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Are human peripheral nerves sensitive to X-ray imaging?

Scopel JF, de Souza Queiroz L, O'Dowd FP, Júnior MC, Nucci A, Hönnicke MG - PLoS ONE (2015)

Bottom Line: The outstanding result is the detection of such structures by phase contrast x-ray tomography of a thick human sciatic nerve section.This may further enable the identification of diverse pathological patterns, such as Wallerian degeneration, hypertrophic neuropathy, inflammatory infiltration, leprosy neuropathy and amyloid deposits.To the best of our knowledge, this is the first successful phase contrast x-ray imaging experiment of a human peripheral nerve sample.

View Article: PubMed Central - PubMed

Affiliation: Instituto de Ciências da Saúde, Universidade Federal de Goiás, Jataí, Goiás, 75804-020, Brazil.

ABSTRACT
Diagnostic imaging techniques play an important role in assessing the exact location, cause, and extent of a nerve lesion, thus allowing clinicians to diagnose and manage more effectively a variety of pathological conditions, such as entrapment syndromes, traumatic injuries, and space-occupying lesions. Ultrasound and nuclear magnetic resonance imaging are becoming useful methods for this purpose, but they still lack spatial resolution. In this regard, recent phase contrast x-ray imaging experiments of peripheral nerve allowed the visualization of each nerve fiber surrounded by its myelin sheath as clearly as optical microscopy. In the present study, we attempted to produce high-resolution x-ray phase contrast images of a human sciatic nerve by using synchrotron radiation propagation-based imaging. The images showed high contrast and high spatial resolution, allowing clear identification of each fascicle structure and surrounding connective tissue. The outstanding result is the detection of such structures by phase contrast x-ray tomography of a thick human sciatic nerve section. This may further enable the identification of diverse pathological patterns, such as Wallerian degeneration, hypertrophic neuropathy, inflammatory infiltration, leprosy neuropathy and amyloid deposits. To the best of our knowledge, this is the first successful phase contrast x-ray imaging experiment of a human peripheral nerve sample. Our long-term goal is to develop peripheral nerve imaging methods that could supersede biopsy procedures.

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Related in: MedlinePlus

Sample preparation for the tomographic study.(a) anatomical position of human sciatic nerve; (b) wedge-shaped cut of the sciatic nerve, allowing it to fit the detector field of view; (c) approximately 3 mm thick sample [preserved in formalin solution (10%)] inside the boron silicate capillary tube, positioned for tomographic image acquisition.
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pone.0116831.g002: Sample preparation for the tomographic study.(a) anatomical position of human sciatic nerve; (b) wedge-shaped cut of the sciatic nerve, allowing it to fit the detector field of view; (c) approximately 3 mm thick sample [preserved in formalin solution (10%)] inside the boron silicate capillary tube, positioned for tomographic image acquisition.

Mentions: The sciatic nerve sample was preserved in a formalin solution (10%) and had a cylindrical shape (diameter ∼ 1 cm and length ∼ 3 cm). It was imaged by propagation-based x-ray phase contrast radiography and tomography, in edge-detection regime [7]. For radiographs, a portion of the nerve was embedded in paraffin, and 10 μm thick longitudinal and axial sections were cut. To avoid huge x-ray attenuation by the use of conventional glass microscope slides, the sample was mounted on polyurethane slides. For tomographic reconstruction, another portion of the nerve, still preserved in formalin solution (10%) and not embedded in paraffin, was cut into wedge-shaped to fit the detector field of view, and inserted into a boron silicate capillary tube with an internal diameter of 3 mm (see Fig. 2). The capillary tube was tapped in order to avoid nerve shrinkage during the tomography scan. A high precision sample rotation stage was mounted on top of a translation stage to set the sample in and out of the beam path. The sample to detector distance was set to 70 mm. The radiography and tomography doses were not measured. However, the absorbed dose (D) was calculated following the equation given elsewhere [33], therefore, modified for a polychromatic x-ray beam, as follows:D=∫E0Efϕ0(Eph).[μρ(Eph)].dEph(1)where E0 and Ef are the start and final x-ray spectrum energies, Φ0(Eph) is the photon flux on area A, μ/ρ(Eph) is the mass energy absorption coefficient and dEph is the differential photon energy.


