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1.
Chinese Journal of Ocular Fundus Diseases ; (6): 349-352, 2010.
Artigo em Chinês | WPRIM | ID: wpr-383629

RESUMO

Objective To observe the characteristics of magnetic resonance diffusion tensor imaging (MR-DTI)for optic nerves and optic radiation in blind patients. Methods The optic nerves and optic radiation of 20 blind patients (blind group) and 20 controls (control group) were scanned by MR-DTI.Fractional anisotropy (FA) and directional encoded color (DEC) maps were acquired through postprocessing with the aid of volume-one 1. 72 software. The signal intensity of optic nerves and optic radiation were then observed. The FA, mean diffusivity (MD), λ∥ and λ⊥ value of bilateral optic nerves and optic radiation in two groups were measured in the DEC maps. Results While the high signal intensity was found in bilateral optic nerves in FA and DEC maps in control group, the signal decreased markedly in the blind group. The FA and λ∥ value of optic nerves in the blind group were declined obviously compared to that in the control group. The difference was statistically significant (t= 16. 294, 14. 660;P=0. 000). The MD and λ⊥ value of optic nerves in the blind group were increased obviously compared to that in the control group, the difference was also statistically significant (t=8. 096, 8. 538;P = 0. 000). The high signal intensity was found in bilateral optic radiation in FA and DEC maps in both the blind and control groups. There were no statistic differences in FA and MD value in bilateral optic radiation between the blind and control groups (Left:t=1.456,1.811;P = 0. 152,0.076. Right:t = 0. 779,0. 073;P = 0. 440,0. 942). Conclusion A low signal intensity of bilateral optic nerves and a high signal intensity of bilateral optic radiation were found in blind patients.

2.
Chinese Journal of Ocular Fundus Diseases ; (6): 306-309, 2010.
Artigo em Chinês | WPRIM | ID: wpr-383601

RESUMO

Functional imaging is a newly arisen interdisciplinary subject compared with the routine radiology displaying anatomy and morphology of lesions. It can exhibit the function-changed information, such as blood flow and metabolism of organs and tissues as visual images or data to provide organizational functions and metabolic information, which makes early diagnosis, more accurate orientation, qualitative definition, and also the prognosis judgment. The ophthalmologists should pay more attention to the functional imaging applications in the field of neuro-ophthalmology.

3.
Chinese Journal of Ocular Fundus Diseases ; (6): 343-348, 2010.
Artigo em Chinês | WPRIM | ID: wpr-383514

RESUMO

Objective To observe the results of function MRI and perimetry in patients with visual pathway diseases. Methods Three patients (6 eyes) with pituitary adenoma and craniopharyngioma diagnosed via pathological examination and three healthy volunteers aged from 24 to 30 were collected. The best corrected visual acuity was non-light perception-1. 0 in the 6 sick eyes and 1. 0 in the healthy eyes;all the involved individuals had no other ocular diseases except myopia and without any contraindications of MRI. Common tests including the best visual acuity, fundus test by direct or indirect ophthalmoscope, center static visual field tested by Octopus 101 perimeter, program 32, tendency oriented perimetry were performed. The visual stimulation subtended a field of view of about 12 degrees,consisted of high contrast and drifting checkerboards. MRI parameters: GE signa VH/i 3. 0T scanner. Functional data: GRE-EPI sequence, 20 slices lying perpendicular to the calcarine sulcus. Anatomical data was obtained using 3DSPGR sequence to acquire high resolution. The cortical surface was unfolded and then cut and inflated. Functional data was presented to the inflated surface and subsequently analyzed by AFNI software. Results In six eyes, three had temporal defects, two had upper temporal visual field defects, and the other one did not finish the visual field test. The retinotopic representations of health adults were obtained by using the phase-encoded visual stimulation. The Eccentricity coordinate maps showed that foveal representations lay in the occipital poles and the representations appeared further anterior as eccentricity increased. The polar angle coordinate maps showed that early retinotopically organized areas had a representation of visual field. The visual cortex beneath the calcarine sulcus matched with the upper visual field of the opposite side and which upon the calcarine sulcus matched with the under visual field of the opposite side. Less or no visual cortex response was revealed in the patients' function MRI or the response in injury side was vanished. The visual cortex response related with the visual field defects could not be induced in function MRI. Conclusion There is a good correlation between function MRI data and the results of perimetric evaluation. The function MRI can show the visual cortex response correlated with the visual field defects of the patients with visual pathway diseases.

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