Value of hybrid imaging of lung perfusion for the detection of possible cause of dyspnea

Overview

50-y-old patient man was sent to our department to exclude pulmonary embolism. He was clinically stable but he suffered from worsening dyspnea. Physical examination did not reveal any significant changes, d-dimer was normal. We performed lung perfusion scintigraphy using ^99mTc-macroaggregated albumin, images were done on dual detector gamma camera. First of all, we performed four planar images according to our algorithm. (Fig. 1) Regional distribution of lung perfusion was not completely homogenous but no segmental defects were present. Images, therefore, rather suggest the distribution of perfusion in chronic obstructive pulmonary disease (COPD). Hybrid images of SPECT together with non-diagnostic CT were added to improve accuracy and to increase diagnostic certainty. (Fig. 2 to 5)

SPECT images confirmed non-homogenous distribution of regional perfusion again without any segmental defect. Non-diagnostic CT revealed normal lung parenchyma denzity except of bilateral basal condensed changes most probably due to infiltrative inflammatory changes. Surprisingly, it detected a large retrocardiac hiatal hernia reaching as far as tracheal bifurcation. This finding could explain both patient dyspnea and non-homogeneity of pulmonary perfusion.

Keywords:

hiatal hernia – dyspnea – hybrid imaging – lung perfusion scintigraphy