Pain et al reported a score for distinguishing placenta percreta from placenta accreta based on imaging findings. The authors are from Cochin Hospital and Universite Paris Centre in Paris.
Patient selection: pregnant woman with a placenta accreta spectrum disorder
Examinations: ultrasonography and MRI
Parameters:
(1) intraplacental lacunae without hyperechogenic halo on ultrasonography
(2) increased vascularization at the uterine serosa-bladder wall interface on ultrasonography
(3) heterogeneous placenta on MRI
(4) dark intraplacental bands on MRI
points for intraplacental lacunae =
= 5 * (number of lacunae)
|
Parameter
|
Finding
|
Points
|
|
increased vascularization
|
no
|
0
|
|
|
yes
|
21.6
|
|
heterogeneous placenta
|
no
|
0
|
|
|
yes
|
35.8
|
|
dark intraplacental bands
|
no
|
0
|
|
|
yes
|
34.2
|
total score =
= SUM(points for all of the parameters)
Interpretation:
• miniimum score: 0
• maximum score: 191.6
value of X =
= (0.04925 * (score)) - 4
probability of percreta =
= 1 / (1+ EXP((-1) * X))
Performance:
• The area under the ROC curve is 0.84.
