Which of the following is the MOST specific MRI criterion for diagnosing adenomyosis?
- A Uterine enlargement with heterogeneous myometrium on T2-weighted imaging
- B Junctional zone (JZ) maximum thickness ≥12 mm on T2-weighted MRI ✓
- C T1 hyperintense foci within myometrium corresponding to blood products
- D Posterior wall thicker than anterior wall by >5 mm
Correct answer: B. Junctional zone (JZ) maximum thickness ≥12 mm on T2-weighted MRI
Explanation
On MRI, the junctional zone (JZ) represents the inner myometrium, which appears hypointense on T2W images. A JZ maximum thickness ≥12 mm is the most specific MRI criterion for adenomyosis (specificity ~96%, sensitivity ~70%). A JZ maximum–minimum difference of ≥5 mm also suggests adenomyosis. T1 hyperintense foci (indicating haemorrhagic glands) are supportive but less specific. General uterine enlargement and posterior wall asymmetry are non-specific findings. MRI is considered superior to ultrasound for diagnosing adenomyosis, especially in differentiating from fibroids.
Reference: Shaw's Textbook of Gynaecology, 17th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.