vaginal ultrasonography vaginal ultrasonography vaginal ultrasonography is a medical ultrasonography that applies an ultrasound transducer (or "probe") in the vagina to visualize organs within the pelvic cavity. it is also called transvaginal ultrasonography because the ultrasound waves go across the vaginal wall to study tissues beyond it. device for both vaginal and abdominal ultrasonography uses further information: gynecologic ultrasonography and obstetric ultrasonography transvaginal ultrasonography procedure vaginal ultrasonography is used both as a means of gynecologic ultrasonography and obstetric ultrasonography. it is preferred over abdominal ultrasonography in the diagnosis of ectopic pregnancy.