Search

Background: Estimated radiation dose is important for assessing and communicating the risks and benefits of pediatric nuclear medicine studies. Radiation dose depends on the radiopharmaceutical, the administered activity, and patient factors such as age and size. Most radiation dose estimates for pediatric nuclear medicine have not been based on administered activities of radiopharmaceuticals recommended by established practice guidelines. The dosage card of the European Association of Nuclear Medicine (EANM) and the North American consensus guidelines each provide recommendations of administered activities of radiopharmaceuticals in children, but there are substantial differences between these two guidelines., Objective: For 12 commonly performed pediatric nuclear medicine studies, two established pediatric radiopharmaceutical administration guidelines were used to calculate updated radiation dose estimates and to compare the radiation exposure resulting from the recommendations of each of the guidelines., Materials and Methods: Estimated radiation doses were calculated for 12 common procedures in pediatric nuclear medicine using administered activities recommended by the dosage card of the EANM (version 1.5.2008) and the 2010 North American consensus guidelines for radiopharmaceutical administered activities in pediatrics. Based on standard models and nominal age-based weights, radiation dose was estimated for typical patients at ages 1, 5, 10 and 15 years and adult. The resulting effective doses were compared, with differences greater than 20% considered significant., Results: Following either the EANM dosage card or the 2010 North American guidelines, the highest effective doses occur with radiopharmaceuticals labeled with fluorine-18 and iodine-123. In 24% of cases, following the North American consensus guidelines would result in a substantially higher radiation dose. The guidelines of the EANM dosage card would lead to a substantially higher radiation dose in 39% of all cases, and in 62% of cases in which patients were age 5 years or younger., Conclusion: For 12 commonly performed pediatric nuclear medicine studies, updated radiation dose estimates can guide efforts to reduce radiation exposure and provide current information for discussing radiation exposure and risk with referring physicians, patients and families. There can be substantial differences in radiation exposure for the same procedure, depending upon which of these two guidelines is followed. This discordance identifies opportunities for harmonization of the guidelines, which may lead to further reduction in nuclear medicine radiation doses in children.

Purpose. We wanted to demonstrate the utility of the radionuclide salivagram in assessing children whose underlying medical problems suggest that aspiration of oral contents is a factor contributing to otherwise unexplained lung disease or recurrent pneumonias. Materials and methods. Following sublingual administration of 300 μCi (11.1 MBq) of technetium-99m sulfur colloid in a drop of saline, serial images were obtained for 60 min and evaluated for entrance of tracer into the major airways and lung parenchyma. Thirty-four studies were performed on 31 patients (age: 3 weeks - 16.7 years, mean 5.5 years) with recurrent pneumonias or unexplained lung disease. All had medical conditions, most frequently neurological, predisposing to aspiration. Results. Pulmonary aspiration was detected in eight patients. All positive studies demonstrated aspirated tracer distal to the tracheal bifurcation, either in bronchi or in bronchi and lung parenchyma. Aspiration was bilateral in six cases. Clearance of aspirated tracer was noted in one patient. Conclusion. The salivagram is an effective tool for demonstrating aspiration of oral contents and the level to which aspirated fluid penetrates the tracheobronchial tree. Additionally, by allowing for the evaluation of clearance of aspirated tracer, the salivagram may provide information on the status of airway-protective mechanisms.

At their initial emergency room presentation, four children were thought to have hip osteomyelitis. Skeletal scintigraphy, however, demonstrated multiple areas of abnormal tracer uptake in the bones in all four, and in three there was abnormal uptake in a soft tissue abdominal mass. The skeletal scintigraphic findings promptly led to the correct diagnosis of neuroblastoma.

Twenty-eight infants with jaundice were evaluated with ultrasound and radionuclide scans. Comparison of these studies with pathologic, surgical and clinical examinations demonstrated good correlation between ultrasonic and radionuclide studies. Ultrasound is an important preliminary study in the workup of such patients. Combined imaging provides the most information in a patient with suspected biliary atresia.

Gallium-67 has been extensively used to diagnose and localize adult and pediatric inflammatory, infectious and malignant disease. Its mechanism of localizing in pathologic foci, although the subject of numerous studies both in vitro and in vivo, has not been clearly understood yet. The presence of normal polymorphonuclear leukocytes has been reported to be important in the accumulation of the tracer in inflammatory sites. We reviewed our experience with Gallium scintigraphy in three children with chronic granulomatous disease, an entity characterized by defective neutrophils and recurrent infection. Radiogallium was found to localize in inflammation in these patients. Hematologic disorders with specific structural or biochemical defects in their polymorphonuclear leukocytes may provide important information as to how these cells contribute to the accumulation of Gallium-67 in inflammation.