What referral criteria should I consider for patients requiring furthe

Guideline-aligned answer with reasoning, red flags and references. Clinically reviewed by Dr Kola Tytler MBBS CertHE MBA MRCGP.

Referral criteria for further imaging following an ultrasound include:

If ultrasound suggests ovarian cancer, refer women using a suspected cancer pathway referral .
If ultrasound is normal but serum CA125 is 35 IU/ml or greater, assess carefully for other clinical causes; if none apparent and symptoms persist or worsen, advise return to GP or consider further imaging .
If ultrasound suggests soft tissue sarcoma or is uncertain and clinical concern persists in adults, consider a suspected cancer pathway referral .
For suspected endometriosis, offer transvaginal ultrasound to identify ovarian endometriomas or deep endometriosis; if ultrasound is normal but symptoms persist, referral to gynaecology or specialist endometriosis services is indicated .
Consider specialist transvaginal ultrasound or pelvic MRI to diagnose and assess extent of deep endometriosis when initial ultrasound is inconclusive .
In children with atypical or recurrent urinary tract infections, ultrasound during acute infection is recommended to identify structural abnormalities; further imaging such as DMSA scintigraphy may be required if diagnosis is unclear or complications suspected .

What referral criteria should I consider for patients requiring further imaging after an ultrasound?