Delineation of Optic Radiation and Stria of Gennari on High-resolution Phase Difference Enhanced Imaging

Rationale and Objectives

Phase difference enhanced (PADRE) imaging technique can selectively enhanced the phase difference between the target and surrounding tissue. Our purpose is to assess the delineations of the optic radiation and primary visual cortex (stria of Gennari) using PADRE.

Materials and Methods

The subjects were 6 healthy volunteers. Axial and coronal high-spatial resolution PADRE images were acquired covering the entire optic radiation using a 3T magnetic resonance system. Two radiologists evaluated the PADRE and susceptibility-weighted imaging (SWI)-like images for the delineation of four layers at the optic radiation (tapetum, internal sagittal stratum, external sagittal stratum, and adjacent white matter) on the basis of the anatomic appearances of the cadaveric specimens stained with Bodian’s method and Kluver-Barrera method. The radiologists also assessed the delineations of the stria of Gennari on PADRE and SWI-like images.

Results

In all 6 healthy subjects, the PADRE images clearly identified the four layers at the optic radiation, as well as the stria of Gennari, which were difficult to appreciate in SWI-like images. The anatomic appearances of the optic radiation on PADRE images were more similar to those seen in the specimens stained with Kluver-Barrera method than with Bodian’s method.

Conclusion

The PADRE technique can delineate the four layers at the optic radiation and the stria of Gennari; the differences in myelin densities can also be enhanced. The PADRE technique may have the potential to reinforce the clinical utility of MRI in the diagnosis of diseases that affect the optic radiation and primary visual cortex.

The primary visual cortex is the first cortical area to receive visual input, which is characterized by an easily identifiable anatomical landmark: the stria of Gennari. The optic radiation is a fiber tract, which begins at the lateral geniculate nucleus, passes through the temporal and parietal lobes, and terminates in the primary visual cortex. In the specimens stained using Bodian’s method, the tapetum, internal sagittal stratum, external sagittal stratum, and adjacent white matter are seen as four layers parallel to the wall of the lateral ventricle at the level of the posterior trigone .

Haacke et al designed a high-spatial-resolution three-dimensional (3D) fast low-angle shot magnetic resonance (MR) imaging technique that can enhance subtle differences in the subvoxel magnetic heterogeneities . This technique is called susceptibility-weighted imaging (SWI), and is obtained by multiplication of the phase and magnitude images. The phase images can provide excellent image contrast and reveal anatomical structures that are not visible on the corresponding magnitude images.

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Materials and methods

MR Imaging

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The PADRE Technique

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ρPADRE=w(Δ)|ρ|. ρ

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)

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Subjects and Histological Specimens

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Image Interpretation

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A Patient with Glioblastoma

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Results

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Discussion

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References

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Delineation of Optic Radiation and Stria of Gennari on High-resolution Phase Difference Enhanced Imaging

Rationale and Objectives

Materials and Methods

Results

Conclusion

Materials and methods

MR Imaging

The PADRE Technique

Subjects and Histological Specimens

Image Interpretation

A Patient with Glioblastoma

Results

Discussion

References

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