Sonographic diagnosis of neurogenic heterotopic ossification in patients with severe acquired brain injury in a neurorehabilitation unit

Abstract

To illustrate the ultrasonographic (US) and power Doppler US (PDUS) features of neurogenic heterotopic ossification (NHO) in consecutive patients with severe acquired brain injury and to evaluate the role of bedside US in diagnosis of NHO. Ninety-two consecutive patients with severe acquired brain injury underwent clinical and laboratory screening for NHO. In 6 of 92 patients, bedside US confirmed the clinical suspicion of NHO. US diagnosis of NHO was then confirmed by other imaging methods. The incidence of clinical NHO was 7% (9/92) with one patient having multifocal involvement. In NHO of the hip, US demonstrated the classic pattern of zone phenomenon, and PDUS demonstrated vascular signal within mineralized NHO and in outer hypoechoic area. No vascular signal was observed in the central hypoechoic core. In NHO of the knee, a heterogeneously hypoechoic mass was seen and in the elbow a hyperechoic mineralized mass was visualized, with vascular signals seen within the lesions. Spectral wave analysis demonstrated low resistance vessels in NHO. Bedside US is a useful tool in the diagnosis of NHO. PDUS adds data regarding neoangiogenetic activity of NHO.