Lung tissue density measured by low-dose CT during pulmonary perfusion SPECT/CT as a tool for differentiation pulmonary embolism from chronic obstructive pulmonary disease – A pilot study

AbstractObjectiveInterpretation of lung perfusion scintigraphy in patients with suspected pulmonary embolism (PE) is difficult, especially in the presence of chronic obstructive pulmonary disease (COPD) and most often has to be combined with pulmonary ventilation scintigraphy. We investigated the data from the CT portion of pulmonary perfusion SPECT/CT for possible resolution of this problem.MethodsWe assessed data from 12 patients (4 male, 8 female, mean age 68y) with perfusion defects, 6 with PE, 6 with COPD. Final interpretation was based on ventilation/perfusion (V/Q) scintigraphy (mismatch or match). Lung tissue density was measured from the CT portion of pulmonary perfusion SPECT/CT. We analyzed 32 areas in mismatch defects (PE), 25 areas in match defects (COPD), and 17 areas without perfusion defects. Perfusion defects cause easily identifiable on X-ray (e.g. effusion) were excluded from the analysis. Data were compared with ANOVA test and Bonferroni post-hoc analysis, p