Hemodynamic analysis of bladder tumors using T1-dynamic contrast-enhanced fast spin-echo MRI

Objectives

To evaluate the hemodynamics of bladder tumors, we developed a method to calculate change in R₁ value (ΔR₁) from T₁-dynamic contrast-enhanced fast spin-echo magnetic resonance imaging (T₁DCE-FSE-MRI).

Materials and methods

On a 1.5-T MR system, T₁DCE-FSE-MRI was performed. This study was applied to 12 patients with urinary bladder tumor, i.e. urothelial carcinoma. We compared ΔR₁–time and ΔSI–time between a peak in the ΔR₁–time and ΔSI–time curve occurred during the first pass within 60 s. Next, we assessed the slope of increase for 180 s after CA injection (Slope_0–180).

Results

The mean slope of the first pass was significantly higher for bladder tumors on both the ΔR₁–time and the ΔSI–time curve compared with normal bladder walls. Moreover, a significant difference was apparent between bladder tumors and normal bladder walls on the mean Slope_0–180 in the ΔR₁-time curve. However, no significant difference in the mean Slope_0–180 was observed on the ΔSI-time curve between bladder tumors and normal bladder walls.

Conclusion

T₁DCE-FSE-MRI offers three advantages: quantitative analysis; high-quality (i.e., artifact-free) images; and high temporal resolution even for SE images. Use of ΔR₁ analysis with T₁DCE-FSE-MRI allows more detailed information on the hemodynamics of bladder tumors to be obtained and assists in differentiation between bladder tumors and the normal bladder wall.