B ultrasound acoustic image of a 38-year-old CSP patient who presented with amenorrhea for 59 days and vaginal bleeding along with low back pain for 10 days. The gestational sac was located on the scar on the anterior wall of uterine isthmus with pulse of the primitive heart tube. The size of the gestational sac is 4.2 × 1.9 × 2.8 cm.