Imaging of the Vasa Nervorum Using Contrast-Enhanced Ultrasound

INTRODUCTION: We describe the use of intravenous contrast-enhanced ultrasonography to study vasa nervorum using contrast-enhanced ultrasound. METHODS: We imaged the median, femoral, or sciatic nerves in 4 patients in longitudinal plane using high-resolution ultrasound after intravenous bolus of activated Perflutren lipid microspheres. The images were acquired as photopic images (in brown color) in real time using 2-dimensional B-Flow mode scan within a selected region of interest. RESULTS: The vasa nervorum was seen as focal ovoid enhancement along either the superior and inferior aspects of the nerve most pronounced during arterial phase (peak enhancement) in all 4 patients. The fluctuating intensity of enchancement during cardiac cycle confirmed the arterial origin of enhacement. Punctate, linear, or diffuse enhancement was also seen along the trunk of the nerve. CONCLUSIONS: We were able to identify the vasa nervorum along the outer aspect of the studied nerves using contrast-enhanced ultrasound.