Measuring venous blood oxygenation in fetal brain using susceptibility-weighted imaging.
OBJECTIVE
To evaluate fetal cerebral venous blood oxygenation, Yv, using principles of MR susceptometry.


METHODS
A cohort of 19 pregnant subjects, with a mean gestational age of 31.6 ± 4.7 weeks were imaged using a modified susceptibility-weighted imaging (SWI) sequence. Data quality was first assessed for feasibility of oxygen saturation measurement, and data from five subjects (mean ± std gestational age of 33.7 ± 3.6 weeks) were then chosen for further quantitative analysis. SWI phase in the superior sagittal sinus was used to evaluate oxygen saturation using the principles of MR susceptometry. Systematic error in the measured Y(v) values was studied through simulations.


RESULTS
Simulations showed that the systematic error in Yv depended upon the assumed angle of the vessel, θ, relative to the main magnetic field and the error in that vessel angle δθ. For the typical vessel angle of θ = 30° encountered in the fetal data analyzed, a δθ as large as ±20° led to an absolute error, δYv, of less than 11%. The measured mean oxygen saturation across the five fetuses was 66% ± 9.4%. This average cerebral venous blood oxygenation value is in close agreement with values in the published literature.


CONCLUSIONS
We have reported the first in vivo measurement of human fetal cerebral venous oxygen saturation using MRI.
Jaladhar
J
Neelavalli
Pavan Kumar
PK
Jella
Uday
U
Krishnamurthy
Sagar
S
Buch
E Mark
EM
Haacke
Lami
L
Yeo
Swati
S
Mody
Yashwanth
Y
Katkuri
Ray
R
Bahado-Singh
Sonia S
SS
Hassan
Roberto
R
Romero
Moriah E
ME
Thomason
D000293:Adolescent; D000328:Adult; D001921:Brain / Q000196:embryology / Q000473:pathology / Q000503:physiopathology*; D002550:Cerebral Veins / Q000196:embryology / Q000473:pathology / Q000503:physiopathology*; D002560:Cerebrovascular Circulation; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D006801:Humans; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D010100:Oxygen / Q000097:blood; D010101:Oxygen Consumption; D011247:Pregnancy; D011296:Prenatal Diagnosis / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult
D010100:Oxygen