الفهرس 
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Abstract
The aim of this work is to show the imaging criteria of neurovascular compression syndrome at the CPA using high resolution T2 3D MRI sequence.
This study was conducted on 15 patients with trigeminal neuralgia, tinnitus, vertigo or Hemi-facial spasm referred to Alexandria University Hospitals.
All MR imaging examinations were performed by using a 1.5T system (Achieva Philips, Netherland) with an 16-channel sense neurovascular head and neck coil. The imaging protocol consisted of axial T2- weighted images of the whole brain (TR/TE, 400–500/10 ms; slice thickness, 3mm ; flip angle, 90°; matrix size, 230x179) and coronal and axial T1-weighted images of the CPA before and after administration of intravenous contrast material (TR shortest, TE shortest; slice thickness, 5mm ; flip angle, 90°; matrix size, 235x170). High resolution 3D T2 fast spin echo weighted image on the CPA was performed with the parameters as follows: (TR shortest, TE 110 ms; slice thickness, .5mm; flip angle, 90°; matrix size, 190x240).
All images were transferred to a workstation. Optimal thresholds were used in each patient to visualize the neurovascular structures. All images were reviewed by neuro-radiologists who was blinded to the clinical symptoms of the patients. The final decision was made by consensus.
The used tests for statistical analysis were Chi-square test, Fisher’s Exact or Monte Carlo correction & Student t-test.
It was found that there is positive relation between aging and the presentation of neuro-vascular compression symptoms
The study showed that that in 10 (66.7%) of our patients AICA was the offending vessel, 4(26.6%) of our patients the SCA was the offending vessel and 1 (6.7%) of our patients the Superficial petrosal vein. Also noted that the AICA was always responsible for vestibulo-cochlear and facial compression and SCA was the responsible for trigeminal nerve compression.
The study showed that (80%) showed no significant nerve distortion or reduction of its caliber and (20%) showed reduction of the nerve caliber and they were operated by MVD surgery
This study concluded that MRI can reproduce the anatomy of the CPA and indicate the presence of a neurovascular conflict. It also eliminates other potential causes such as a tumoral process or multiple sclerosis. The single presence of a neurovascular contact is not sufficient, however, a perpendicular contact between the vascular loop and the cranial nerve, distortion of the course of the cranial nerve as well as reduction of the nerve caliber and also the site of the contact are all radiological criteria for diagnosis of neurovascular compression syndrome . When we perform MRI in healthy individuals with no symptoms, sometimes, we find one or more of the radiological criteria of the offending vessel with no clinical complaint as the pathological process is not well established. Thus, only symptomatic cases with MRI criteria, after excluding other causes of the disease, are candidates of MVD operation.