Three-dimensional image fusion of volume rendering SPECT/CT images for evaluation of pulmonary lobe function

Evaluating pulmonary regional function using pulmonary perfusion scintigraphy is so easy that it is used in daily clinical practice. However, this may not seem suitable for prediction of post-lobectomy lung function because it is difficult to divide lobar radioactive counts from pulmonary radioactivity on planar scintigraphic images. On the other hand, pulmonary perfusion SPECT with attenuation and scatter correction may help calculate lobar perfusion of the lung. We developed a new method for assessing pulmonary lobe function using three-dimensional (3D) image fusion of volume rendering SPECT/CT images. Our study showed that lobe-to-entire lung perfusion ratio with this 3D method (%lobe3D) was reproducible between 2 observers (rs = 0.97, ICC = 0.98). In addition, there was a high correlation between %lobe3D and lobe-to-entire lung perfusion ratio with 2D method (rs=0.98-0.99). In conclusion, our proposed method provides an accurate assessment for pulmonary lobar perfusion.