SAQ 299 – Gynaecology – ovarian torsion diagnosis

Gynaecology – ovarian torsion diagnosis.

a. False-negative urine beta-hCG

• Very early pregnancy with urine hCG below the test threshold.
• Dilute urine sample.
• Equipment, operator, or test error.
• High-dose hook effect.
• Abnormal hCG variants not detected by the assay.

b. Torsion risk factors

• Pregnancy.
• Large ovarian cyst or tumour, especially >4-5 cm.
• Polycystic ovaries.
• Ovulation induction or ovarian hyperstimulation.
• Tubal ligation.
• Adhesions from previous surgery, endometriosis, or pelvic inflammatory disease.

c. Ultrasound features

• Reduced or asymmetric venous flow.
• Enlarged oedematous ovary, often >4-5 cm, cyst, or mass.
• Ovarian oedema, haemorrhage, or venous engorgement.
• Whirlpool sign or twisted vascular pedicle.
• Focal tenderness over the ovary.
• Abnormal ovarian location or changed position.
• Tilted uterus.
• Reversed diastolic flow.

d. Preserved arterial flow

• Dual ovarian and uterine arterial supply.
• Intermittent torsion-detorsion.
• Early torsion where venous outflow is compromised before arterial inflow.