Rapid measurement of major cortical and subcortical venous oxygenation using EPI-based T-relaxation-under-phase-contrast.

Publication date: Jul 14, 2025

Cerebral venous oxygenation (Y) is an important physiological parameter indicating the brain’s homeostasis of oxygen demand and supply. This study aims to develop a quantitative MRI technique to provide regional Y assessment in approximately 1 min. The new pulse sequence is referred to as EPI-based T-relaxation-under-phase-contrast (EPI-TRUPC). It consists of a phase-contrast module to isolate pure blood signal, a T-preparation module to modulate the T-weighting of the signal, and a post-saturation module to reset spin history. An EPI phase-contrast scheme was used for rapid data acquisition. Two experimental studies were conducted. In the first study (four males and four females, 26. 1 +/- 5. 3 y), we quantified Y values in regional veins of the brain and compared the sequence to existing techniques in terms of accuracy and test-retest reproducibility. In the second study (four males and four females, 24. 4 +/- 2. 7 y), we demonstrated its sensitivity in detecting Y increases and decreases by applying O and caffeine challenge, respectively. Y values of five major cerebral veins, specifically internal cerebral vein (ICV), straight sinus (SS), posterior superior sagittal sinus (SSS), middle SSS, and anterior SSS, were found to be 72. 7 +/- 4. 0% (mean +/- SD across participants), 68. 2 +/- 4. 3%, 66. 1 +/- 6. 0%, 69. 8 +/- 4. 4%, and 72. 6 +/- 2. 5%, respectively. The intra-session coefficient of variance (CoV) in Y measured by EPI-TRUPC of all cortical and subcortical veins was around 2%-3%. Y increased during O inhalation, with an average increase of 6. 4% in absolute value. Following caffeine challenge, Y revealed a gradual decrease over a period of 40 min. EPI-TRUPC MRI has the potential to provide quantitative and reliable measurement of cortical and subcortical venous oxygenation within clinically feasible scan time.

Semantics

Original Article