Fig. 4From: Automatic delineation and quantification of pulmonary vascular obstruction index in patients with pulmonary embolism using Perfusion SPECT-CT: a simulation studyInfluences of intensity gradient strenght (first row) and lung volumes (second row) on DicePE coefficients according to the segmentation methods. Using the RelDiff method with a − 50% threshold, there was no significant influence of the gradient strength and low influence of lungBack to article page