The hot stripe sign. An unusual variation.

Causes of focally increased radiotracer activity on Tc-99m SC liver-spleen scintigraphy include vena caval obstruction, Budd-Chiari syndrome, focal nodular hyperplasia, and tricuspid insufficiency. Artifactually increased activity may result from a malpositioned central venous catheter, free pertechnetate in the stomach, or an overlying breast. An unusual variation of this last artifact, also known as the "hot stripe sign," was encountered during routine liver-spleen imaging of a 65-year-old woman who had breast carcinoma.

Detection of abnormalities in febrile AIDS patients with In-111-labeled leukocyte and Ga-67 scintigraphy.

Thirty-six patients with acquired immunodeficiency syndrome (AIDS), who were febrile but without localizing signs, underwent indium-111 leukocyte scintigraphy 24 hours after injection of labeled white blood cells (WBCs) and were restudied 48 hours after injection of gallium-67 citrate. Fifty-six abnormalities were identified as possible sources of the fever; 27 were confirmed with biopsy. Of these 27, 15 were identified only on In-111 WBC scans (including colitis, sinusitis, and focal bacterial pneumonia); six, only on Ga-67 scans (predominantly Pneumocystis carinii pneumonia and lymphadenopathy); and six, on both studies (predominantly pulmonary lesions). In-111 WBC scanning revealed 21 of 27 abnormalities (78%) and gallium scanning, 12 of 27 (44%). If only one scintigraphic study has been performed, particularly with Ga-67, a significant number of lesions would not have been detected. The authors believe radionuclide evaluation of the febrile AIDS patient without localizing signs should begin with In-111 WBC scintigraphy. Gallium scanning may be used depending on results of In-111 WBC scans or if there is a high index of suspicion for P carinii pneumonia.

Acute radiation nephritis. Its evolution on sequential bone imaging.

Acute radiation nephritis typically affects the kidneys 3-12 months after radiation exposure and may occur with doses as low as 2500 rads. After an initial latent period, the affected portions of the kidneys become swollen and edematous, and develop multiple petechiae. Necrotizing vasculitis and interstitial hemorrhage occur, and the end stage is that of scarring. Two patients are presented in whom localized acute radiation nephritis developed, and whose kidneys demonstrated the characteristic sequential changes of this entity on serial bone imaging.