PMC3973438_01
Transabdominal ultrasound scan. The mirror artifact is observed behind the uterus. Note the high acoustic interphase between the bowel and the posterior wall of the uterus. The mirror artifact is only visible when the reflective surface is perpendicular to the ultrasound beam.
nihms-520652-f0001.jpg
PMC3973438_01_nihms-520652-f0001.jpg
F1
As the location of the second gestational sac appeared to be outside the uterine cavity, the diagnosis of an abdominal heterotopic abdominal pregnancy was considered (Figure 1).
Transvaginal ultrasound showing the reflection artifact creating the mirror image in the right side of the picture. The shape of the transvaginal ultrasound probe opens the emission of the ultrasound beam, the reflected signals travel at different angle as compared with the transabdominal ultrasound scan. The reflective surface is not completely perpendicular to the US beam, making the image more blurred and distorted.
nihms-520652-f0002.jpg
PMC3973438_01_nihms-520652-f0002.jpg
F2
Their length was similar to those of the fetus observed in the uterine cavity (Figure 2).