Rapid detection of acute appendicitis with Tc-99m-labeled intact polyvalent human immune globulin.

BACKGROUND: Acute appendicitis remains problematic for emergency clinicians. A rapid and definitive test is needed for detecting acute appendicitis before surgical intervention. The purpose of this clinical trial was to determine the efficacy of Tc-99m-labeled intact polyvalent human immune globulin (Tc-99m IgG) in the evaluation of acute appendicitis. STUDY DESIGN: Thirty-five patients with clinically suspected acute appendicitis were evaluated with Tc-99m IgG. After the intravenous injection of 25 mCi (92.5 MBq) of Tc-99m IgG, anterior flow, single photon emission computerized tomography (SPECT) and planar delayed images of the abdomen were obtained. Any abnormal focal uptake of Tc-99m IgG in the right lower quadrant was considered to be a positive scan. RESULTS: Twenty-one patients with a positive Tc-99m IgG scan underwent laparotomy and were found to have acute appendicitis. Of the 14 patients who had negative scans, 7 underwent surgery. In this series, Tc-99m IgG study yielded 21 true-positive, 12 true-negative, and 2 false-negative results with a sensitivity, specificity, and accuracy of 91%, 100%, and 94%, respectively. The positive and negative predictive values were 100% and 86%, respectively. There were no false-positive results. CONCLUSIONS: Tc-99m IgG scintigraphy can provide the clinicians a simple, rapid, and definitive test for the diagnosis of acute appendicitis.

Gorham's disease of the radius: radiographic, scintigraphic, and MRI findings with pathologic correlation. A case report and review of the literature.

A rare case of Gorham's disease affecting the radius in a 46-year-old woman is presented. It was studied by plain radiography, MRI, and scintigraphy, including three-phase radionuclide bone scan and thallium scan. Three-phase bone scan demonstrated slightly decreased activity in the affected portion of the forearm in the early phase, but showed increased activity on the blood pool and delayed imaging. A thallium scan revealed no abnormalities. Histopathologic examination revealed osteoclastic activity and scar tissue with minimal remaining vasculature.

Importance of the lateral view in the evaluation of suspected brain death.

The authors present two cases of clinical brain death that failed to meet the criteria for whole brain death using Tc-99m HMPAO. Conventional anterior cerebral flow studies demonstrated no intracerebral perfusion. Anterior static images also failed to show cerebral activity. However, the lateral images clearly demonstrate cerebellar activity. These cases demonstrate the importance of Tc-99m HMPAO as the agent of choice in evaluating brain death and the necessity of lateral views to meet the criteria for whole brain death. Cerebellar perfusion challenges the present criteria for whole brain death. New criteria must re-evaluate the present technology.

Hemobilia presenting as intermittent gastrointestinal hemorrhage with sincalide confirmation. A case report.

An 82-year-old man had his third episode of melanotic stool. Two previous workups had failed to localize the source of bleeding. A Tc-99m labeled RBC scan visualized the gallbladder early in the study. Administration of sincalide visually decreased the activity, confirming gallbladder activity. Three months later, at his second surgery, hepatic metastases were finally identified as the source of bleeding. In retrospect, the hepatic activity is inhomogeneous with at least two cold defects that could have represented hepatic metastases.

Direct comparison of Tc-99m DTPA and Tc-99m HMPAO for evaluating brain death.

Portable cerebral perfusion studies provide a quick and accurate alternative to traditional confirmatory examinations (such as four-vessel angiography and electroencephalography) to determine brain death. The authors retrospectively analyzed 26 cerebral perfusion studies using both Tc-99m DTPA and Tc-99m HMPAO. The flow agents gave identical results. Additionally, the delayed-phase Tc-99m HMPAO images gave the same results for brain death (14 positive and 12 negative) as the flow images from either agent. Because the Tc-99m HMPAO delayed images can be used for diagnosis, many technical problems become less crucial. Unlike Tc-99m DTPA, Tc-99m HMPAO normally visualizes the gray matter of the cerebellum, midbrain, and medulla. These areas must be evaluated to ensure that they meet the strict criteria for brain death. These differences and the present study suggest that Tc-99m HMPAO is a superior agent for cerebral perfusion studies to determine brain death.

