Purpose
Recently, several methods for evaluating the spatial resolution of magnetic resonance imaging (MRI) have been reported. However, these methods are not simple and can only be used for specific devices. The International Electrotechnical Commission (IEC) 62464-1 recommends a method that uses a periodic array pattern to evaluate the spatial resolution of an MRI device. In this study, we develop a new method (the ladder method) and evaluate its measurement accuracy by adapting the IEC method to evaluate the spatial resolution.
Methods
First, the adaptation of the IEC method is analyzed by simulating the ladder method using a phantom with a periodic pattern, which is constructed using acrylic plates and a nickel sulfate aqueous solution. Subsequently, the ladder method is evaluated in terms of spatial resolution by dividing the standard deviation (SD) by the average signal in the region of interest (ROI) on the ladder phantom image. To evaluate the precision of the ladder method, it is compared with the modulation transfer function (MTF) using a magnitude image with the partial volume effect of the edge image.
Results
The simulation result shows that the evaluation of the spatial resolution using the ladder method is viable, in which a coefficient of correlation of 0.90 or higher is obtained for all evaluations using the ladder and MTF methods.
Conclusions
The ladder method can be assessed using only the signal mean value and SD in the ROI on the target image. Therefore, the ladder method is a promising method as a substitute for the MTF.