Experimental Fusion of Contrast Enhanced High-Field Magnetic Resonance Imaging and High-Resolution Micro-Computed Tomography in Imaging the Mouse Inner Ear

Abstract

Objective: Imaging cochlear, vestibular, and 8th cranial nerve abnormalities remains a challenge. In this study, the membranous and osseous labyrinths of the wild type mouse inner ear were examined using volumetric data from ultra high-field magnetic resonance imaging (MRI) with gadolinium contrast at 9.4 Tesla and high-resolution micro-computed tomography (µCT) to visualize the scalae and vestibular apparatus, and to establish imaging protocols and parameters for comparative analysis of the normal and mutant mouse inner ear. Methods: For in vivo MRI acquisition, animals were placed in a Milleped coil situated in the isocenter of a horizontal 9.4 T Varian magnet. For µCT examination, cone beam scans were performed ex vivo following MRI using the µCT component of a nanoScan PET/CT in vivo scanner. Results: The fusion of Gd enhanced high field MRI and high-resolution µCT scans revealed the dynamic membranous labyrinth of the perilymphatic fluid filled scala tympani and scala vestibule of the cochlea, and semicircular canals of the vestibular apparatus, within the µCT visualized contours of the contiguous osseous labyrinth. The ex vivo µCT segmentation revealed the surface contours and structural morphology of each cochlea turn and the semicircular canals in 3 planes. Conclusions: The fusion of ultra high-field MRI and high-resolution µCT imaging techniques were complementary, and provided high-resolution dynamic and static visualization of the complex morphological features of the normal mouse inner ear structures, which may offer a valuable approach for the investigation of cochlear and vestibular abnormalities that are associated with birth defects related to genetic inner ear disorders in humans.

Optimization of 3D-Visualization of Micro-Anatomical Structures of the Human Inner Ear in Osmium Tetroxide Contrast Enhanced Micro-CT Scans

“…Details up to a sub-cellular level can be visualized by high-resolution tomography of a part of an osmium stained inner ear (Lareida et al, 2009 ). Except for staining, histology or different imaging techniques, such as MRI (Counter et al, 2015 ) or transmission electron microscopy (Handschuh et al, 2013 ), can be combined with micro-CT images to obtain more detailed volumes. This combination could result in better visibility of, for example, the endolymphatic ducts.…”

Combining CT Images and Clinical Features of Four Periods to Predict Whether Patients Have Rectal Cancer

“…The incidence of rectal cancer is one of the most malignant tumors in the world [ 1 – 3 ]. Accurate clinical staging is the key to treatment decision, especially for rectal cancer [ 2 , 3 ]. In the past century, medical imaging technology has experienced various hardships and achieved many new achievements in its continuous development [ 3 – 5 ].…”

Usefulness of Intravital Multiphoton Microscopy in Visualizing Study of Mouse Cochlea and Volume Changes in the Scala Media

“…Thus, intravital MPM eliminates the need for invasive tissue sampling and complex preparation, while enabling the volumetric visualization of a specimen. Various methods, such as laser-Doppler flowmetry ( 11 , 12 ), micro-computed tomography (CT) ( 13 , 14 ), and magnetic resonance imaging ( 15 ), have been applied to visualize the microstructures over the cochlear bone. However, these techniques reveal only the blood vessels over the cochlear bone or require the invasive use of contrast media to identify the microstructure of the SM.…”