Gary F. Gates

Cardiac shunt assessment in children with macroaggregated albumin technetium-99m.

Right-to-left cardiac shunting is calculated following intravenous administration of macroaggregated albumin (MAA) tagged with 99mTa MAA entering the pulmonic circuit lodges in its capillary bed while that bypassing the lungs is impacted in the systemic circuit. A total body count is obtained with a gamma camera. Lung activity is measured separately. From these activity counts, the magnitude of right-to-left cardiac shunting is determined.

Acute Cardiac Herniation with Incarceration Following Pneumonectomy

Abstract A case of acute cardiac herniation following a right pneumonectomy with the intrapericardial ligation of the pulmonary vessels has been presented. Due to herniation superior vena cava syndrome developed. Review of the literature shows that herniation may occur on either side and may be associated with either the presenting symptoms of shock or superior vena cava obstruction.

Maxillary-Facial Abnormalities Assessed by Bone Imaging

Eighty-eight patients with maxillary-facial abnormalities were studied with 99mTc-labeled phosphate compounds. Straight and tilted anterior views plus oblique orbital and lateral views were correlated with 201 thallium transmission images of a dried skull. Interpretation of any single view may be hampered by various superimposed structures. Careful patient positioning with multiple views allows for parallactic correlation which is crucial if radiotherapy, biopsy, or corroborative studies are planned.

Detection of craniosynostosis by bone scanning

Growth patterns of the cranial sutures were studied by bone scanning in 29 children, 13 of whom had craniosynostosis. Primary craniosynostosis was initiated by localized bony fusion across a suture, associated with an abnormal accumulation of bone-seeking radiopharmaceuticals. As the abnormal fusion process extended along the suture, there was a corresponding spread of radionuclide. With complete fusion, uptake diminished. In addition to calvarial scanning, three abnormal sutures were scanned following surgical excision, which allowed direct comparison in vivo and in vitro. Calvarial bone scanning is helpful in the early detection of primary craniosynostosis.

Thoracic Duct Leakage in Neonatal Chylothorax Visualized by 198Au Lymphangiography

A case of congenital chylothorax is presented to demonstrate the use of radionuclide lymphangiography in detecting this entity. Seepage from the thoracic duct into the pleural space was successfully shown. Radionuc1ide lymphangiography is a safe noninvasive method of demonstrating the anatomical integrity of the thoracic duct.

Scintigraphy of Discitis

Four children with discitis were studied with 99mTcpolyphosphate bone scintigraphy. All showed narrowing of the intravertebral disc space with accentuated nuclide accumulation in adjacent vertebral bodies. This image pattern may be unique to discitis and when occurring in a young child with a painful back should strongly suggest that diagnosis.

Hypoxemia Unassociated With Anatomic Shunting in Pulmonary Disease

Forty-two patients with various pulmonary abnormalities had anatomic right-to-left shunting determined during perfusion lung scintigraphy. In no instance was an abnormal shunt detected despite some severe pulmonary vascular or airway abnormalities. Twelve patients had arterial blood gas determinations performed within 24 hours of scintigraphy; several were hypoxemic despite the lack of abnormal shunting. Ventilation-perfusion mismatching or physiologic shunting was the probable cause of hypoxemia in those cases. Anatomic shunting undoubtedly occurs in some pulmonary abnormalities but should not be evoked offhandedly as a proximate cause of hypoxemia in all cases.