Simultaneous multislice acquisition without trajectory modification for hyperpolarized C experiments.

PURPOSE

To investigate the feasibility of performing large FOV hyperpolarized C metabolic imaging using simultaneous multislice excitation.

METHODS

A spectral-spatial multislice excitation pulse was constructed by cosine modulation and incorporated into a C spiral imaging sequence. Phantom and in vivo pig experiments were performed to test the feasibility of simultaneous multislice data acquisition and image reconstruction. In vivo cardiac-gated images of hyperpolarized pyruvate, bicarbonate, and lactate were obtained at 1 × 1 × 1 cm resolution over a 48 × 48 × 24 cm FOV with 2-fold acceleration in the slice direction. Sensitivity encoding was used for image reconstruction with both autocalibrated and numerically calculated coil sensitivities.

RESULTS

Simultaneous multislice images obtained with 2-fold acceleration were comparable to reference unaccelerated images. Retained SNR figures greater than 80% were achieved over the part of the image containing the heart.

CONCLUSION

This method is anticipated to enable large FOV imaging studies using hyperpolarized C substrates, with an aim toward whole-body exams that have to date been out of reach.