People's Republic of, 2MR Collaborations NE Asia, Siemens Healthcare, Beijing, China, Beijing, China, People's Republic of, 3Siemens AG Healthcare Sector MR, Erlangen, Germany
Synopsis
In recent years, use of the MRI T1 mapping technique to
detect diffuse myocardial fibrosis has received increasing attention. Although previous studies have
verified the relationship between T1 mapping and pathological findings, our
study is the first to show continuity during the observation of a single
disease while avoiding interference caused by other diseases. In addition, the
pathology can be fully verified in real time using animal experiments.
The main findings of this study were that (1) the ECV
obtained from the MRI T1 mapping sequence
was highly correlated with the CVF in terms of the degree of histologically diffuse interstitial fibrosis; (2) the correlation between the native T1 value and
the CVF change was
not strong; and (3) the rabbit is a suitable model for cardiac magnetic resonance research using clinical equipment.
Background
The technology of
cardiac magnetic resonance (CMR) T1 mapping
can noninvasively detect diffuse myocardial fibrosis. However, the
accuracy of the native T1 value, the post-contrast T1 value,
and the extracellular volume fraction (ECV) in detecting fibrosis remains
controversial in current studies. Our aim was to pathologically verify
the accuracy of the native T1 value, the post-contrast T1 value and the ECV in the detection of diffuse myocardial fibrosis. Another purpose of this study was to
test whether rabbits can be used to perform
cardiac imaging in clinical 3T magnetic resonance imaging (MRI) equipment.
Methods
Thirty New Zealand white rabbits were randomly
divided into either a control group (n = 6) or a diabetes mellitus (DM) group
(induced with alloxan, n = 24) and underwent clinical 3.0 T (Magnetom Verio; Siemens Healthcare Sector) with pre- and
post-contrast MOLLI T1 mapping after three, six, and nine months. For the histological
study, six diabetic rabbits were sacrificed at three, six, and nine months, and
left ventricular myocardium Masson staining was performed to calculate the collagen
volume fraction
(CVF). Pre- and post-contrast T1 values and the ECV were compared to the CVF using
Pearson’s correlation coefficients.
Results
The pre- and post-contrast T1 values and the ECV were successfully obtained in
all rabbits. The ECV calculated from pre- and post-contrast T1 values showed an
excellent correlation (r=0.876,
p<0.001) with the CVF, while post-contrast T1 values exhibited a moderate
correlation (r= −0.564, p=0.004) with the CVF. In contrast, pre-contrast T1
values showed no correlation (r=0.311, p=0.139) with the CVF.
Conclusion
ECV has an excellent correlation with the pathological collagen volume fraction (CVF) and may reflect
the degree of diffuse myocardial fibrosis
as a non-invasive method, whose performance is better than the post-contrast T1 value. The pre-contrast T1 value does not reflect the
degree of diffuse myocardial fibrosis well. Rabbit is a good animal
model for clinical 3T MR cardiac imaging.
Acknowledgements
No acknowledgement found.References
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