Rapid Fire 10- Pediatric/Congenital Heart Disease IX
Creation of “Patchwork MOLLI Image” from Multiple Free-Breathing MOLLI Images: Feasible Technique to Enable Efficient T1 Mapping for Free-Breathing Children (RF_SA_484)
Head physician Shizuoka Children's Hospital, Japan
Background: T1 mapping is now widely used for the diagnosis and evaluation of myocardial diseases such as myocarditis and cardiomyopathy in adult patients, but it is not yet widely used in pediatric patients. The reason for the slow spread of T1 mapping in the pediatric population is that the MOLLI images used for T1 mapping require breath-hold imaging. Furthermore, while there are sequences that can be used for free-breathing imaging, they can only be used with limited machines. Then, we thought that it would be possible to perform T1 mapping by extracting images with the same respiratory phase from multiple MOLLI images taken under free breathing and creating a series of images from these images like a patchwork ("Patchwork MOLLI Image"). Therefore, the aim of this study was to assess whether valid T1 mapping is possible with "Patchwork MOLLI Image".
Methods: 13 patients who underwent CMR between January 2024 and August 2024 were eligible for this feasibility study. CMR examinations were performed with Ingenia 1.5T (Philips). Multiple MOLLI sequence was performed in three cross sections: left ventricular base, middle, and apex. The images were taken under conventional breath-hold, followed by three free-breathing images. Post-processing was performed with cvi42. Images obtained under breath-hold were post-processed as usual. For the images taken under free breathing, the same respiratory phase was extracted from the three images to create a series of "Patchwork MOLLI Image", which was then post-processed. T1 values were compared between the conventional image and "Patchwork MOLLI Image".
Results: The age of 13 patients was 18.5±7.5 years old. And the diagnosis was pulmonary atresia with ventricular septal defect for 2 patients, aortic valve stenosis for 2 patients, tetralogy of Fallot for 1 patient, Ebstein’s anomaly for 1 patient, atrial septal defect for 1 patient, myocarditis for 1 patient, hypertrophic cardiomyopathy for 1 patient, coronary artery aneurysm after Kawasaki disease for 1 patient, coarctation of aorta for 1 patient, transposition of great arteries for 1 patient and truncus arteriosus for 1 patient. There was no significant difference in the global T1 value. Furthermore, there were no significant differences in T1 values between the conventional and patchwork images in all 16 segments of the AHA classification except for the apex (p=0.16-0.98).
Conclusion: T1 mapping values measured with "patchwork MOLLI image" created from multiple free-breathing MOLLI images were valid and not significantly different from T1 mapping values measured with MOLLI images taken under breath-hold. Therefore, T1 mapping with "patchwork MOLLI image" can be widely applied not only to children but also to adults, for whom breath-hold imaging is difficult.
