Pulse Repetition Time and Contrast Enhancement

摘要: Objectives: To investigate theoretically enhancement and optimal pulse repetition times for Gd-BOPTA Gd-DTPA enhanced brain imaging at 0.23, 1.5, 3.0 T. Methods: The theoretical relaxation of unenhanced, conventional contrast agent (Gd-DTPA) new generation (Gd-BOPTA) glioma were calculated. Then, simulation the signals contrasts as a function concentration time (TR) in spin echo sequence was done effect (TE) on tumor-white matter also clarified. Three patient cases imaged 0.23 T test principle. Results: may give substantially better glioma-to-white than but is more sensitive to length TR. These characteristics are accentuated Optimal TR lengths shorter all field strengths. optimized thus suboptimal imaging. Higher with further by short TE. Conclusion: Appropriate TRs appear be approximately 300 400 milliseconds 250 milliseconds, 1.5 500 600 450 550 650 475 525 using Gd-BOPTA, respectively. For imaging, it seems justified optimize according seek options like parallel excitation (Hadamard encoding) increasing number slices SNR.