Methods: Study participants comprised five healthy volunteers (mean age, 27.2 years) and 27 patients with LSS (mean age, 58.4 years) who were individually assessed using 3.0 Tesla magnetic resonance imaging. Intraspinal ADC and FA values of 10 intervertebral discs from healthy volunteers and 52 intervertebral discs from LSS patients were measured. Also, intraspinal canal area, Schizas classification (A: normal, B: mild stenosis, C: severe stenosis) and correlations with symptoms were investigated. Clinical symptoms were checked for the presence of low back pain (LBP), intermittent claudication (IMC), and bladder and bowel dysfunction (BBD). Results: Compared to healthy individuals, LSS patients had significantly lower ADC (p<0.05) and significantly higher FA values (p<0.01). In Schizas classification, stenosis worsened from A to C. ADC values decreased significantly while FA values increased significantly in that order (p<0.05). A positive correlation was found between intraspinal canal area and ADC values (r=0.63, p<0.01) and a negative correlation between intraspinal canal area and FA values (p=−0.61, p<0.01). No correlations were noted between LBP and ADC or FA values. On the other hand, ADC values were significantly lower (p<0.05) and FA values were significantly higher (p<0.05) in patients with IMC or BBD. Conclusions Intraspinal DTI parameters such as ADC and FA values were associated with the Schizas classification, intraspinal canal area, and clinical symptoms, suggesting that ADC and FA may be useful for quantitative assessment of LSS.

Methods: Study participants comprised five healthy volunteers (mean age, 27.2 years) and 27 patients with LSS (mean age, 58.4 years) who were individually assessed using 3.0 Tesla magnetic resonance imaging. Intraspinal ADC and FA values of 10 intervertebral discs from healthy volunteers and 52 intervertebral discs from LSS patients were measured. Also, intraspinal canal area, Schizas classification (A: normal, B: mild stenosis, C: severe stenosis) and correlations with symptoms were investigated. Clinical symptoms were checked for the presence of low back pain (LBP), intermittent claudication (IMC), and bladder and bowel dysfunction (BBD). Results: Compared to healthy individuals, LSS patients had significantly lower ADC (p<0.05) and significantly higher FA values (p<0.01). In Schizas classification, stenosis worsened from A to C. ADC values decreased significantly while FA values increased significantly in that order (p<0.05). A positive correlation was found between intraspinal canal area and ADC values (r=0.63, p<0.01) and a negative correlation between intraspinal canal area and FA values (p=−0.61, p<0.01). No correlations were noted between LBP and ADC or FA values. On the other hand, ADC values were significantly lower (p<0.05) and FA values were significantly higher (p<0.05) in patients with IMC or BBD. Conclusions Intraspinal DTI parameters such as ADC and FA values were associated with the Schizas classification, intraspinal canal area, and clinical symptoms, suggesting that ADC and FA may be useful for quantitative assessment of LSS.

Methods: We performed 3T MRI in 10 healthy volunteers and 13 patients with LSS. The ADC values in the spinal canal were evaluated at 46 vertebrae (L4/5 and L5/S1 for each participant), and the reduced and conventional fields of view were compared. Results: The ADC values were 2.72±0.12 at L4/5 in healthy volunteers, 2.76±0.19 at L5/S1 in healthy volunteers, 1.77±0.58 at L4/5 in patients with LSS, and 2.35±0.29 at L5/S1 in patients with LSS. The ADC value at L4/5 in patients with LSS was significantly lower than that at L5/S1 in patients with LSS and that at L4/5 and L5/S1 in healthy volunteers (p <0.05). With an ADC cutoff value of 2.46 to identify LSS, this approach provided an area under the curve of 0.81, sensitivity of 0.92, and specificity of 0.76 (p <0.05). Conclusions Preoperative examination using ADC maps permits visualization and quantification of spinal canal lesions, thus proving the utility of ADC maps in the selection of decompression surgery for LSS.