Technetium-99m M.A.A. perfusion images
View main image(vq) in a separate image viewer
View second image(vq). Xenon-133 ventilation images
View third image(xr). Frontal and lateral chest radiographs
View fourth image(ct). Axial post-contrast CT images of the thorax
Full history/Diagnosis is available below
Based on the distribution of Xe-133 during the early washin phase, the right lung contributes 46% and the left lung contributes 54% of total pulmonary ventilation. The right lung receives 76% and the left lung receives 24% of total pulmonary perfusion.
The chest radiograph demonstrated no infiltrate or effusion. A rounded density is present posterior to the trachea.
Computed tomography demonstrated pulmonary sling with an aberrant origin of the left pulmonary artery (PA)from the right main PA. The left PA passes posterior to the trachea and appears slightly compressed as it passes to the left. Significant narrowing of the artery is noted which is responsible for findings on the ventilation/perfusion lung scan.
A pulmonary sling (aberrant left pulmonary artery) is due to failure of development or resorption of the ventral portion of the sixth aortic arch, leaving the developing left pulmonary plexus to connect with the right sixth aortic arch. The sling originates from the right pulmonary artery, passes to the left between the trachea and esophagus to the left hilum.
Mettler, FA, Guiberteau, MJ. Essentials of Nuclear Medicine Imaging. Philadelphia: WB Saunders, 1998.
Fraser, RG, Pare, JAP, Pare, FD, Fraser, RS and Genereux, GP. Diagnosis of Diseases of the Chest. Philadelphia: WB Saunders, 1988.
References and General Discussion of Ventilation Perfusion Scintigraphy (Anatomic field:Heart and Great Vessels, Category:Normal, Technique, Congenital Anomaly)
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