2.3. Image analysis
Ultrasound analysis (transabdominal approach) was performed
by a qualified consultant of obstetrics and gynecology
(E.W.) who is M.D. certified (lecturer: 10 years experience).
Second look ultrasound (transabdominal and translabial
approaches) and MR image analysis was performed by a qualified
consultant of radiology (M.S.), M.D. certified (lecturer:
9 years experience).
The authors were blinded to results regarding US analysis
performed by each of them and initial evaluation was performed
without knowledge of the operative findings.
Placenta previa was subdivided according to the position of
the placenta relative to the internal cervical os following
Elsayes et al. (1) into: (1) low-lying, (2) marginal, (3) complete,
(4) central.
Placenta previa findings that were considered suggestive of
accreta/percreta on US had been based on Comstock et al. (6)
and Wong et al. (7) and included: (1) loss of the retroplacental
hypoechoic clear zone, (2) loss of the bladder wall-uterine
interface, (3) presence of placental lacunae (vascular spaces),
and (4) presence of hypervascularity of the interface between
the uterine serosa and the bladder wall on color Doppler
imaging.
Regarding MRI; findings of placenta accreta/percreta
following Baugham et al. (8) in addition of being previa