Separating spin compartments in arterial spin labeling using delays alternating with nutation for tailored excitation (DANTE) pulse: A validation study using T2‐relaxometry and application to arterial cerebral blood volume imaging

• Published in: Magnetic resonance in medicine Vol. 87; no. 3; pp. 1329 - 1345
• Main Authors: Ishida, Shota, Kimura, Hirohiko, Takei, Naoyuki, Fujiwara, Yasuhiro, Matsuda, Tsuyoshi, Kanamoto, Masayuki, Matta, Yuki, Kosaka, Nobuyuki, Kidoya, Eiji
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc 01-03-2022
• Subjects: arterial cerebral blood volume; arterial spin labeling; Arteries; Blood; Blood flow; Blood volume; breath‐holding task; Cerebral blood flow; DANTE‐pulse; Excitation; Labeling; Microvasculature; Modules; Nutation; Spin labeling; T2‐relaxometry; Transit time
• ISSN: 0740-3194; 1522-2594
• DOI: 10.1002/mrm.29052

Purpose
To clarify the type of spin compartment in arterial spin labeling (ASL) that is eliminated by delays alternating with nutation for tailored excitation (DANTE) pulse using T2‐relaxometry, and to demonstrate the feasibility of arterial cerebral blood volume (CBVa) imaging using DANTE‐ASL in combination with a simplified two‐compartment model.
Method
The DANTE and T2‐preparation modules were combined into a single ASL sequence. T2 values under the application of DANTE were determined to evaluate changes in T2, along with the post‐labeling delay (PLD) and the relationship between transit time without DANTE (TTnoVS) and T2. The reference tissue T2 (T2_ref) was also obtained. Subsequently, the DANTE module was embedded into the Hadamard‐encoded ASL. Cerebral blood flow (CBF) and CBVa were computed using two Hadamard‐encoding datasets (with and without DANTE) in a rest and breath‐holding (BH) task.
Results
While T2 without DANTE (T2_noVS) decreased as the PLD increased, T2 with DANTE (T2_DANTE) was equivalent to T2_ref and did not change with the PLD. Although there was a significant positive correlation between TTnoVS and T2_noVS with short PLD, T2_DANTE was not correlated with TTnoVS nor PLD. Baseline CBVa values obtained at rest were 0.64 ± 0.12, 0.64 ± 0.11, and 0.58 ± 0.15 mL/100 g for anterior, middle, and posterior cerebral arteries, respectively. Significant CBF and CBVa elevations were observed in the BH task.
Conclusion
Microvascular compartment signals were eliminated from the total ASL signals by DANTE. CBVa can be measured using Hadamard‐encoded DANTE‐ASL in combination with a simplified two‐compartment model.