T₁andT₂estimation in complex domain: First results on clinical data

Purpose The article provides a practical method for generating T 1 and T 2 maps from multiple, sequentially acquired Spin Echo images. First results on real data for diagnostic purposes are presented and discussed in order to investigate the possible clinical usages of the proposed technique. The main advantage of the method is its ability in identifying even very small variation in one or both relaxation time maps, allowing a more clear differentiation of tissues across the whole image, instead of highlighting only high vascularized regions, such as in contrast medium based images. Theory and Methods For the joint estimation of relaxation time maps, the method exploits the full complex acquired data instead of amplitude acquisitions. This allows having an estimator able to provide unbiased results even in case of tissues characterized by weak Signal to Noise Ratio. Results The effectiveness of the proposed approach is shown on different real case studies: a phantom dataset for quantitative analysis and three human brain datasets for diagnostic purposes. Conclusion The proposed method shows very interesting and promising results when applied to clinical datasets. The innovative technique is able to evaluate the biological topography and highlight lesions not otherwise easily distinguishable with standard examinations.