Are human peripheral nerves sensitive to X-ray imaging?

Scopel JF, de Souza Queiroz L, O'Dowd FP, Júnior MC, Nucci A, Hönnicke MG - PLoS ONE (2015)

Sample preparation for the tomographic study.(a) anatomical position of human sciatic nerve; (b) wedge-shaped cut of the sciatic nerve, allowing it to fit the detector field of view; (c) approximately 3 mm thick sample [preserved in formalin solution (10%)] inside the boron silicate capillary tube, positioned for tomographic image acquisition.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4355589&req=5

pone.0116831.g002: Sample preparation for the tomographic study.(a) anatomical position of human sciatic nerve; (b) wedge-shaped cut of the sciatic nerve, allowing it to fit the detector field of view; (c) approximately 3 mm thick sample [preserved in formalin solution (10%)] inside the boron silicate capillary tube, positioned for tomographic image acquisition.
Mentions: The sciatic nerve sample was preserved in a formalin solution (10%) and had a cylindrical shape (diameter ∼ 1 cm and length ∼ 3 cm). It was imaged by propagation-based x-ray phase contrast radiography and tomography, in edge-detection regime [7]. For radiographs, a portion of the nerve was embedded in paraffin, and 10 μm thick longitudinal and axial sections were cut. To avoid huge x-ray attenuation by the use of conventional glass microscope slides, the sample was mounted on polyurethane slides. For tomographic reconstruction, another portion of the nerve, still preserved in formalin solution (10%) and not embedded in paraffin, was cut into wedge-shaped to fit the detector field of view, and inserted into a boron silicate capillary tube with an internal diameter of 3 mm (see Fig. 2). The capillary tube was tapped in order to avoid nerve shrinkage during the tomography scan. A high precision sample rotation stage was mounted on top of a translation stage to set the sample in and out of the beam path. The sample to detector distance was set to 70 mm. The radiography and tomography doses were not measured. However, the absorbed dose (D) was calculated following the equation given elsewhere [33], therefore, modified for a polychromatic x-ray beam, as follows:D=∫E0Efϕ0(Eph).[μρ(Eph)].dEph(1)where E0 and Ef are the start and final x-ray spectrum energies, Φ0(Eph) is the photon flux on area A, μ/ρ(Eph) is the mass energy absorption coefficient and dEph is the differential photon energy.

Bottom Line: The outstanding result is the detection of such structures by phase contrast x-ray tomography of a thick human sciatic nerve section.This may further enable the identification of diverse pathological patterns, such as Wallerian degeneration, hypertrophic neuropathy, inflammatory infiltration, leprosy neuropathy and amyloid deposits.To the best of our knowledge, this is the first successful phase contrast x-ray imaging experiment of a human peripheral nerve sample.

View Article: PubMed Central - PubMed

Affiliation: Instituto de Ciências da Saúde, Universidade Federal de Goiás, Jataí, Goiás, 75804-020, Brazil.

ABSTRACT
Diagnostic imaging techniques play an important role in assessing the exact location, cause, and extent of a nerve lesion, thus allowing clinicians to diagnose and manage more effectively a variety of pathological conditions, such as entrapment syndromes, traumatic injuries, and space-occupying lesions. Ultrasound and nuclear magnetic resonance imaging are becoming useful methods for this purpose, but they still lack spatial resolution. In this regard, recent phase contrast x-ray imaging experiments of peripheral nerve allowed the visualization of each nerve fiber surrounded by its myelin sheath as clearly as optical microscopy. In the present study, we attempted to produce high-resolution x-ray phase contrast images of a human sciatic nerve by using synchrotron radiation propagation-based imaging. The images showed high contrast and high spatial resolution, allowing clear identification of each fascicle structure and surrounding connective tissue. The outstanding result is the detection of such structures by phase contrast x-ray tomography of a thick human sciatic nerve section. This may further enable the identification of diverse pathological patterns, such as Wallerian degeneration, hypertrophic neuropathy, inflammatory infiltration, leprosy neuropathy and amyloid deposits. To the best of our knowledge, this is the first successful phase contrast x-ray imaging experiment of a human peripheral nerve sample. Our long-term goal is to develop peripheral nerve imaging methods that could supersede biopsy procedures.

Show MeSH
Related in: MedlinePlus