Quantitative analysis of spinel CSF dynamics using magnetic resonance imaging: Experimental and clinical studies

Quantitative Analysis of Spinel CSF Dynamics using Magnetic Resonance Imagi ng: Experimental and Clinical Studies. Purpose: Measurement of the oscillat ing CSF flow in the spinal canal (SC) of healthy volunteers and in patients with post-traumatic syringomyelia (PTS) using an optimized MRI protocol as well as to determine whether stenosis induced velocity changes are detecta ble using MRI. Methods: In 68 healthy volunteers quantitative studies of CS F flow in the cervical, thoracic, and lumbar regions were performed. First, an optimized sequence was developed and tested in 19 volunteers using four different flow-encoding velocities (4, 8, 12, 16 cm/s). Secondly, the opti mized sequence was employed in 49 volunteers to measure the different CSF p atterns in the cervical, thoracic, and lumbar spinal canals (CSC, TSC, LSC) . Part three of the study, in which patients with PTS are being examined is still underway. We measured the maximum velocity (cm/s), the pixel area (m m(2)),and the stroke volume (ml/s). Using a flow model the velocities prior to and after compression with 5 different power levels were measured at th e stenosis and at a distance of 70 cm. Results: A total of 226 dynamic meas urements have been performed - so far 76 in the first part (62=81.5% evalua ble) and 150 in the second part - using the optimized sequence and optimal flow velocities. A flow-encoding sequence of 12 cm/s was found best in the CSC and one of 6 cm/s in the TSC and LSC. The maximum velocity in the CSC w as 0.95 cm/s with the flow being directed caudal and 0.38 cm/s with the flo w being directed cranial. In the TSC the values were 4.7 cm/s and 1.65 cm/s and in the LSC 0.96 cm/s and 0.59 cm/s. The highest velocities were found at the TSC, which has the smallest diameter compared to the CSC and LSC. In the 4 patients with PTS, the maximum velocities were between 0.09 cm/s and 0.97 cm/s with the flow being directed cranial and between 0.04 cm/s and 1 .03 cm/s with the flow being directed caudal. The stroke volumina in the CS C were between 0.1 and 1.23 ml/s (mean: 0.48 ml/s) and 0.2 and 2.45 ml/s (m ean: 0.66 ml/s) in the TSC and in the LSC 0.08 ml/s and 0.67 ml/s (mean: 0. 29 ml/s). The results of the flow model studies showed an increase of veloc ity between 2.06 and 4.94 cm/s (mean: 3.31 cm/s) at the stenosis and 1.1 an d 1.33 cm/s (mean: 1.23 cm/s) at a distance of 70 cm. Conclusion: Quantitat ive measurement of the oscillating CSF flow in the entire spinal canal (SC) is possible using an optimized MRI protocol as well as to detect stenosis induced velocity changes, Due to the high interindividual variability in th e data of spinal CSF dynamics, further studies are necessary to collect nor mal data. The detection of movement of CSF in a post-traumatic spinal cord lesion may alter the therapeutic management.