Symbia net

After acquiring 2D images with the same gamma camera (SYMBIA T2; Siemens, Knoxville, TN), SPECT and CT acquisitions were performed immediately (without moving the lungs) which have a 2-slice spiral CT for a more rapid and accurate attenuation correction and anatomical mapping. A 3D SPECT acquisition of the lungs was performed with 64 (2 × 32) projection images, each of 30s. Finally, a CT was performed with the following parameters: 130 kV, 90 mAs, 1.25 mm slice thickness, 0.9 mm increment, 1.6 mm pitch, and rotation time of 1.5 s. A multimodality computer platform (Symbia net; Siemens) was used for image reviews and manipulations. Both the transmission and emission scans were reconstructed using 3D OSEM by default (8 subsets, 5 iterations), with pre-reconstruction smoothing using a 3D Butterworth filter (cutoff: 0.45 cycles/cm; order 5), a 128 × 128 image matrix, a 1.23 zoom, and a pixel size of 3.9 mm. SPECT images were reconstructed using scatter correction (scatter energy window) and CT attenuation correction. CT and SPECT images were matched and fused into trans-axial images. A multimodality computer platform (Symbia net; Siemens) was used for image review and manipulation. Different 3D ROIs were drawn on the CT images with the software to delimit peripheral areas from proximal tracheobronchial areas of the lungs.

A tomography was performed for one respiratory tract. After acquiring 2D images with the same gamma camera (SYMBIA T2; Siemens, Knoxville, USA), SPECT and CT acquisitions were performed immediately with a 2-slice spiral CT for a more rapid and accurate attenuation correction and anatomical mapping. 3D SPECT acquisition of the respiratory tract was performed with 64 (2 × 32) projection images, each of 30 s. Finally, the CT was performed with the following parameters: 130 kV, 90 mAs, 1.25 mm slice thickness, 0.9 mm increment, 1.6 mm pitch, and rotation time of 1.5 s. A multimodality computer platform (Symbia net, Siemens, Germany) was used for image reviews and manipulations. Both the transmission and emission scans were reconstructed using 3D OSEM by default (8 subsets, 5 iterations), with pre-reconstruction smoothing using a 3D Butterworth filter (cutoff: 0.45 cycles/cm; order 5), a 128 × 128 image matrix, a 1.23 zoom, and a pixel size of 3.9 mm. SPECT images were reconstructed using scatter correction (scatter energy window) and CT attenuation correction. CT and SPECT images were matched and fused into trans-axial images. Images obtained were visually compared to 2D imaging, assessing the homogeneous distribution of the aerosol over pulmonary parenchyma.