Cardiac, MR, Computer Applications-Detection, diagnosis, Tissue characterisation
G. L. Chevreau1, H. Nivet2, M. Salel3, T. Ait Ali1, O. Corneloup1, V. Latrabe1, M. Montaudon1, F. Laurent1, H. Cochet1; 1Pessac/FR, 2Bordeaux/FR, 3Vigoulet-Auzil/FR
Methods and Materials
Population. Consecutive patients referred for cardiac MRI were prospectively included,
the inclusion criterion being indication for cardiac MRI according to current guidelines.
Exclusion criteria were any contraindications to MRI,
history of an acute cardiac event in the preceding 3 months and history of prior cardiac ablation or cardiac surgery.
Out of a total of 817 patients,
587 were excluded and 190 patients were finally included in the study.
Magnetic Resonance Imaging. MRI studies were conducted on a 1.5 T clinical system (Avanto,
Siemens Medical Solutions,
All patients underwent atrial DE imaging using a 3-dimensional,
respiration-navigated gradient-echo pulse sequence with fat-saturation (4).
DE imaging was initiated 15 min after the intravenous injection of 0.2 mmol/Kg gadoterate meglumine (Guerbet,
Image Analysis. Segmentation of the left atrial wall was performed using the software Corview (CARMA,
Salt Lake City,
Significant DE was segmented by adaptive thresholding of myocardial voxels as described previously (4),
using an algorithm developed as a plugin of the software Osirix 3.9.4 (OsiriX foundation,
The output was a global quantification of DE extent,
expressed in % of the left atrial wall,
and a patient-specific 3D map of DE over the left atrial endocardial geometry.
To study the distribution of DE in sub-populations,
all patient-specific DE maps were registered to a template.
Registered datasets were arranged according to clinical characteristics in order to compute statistical maps displaying the likelihood of DE over the left atrial wall in subpopulations.
To compare DE likelihood between atrial regions,
the template was divided into 4 regions: anterior,
lateral and septal.
Statistical Analysis. Multiple logistic regression was used to study the clinical correlates of DE in the general population,
in the population with AF and in the one without AF.
Reapeated measures ANOVA was used to compare the extent of DE between atrial segments.
A P value <0.05 was considered to indicate statistical significance.