Sources of the increased longitudinal relaxation rates observed in melanotic melanoma. An in vitro study of synthetic melanins

Investigative Radiology
W S EnochsH M Swartz

Abstract

Researchers have suggested that the increased longitudinal relaxation rates (1/T1) of solvent water protons often found in melanoma result either from the paramagnetism of stable free radicals occurring in melanin or from that of methemoglobin in nonacute hemorrhagic regions of the tumor. However, field-cycling relaxometry and model solutions of synthetic melanin produced data which show that free radicals in melanin do not contribute significantly to 1/T1; instead, aggregation of melanin into macromolecular particles and binding of biologically-common paramagnetic metal ions (ie Fe3+, Mn2+, and Cu2+) to melanin effectively do increase 1/T1. These data have been combined with published histochemical data on melanin-containing tissues, while disregarding any additional effect related to hemorrhage. The result indicates that in melanoma the expected contribution of melanin-bound Fe3+ to 1/T1, at typical imaging fields, predominates under estimated in vivo conditions; furthermore, the total contribution from all sources, specifically due to the presence of melanin, is sufficient to account for reported measurements of 1/T1 in melanoma. Comparing the latter results with published data on T1 relaxation in model solutions of methemog...Continue Reading

Citations

Jul 11, 1992·Magnetic Resonance in Medicine : Official Journal of the Society of Magnetic Resonance in Medicine·J M ToskL P Bozzetti
Jun 7, 2002·Australasian Physical & Engineering Sciences in Medicine·D Shahbazi-GahroueiB J Allen
Jan 1, 1995·Magnetic Resonance Imaging·D R OlsenE K Rofstad
Oct 16, 2003·Magnetic Resonance Imaging·Matthias H J KrauseLucy H Y Young
Feb 24, 2001·Academic Radiology·C Bremer, R Weissleder
Oct 30, 2009·Radiology·Jim S Wu, Mary G Hochman
Nov 20, 2012·Seminars in Roentgenology·Mahmud Mossa-Basha, Ari M Blitz
Mar 5, 2016·Japanese Journal of Radiology·Tomonori KandaShigeru Furui
Dec 5, 2009·Neuroimaging Clinics of North America·L A Massey, T A Yousry
Apr 15, 2011·Movement Disorders : Official Journal of the Movement Disorder Society·Stefan T SchwarzDorothee P Auer
Jul 6, 2004·Magnetic Resonance Imaging·Matthias H J KrauseLucy H Y Young
Jan 18, 2003·Magnetic Resonance Imaging Clinics of North America·Laurie A Loevner, Adina I Sonners
Oct 19, 2004·Neuroimaging Clinics of North America·Laurie A Loevner, Adina I Sonners
Dec 27, 2016·Magnetic Resonance in Medicine : Official Journal of the Society of Magnetic Resonance in Medicine·Paula TrujilloAntonella Costa
Sep 1, 1991·Journal of Magnetic Resonance Imaging : JMRI·J J CrowleyS E Wang
Nov 1, 1992·Journal of Magnetic Resonance Imaging : JMRI·J O DeJordyH Degani
Jul 1, 1993·Journal of Magnetic Resonance Imaging : JMRI·J VymazalR A Brooks
Jan 1, 1996·Journal of Magnetic Resonance Imaging : JMRI·A PremkumarD Schwartzentruber
Apr 25, 2007·NMR in Biomedicine·Assaf A GiladJeff W M Bulte
Feb 20, 2020·Magnetic Resonance in Medical Sciences : MRMS : an Official Journal of Japan Society of Magnetic Resonance in Medicine·Midori KusamaKenji Miyagi
Jul 22, 2019·Brain : a Journal of Neurology·Matthew J BettsDorothea Hämmerer
Aug 10, 2019·Clinical Neuroradiology·Sina StraubTill M Schneider
Dec 12, 2018·Cognitive, Affective & Behavioral Neuroscience·Anne S BerryMing Hsu
Feb 26, 2021·PeerJ·Andrés Guinea-IzquierdoCarles Soriano-Mas
Jun 25, 2019·NeuroImage·Paula TrujilloDaniel O Claassen

❮ Previous
Next ❯

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.