Our laboratory has pioneered the use of blood oxygenation level dependent (BOLD) MRI the kidneys as a way
of evaluating its oxygenation status. Several investigators around the world have validated the technique.
However, it remains as a qualitative measure and its specificity to oxygenation is not validated. Even though it
is known theoretically that a role exists for the fractional blood volume (fraction of the tissue occupied by blood
vessels) in BOLD MRI, with the lack of data it has been tacitly assumed to be either small or non-existent.
However, recent developments allow us to measure regional fBV using blood pool contrast agents.
Here, we want to for the first time measure regional fBV in human kidneys and see (i) whether it is different in
cortex and medulla; (ii) whether medullary fBV reduces when administering furosemide as suggested by recent
data in rat kidneys; and (iii) whether regional fBV is reduced in individuals with chronic kidney disease (CKD).
If the proposed study is successful, it may support the use of fBV as an independent imaging marker. In
addition, the data will have a significant impact on the interpretation of renal BOLD MRI data.