Beaded appearance of the arterial wall in the mid-to-distal renal artery is most characteristic of which disease?

• A. Fibromuscular dysplasia
• B. Atherosclerotic disease
• C. Renal cell carcinoma
• D. Polycystic kidney disease

Answer: (A)

Beaded appearance on renal artery imaging is classic for fibromuscular dysplasia. This non-atherosclerotic, non-inflammatory condition causes alternating segments of narrowing and dilation in medium-sized arteries, most often the renal and carotid arteries. In the renal arteries, the pattern typically appears in the mid-to-distal segments and creates a string-of-beads look on angiography, reflecting the underlying medial fibroplasia.

This differs from atherosclerotic disease, which usually involves proximal or ostial renal artery segments, occurs in older patients with risk factors, and shows calcified, irregular narrowing rather than a bead-like pattern. Renal cell carcinoma and polycystic kidney disease can cause hypertension for other reasons but do not produce this characteristic arterial beading on imaging.