Yuuki Kanazawa RT, Presenter: Nothing to Disclose

Tosiaki Miyati PhD, Abstract Co-Author: Nothing to Disclose

Osamu Sato MD, PhD, Abstract Co-Author: Nothing to Disclose

To evaluate in more detail the hemodynamics of urinary bladder tumor, we report the clinical utility of T1 dynamic contrast-enhanced (T1-DCE) MR imaging with the fast spin-echo (FSE) sequence. The method of calculation of the T1 value is introduced.

On a 1.5-T MR system, T1-DCE MR images were obtained using the FSE sequence. First, T1 values before contrast agent injection were measured with imaging parameters that had different TR and fixed TE. Next, dynamic contrast-enhanced imaging data were acquired for the imaging parameters using TE and TR in the same way as before contrast agent injection, and the T1 value of the tissue at contrast enhancement was measured. This method was applied to 10 patients with urinary bladder tumor (including 15 masses). Changes in T1 during the first pass of contrast agent were compared between urinary bladder tumors and normal bladder.

Changes in absolute T1 were clearly demonstrated on the parametric map. The T1 values (mean ± SD) before injection contrast agent were as follow; urinary bladder tumor (n=15; 1.215 ± 0.258 second), normal bladder wall (n=10; 1.134 ± 0.364 second). The hemodynamic of urinary bladder tumor was demonstrated on two patterns; one had the peak within 1 minute, another had rapidly increased for 3 minutes. On the other hand, the hemodynamic of normal bladder wall was increased more gradually than bladder tumors. The mean gradient after the first pass was statistically higher for urinary bladder tumor than for normal bladder wall (P < 0.05; urinary bladder tumor, 0.085 ± 0.057 second-1 / second; normal bladder wall, 0.025 ± 0.013 second-1 / second).

This method using the FSE sequence can easily be applied to clinical settings, and makes it possible to keep high spatial, contrast, and temporal resolution. Moreover, our findings show considerable promise for isolating hemodynamics of urinary bladder tumor.

T1-DCE MR imaging using the FSE sequence can easily be applied to clinical settings, and makes it possible to keep high spatial and temporal resolution.

Kanazawa, Y, Miyati, T, Sato, O, Why Do We Have to Calculate T1 Value When Evaluation of Urinary Bladder Tumor?.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6019685.html