title: Appendicitis: evaluation by Tc-99m leukocyte scan.
abstract: Diagnosing appendicitis may be difficult. We report the use of a new technetium-99m-albumin colloid white blood cell (TAC-WBC) scan in the evaluation of appendicitis. In a synthesis requiring 75 minutes, autologous neutrophils and macrophages from 40 mL of whole blood were labelled with technetium-99m-albumin colloid and administered to 100 patients with possible appendicitis. The entire process, from labelling the cells to completion of the scan took a maximum of 5 1/4 hours. Two patients had second scans on separate hospitalizations. Twenty-six patients had appendicitis; 12 had perforations, five of whom had an abscess. Eighty-five scans were read as either positive or negative for appendiceal pathology with a sensitivity of 89%, a specificity of 92%, and an accuracy of 92% in diagnosing appendicitis. Seventeen scans were indeterminant; eight of these patients had appendicitis. The value of the TAC-WBC scan in the evaluation of appendicitis lies in its ability to be used emergently, its high negative predictive value for men and women (NPV = 97%), and its high positive predictive value for men (PPV = 93%). At present, the scan does not appear to be reliable in diagnosing appendicitis in women (PPV = 43%). It is most useful in those patients in whom diagnosis is uncertain, and should not be used in patients with clear-cut appendicitis in whom its use will delay definitive surgical care.
authors.affiliation: Department of Emergency Medicine, Harbor-UCLA Medical Center, Torrance 90509.
authors.forename: P L
authors.initials: PL
authors.lastname: Henneman
authors.forename: C S
authors.initials: CS
authors.lastname: Marcus
authors.forename: J A
authors.initials: JA
authors.lastname: Butler
authors.forename: E S
authors.initials: ES
authors.lastname: Freedland
authors.forename: S E
authors.initials: SE
authors.lastname: Wilson
authors.forename: R J
authors.initials: RJ
authors.lastname: Rothstein
mesh_terms: D000038:Abscess / Q000000981:diagnostic imaging; D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001064:Appendicitis / Q000000981:diagnostic imaging*; D002648:Child; D004630:Emergencies; D005188:False Negative Reactions; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007416:Intestinal Perforation / Q000000981:diagnostic imaging; D007962:Leukocytes; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011877:Radionuclide Imaging; D012422:Rupture, Spontaneous; D012680:Sensitivity and Specificity; D013668:Technetium Tc 99m Aggregated Albumin
chemical_list: D013668:Technetium Tc 99m Aggregated Albumin