For a woman with left adnexal tenderness, which ultrasound approach should be ordered?

Ultrasound for Left Adnexal Tenderness

Order a combined transabdominal and transvaginal ultrasound with Doppler for a woman presenting with left adnexal tenderness. This is the first-line imaging modality recommended by the American College of Radiology for evaluating acute pelvic pain with suspected gynecologic etiology 1, 2.

Recommended Imaging Approach

Primary Imaging Study

• Combined transabdominal and transvaginal ultrasound with Doppler should be performed together as complementary procedures 1
• Both techniques provide unique information: transabdominal offers a larger field of view for overall pelvic assessment and free fluid detection, while transvaginal provides superior resolution of the adnexa due to probe proximity 1
• Doppler evaluation is an integral component and should be included routinely, not ordered separately 1

Why Both Techniques Are Necessary

• Transvaginal ultrasound alone may miss adnexa positioned high in the pelvis, distant from the probe 1
• Transabdominal imaging provides better visualization when large masses are present or when patient body habitus limits transvaginal views 1
• The combined approach demonstrated superior diagnostic accuracy (63% of cases) compared to either technique alone 3

Critical Diagnostic Considerations for Adnexal Tenderness

Ovarian Torsion (Time-Sensitive Emergency)

• Doppler findings are crucial: absent or abnormal ovarian venous flow has 100% sensitivity and 97% specificity for torsion 1
• Look for enlarged ovary (>4 cm or volume >20 cm³), peripheral follicles, and whirlpool sign 1
• Important caveat: 5% of torsed ovaries appear normal size, and arterial flow may be preserved in early torsion 1
• Absence of arterial flow has 76% sensitivity and 99% specificity 1

Pelvic Inflammatory Disease/Tubo-Ovarian Abscess

• Power Doppler transvaginal ultrasound demonstrated 100% sensitivity and 80% specificity for PID diagnosis 1
• Specific findings include tubal wall thickness >5 mm, cogwheel sign, incomplete septa, and cul-de-sac fluid 1
• Doppler shows hyperemia and lower pulsatility index in acute PID versus hydrosalpinx 1

Other Adnexal Pathology

• Transvaginal ultrasound has 78.4% overall sensitivity for hemorrhagic cysts (88.2%), endometriomas (84%), and tubo-ovarian abscess (58.3%) 1
• Doppler helps differentiate solid tissue from debris or clot within cystic structures 1

When Transvaginal Ultrasound Cannot Be Performed

If transvaginal approach is not feasible (patient discomfort, vaginal stenosis, sexually naïve patient, or patient preference):

• Transabdominal ultrasound alone is an acceptable alternative 1
• Ensure full bladder for optimal acoustic window 1
• Be aware: diagnostic accuracy may be reduced, particularly for small adnexal structures 3

Alternative/Follow-Up Imaging

MRI Pelvis (Not First-Line)

• Reserve for indeterminate masses after ultrasound or when ultrasound is technically limited 1
• MRI with contrast is superior to ultrasound for soft tissue characterization but should not replace ultrasound as initial imaging 1

CT Pelvis (Generally Not Appropriate)

• CT has suboptimal soft tissue delineation for adnexal pathology 1
• Consider only if extra-ovarian disease or malignancy with metastases is suspected 2, 4

Common Pitfalls to Avoid

• Do not order transabdominal ultrasound alone when transvaginal is feasible—you will miss critical diagnostic information 1, 3
• Do not order Doppler as a separate study—it should be performed simultaneously with grayscale imaging 1
• Do not rely on arterial flow alone for torsion diagnosis—venous flow assessment is more sensitive 1
• Do not skip ultrasound and proceed directly to CT or MRI for acute adnexal tenderness—ultrasound is superior for gynecologic pathology 1, 2