Benign incidental lesion of the calcaneus: the calcaneal vascular remnant.

BACKGROUND: The calcaneal vascular remnant, first described by Fleming et al. in 2005, is a benign intramedullary lesion of the calcaneus with a vascular origin. PURPOSE: To determine the prevalence and magnetic resonance imaging (MRI) characteristics of incidental calcaneal vascular remnant on routine ankle MRI. MATERIAL AND METHODS: We retrospectively reviewed 457 ankle MRI scans for the presence of calcaneal vascular remnant. MRI was considered positive when a focal cyst-like area was seen on a T2-weighted sequence, and a low signal intensity was identified on a T1-weighted image beneath the calcaneal sulcus. Patients with calcaneal vascular remnants were further evaluated for age, gender, right or left foot location, size, and lesion characteristics. RESULTS: The prevalence of incidental calcaneal vascular remnant was 21.7% on our consecutive ankle MR examinations. The average lesion size was 5.5 mm. No statistically significant difference was noted in the frequency of lesion detection between gender, age, and side of the lesions (P > 0.05). Multilobulated lesions were detected predominantly in women (P = 0.013) and classic type lesions were detected predominantly in men (P = 0.036). CONCLUSION: This report is the first to determine the prevalence and MRI characteristics of calcaneal vascular remnants. Detecting and reporting this lesion on routine MRI is essential to avoid confusion with other pathologic entities.