Image subtraction in acute gastrointestinal bleeding studies using 99Tcm-DTPA.
99Tcm-DTPA has been evaluated in our clinical and experimental programme for the detection of acute gastrointestinal bleeding. As an adjunct to this programme, a protocol for image subtraction has been developed. The patient remains still while sequential static images I(i) (i = 1, . . ., N) are taken. They are first normalized to equal total counts and then subtracted images are produced according to the following three methods (a) I(i + 1)-I(i) (b) I(i) - I(mask) (c) I(mask) - I(i) where i not equal to mask and I(mask) denotes a user-selected mask image. Method (a) demonstrates fresh bleeding and sequential movement of blood in the bowel. Methods (b) and (c) demonstrate overall migration of blood and accumulated bleeding depending on the choice of the mask image.
D000208:Acute Disease; D003106:Colon / Q000000981:diagnostic imaging; D004381:Duodenal Ulcer / Q000000981:diagnostic imaging; D004912:Erythrocytes; D004932:Esophageal and Gastric Varices / Q000000981:diagnostic imaging; D006471:Gastrointestinal Hemorrhage / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D004369:Pentetic Acid; D010438:Peptic Ulcer Hemorrhage / Q000000981:diagnostic imaging; D011877:Radionuclide Imaging; D013276:Stomach Ulcer / Q000000981:diagnostic imaging; D013382:Subtraction Technique; D013667:Technetium; D016284:Technetium Tc 99m Pentetate; D013671:Technetium Tc 99m Sulfur Colloid
D013671:Technetium Tc 99m Sulfur Colloid; D013667:Technetium; D004369:Pentetic Acid; D016284:Technetium Tc 99m Pentetate