"ventral and dorsal plates should be smooth, homogenous, and continuous"
"The trilaminar, keratinised nail plate is anchored firmly to the nail bed on its volar surface; it extends from the proximal eponychium, passing over the lunula of the nail matrix and meeting the onychodermal band as it approaches the hyponychium distally at its lone free margin. The nail plate is anchored laterally and proximally by overlapping specialised ridges of skin 4."
"The proper digital arteries communicate through numerous transverse arches and an arcade of paired dorsal and palmar arches formed just distal to the insertion of the flexor digitorum profundus muscle; this dorsal arcade (dorsal nail fold arch) supplies the proximal nail fold, extensor tendon insertion, and has some contribution to the matrix. Subsequent anastomosis with the palmar arch results in the formation of the middle and distal matrix arches and an underlying capillary network perfusing the nail bed, nail matrix, nail folds and hyponychium."
"The nail plate appears as a trilaminar structure, with the hyperechoic outer layers representing the dorsal and ventral plates and the intermediate layer the anechoic interplate space. Note should be made of the hyperechoic, smooth bony cortex of the distal phalanx in the far field. The nail bed will be found deep to the nail plate and superficial to bone; it will be continuous proximally with the nail matrix which can be identified due to higher echogenicity and location beneath the eponychium 13."
"associated cortical irregularity, retracted distal end of tendon, hyperechoic intratendinous structure; concern for avulsion fracture"
"appears to help differentiate psoriatic arthritis similar presentations (e.g. rheumatoid arthritis)"