Gabriele Masselli MD, Presenter: Nothing to Disclose

Roberto Brunelli, Abstract Co-Author: Nothing to Disclose

Maria Giulia Bernieri MD, Abstract Co-Author: Nothing to Disclose

Saadi Sollaku, Abstract Co-Author: Nothing to Disclose

Riccardo Caprasecca, Abstract Co-Author: Nothing to Disclose

Elisabetta Polettini, Abstract Co-Author: Nothing to Disclose

Gian Franco Gualdi MD, Abstract Co-Author: Nothing to Disclose

To prospectively evaluate the placental perfusion in both normal and Intra-Uterine Growth Restriction (IUGR) complicated pregnancies  by means of magnetic resonance imaging (MRI), using Arterial Spin Labeling (ASL).

This study was approved by the local ethics committee and all participants provided written informed consent. 40 women with singleton pregnancies at a gestational age between 26-39 weeks who underwent MRI for evaluating fetal abnormalities or to rule out placental adhesive disorders were enrolled in the present investigation. 33 patients displayed a fetal growth appropriate for gestational age; 7 pregnancies were complicated by late IUGR. All participants had an ultrasound scan performed on the very same day of MRI and fetal weight, amniotic fluid index and doppler interrogation of uterine and umbilical arteries were assessed. The position of ASL slice was carried out through the placenta long axis, from which placenta resulted as a discoid-shape on image. The inversion slice was positioned over spiral arteries in order to label mother blood spins. ASL parameters were: TR/TE= 2500/27; FOV=320; Matrix=100x100; TI= 1645; slice=8 mm. Measure was performed with 90 averages. Two experienced radiologists placed ROI over the perfusion maps including only the placenta and mean value was recorded.

Mean perfusion value in normal pregnancies was 190,28 ml/100g/min. We observed a positive correlation between placental perfusion and gestation age (R2=0.167). Perfusion values were significantly lower in all the 7 pregnancies complicated by IUGR (134,43 vs. 190,28 p=0.03). In 4 IUGR patients with the lower perfusion index, we observed after a mean interval of 4 days from MRI, the onset of fetal brain sparing (cerebral vasodilatation). Notably, the PI indexes of both uterine and umbilical arteries of these patients were not significantly different from those of the remaining study population.

ASL MR imaging of placental perfusion provides a suitable non invasive tool to measure placental perfusion and can be used to differentiate fetuses small for gestational age from those with late forms of fetal IUGR, i.e. with a normal pulsatility index of the umbilical arteries.

Arterial Spin Labeling  MRI  is a feasible non invasive new tool for evaluating and quantifying placental perfusion that may be potentially useful for the treatment of some forms of IUGR.

Masselli, G, Brunelli, R, Bernieri, M, Sollaku, S, Caprasecca, R, Polettini, E, Gualdi, G, Arterial Spin Labelling in the Human Placenta: Mapping Perfusion.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14045638.html