A QUANTITATIVE DESCRIPTION OF ECHOGRAPHIC IMAGES OF SCLEROTIC SKIN INPATIENTS WITH SYSTEMIC-SCLEROSIS, AS ASSESSED BY COMPUTERIZED IMAGE-ANALYSIS ON 20 MHZ B-SCAN RECORDINGS

The aim of our study was to find image descriptors enabling the charac terization of sclerotic skin and its differentiation from normal skin, in order to find an objective method for the assessment of skin invol vement in systemic sclerosis (SSc), Echographic evaluations were carri ed out using a 20 MHz B-scanner, on 18 female patients with SSc and on 20 healthy women serving as controls, at 3 different skin sites (fore head, cheek and back of the hand), Images mere processed by a program, based on segmentation procedures and object description, employing 5 different amplitude bands and the following parameters: 1) the extensi on of image areas marked by amplitude bands of interest, 2) the percen tage of the image surface reflecting within a homogeneous amplitude ba nd, 3) the number of objects composing the image, 4) the average objec t size, and 5) the ''density'' of the objects. At all 3 skin sites, ma rked differences in the echostructure of the tissue between patients w ith SSc and the controls were observable, In SSc patients forehead ski n appeared thinner and more echogenic, with smaller hypo-reflecting ob jects and greater hyper-reflecting areas; cheek skin showed an increas e in intermediate-high amplitude components, with greater and more num erous hyper-reflecting objects, and smaller and less numerous hypo-ref lecting ones; the skin on the back of the hand was thicker, less echog enic, with large hypo-reflecting areas and small hyper-reflecting obje cts, By image processing these parameters were numerically described, Values referring to sclerotic skin significantly differed from those o f normal skin, This echographic procedure is proposed as a method repr esenting a first step towards the quantification of the spontaneous co urse of SSc and of response to therapy.