MRI of thiel-embalmed human cadavers

Purpose To explain the observed considerable loss of signal and contrast when Thiel-embalmed human cadavers are imaged using clinical magnetic resonance imaging (MRI) sequences, especially those based on spin-echo MRI. Materials and Methods All cadavers were imaged with a medical 1.5T scanner using standard MRI sequences. Dual angle B1+ magnitude mapping and electromagnetic (EM) simulations that characterize the radiofrequency (RF) penetration in a male human body model (HBM) were carried out for a range of tissue conductivities. Results The EM simulations show that RF penetration issues begin to affect the image quality for values of electrical conductivity as low as 2.6 S/m. The electrical conductivity values of the embalming fluids were found to be within the range of 5-10.6 S/m, thus strongly suggesting that the observed loss in signal and contrast is due to diminished RF penetration inside the cadavers. Furthermore, it was demonstrated that gradient-echo (GRE)-based MRI sequences perform better than spin-echo (SE)-based sequences, as they are less susceptible to imperfections in the flip angle that are inevitably present when imaging Thiel cadavers. Conclusion: The diminished signal and contrast observed when imaging Thiel-embalmed human cadavers may be attributed to the high conductivity of the embalming liquids. J. Magn. Reson. Imaging 2014;39:576-583. © 2013 Wiley Periodicals, Inc. Copyright © 2013 Wiley Periodicals, Inc.