Analysis of Ultrasonic Pancreatic Histograms in Diabetes Mellitus

Abstract

Problems have been involved in the sonographical diagnosis of diffuse pancreatic and hepatic diseases in terms of its quantitativity and objectivity, because the diagnosis relies highly on the examiner's subjective judgement. This study was attempted for a easier and more objective assessment on the sonographical changes in the pancreas of the diabetics by analysing the histograms of echoic levels and pixel distribution. Fifty six patients with their age nearly equally distributed from 10 through 89 years with impaired glucose tolerance were subjected to the clinical study, along with 112 healthy controls of the similar age distribution. Sixteen other cases diagnosed as having diabetes mellitus both clinically and histologically and 13 controls having healthy pancreas and liver were chosen for the postmortem study. A 3. 5 MHz transducer was used for both studies. A region of interest (ROI) of a square centimeter was designated on sagittal scanning in the pancreas body and in the liver at the same depth from the body surface in the clinical study. Water immersion technique was employed for the postmortem study. To avoid multiple reflection, the ROI was placed inside the pancreas and the liver within the depth of 3cm below the water surface. A ROI consists of 3600 pixels and the luminance of pixels can be devided into 64 levels. The level of luminance having [the maximum number of pixels is given by "L" and the number of pixels is shown by "M" or the histogram at the L on the visual display. L : pancreas/liver (1) , L : pancreas-liver (2) , M : pancreas/liver (3) and M : pancreas-liver (4) were then calculated from the data displayed. Among the healthy controls, both (1) and (2) were significantly bigger in the group over 70 years of age than in those of the remaining age categories. The postmortem histology showed that the age-related change was due to degeneration and irregularity of acinar structure accompanied by fibrosis. Among the diabetics, (3) and (4) were significantly lower, compared with those of the healthy controls. Histologically, the decrease was associated with degeneration (hyalinosis) of the islets.