• Images have been acquired in neck extension and in neck flexion. The cervical canal remains capacious throughout. There is no cord signal change.
• In the extended position, there is indeed widening of the atlanto- dental distance, which is estimated as 4.5 mm . This widening appears to be secondary to pannus that returns low signal on the T1-weighted images and heterogenous signal on the fluid sensitive sequences. There is no gross erosion of the odontoid peg. On neck flexion, the atlanto dental distance widens to 7.8 mm.
• Vertebral body height is preserved. There is minimal degenerative retrolisthesis at C3-C4, and to a lesser extent at C5-C6. There is no significant change in alignment during neck flexion. Moderate disc degeneration is noted throughout the cervical spine.
• At C3-C4, there is a right foraminal discophytic bar with moderate foraminal narrowing and potential impingement on the exiting right C4 nerve root. Clinical correlation is needed for this.
• At C5-C6, and C6-C7, there are broad-based bi-foraminal discophytic bars. There may be impingement on both exiting C6 and C7 nerve roots respectively.
• IMPRESSION: MRI evidence of atlantodental instability during neck flexion and extension as described above. No evidence of sub axial instability. Cervical disc degeneration, with foraminal discophytic bars as described above, with potential impingement on the right C4, both C6 and both C7 nerve roots. This requires clinical correlation.