technetium-tc-99m-exametazime and Diverticulitis

Patients with acute lower abdominal pain remain a diagnostic challenge. Although acute appendicitis is the most common surgical disorder, its accurate and timely diagnosis can be difficult. Historically, females of childbearing age are the most difficult patient group in whom to make the diagnosis of acute appendicitis; they have reported negative laparotomy rates ranging from 30 to 50 percent. Tc-99 hexamethylpropyleneamineoxide (HMPAO) labeled leukocyte scan has previously been shown to be very accurate in the detection of acute appendicitis.. One year ago, a blinded study using Tc-99 HMPAO labeled leukocyte scan was reported for the detection of acute appendicitis. That study consisted of 27 patients who presented with abdominal pain. The present report is a follow-up study of 37 additional patients in whom the Tc-99 HMPAO leukocyte scan was used to diagnose or discount acute appendicitis.. Twenty-seven patients had histologically proved acute appendicitis. Twenty-three of these were correctly diagnosed using the leukocyte scan, for a sensitivity rate of 85 percent. The overall specificity rate was 93 percent, with an overall accuracy rate of 89 percent. Thirty-one of 64 patients were females of reproductive age and represented 56 percent of all patients in the study with appendicitis. In this group, the Tc-99 HMPAO leukocyte scan had a sensitivity rate of 87 percent, specificity rate of 92 percent, and an overall accuracy rate of 89 percent. The Tc-99 HMPAO leukocyte scan also proved to be valuable in the diagnosis of other intra-abdominal inflammatory conditions. Eight scans interpreted as negative for acute appendicitis were positive for other conditions, including five that were positive for diverticulitis, one for a tumor, one for a tubo-ovarian abscess, and one for a small intestinal infarction.. The Tc-99 HMPAO leukocyte scan is a highly accurate, diagnostic, and minimally invasive test of use in patients with abdominal pain of unclear cause, in which the differential diagnosis includes acute appendicitis. It is of particular value in females of childbearing age, in whom the cause of lower abdominal pain is unclear.

Topics: Abdominal Pain; Acute Disease; Adult; Appendicitis; Diagnosis, Differential; Diverticulitis; Female; Follow-Up Studies; Humans; Inflammation; Leukocytes; Male; Organotechnetium Compounds; Oximes; Prospective Studies; Radionuclide Imaging; Sensitivity and Specificity; Single-Blind Method; Technetium Tc 99m Exametazime; Ultrasonography

The diagnostic value of early 99mTc-HMPAO-leukocyte images (2 min, 0.5 hr, 2 hr and 4 hr) was studied in 87 prospectively performed investigations in 80 patients with a suspicion of abdominal inflammation or infection. Sensitivity, specificity and accuracy were 74%, 85% and 77% in the 2-min scans, 88%, 81% and 86% in the 0.5-hr scans, 95%, 85% and 92% in the 2-hr scans, and 96%, 92% and 95% in the 4-hr scans. Nonspecific bowel accumulation was seen in 7% of patients at 2 hr and in 28% at 4 hr but was easily distinguishable from pathologic activity. The uptake in early images represents an active accumulation of granulocytes at the site of inflammation rather than nonspecific blood-pool activity judged by results of 99mTc-HMPAO-RBC imaging. We found that imaging within 2 hr from injection has a high diagnostic value, and that the activity accumulates in areas of infection and inflammation faster than in the intestinal background.

Topics: Abdomen; Abscess; Diverticulitis; Erythrocytes; Evaluation Studies as Topic; Female; Humans; Inflammatory Bowel Diseases; Leukocytes; Male; Middle Aged; Organotechnetium Compounds; Oximes; Predictive Value of Tests; Prospective Studies; Radionuclide Imaging; Sensitivity and Specificity; Technetium Tc 99m Exametazime; Time Factors