Influence of paramagnetic melanin on the MRI contrast in melanoma: a combined high-field (11.7 T) MRI and EPR study
Influence of paramagnetic melanin on the MRI contrast in melanoma: a combined high-field (11.7 T) MRI and EPR study
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DOI：
10.1002/cmmi.1554
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发表时间：
2014-03-01
影响因子：
--
通讯作者：
Gallez, B.
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文献类型：
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作者：
Godechal, Q.;Mignion, L.;Gallez, B.
黑色素瘤是最危险的皮肤癌，其发病率逐年上升。由于当前基于肿瘤视觉方面的诊断方法存在局限性，因此出现了几种有助于诊断的新技术，其中包括磁共振成像（MRI）和电子顺磁共振（EPR）。在 T-1 和 T-2 加权图像中黑色素瘤中观察到的典型对比图案的起源仍有待阐明，并且是一个争议的根源。此外，黑色素可以产生足够的磁不均匀性，以便使用高场 MRI 在 T-2* 加权图像上进行可视化。为了阐明黑色素在黑色素瘤 MRI 对比度中的可能作用，本研究旨在将黑色素中的顺磁性含量与 T-1、T-2 和 T-2* 加权图像的对比度相关联。使用四种具有不同色素沉着的实验肿瘤（B16、HBL、LND1 黑色素瘤和 KHT 肉瘤）在 11.7 T 下获得体内 MR 图像。通过EPR测量黑色素中的顺磁性含量。黑色素含量与弛豫时间T-1、T-2和T-2*之间没有观察到显着相关性，这强调了色素单独存在对MRI对比度的影响可以忽略不计。版权所有 (c) 2014 约翰·威利父子有限公司
Melanoma is the most dangerous form of skin cancer and its incidence is rising each year. Because the current methods of diagnosis based on the visual aspect of the tumor show limitations, several new techniques are emerging to help in this diagnosis, amongst which are magnetic resonance imaging (MRI) and electron paramagnetic resonance (EPR). The origin of the typical contrast pattern observable in melanoma in T-1- and T-2-weighted images remains to be elucidated and is a source of controversy. In addition, melanin could create sufficient magnetic inhomogeneities to allow its visualization on T-2*-weighted images using high-field MRI. In order to elucidate the possible role of melanin in the MRI contrast of melanoma, the present study was designed to correlate the paramagnetic content in melanin pigment to the contrast on T-1-, T-2- and T-2*-weighted images. MR images were obtained in vivo at 11.7 T using four types of experimental tumors with different pigmentations (B16, HBL, LND1 melanomas and KHT sarcomas). The paramagnetic content in melanin pigment was measured by EPR. No significant correlation was observed between the content in melanin and the relaxation times T-1, T-2 and T-2*, emphasizing that the presence of pigment alone has negligible effect on the MRI contrast. Copyright (c) 2014 John Wiley & Sons, Ltd.