The correlation between diffusion tensor imaging of the sacral cord and bladder contractility in people with tetraplegia.

STUDY

DESIGN

Cross-sectional descriptive study.

OBJECTIVES

To compare the diffusion tensor imaging (DTI) changes of the sacral cord in people with complete cervical spinal cord injury (SCI) and neurogenic bladder versus people without SCI, and to explore the relationship between sacral cord DTI changes and bladder contractility.

SETTING

First Affiliated Hospital of Soochow University, Jiangsu Province, China.

METHODS

Forty participants were included: 25 participants with complete cervical SCI and 15 without SCI. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were calculated by DTI for ventral horn and intermediate column of sacral cord at S2-S4 level. All participants underwent urodynamic examination. The urodynamic parameters (voiding efficiency (VE), and bladder contractility index (BCI)) and DTI parameters were compared between people with and without SCI. The correlations between DTI values (FA and ADC) and urodynamic parameters were analyzed.

RESULTS

The FA values were significantly lower and the ADC values were significantly higher in the intermediate column and ventral horn at S2-S4 level of the participants with SCI compared with their able-bodied counterparts (p < 0.05). VE and BCI were significantly different between the two groups (p < 0.05). The FA values of intermediate column positively correlated with BCI (r = 0.749, p < 0.05) and the ADC values negatively correlated with BCI (r = -0.471, p < 0.05) in participants with SCI. The DTI values of sacral cord were not correlated with each urodynamic parameter in participants without SCI (p > 0.05).

CONCLUSIONS

Complete cervical SCI might lead to microstructural changes of the sacral cord, which might further affect bladder contraction.