Magnetic Resonance Imaging and Multidetector Computed Tomography Evaluation of Craniovertebral Junction Abnormalities

Abstract

BACKGROUND The craniovertebral junction is a complex articulation between occiput, atlas, axis and supporting ligaments enclosing the soft tissue structures of cervicomedullary junction which includes medulla, spinal cord and lower cranial nerves. The incidence of different types of CVJ anomalies varies with demographic environment & ill-defined genetic factors. CVJ anomalies are more frequently found in Indian subcontinent than anywhere else in the world. Even in India, these anomalies are more frequently documented from Bihar, Uttar Pradesh, Rajasthan and Gujarat. The reason for this geographical clustering is more speculative. The CVJ anomalies can be either due to bony or soft tissue anomalies. They are common in all age groups and almost equal in both sex groups. The anomalies can be due to congenital or acquired causes. There has been a renewed interest in the normal anatomy & pathological lesions of CVJ anomalies with dynamic xrays, computed tomography (CT) and magnetic resonance imaging (MRI). The clinical features are often delayed up to 2 nd or 3rd decade, since they are subtle and often missed. Various congenital anomalies and acquired disease processes can affect the craniovertebral junction. They often cause diagnostic dilemmas. Only few studies have been conducted in this regard. This study is an attempt to define importance of precise diagnosis for pre-treatment evaluation and systematic classification of CVJ abnormalities with MRI and multi-detector computed tomography (MDCT). METHODS We conducted this cross-sectional descriptive study with 55 patients, who had been referred to us for CT / MRI from Department of Neurology. 3 Tesla MRI (GE Healthcare) and 16 slice MDCT (Philips) were used in this study. RESULTS In our study, congenital anomalies were the most common type of CVJ abnormality followed by degenerative changes and trauma. MRI proved to be better at detecting soft tissue abnormalities and assessing spinal cord compression, although CT was very much accurate at demonstrating bony lesions with short scan times and ability to reconstruct in three orthogonal planes. CONCLUSIONS CT and MRI cannot be compared in imaging the craniovertebral junction and should be complementary to each other. KEYWORDS Craniovertebral Junction, MRI, MDCT