What are the steps and precautions for a vaginal ultrasound procedure?

Instructions for Vaginal Ultrasound

Vaginal ultrasound should be performed with an empty bladder, using proper patient positioning and systematic scanning technique to evaluate the uterus, ovaries, and surrounding pelvic structures. 1

Pre-Procedure Preparation

Patient Preparation

• The patient should completely empty their bladder before the transvaginal examination, as an empty bladder provides optimal imaging quality 1, 2
• A chaperone must be present for all endovaginal examinations 1
• Consider performing the transabdominal portion first (with full bladder) to assess bladder fullness, uterine position, and anatomic variations, which can minimize the need for transvaginal scanning if an intrauterine pregnancy is already documented 1

Patient Positioning (Two Options)

• Option 1: Patient lies supine on stretcher/bed with legs flexed; place folded sheets or pads under buttocks to elevate pelvis above examination table, allowing room for transducer manipulation 1
• Option 2: Patient positioned on pelvic examination table with feet in stirrups 1

Equipment Requirements

• Endovaginal transducer with frequency range of approximately 4 to 8 MHz 1
• Color or power Doppler and pulsed wave Doppler are critical if blood flow assessment will be performed 1
• Both portable and cart-based ultrasound machines may be used depending on location and setting 1

Probe Insertion and Handling

Probe Placement

• The probe may be placed in the vagina by either the patient or the examiner 1
• Cover the transvaginal probe with appropriate protective covering and coupling gel 1

Common Pitfall to Avoid

• Never perform transvaginal ultrasound with a full bladder, as this significantly degrades image quality and diagnostic accuracy 2

Systematic Scanning Technique

Uterine Examination

• Examine the uterus entirely in two planes (sagittal and coronal) 1
• In sagittal plane: sweep the transducer laterally to both sides to visualize the entire uterus, as it is often deviated to one side 1
• Rotate the transducer 90 degrees counterclockwise to obtain coronal view 1
• Angle the transducer anteriorly, posteriorly, and to each side for complete uterine assessment 1

Adnexal Structures

• After fully interrogating the uterus in sagittal and coronal planes, visualize other pelvic structures including the cul-de-sac, fallopian tubes, and ovaries 1
• The cul-de-sac is located inferior to the uterus 1
• Ovaries are positioned lateral to the uterus, usually lying anterior to the internal iliac veins and medial to the external iliac vessels 1
• Normal fallopian tubes can be visualized originating from the cornua of the uterus; visualization may be limited by bowel gas or enhanced when distended by fluid (hydrosalpinx or tubo-ovarian abscess) 1

Specific Anatomic Considerations

• Ovarian examination may identify unexpected causes of pain despite intrauterine pregnancy, such as ovarian masses, cysts, or ovarian torsion 1
• Both ureters should be assessed when evaluating gynecologic pathology, as they can be clearly visualized in the vast majority of cases (92.7%) 3

Special Protocols for Specific Indications

Endometriosis Assessment

• Expanded protocol transvaginal ultrasound for deep endometriosis requires special training (learning curve of at least 40 examinations) and includes evaluation of uterosacral ligaments, anterior rectosigmoid wall, appendix, and dynamic sliding maneuvers to assess organ mobility 1
• Imaging is typically performed after bowel preparation or enema for detection and characterization of bowel lesions 1
• Some protocols include 3-D ultrasound imaging and saline contrast sonovaginography 1

Abnormal Uterine Bleeding

• Transvaginal ultrasound is the first-line imaging test for evaluating abnormal uterine bleeding in both premenopausal and postmenopausal women 4
• Traditional 2-dimensional imaging is often enhanced by 3-dimensional imaging with coronal reconstruction and saline infusion sonohysterography 4

Documentation Requirements

Essential Documentation Elements

• Document the indication for the procedure 1
• Provide a description of the organs or structures studied 1
• Include interpretation of findings 1
• Store images as part of the medical record in accordance with facility policy requirements 1

Important Caveat

• Timely delivery of care should not be delayed by archiving ultrasound images, given the often emergent nature of such examinations 1

Clinical Context and Diagnostic Value

Diagnostic Utility

• Transvaginal probes produce high-resolution images of pelvic organs, providing reliable and reproducible information without need for full bladder 5
• Common gynecological pathology involving the uterus, fallopian tube, and/or ovary can be diagnosed with confidence 5
• Non-gynecological pathology involving the bowel can also be diagnosed with accuracy 5

Negative Predictive Value

• If the patient has a negative pregnancy test, no pelvic tenderness on bimanual examination, and a normal scan, significant pathology is very unlikely 5