J Magn Reson Imaging 2022 Jan 25. Epub 2022 Jan 25.
Department of Radiology and Nuclear Medicine, Amsterdam University Medical Centers, Amsterdam Cardiovascular Sciences, University of Amsterdam, Amsterdam, The Netherlands.
Background: Venous blood oxygenation (Yv), which can be derived from venous blood T (T b), combined with oxygen-extraction fraction (OEF) and cerebral metabolic rate of oxygen, is considered indicative for tissue viability and brain functioning and frequently assessed in patients with sickle cell disease. Recently, T -Prepared-Blood-Relaxation-Imaging-with-Inversion-Recovery (T -TRIR) was introduced allowing for simultaneous measurements of blood T and T (T b), potentially improving Yv estimation by overcoming the need to estimate hematocrit.
Purpose: To optimize and compare T -TRIR with T -relaxation-under-spin-tagging (TRUST) sequence.
Study Type: Prospective.
Population: A total of 12 healthy volunteers (six female, 27 ± 3 years old) and 7 patients with sickle cell disease (five female, 32 ± 12 years old).
Field Strength/sequence: 3 T; turbo field echo planar imaging (TFEPI), echo planar imaging (EPI), and fast field echo (FFE).
Assessment: T b, Yv, and OEF from TRUST and T -TRIR were compared and T -TRIR-derived T b was assessed. Within- and between-session repeatability was quantified in the controls, whereas sensitivity to hemodynamic changes after acetazolamide (ACZ) administration was assessed in the patients.
Statistical Tests: Shapiro-Wilk, one-sample and paired-sample t-test, repeated measures ANOVA, mixed linear model, Bland-Altman analysis and correlation analysis. Sidak multiple-comparison correction was performed. Significance level was 0.05.
Results: In controls, T b from T -TRIR (70 ± 11 msec) was higher compared to TRUST (60 ± 8 msec). In patients, T b values were lower pre- compared to post-ACZ administration (TRUST: 80 ± 15 msec and 106 ± 23 msec and T -TRIR: 95 ± 21 msec and 125 ± 36 msec). Consequently, Yv and OEF were lower and higher pre- compared to post-ACZ administration (TRUST Yv: 68% ± 7% and 77% ± 8%, T -TRIR Yv: 74% ± 8% and 80% ± 6%, TRUST OEF: 30% ± 7% and 21% ± 8%, and T -TRIR OEF: 25% ± 8% and 18% ± 6%).
Data Conclusion: TRUST and T -TRIR are reproducible, but T -TRIR-derived T b values are significantly higher compared to TRUST, resulting in higher Yv and lower OEF estimates. This bias might be considered when evaluating cerebral oxygen homeostasis.
Evidence Level: 2 TECHNICAL EFFICACY: Stage 2.