磁性奈米粒子溶液又稱為磁流體，在高場核磁共振系統常被當作T2顯影劑。磁流體為超順磁顯影劑，相較於其他顯影劑，具有較好的生物相容性。而在過去的研究指出低磁場磁振造影下T1對比效果可被增強，因此期望應用低場磁振造影系統並與傳統高場磁振造影系統，探討磁性奈米粒子顯影劑在高場與低場下的對比效應。為此本研究使用並改進自製的低場核磁共振系統以及7T核磁共振系統，量測不同濃度磁流體的T1及T2弛緩時間，以得到高場以及低場的弛緩率R1及R2。驗證磁流體在高、低場下的T1與T2對比效果。並透過磁振造影影像強度，驗證了磁流體在低場的T1權重造影對比度比高場佳；而含鐵量高的磁流體T2權重造影在高場對比度比低場佳；含鐵量低的磁流體T2權重造影在低場對比度比高場佳。確立磁流體在低場磁振造影下，僅需較低劑量即能有良好的對比效益。故能降低劑量以及成本，且能減少因劑量而產生的副作用風險，具有臨床應用的潛力。

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