Simultaneous Volumetric T1 and T2 Mapping With Blood- and Fat-Suppression in Abdominal Aortic Aneurysms

To develop and validate a protocol for simultaneous volumetric T1 and T2 mapping with blood- and fat-suppression, and apply it to patients with abdominal aortic aneurysms (AAA) to assess tissue characteristics.

A spoiled gradient echo (SPGR) variable flip angle (VFA) acquisition was modified with preparation modules to suppress blood and fat signals. To account for the additional T1 and T2 weighting introduced by these preparation blocks, a dedicated signal model was developed, enabling accurate simultaneous T1 and T2 quantification. The method was validated through Bloch simulations and phantom experiments. Subsequently, the protocol was applied to 20 AAA patients.

Bloch simulations perfectly overlaid the signal model, validating the model. In phantom experiments, the bias for T1 was reduced from -781 to 100 ms when incorporating the signal model, and the bias for T2 was -7 ms. In vivo application in 20 AAA patients demonstrated the feasibility of generating volumetric T1 and T2 maps of the aortic vessel wall with blood- and fat-suppression.

The proposed method enables simultaneous T1 and T2 mapping with blood- and fat-suppression in AAA patients. Validation in simulations and phantom experiments confirmed accuracy, while in vivo experiments demonstrated technical feasibility, providing a foundation for future clinical studies on vessel wall tissue characterization.