Air traffic controller lightning strike.

Andersen Air Force Base in Guam boasts the tallest control tower in the Air Force. In 1986, an air traffic controller was struck by lightning as the bolt proceeded through the tower. Although he received only a backache, the lightning left a hole with surrounding scorch marks on his fatigue shirt and his undershirt. The lightning strike also ignited a portion of the field lighting panel, which caused the runway lights to go out immediately. Lack of a lightning rod is the most likely reason the controller was struck. Proper precautions against lightning strikes can prevent such occupational safety hazards.

Radionuclide imaging in forme fruste of melorheostosis.

Scintigraphy was instrumental in two histologically proven cases of forme fruste melorheostosis. Radionuclide bone scans demonstrated a moderately increased uptake of radiopharmaceutical localized to the "flowing" cortical hyperostosis of melorheostosis observed radiographically. The medullary portion of the affected bones showed no increase in tracer activity. In one case, imaging with Tl-201 chloride demonstrated increased focal activity of the lesion. These scintigraphic findings can help distinguish the mildest manifestation (forme fruste) of melorheostosis from the well-ossified lesions of myositis ossificans and parosteal or periosteal osteosarcoma. The findings of MRI are also described in one patient.

False-positive Meckel's imaging and true-positive imaging of a gastrointestinal bleed and surgical lesion.

A 76-year-old woman presented after 1 day of melena and anemia. A Meckel's scan revealed an upper mid abdominal focus of activity that paralleled stomach activity. Later, the surgeon removed the corresponding lesion in the mid ilium. Pathology confirmed that the lesion was a carcinoid tumor, not ectopic gastric mucosa. The false-positive Meckel's scan had revealed the true source of gastrointestinal bleeding and an unsuspected solitary carcinoid tumor. This is the third published case of a carcinoid tumor discovered by a false-positive Meckel's scan.

Late "rim sign"--a variant of an old sign.

Classically, the "rim sign" has been described throughout the hepatobiliary scan. The authors present a case of a late rim sign visualized at 25 minutes postinjection that proved to be acute upon chronic acalculous cholecystitis without gangrene.

Osteosarcoma presenting as intestinal obstruction.

Osteosarcoma commonly presents with osseous and pulmonary metastases. We present an unusual case of extraosseous metastatic abdominal chondroblastic osteosarcoma presenting as intestinal obstruction.

The determination of dual pancreatic and renal transplant graft vascular patency with Tc-99m HMPAO.

Combined pancreatic-renal transplants promise the restoration of physiologic control of serum glucose and normal renal function. As pancreatic transplantation becomes more common, there is an increased need for rapid, noninvasive evaluation of vascular graft patency and function. Pancreatic transplants share the renal transplant's complications of ischemia at harvest but are at greater risk. Tc-99m HMPAO is a lipophilic complex that clears rapidly from the blood after intravenous injection, and tissue accumulation is proportional to regional perfusion. Using Tc-99m HMPAO to monitor the vascular competency has the advantage of a high count rate during dynamic scintigrams but, in contrast to Tc-99m DTPA, has excellent delayed static images. Four patients who received combined cadaveric pancreatic-renal transplants and had a total of eight Tc-99m HMPAO scintigraphic examinations were reviewed.

Unsuspected meningitis diagnosed by In-111 labeled leukocytes. A case report.

Clinically unsuspected bacterial meningitis was found in a patient with fever of unknown origin. Blood and urine cultures were negative for growth. Chest radiography and abdominal CT were negative for infection. Triple-phase bone imaging was performed to rule out osteomyelitis from a gunshot wound. A left posterior iliac crest hot spot may have represented osteomyelitis, but In-111 labeled leukocyte imaging instead disclosed unsuspected meningitis. The CSF culture after the imaging was positive for Enterobacter aerogenes.