TY - JOUR
T1 - Venous Blood Oxygenation Measurements Using TRUST and T2-TRIR MRI During Hypoxic and Hypercapnic Gas Challenges
AU - Baas, Koen P. A.
AU - Vu, Chau
AU - Shen, Jian
AU - Coolen, Bram F.
AU - Biemond, Bart J.
AU - Strijkers, Gustav J.
AU - Wood, John C.
AU - Nederveen, Aart J.
N1 - Funding Information: Koen P.A. Baas, Bart J. Biemond, John C. Wood, and Aart J. Nederveen are supported by the National Heart, Lung, and Blood Institute (1R01‐HL136484‐01A1). Publisher Copyright: © 2023 The Authors. Journal of Magnetic Resonance Imaging published by Wiley Periodicals LLC on behalf of International Society for Magnetic Resonance in Medicine.
PY - 2023/12
Y1 - 2023/12
N2 - Background: Oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO2) may serve as biomarkers in several diseases. OEF and CMRO2 can be estimated from venous blood oxygenation (Yv) levels, which in turn can be calculated from venous blood T2 values (T2b). T2b can be measured using different MRI sequences, including T2-relaxation-under-spin-tagging (TRUST) and T2-prepared-blood-relaxation-imaging-with-inversion-recovery (T2-TRIR). The latter measures both T2b and T1 (T1b) but was found previously to overestimate T2b compared to TRUST. It remained unclear, however, if this bias is constant across higher and lower oxygen saturations. Purpose: To compare TRUST and T2-TRIR across a range of O2 saturations using hypoxic and hypercapnic gas challenges. Study Type: Prospective. Population: Twelve healthy volunteers (four female, age 36 ± 10 years). Field Strength/Sequence: A 3T; turbo-field echo-planar-imaging (TFEPI), echo-planar-imaging (EPI), and fast-field-echo (FFE). Assessment: TRUST- and T2-TRIR-derived T2b, Yv, OEF, and CMRO2 were compared across different respiratory challenges. T1b from T2-TRIR was used to estimate Hct (HctTRIR) and compared with venipuncture (HctVP). Statistical Tests: Shapiro–Wilk, one-sample and paired-sample t-test, repeated measures ANOVA, Friedman test, Bland–Altman, and correlation analysis. Bonferroni multiple-comparison correction was performed. Significance level was 0.05. Results: A significant bias was observed between TRUST- and T2-TRIR-derived T2b, Yv, and OEF values (−13 ± 11 msec, −5.3% ± 3.5% and 5.9 ± 4.1%, respectively). For Yv and OEF, this bias was constant across the range of measured values. T1b was significantly lower during severe hypoxia and hypercapnia compared to baseline (1712 ± 86 msec and 1634 ± 79 msec compared to 1757 ± 90 msec). While no significant bias was found between HctVP and HctTRIR (0.02% ± 0.06%, P = 0.20), the correlation between these Hct values was significant but weak (r = 0.19). Data Conclusion: Given the constant bias, TRUST- and T2-TRIR-derived venous T2b values can be used interchangeably to estimate Yv, OEF, and CMRO2 across a broad range of oxygen saturations. Hct from T2-TRIR-derived T1-values only weakly correlated with Hct from venipuncture. Evidence Level: 2. Technical Efficacy: Stage 2.
AB - Background: Oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO2) may serve as biomarkers in several diseases. OEF and CMRO2 can be estimated from venous blood oxygenation (Yv) levels, which in turn can be calculated from venous blood T2 values (T2b). T2b can be measured using different MRI sequences, including T2-relaxation-under-spin-tagging (TRUST) and T2-prepared-blood-relaxation-imaging-with-inversion-recovery (T2-TRIR). The latter measures both T2b and T1 (T1b) but was found previously to overestimate T2b compared to TRUST. It remained unclear, however, if this bias is constant across higher and lower oxygen saturations. Purpose: To compare TRUST and T2-TRIR across a range of O2 saturations using hypoxic and hypercapnic gas challenges. Study Type: Prospective. Population: Twelve healthy volunteers (four female, age 36 ± 10 years). Field Strength/Sequence: A 3T; turbo-field echo-planar-imaging (TFEPI), echo-planar-imaging (EPI), and fast-field-echo (FFE). Assessment: TRUST- and T2-TRIR-derived T2b, Yv, OEF, and CMRO2 were compared across different respiratory challenges. T1b from T2-TRIR was used to estimate Hct (HctTRIR) and compared with venipuncture (HctVP). Statistical Tests: Shapiro–Wilk, one-sample and paired-sample t-test, repeated measures ANOVA, Friedman test, Bland–Altman, and correlation analysis. Bonferroni multiple-comparison correction was performed. Significance level was 0.05. Results: A significant bias was observed between TRUST- and T2-TRIR-derived T2b, Yv, and OEF values (−13 ± 11 msec, −5.3% ± 3.5% and 5.9 ± 4.1%, respectively). For Yv and OEF, this bias was constant across the range of measured values. T1b was significantly lower during severe hypoxia and hypercapnia compared to baseline (1712 ± 86 msec and 1634 ± 79 msec compared to 1757 ± 90 msec). While no significant bias was found between HctVP and HctTRIR (0.02% ± 0.06%, P = 0.20), the correlation between these Hct values was significant but weak (r = 0.19). Data Conclusion: Given the constant bias, TRUST- and T2-TRIR-derived venous T2b values can be used interchangeably to estimate Yv, OEF, and CMRO2 across a broad range of oxygen saturations. Hct from T2-TRIR-derived T1-values only weakly correlated with Hct from venipuncture. Evidence Level: 2. Technical Efficacy: Stage 2.
KW - T2-TRIR
KW - TRUST
KW - blood T2
KW - cerebral metabolic rate of oxygen
KW - oxygen extraction fraction
KW - oxygenation
UR - http://www.scopus.com/inward/record.url?scp=85153535974&partnerID=8YFLogxK
U2 - https://doi.org/10.1002/jmri.28744
DO - https://doi.org/10.1002/jmri.28744
M3 - Article
C2 - 37092724
SN - 1053-1807
VL - 58
SP - 1903
EP - 1914
JO - Journal of magnetic resonance imaging
JF - Journal of magnetic resonance imaging
IS - 6
ER -