Which of the following is not a sonographic criterion for cesarean scar pregnancy: (A) Anterior uterine isthmic mass, (B) Hourglass uterine shape, (C) Empty cervical canal, (D) Hyperechoic thin endometrial stripe
Answer is B. Sonographic criteria for cesarean scar pregnancy include 

Empty uterine cavity - bright hyperechoic endometrial stripe
Empty cervical canal
Intrauterine mass seen in anterior part of uterine isthmus.