Accuracy of Contrast Agent Quantification in MRI: A Comparison Between Two k-space Sampling Schemes

Dynamic contrast-enhanced magnetic resonance imaging (DCE MRI) plays an important role in many applications, such as perfusion imaging in oncology. Several aspects of data acquisition should be taken into account when developing protocols for DCE MRI both to facilitate integration of results from multiple institutions and to ensure that the data reflect the underlying physiology as accurately as possible.In this study we focused on the trade-off between accurate contrast agent (CA) quantification ad temporal resolution. The commonly used spoiled gradient-echo k-space scheme known as Fast Low Angle SHot (FLASH) can suffer from low temporal resolution if a large field of view must be scanned. Recently, a k-space under-sampling and data-sharing method known as Time-resolved angiography With Stochastic Trajectories (TWIST) has been proposed to obtain high temporal resolution without sacrificing the spatial resolution. However, the losses in CA quantification have not been analyzed yet.The aim of this study was to evaluate the accuracy of TWIST CA quantification with respect to FLASH.Seven vials containing different Gd-DTPA solutions were prepared. Images were acquired using breast coils and several combinations of the different parameters of the two schemes analyzed. Quantification accuracy has been evaluated in terms of relative error and standard deviation. Also the repeatability for both sequence was evaluated on ten measures.The accuracy of CA quantification with both sequences depends on the specific amount of Gd-DTPA present in the prepared solutions.However, our results show that FLASH and TWIST give comparable accuracy