Influence of paramagnetic melanin on the MRI contrast in melanoma: a combined high‐field (11.7 T) MRI and EPR study. (March 2014)

• Record Type: Journal Article
• Authors: Godechal, Q.; Mignion, L.; Karroum, O.; Magat, J.; Danhier, P.; Morandini, R.; Ghanem, G. E.; Leveque, P.; Gallez, B.
• Is Part Of: Contrast media & molecular imaging. Volume 9:Number 2(2014:Mar./Apr.)
• Page Start: 154
• Page End: 160
• Publication Date: 2014-03
• Subjects: Diagnostic imaging -- Periodicals; Magnetic resonance imaging -- Periodicals; Contrast media (Diagnostic imaging) -- Periodicals; Contrast Media -- Periodicals; Diagnostic Imaging -- Periodicals; Substances de contraste -- Périodiques; Diagnostics moléculaires -- Périodiques; Imagerie médicale; Substance de contraste; Périodique électronique (Descripteur de forme); Ressource Internet (Descripteur de forme); 616.0754
• DOI: 10.1002/cmmi.1554
• Languages: English
• ISSNs: 1555-4309

Abstract

<abstract abstract-type="main"> <title> <x xml:space="preserve">Abstract</x> </title> <p>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 <italic>T</italic><sub>1</sub>‐ and <italic>T</italic><sub>2</sub>‐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 <italic>T</italic><sub>2</sub>*‐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 <italic>T</italic><sub>1</sub>‐, <italic>T</italic><sub>2</sub>‐ and <italic>T</italic><sub>2</sub>*‐weighted images. MR images were obtained <italic>in vivo</italic> 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 <italic>T</italic><sub>1</sub>, <italic>T</italic><sub>2</sub> and <italic>T</italic><sub>2</sub>*, emphasizing that the presence of pigment alone has negligible effect on the MRI contrast. Copyright © 2014 John Wiley & Sons, Ltd.</p> </abstract>