Cerebral oxygen extraction fraction declines with ventricular enlargement in patients with normal pressure hydrocephalus.

Publication Type	Academic Article
Authors	Zhuang H, Cho J, Chiang G, Kovanlikaya I, Heier L, Dyke J, Wang Y
Journal	Clin Imaging
Volume	97
Pagination	22-27
Date Published	02/10/2023
ISSN	1873-4499
Keywords	Hydrocephalus, Normal Pressure, Neurodegenerative Diseases
Abstract	OBJECTIVE: Normal pressure hydrocephalus (NPH) is a neurodegenerative disease that is potentially reversible by shunt surgery in approximately 60% of patients. Imaging may provide a means to investigate brain tissue viability and oxygen metabolism in NPH patients. METHODS: Oxygen extraction fraction (OEF) mapping was generated from 3D multi-echo gradient echo MRI (mGRE) data using QQ-CCTV algorithm and cerebral blood flow (CBF) using 3D arterial spin labeling (ASL) MRI data, thereby calculating the cerebral metabolic rate of oxygen (CMRO2 = CBF × OEF × [H]a) in 16 NPH patients. Regression analyses using cortical gray matter and deep gray matter regions were conducted with age, gender, CSF stroke volume and normalized ventricular volume as independent variables. RESULTS: OEF showed significant negative correlations with normalized brain ventricular volumes in the whole brain (p = 0.004, q = 0.01), cortical gray matter (p = 0.004, q = 0.01), caudate (p = 0.02, q = 0.04), and pallidum (p = 0.03, q = 0.04), but no significant correlation with CSF stroke volume (q > 0.05). There was no significant finding with CBF or CMRO2. CONCLUSION: In NPH patients, low OEF in several regions was significantly correlated with large ventricular volumes, indicating decreased tissue oxygen metabolism with increased NPH severity. OEF mapping may provide a functional understanding of neurodegeneration in NPH and may improve monitoring of disease course and treatment outcomes.
DOI	10.1016/j.clinimag.2023.02.001
PubMed ID	36871361
PubMed Central ID	PMC10081162