Dynamic MR imaging of the upper abdomen: timing optimization and pulse sequence selection

Since breath-hold gradient-echo MR imaging was introduced, dynamic MR study has played an important role in the MR investigation of the upper abdomen. In this article, the importance of tailoring imaging delay in each individual patient is stressed, with special attention given to a logical aspect of setting delay time based upon the bolus transfer time obtained by test injection. Also discussed is the importance of selecting types and parameters of pulse sequence to maximize the enhancement effect. It should be noted that alteration of gadolinium concentration in vivo following intravenous injection could result in a large change in signal intensity change on one sequence but little change on another. Double-dose 3DFISP with tailored delay time utilizing the test injection method, which is currently used for dynamic MR imaging in our institute, is presented.