Pelvic ultrasonography is one of the best imaging modalities used to evaluate nonspecific pelvic pain, pregnancy complications, anatomy of pelvic organs, and various ovarian pathologies. [1, 2, 3, 4, 5]
In transabdominal scanning, using a low-frequency transducer, a full bladder is used to displace bowel gas and serve as an acoustic window to improve image resolution and to allow a large viewing field of the pelvis. Endovaginal scanning, using a high-frequency transducer, is the preferred technique for the evaluation of ovarian pathologies, and a full bladder is not necessary.  It also provides higher resolution, which allows better evaluation of the structure, anatomy, and pathology of pelvic organs. 
Endovaginal scanning is preferred over computed tomography because of improved visualization of pelvic organs, the absence of radiation exposure with ultrasonography, decreased time of hospital stay, and decreased cost to the patient. 
According to the American Institute of Ultrasound in Medicine (AIUM), indications for pelvic ultrasonography include but are not limited to the following  :
The video below depicts a demonstration of transvaginal ultrasonography.
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Shoreh Kooshesh, MD Resident Physician, Division of Emergency Medicine, Stanford University School of Medicine
Shoreh Kooshesh, MD is a member of the following medical societies: American College of Emergency Physicians, American Medical Student Association/Foundation, American Medical Womens Association, Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.
Laleh Gharahbaghian, MD, FACEP, FAAEM Clinical Associate Professor of Emergency Medicine, Medical Director, Adult Emergency Medicine, Patient Safety Champion, Emergency Medicine, Stanford HealthCare, Director Emeritus, Emergency Ultrasound Program, Department of Emergency Medicine, Stanford University Medical Center and Stanford University School of Medicine
Laleh Gharahbaghian, MD, FACEP, FAAEM is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, American Medical Association, Society for Academic Emergency Medicine
Disclosure: Serve(d) as a director, officer, partner, employee, advisor, consultant or trustee for: Exo Imaging.
Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference
Disclosure: Received salary from Medscape for employment. for: Medscape.
Mark Zwanger, MD, MBA
Mark Zwanger, MD, MBA is a member of the following medical societies: American College of Emergency Physicians
Disclosure: Nothing to disclose.
Gowthaman Gunabushanam, MD, FRCR Assistant Professor, Department of Diagnostic Radiology, Yale University School of Medicine
Disclosure: Nothing to disclose.
James Quan-Yu Hwang, MD, RDMS, RDCS, FACEP Staff Physician, Emergency Department, Kaiser Permanente
James Quan-Yu Hwang, MD, RDMS, RDCS, FACEP is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, American Institute of Ultrasound in Medicine, Society for Academic Emergency Medicine
Disclosure: Received salary from 3rd Rock Ultrasound, LLC for speaking and teaching; Received consulting fee from Schlesinger Associates for consulting; Received consulting fee from Philips Ultrasound for consulting.
The authors and editors of Medscape Reference gratefully acknowledge the contributions of previous authors Verena T Valley, MD, and Christopher A Fly, MD, to the development and writing of this article.
Medscape Reference thanks Meghan Kelly Herbst, MD, Emergency Ultrasound Director, Department of Emergency Medicine, Hartford Hospital, for assistance with the video contribution to this article. Medscape Reference also thanks Yale School of Medicine, Emergency Medicine for assistance with the video contribution to this article.
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