Evaluation of Anterior Visual Pathway Lesions Using CT and MRI: A Prospective Descriptive Study

Background:Visual impairment may arise via many diseases. Imaging assessment using computed tomography (CT) and/or magnetic resonance imaging (MRI) can help localize and characterize these kinds of diseases. This study aimed to describe and compare the role of CT and MRI in the evaluation of anterior visual pathway lesions.Methods: A prospective descriptive study was conducted on 30 patients with symptoms related to the visual pathway (13 females and 17 males; mean age 30.7 ± 8.2 years; range 4-70 years).Considering the anatomical site of lesions, our patients were subdivided into three main groups: optic nerve lesions (n= 9), optic chiasm lesions (n= 17), and lesions involving optic tract and lateral geniculate body (n= 4). The imaging findings of CT and MRI were described and compared.
Results: We found nine patients with optic nerve lesions (five optic nerve gliomas, one optic nerve meningioma, and three lesions infiltrating the optic nerve),17 patients with optic chiasm lesions (seven pituitary macroadenomas, six craniopharyngiomas, two olfactory groove meningiomas, and two empty sella syndromes), and four patients with lesions involving optic tract and lateral geniculate body (two AVMs,one parasellar meningioma and one acute right thalamic hematoma). MRI is considered an excellent diagnostic modality for providing perfect anatomical details and efficient data concerning the presence, level, and extent of anterior visual pathway lesions, but CT provides greater definition than MRI for bone destruction or erosion as well as for tumoral calcification or acute haemorrhage
Conclusion: CT and MRI are complimentary imagings for evaluating abnormalities of the anterior visual pathway.