ontrast-weighted images are commonly acquired in MRI, where one tissue-related parameter usually dominates the contrast, such as T1 or T2 weighting. Relative contrast differences across one image indicate different underlying tissue parameters, but this requires several sequences with different contrast weighting for a final diagnosis. These weighted contrasts provide only qualitative information, which limits the ability of qualitative MRI to depict mostly morphologic abnormalities. Pathologic conditions that alter tissue characteristics on a global or diffuse scale may be missed (1). Instead of indirectly visualizing tissue characteristics by using weighted contrasts, quantitative MRI attempts to directly measure them. Thereby, quantitative MRI could facilitate identification of physiologic changes that do not manifest themselves in morphologic changes or could help detect diffuse tissue changes (eg, in liver [2] and cardiac fibrosis [3]) that remain undetected by using qualitative MRI. It can provide more specific information than does qualitative MRI for characterizing pathologic conditions, such as multiple sclerosis (4) or brain tumors (5). Furthermore, quantitative MRI can be used to assess treatment response (6) or can aid in cases where no side comparison can be performed, such as hippocampal sclerosis (7). With quantitative MRI, diseases can be detected before gross morphologic

Purpose To develop and evaluate the magnetic resonance field fingerprinting method that simultaneously generates T1, T2, B0, and B1+ maps from a single continuous measurement. Methods An encoding pattern was designed to integrate true fast imaging with steady‐state precession (TrueFISP), fast imaging with steady‐state precession (FISP), and fast low‐angle shot (FLASH) sequence segments with varying flip angles, radio frequency (RF) phases, TEs, and gradient moments in a continuous acquisition. A multistep matching process was introduced that includes steps for integrated spiral deblurring and the correction of intravoxel phase dispersion. The method was evaluated in phantoms as well as in vivo studies in brain and lower abdomen. Results Simultaneous measurement of T1, T2, B0, and B1+ is achieved with T1 and T2 subsequently being less afflicted by B0 and B1+ variations. Phantom results demonstrate the stability of generated parameter maps. Higher undersampling factors and spatial resolution can be achieved with the proposed method as compared with solely FISP–based magnetic resonance fingerprinting. High‐resolution B0 maps can potentially be further used as diagnostic information. Conclusion The proposed magnetic resonance field fingerprinting method can estimate T1, T2, B0, and B1+ maps accurately in phantoms, in the brain, and in the lower abdomen.

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