Measurement of Ultrasonic Attenuation in Diabetic Neuropathic Sciatic Nerves for Diagnostic and Therapeutic Applications

Abstract

Measurements of ultrasonic attenuation in the sciatic nerves of rats were performed to verify the feasibility of ultrasound diagnosis of peripheral neuropathy and to avoid damage to the nerves caused by overheating in pain management applications. A rat model of diabetic peripheral neuropathy was established. The proximal-segment and middle-segment sciatic nerves of control and neuropathic rats were dissected for the attenuation measurement. Two commercial ultrasound transducers and a self-developed experimental platform were used in the measurements. Using H&E staining and transmission electron (TE) microscopy, morphological analysis of the control and neuropathic nerves was performed to determine the relationship between attenuation and the histology of the nerves. The experimental results showed that the attenuation coefficients of the control, second-week, fourth-week, and eighth-week neuropathic nerves were -6.68 ± 0.50, -5.61 ± 0.34, -6.27 ± 0.40, and -7.10 ± 0.35 dB/cm at 2.68 MHz, respectively. The respective values at 7.50 MHz were -14.96 ± 0.79, -12.65 ± 0.28, -13.98 ± 1.07, and -16.00 ± 0.54 dB/cm. The changes in the attenuation coefficients were significantly different among the second-week, fourth-week, and eighth-week DN nerves. Additionally, the ultrasonic attenuation coefficient of the rat sciatic nerve was fourfold that of the cat brain and cow liver and twofold that of human muscle.

High-resolution ultrasound of peripheral nerves in systemic sclerosis: a pilot study of computer-aided quantitative assessment of nerve density

“…This result is concordant with the intrinsic characteristic of SSc that is a chronic disease characterized by an enhanced fibroblast activity [6,7,16]. The quantitative nerve density assessment could be an improvement of standard peripheral nerve evaluation with US because it can detect an abnormality even with no lcSSclimited cutaneous systemic sclerosis changes in cross-sectional areas [9][10][11][12][13][14]; therefore, a peripheral nerve in patients with SSc may be considered abnormal for two reasons-if cross-sectional area is enlarged and if nerve density is reduced. Our study suggests that a non-invasive, comprehensive, repeatable, easy and cheap evaluation of peripheral nerves is possible in patients with SSc.…”

“…US internal structural analysis of the nerve is now supported not only by a subjective evaluation but also by a quantitative evaluation of nerve echotexture, called nerve density [9][10][11]. Nerve density, or fascicular ratio or echo intensity, is the ratio between the fascicular and non-fascicular structure quantified on ultrasound [9][10][11][12][13][14]. It has been studied that a quantitative evaluation of nerve density can separate normal nerves from pathologic nerves of patients with carpal tunnel syndrome and neurofibroma [9].…”

Anatomically realistic ultrasound phantoms using gel wax with 3D printed moulds

“…The gel wax material that represented nerves comprised 2 w/w% glass spheres and 5 w/w% paraffin, that which represented vessels had no additives, and that which represented surrounding tissue comprised 0.5 w/w% glass spheres and 2 w/w% paraffin wax. The choices for paraffin wax concentrations were made based on the acoustic attenuation contrasts between nerves (Chen et al 2014 ), blood vessels (Treeby et al 2011 ) and background tissue (Mast 2000 ); The nerves (5 mm in diameter) and vessels (5 mm in diameter) were first cast using a 3D printed cylindrical mould. When solidified and removed from the mould, they were hung vertically within the plastic mould (64 × 48 × 42 mm).…”

Quantitative Ultrasound and B-Mode Image Texture Features Correlate with Collagen and Myelin Content in Human Ulnar Nerve Fascicles

“…Our results complement those from several other investigators who have suggested that QUS can be used to characterize nerves. The AC parameter of the whole rat sciatic nerve in vitro was used to estimate nerve damage due to diabetic peripheral neuropathy (Chen, et al 2014). Tissue echogenicity was assessed via the nerve density measure and was found to be an important factor in diagnosis of carpal tunnel syndrome (Tagliafico, et al 2010).…”