1. Chronic pulmonary embolism
Chronic pulmonary embolism. (A) CT angiogram demonstrates a partially occlusive eccentric filling defect within the posterior basal segment of the left lower lobe as well as an occlusive filling defect in the posterior basal segment of the right lower lobe (white arrows). The morphology of the thrombus in the left lower lobe suggests chronic pulmonary embolism. (B) Different section from the same study demonstrates low attenuation thrombus around the tip of a central catheter (white arrow), which could be a source of emboli. This was a cancer patient with an indwelling port-catheter. (C) Whole body MIP from a PET-CT performed the next day demonstrates foci of low level FDG uptake within the medial lung bases bilaterally as well as slightly higher in the mediastinum (black arrows). Physiologic excretion is seen within the renal pelvises, along the ureters, and in the bladder. Malignant foci are present in the right groin. (D) An axial section from the PET portion of the study localizes the two lower foci to the posterior basal segments bilaterally (white circles). (E) Fused PET-CT image demonstrates that these foci are within the pulmonary arteries, corresponding to the filling defects seen on the prior CTPA (white circles). (F) Another fused PET-CT image demonstrates low-level uptake within the catheter tip thrombus as well (white arrow). Low-level uptake in the esophagus (white arrowhead) is likely physiologic. It is thought that FDG uptake may be secondary to glucose metabolism by the inflammatory cellular infiltrate including activated macrophages, neutrophils, and fibroblasts within an organizing thrombus.
Source: Cardiothoracic Imaging, Introduction to Diagnostic Radiology
Citation: Elsayes KM, Oldham SA. Introduction to Diagnostic Radiology; 2015 Available at: Accessed: October 07, 2017
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