Evaluation of intrasyrinx fluid motion by spatial modulation of magnetization-magnetic resonance imaging in syringomyelia with long-term follow-up: a predictor of postoperative prognosis?

Abstract

OBJECTIVE: To evaluate the use of measuring intrasyrinx fluid motion in syringomyelia by spatial modulation of magnetization (SPAMM)-magnetic resonance imaging (MRI) for predicting postoperative results.

MATERIALS AND METHODS: Fourteen patients with syringomyelia, who underwent surgery between 1995 and 2004 and took both preoperative SPAMM-MRI and postoperative MRI, were reviewed retrospectively. The SPAMM-MRI was obtained on a 1.5-T system using the electrocardiogram-triggered multiphase image technique with repetition time/time to echo/diffusion time/flip angle = 42 milliseconds/7.2 milliseconds/0 to 600 milliseconds/20 degrees. Three radiologists analyzed the tagging band shifting of the intrasyrinx fluid motions on the preoperative SPAMM-MRI. If the tagging band shifting during the systolic phase was more than half of the band space, it was regarded as good fluid motion. The correlation between the preoperative intrasyrinx fluid motion and the postoperative shrinkage of the syrinx was statistically analyzed.

RESULTS: The underlying causes of the syringomyelia were Arnold-Chiari malformation (7 patients), trauma (4 patients), and infectious disease (3 patients). Eight of 9 patients who had good fluid motion in the syrinx showed postoperative shrinkage of the syrinx. However, the 5 patients who had poor fluid motion showed no shrinkage of the syrinx. The fluid motion of the syrinx was highly correlated with the postoperative shrinkage of the syrinx (P < 0.01).

CONCLUSIONS: Evaluation of the intrasyrinx fluid motion in syringomyelia using the SPAMM-MRI can be a useful predictor of postoperative results and may indicate how well the pulse wave is transmitted from the heart to the syrinx