Micro-CT imaging of Thiel-embalmed and iodine-stained human temporal bone for 3D modeling

Sebastian Halm,Andreas Arnold,Valentin Djonov,David Haberthür,Elisabeth Eppler

doi:10.1186/s40463-021-00522-0

Sebastian Halm, Andreas Arnold + Show 3 more

Open Access

https://doi.org/10.1186/s40463-021-00522-0

Copy DOI

Abstract

IntroductionThis pilot study explores whether a human Thiel-embalmed temporal bone is suitable for generating an accurate and complete data set with micro-computed tomography (micro-CT) and whether solid iodine-staining improves visualization and facilitates segmentation of middle ear structures.MethodsA temporal bone was used to verify the accuracy of the imaging by first digitally measuring the stapes on the tomography images and then physically under the microscope after removal from the temporal bone. All measurements were compared with literature values.The contralateral temporal bone was used to evaluate segmentation and three-dimensional (3D) modeling after iodine staining and micro-CT scanning.ResultsThe digital and physical stapes measurements differed by 0.01–0.17 mm or 1–19%, respectively, but correlated well with the literature values. Soft tissue structures were visible in the unstained scan. However, iodine staining increased the contrast-to-noise ratio by a factor of 3.7 on average. The 3D model depicts all ossicles and soft tissue structures in detail, including the chorda tympani, which was not visible in the unstained scan.ConclusionsMicro-CT imaging of a Thiel-embalmed temporal bone accurately represented the entire anatomy. Iodine staining considerably increased the contrast of soft tissues, simplified segmentation and enabled detailed 3D modeling of the middle ear.

Highlights

This pilot study explores whether a human Thiel-embalmed temporal bone is suitable for generating an accurate and complete data set with micro-computed tomography and whether solid iodine-staining improves visualization and facilitates segmentation of middle ear structures
Visibility and demarcation of the structures of interest (SOI) were pronouncedly enhanced after solid iodine-staining, due to an improved contrast of the soft tissue structures, including the tympanic membrane
The largest contrast to noise ratio (CNR) increase occurred for the stapedius muscle (Δ 5.59) and the lateral malleal ligament (Δ 5.41)

Summary

Introduction

This pilot study explores whether a human Thiel-embalmed temporal bone is suitable for generating an accurate and complete data set with micro-computed tomography (micro-CT) and whether solid iodine-staining improves visualization and facilitates segmentation of middle ear structures. Research and development of modern hearing loss treatment options such as middle ear implants demand for enhanced visualization and virtual 3D reconstruction of fine structures within the petrous part of the temporal bone. To achieve high resolution and high precision morphologic data while preserving the integrity of the tissue, micro-computed tomography (micro-CT) imaging is a widely used method [1,2,3,4,5]. Iodine has been reported to significantly improve the contrast-to-noise ratio of submillimeter middle ear connective tissue structures [6]. Boyde et al successfully applied solid iodine using vapor staining [14]

Methods

Results

Conclusion