Brain BOLD and NIRS response to hyperoxic challenge in sickle cell disease and chronic anemias - PubMed (original) (raw)

Brain BOLD and NIRS response to hyperoxic challenge in sickle cell disease and chronic anemias

Chau Vu et al. Magn Reson Imaging. 2023 Jul.

Abstract

Purpose: Congenital anemias, including sickle cell anemia and thalassemia, are associated with cerebral tissue hypoxia and heightened stroke risks. Recent works in sickle cell disease mouse models have suggested that hyperoxia respiratory challenges can identify regions of the brain having chronic tissue hypoxia. Therefore, this work investigated differences in hyperoxic response and regional cerebral oxygenation between anemic and healthy subjects.

Methods: A cohort of 38 sickle cell disease subjects (age 22 ± 8 years, female 39%), 25 non-sickle anemic subjects (age 25 ± 11 years, female 52%), and 31 healthy controls (age 25 ± 10 years, female 68%) were examined. A hyperoxic gas challenge was performed with concurrent acquisition of blood oxygen level-dependent (BOLD) MRI and near-infrared spectroscopy (NIRS). In addition to hyperoxia-induced changes in BOLD and NIRS, global measurements of cerebral blood flow, oxygen delivery, and cerebral metabolic rate of oxygen were obtained and compared between the three groups.

Results: Regional BOLD changes were not able to identify brain regions of flow limitation in chronically anemic patients. Higher blood oxygen content and tissue oxygenation were observed during hyperoxia gas challenge. Both control and anemic groups demonstrated lower blood flow, oxygen delivery, and metabolic rate compared to baseline, but the oxygen metabolism in anemic subjects were abnormally low during hyperoxic exposure.

Conclusion: These results indicated that hyperoxic respiratory challenge could not be used to identify chronically ischemic brain. Furthermore, the low hyperoxia-induced metabolic rate suggested potential negative effects of prolonged oxygen therapy and required further studies to evaluate the risk for hyperoxia-induced oxygen toxicity and cerebral dysfunction.

Keywords: BOLD MRI; Brain; Neurovascular insufficiency; Oxygen; Sickle cell anemia.

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Conflict of interest statement

Declaration of Competing Interest None.

Figures

Figure 1.

Experimental setup. Anatomical 3D T1 and T2-FLAIR, BOLD, T2-Relaxation-Under-Spin-Tagging (TRUST) and phase contrast scans were performed in all subjects under normoxia and hyperoxia conditions. BOLD imaging was performed under 50 seconds of normoxia and 4 minutes of hyperoxia to capture the cerebral hemodynamic response to 100% oxygen inspiration. Near-infrared spectroscopy (NIRS) and peripheral SpO2 were measured simultaneously with the BOLD acquisition during hyperoxia.

Figure 2.

Sustained hyperoxia model signals. Representative recordings of (A) global BOLD, SpO2, tissue oxygen TOI, (B) deoxygenated hemoglobin DeoxyHb, oxygenated hemoglobin OxyHb and total hemoglobin TotalHb changes during the hyperoxia challenge.

Figure 3.

Correlation between changes in BOLD, NIRS and pulse oximetry signals. Correlation between ΔBOLD and (A) pulse oximetryΔSpO2, (B) tissue oxygenation ΔTOI, (C) oxygenated hemoglobinΔOxyHb, and (D) deoxygenated hemoglobinΔDeoxyHb.

Figure 4.

Group ΔBOLD response to hyperoxic ventilation for sickle cell disease (SCD), non-sickle anemic (ACTL) and healthy controls (CTL). Mean ΔBOLD maps for each group. T-scores between SCD and ACTL groups versus control subjects failed to identify any systematically different regional behavior (not shown).

References

1. Mentzer WC, Kan YW. Prospects for research in hematologic disorders: Sickle cell disease and thalassemia. J Am Med Assoc. 2001;285(5):640–642. doi: 10.1001/jama.285.5.640 -DOI -PubMed
1. Borzage MT, Bush AM, Choi S, et al. Predictors of cerebral blood flow in patients with and without anemia. J Appl Physiol. 2016;120(8):976–981. doi: 10.1152/JAPPLPHYSIOL.00994.2015 -DOI -PMC -PubMed
1. Bush AM, Borzage MT, Choi S, et al. Determinants of resting cerebral blood flow in sickle cell disease. Am J Hematol. 2016;91(9):912–917. doi: 10.1002/AJH.24441 -DOI -PMC -PubMed
1. Chai Y, Bush AM, Coloigner J, et al. White matter has impaired resting oxygen delivery in sickle cell patients. Am J Hematol. 2019;94(4):467–474. doi: 10.1002/AJH.25423 -DOI -PMC -PubMed
1. Fields ME, Guilliams KP, Ragan DK, et al. Regional oxygen extraction predicts border zone vulnerability to stroke in sickle cell disease. Neurology. 2018;90(13):e1134–e1144. doi: 10.1212/WNL.0000000000005194 -DOI -PMC -PubMed

Brain BOLD and NIRS response to hyperoxic challenge in sickle cell disease and chronic anemias - PubMed (original) (raw)