Imaging of the Vasa Nervorum Using Contrast-Enhanced Ultrasound.
We describe the use of intravenous contrast-enhanced ultrasonography to study vasa nervorum using contrast-enhanced ultrasound. 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. 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. We were able to identify the vasa nervorum along the outer aspect of the studied nerves using contrast-enhanced ultrasound.