Photography, DentalLeukoplakia, OralLichen PlanusTooth DiscolorationMouth MucosaEgg WhiteMagnetic Resonance ImagingNerve Fibers, MyelinatedEuropean Continental Ancestry GroupBrainAdipose Tissue, WhitePrecancerous ConditionsDiffusion Magnetic Resonance ImagingAdipocytes, WhiteBrain DiseasesAfrican Continental Ancestry GroupTime FactorsTomography, X-Ray ComputedAnisotropyDiffusion Tensor ImagingWhite spot syndrome virus 1LeukoencephalopathiesRetrospective StudiesSensitivity and SpecificityImmunohistochemistry