Michael E. Spieth

Gorham’s disease of the radius: radiographic, scintigraphic, and MRI findings with pathologic correlation

Abstractu2002A 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.

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.

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.

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 TI-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.

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

BACKGROUNDnAcute 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.nnnSTUDY DESIGNnThirty-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.nnnRESULTSnTwenty-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.nnnCONCLUSIONSnTc-99m IgG scintigraphy can provide the clinicians a simple, rapid, and definitive test for the diagnosis of acute appendicitis.

Missed torsion of an undescended testicle detected by testicular scintigraphy.

The authors present a case in which a Tc-99m pertech-netate scan revealed a missed torsion of an undescended testis in a 7-month-old boy who presented with persistent pain in the right inguinal region for 3 days.

Hepatocellular carcinoma with intravascular extension: Ga-67 scintigraphic findings.

To the authors knowledge, extension of hepatocellular carcinoma into vascular structures demonstrated by Ga-67 scintigraphy has not been reported. Presented is a case that demonstrates Ga-67 uptake not only by the tumor within the liver but also by the tumor thrombus in the inferior vena cava.

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 falled 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.

Ga-67 Imaging in Bone Marrow Hyperplasia

Abnormal gallium uptake due to osteomyelitis is well documented. However, increased gallium uptake in bone marrow hyperplasia has never been reported. In bone marrow hyperplasia, there is expansion of the erythrons, as well as the reticuloendothelial system. Expansion of the reticuloendothelial system explains the increased sulfur colloid uptake. By the same reason, the expansion of the erythrons could explain the increased gallium uptake. This report demonstrates such a case in a patient with sickle cell anemia. It is important to consider this possibility to avoid overdiagnosing osteomyelitis in patient with bone marrow hyperplasia.

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

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