[Value of gray scale analysis for the assessment of ultrasound detected structures in the area of the abdomen].
The characteristics of the echo structure constitute an important criterion for the appraisal of sonograms. Since every pixel usually represents one out of 64 gray values, it should be possible to use the density as an objective parameter of the echo structure. In this study, the echogenicity of the pancreas was examined. The density of the pancreas became higher with increasing accumulation of fatty connective tissue or as a result of air in the intestine. In 42 people with varying degrees of obesity, the echo structure was compared with the gray scale distribution of the lumen of the gallbladder, aorta and the water-filled stomach. The results indicated that the increasing echodensity is attributable to reflections and scatter of the ultrasound in adjacent regions. The presence of air gave rise to the same effect. On the basis of standardized investigations at 15-minute intervals, the density and the visual index under the influence of a quick-acting simethicone preparation (Lefax) were compared. The density also decreased significantly within 30 to 45 minutes parallel to the reduction of superimpositional interferences due to air. The present investigations confirm the relevance of gray scale analysis for objective confirmation of sonographic structures. However, they make it evident that the echo pattern is quantifiable only under standardized conditions and when the projection plane is largely occupied. Misleading mixed values are measured in marginal zones and in superimpositions.
Wildgrube
H J
HJ
Institut für angewandte Diagnostik, Hanau/Main.
Dehwald
H
H
D001011:Aorta / Q000473:pathology; D003937:Diagnosis, Differential; D005704:Gallbladder / Q000473:pathology; D006801:Humans; D008099:Liver / Q000473:pathology*; D008107:Liver Diseases / Q000175:diagnosis*; D010179:Pancreas / Q000473:pathology*; D010182:Pancreatic Diseases / Q000175:diagnosis*; D012016:Reference Values; D012841:Simethicone / Q000008:administration & dosage; D013270:Stomach / Q000473:pathology; D014463:Ultrasonography / Q000379:methods*
D012841:Simethicone
Zur Wertigkeit von Grauwert-Analysen für die Beurteilung sonographisch erfassbarer Strukturen im Abdominalbereich.