Quantification of pathophysiological alterations in venous oxygen saturation: A comparison of global MR susceptometry techniques.

The purpose of this study was to compare the Infinite Cylinder and Forward Field methods of quantifying global venous oxygen saturation (Y _v ) in the superior sagittal sinus (SSS) from MRI phase data, and assess their applicability in systemic cerebrovascular disease.15 children with sickle cell disease (SCD) and 10 healthy age-matched controls were imaged on a 3.0 T MRI system. Anatomical and phase data around the superior sagittal sinus were acquired from a clinically available susceptibility weighted imaging sequence and converted to Y _v using the Infinite Cylinder and Forward Field methods. Y _v was significantly higher when calculated using the Infinite Cylinder method compared to the Forward Field method in both patients (p = 0.003) and controls (p < 0.001). A significant difference in Y _v was observed between patients and controls for the Forward Field method only (p = 0.006). While various implementations of Y _v quantification can be used in practice, the results can differ significantly. Simplistic models such as the Infinite Cylinder method may be easier to implement, but their dependence on broad assumptions can lead to an overestimation of Y _v , and may reduce the sensitivity to pathophysiological changes in Y _v .
(Copyright © 2019. Published by Elsevier Inc.)