A 26-year-old woman presents with claudication of both upper limbs. Her right radial pulse is absent, blood pressure differs by 40 mmHg between arms, and she has an elevated ESR. MR angiography shows narrowing of the aortic arch and its major branches. Which investigation best assesses disease activity beyond acute phase reactants?

• A Ankle brachial index measurement
• B Digital subtraction angiography of the abdominal aorta
• C Serum anti-endothelial cell antibody titre
• D PET-CT showing FDG uptake in the aortic wall ✓

Explanation

Takayasu arteritis is a granulomatous large vessel arteritis of young women affecting the aorta and its branches. Because luminal narrowing reflects irreversible damage rather than active inflammation, PET-CT demonstrating FDG uptake in the aortic wall is the best modality for assessing active wall inflammation when ESR is unreliable. Conventional angiography maps stenoses and aneurysms but cannot distinguish active inflammation from fixed fibrosis, and the ankle brachial index measures established obstruction only.

Reference: Harrison's Principles of Internal Medicine, 21st ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.