MR Oximetry

MR oximetry includes methods for assessing tissue oxygenation. This chapter focuses on direct measurements of oxygenation. These can be divided into three methods. The first and most common has been termed BOLD MRI and relates to the quantification of deoxyhemoglobin. The second method uses an injected fluorinated agent which has a T ₁ that is sensitive to tissue oxygen levels. The third is a direct measurement of T ₁ under conditions where the variation in T ₁ can be limited to that caused by changes in pO₂ . These conditions can be met in the vitreous of the eye or the cerebrospinal fluids. Such changes in the eye have been called the retinal oxygenation response.