2 research outputs found
Perfusion and apparent oxygenation in the human placenta (PERFOX)
Purpose: To study placental function - both perfusion and an oxygenation
surrogate (T2*)-simultaneously and quantitatively in-vivo.
Methods: 15 pregnant women were scanned on a 3T MR scanner. For perfusion
measurements, a velocity selective arterial spin labelling preparation module
was placed before a multi-echo gradient echo EPI readout to integrate T2* and
perfusion measurements in one joint perfusion-oxygenation (PERFOX) acquisition.
Joint motion correction and quantification were performed to evaluate changes
in T2* and perfusion over GA.
Results: The optimised integrated PERFOX protocol and post-processing allowed
successful visualization and quantification of perfusion and T2* in all
subjects. Areas of high T2* and high perfusion appear to correspond to
placental sub-units and show a systematic offset in location along the
maternal-fetal axis. The areas of highest perfusion are consistently closer to
the maternal basal plate and the areas of highest T2* closer to the fetal
chorionic plate. Quantitative results show a strong negative correlation of
gestational age with T2* and weak negative correlation with perfusion.
Conclusion: A strength of the joint sequence is that it provides truly
simultaneous and co-registered estimates of local T2* and perfusion, however,
to achieve this, the time per slice is prolonged compared to a perfusion only
scan which can potentially limit coverage. The achieved interlocking can be
particularly useful when quantifying transient physiological effects such as
uterine contractions. PERFOX opens a new avenue to elucidate the relationship
between maternal supply and oxygen uptake, both of which are central to
placental function and dysfunction