ABSTRACT Purpose Blood T 1 is a key parameter for hemodynamic quantification in both non‐contrast‐ and contrast‐enhanced imaging. Individual vessel T 1 has been measured using a modified Look–Locker scheme with multi‐shot EPI or FLASH in high spatial resolution, requiring ∼1 min. Here, by exploiting the temporal sparsity from the excessive number of inversion delays, we apply Golden Angle rotated Spiral k‐t Sparse Parallel imaging (GASSP) to enable blood T 1 measurement in a single shot of 10 s. Methods The pulse sequence with single‐shot GASSP reconstruction was developed for T 1 measurement from the internal jugular vein (IJV) with 1 × 1 mm 2 in‐plane resolution. On nine healthy volunteers, the single‐shot GASSP was compared to the segmented EPI readout and was repeated to assess its intra‐scan reproducibility. Another experiment was performed on three patients, during which the 10 s GASSP was obtained at different time points prior to and following the Gadolinium (Gd) administration to assess dynamic changes in blood T 1 . Results The blood T 1 values measured with the highly undersampled GASSP method were strongly correlated ( r = 0.83) with those using the multi‐shot EPI readout and exhibited high reproducibility ( r = 0.88) within the session. The baseline IJV T 1 values measured were 1700–2000 ms. Following the Gd injection, the T 1 values of IJVs gradually recovered from ∼300–400 to ∼500 ms within 10–15 min. Conclusion The feasibility of an ultrafast blood T 1 measurement was demonstrated with high spatial resolution in a single shot of 10 s, applicable to both pre‐ and post‐contrast conditions.
Xu et al. (Fri,) studied this question.