Human umbilical cord blood relaxation times and susceptibility at 3 T. Issue 6 (24th October 2017)

• Record Type: Journal Article
• Authors: Portnoy, Sharon; Milligan, Natasha; Seed, Mike; Sled, John G.; Macgowan, Christopher K.
• Is Part Of: Magnetic resonance in medicine. Volume 79:Issue 6(2018)
• Page Start: 3194
• Page End: 3206
• Publication Date: 2017-10-24
• Subjects: umbilical cord blood -- longitudinal relaxation -- transverse relaxation -- susceptibility -- oxygen saturation -- hematocrit; Nuclear magnetic resonance -- Periodicals; Electron paramagnetic resonance -- Periodicals; 616.07548
• DOI: 10.1002/mrm.26978
• Languages: English
• ISSNs: 0740-3194

Abstract

Abstract : Purpose: To characterize the magnetic susceptibility and relaxation times (T1 and T2 ) of fetal blood at 3 T as a function of the hematocrit (Hct) and oxygen saturation (sO2 ). Methods: Susceptibility and relaxometry measurements were performed on cord blood specimens ( N = 90, derived from six caesarean deliveries) with a range of hematocrits and oxygen saturations (0.09 < Hct < 0.82, 7 < sO2 < 100%). To obtain simple, analytic relationships between MRI properties and blood properties, data were fit to established two‐compartment (plasma and erythrocytes) models. Results: Two‐compartment models effectively described the cord blood data. The root‐mean‐squared deviation between the model and the data was 6.3, 10.3, and 1.3% for fits to T1, T2, and susceptibility measurements. Relaxometry data and estimated T1 and T2 model parameters were generally consistent with those reported in cord blood at 1.5 T and comparable to published values for adult blood. Notably, the measured value of Δχdeo, the susceptibility difference between fully oxygenated (sO2 = 100%) and deoxygenated (sO2 = 0) cord blood was approximately 20% lower than the established adult blood value (Δχdeo, cord = 2.64 ppm, Δχdeo, adult = 3.4 ppm). Conclusions: The described models and associated parameter values can be used to inform acquisition parameters, and interpret fetal/neonatal blood susceptibility measurements and relaxometry data acquired at 3 T with respect to hematocrit and sO2 . Magn Reson Med 79:3194–3206, 2018. © 2017 International Society for Magnetic Resonance in Medicine.