Abstract
Purpose
To develop an efficient method for extracting maps of the corrected T~1~ from images generated using the T One by Multiple Read Out Pulses (TOMROP) sequence.
Materials and Methods
An expression is developed for the true T~1~ in terms of the parameters from a threeβparameter fit of the TOMROP data. Solutions of gadodiamide in normal saline with concentrations of 0.0, 0.06, 0.11, 0.23, 0.46, and 0.91 mM were prepared and T~1~ measurements were performed using both the inversion recovery (IR) and the TOMROP methods. The TOMROP data were analyzed using the proposed technique and the results compared to those from the IR measurements.
Results
The T~1~ estimates generated from the TOMROP data using the proposed method were consistent with the IR results. However, systematic errors were observed in the T~1~ estimates when the repetition time was not sufficient for full recovery of axial magnetization. Relaxation times determined using the proposed method were within 1% of the spectroscopiclly determined values for T~1~ values in the range of 0.28β2.8 seconds when a suitable delay was employed.
Conclusion
The proposed method of analysis was found to yield accurate T~1~ estimates when the assumptions used in the analysis were not violated. J. Magn. Reson. Imaging 2004;19:508β512. Β© 2004 WileyβLiss, Inc.