Which imaging modalities are recommended for the diagnosis of endometriosis in primary care settings?

Recommended imaging modalities for diagnosing endometriosis in primary care settings include:

• A transvaginal ultrasound scan should be offered to all women or people with suspected endometriosis, even if pelvic or abdominal examination is normal, to identify ovarian endometriomas, deep endometriosis (including bowel, bladder, or ureter involvement), and to rule out other pathology. This scan should be organised by the general practice.
• If a transvaginal ultrasound scan is declined or not suitable, a transabdominal ultrasound scan of the pelvis should be considered as an alternative.
• Pelvic MRI is not recommended as a primary investigation in primary care but may be considered later to assess the extent of deep endometriosis involving bowel, bladder, or ureter.

Serum CA125 should not be used to diagnose endometriosis.

Referral for further specialist imaging or laparoscopy may be necessary even if ultrasound findings are normal, depending on symptoms and clinical suspicion.

Summary: In primary care, transvaginal ultrasound is the first-line imaging modality for suspected endometriosis, with transabdominal ultrasound as an alternative if needed. MRI and laparoscopy are reserved for specialist settings.

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