Abstract
Purpose
To study placental function—both perfusion and an oxygenation surrogate (T*2)—simultaneously and quantitatively in‐vivo.
Methods
Fifteen pregnant women were scanned on a 3T MR scanner. For perfusion measurements, a velocity selective arterial spin labeling preparation module was placed before a multi‐echo gradient echo EPI readout to integrate T*2 and perfusion measurements in 1 joint perfusion‐oxygenation (PERFOX) acquisition. Joint motion correction and quantification were performed to evaluate changes in T*2 and perfusion over GA.
Results
The optimized integrated PERFOX protocol and post‐processing allowed successful visualization and quantification of perfusion and T*2 in all subjects. Areas of high T*2 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 T*2 closer to the fetal chorionic plate. Quantitative results show a strong negative correlation of gestational age with T*2 and weak negative correlation with perfusion.
Conclusions
A strength of the joint sequence is that it provides truly simultaneous and co‐registered estimates of local T*2 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.
To study placental function—both perfusion and an oxygenation surrogate (T*2)—simultaneously and quantitatively in‐vivo.
Methods
Fifteen pregnant women were scanned on a 3T MR scanner. For perfusion measurements, a velocity selective arterial spin labeling preparation module was placed before a multi‐echo gradient echo EPI readout to integrate T*2 and perfusion measurements in 1 joint perfusion‐oxygenation (PERFOX) acquisition. Joint motion correction and quantification were performed to evaluate changes in T*2 and perfusion over GA.
Results
The optimized integrated PERFOX protocol and post‐processing allowed successful visualization and quantification of perfusion and T*2 in all subjects. Areas of high T*2 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 T*2 closer to the fetal chorionic plate. Quantitative results show a strong negative correlation of gestational age with T*2 and weak negative correlation with perfusion.
Conclusions
A strength of the joint sequence is that it provides truly simultaneous and co‐registered estimates of local T*2 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.
| Original language | English |
|---|---|
| Pages (from-to) | 549-560 |
| Number of pages | 12 |
| Journal | Magnetic resonance in medicine |
| Volume | 83 |
| Issue number | 2 |
| Early online date | 21 Aug 2019 |
| DOIs | |
| Publication status | Published - Feb 2020 |
Keywords
- Arterial Spin Labeling (ASL)
- perfusion
- placenta
- pre-eclampsia
- relaxometry
- velocity-selective ASL