Xeleris 3 workstation

The acquisition method of SPECT was similar to previous description [8 (link)]. Briefly, ^99mTc-labeled methylene diphosphonate (99mTc-MDP) 555 to 851MBq (14.8MBq/Kg) was injected intravenously four hours before imaging. SPECT was conducted with a SPECT scanner (GE Healthcare, USA) supplied with a low-energy high resolution collimator (LEHR). 140 keV and a 20% symmetrical window were set as the photopeak, and a circular orbit was used for obtaining emission data in the supine position with a matrix of 128 × 128. Each head circulated 180° with 30 stops, with each stop setting at 6°. Coronal, sagittal, and trans-axial tomograms were reconstructed by a Butterworth filter and ordered-subset expectation maximization iterative reconstruction. An ROI of 16 pixels 3 slices was drawn over bilateral condylar heads. The individual condylar counts within the ROIs were calculated and the clivus bone was used as a control [14 (link), 15 (link)], and calculation of the uptake ratio was performed by the following formula:
Condylar uptake =
Condylar uptake of at least 55% with a difference of at least 10% between both sides, was regarded as active unilateral condylar hyperplasia on the reference standard [8 (link)]. All ROI analyses and image interpretations were acquired by a Xeleris 3 workstation (GE Healthcare, USA).

Planar images were assessed by experienced nuclear medicine physicians. For planar images, precise regions of interest (ROIs) were drawn over the condyles. For planar image, ROI was drawn over one condyle in one lateral planar image and was copied and placed to contralateral condyle to ensure a fixed size of ROI in the planar image (Fig. 2), mean radiotracer count ratio between the condyles was then calculated. All the image interpretations and ROI analyses were performed on a Xeleris 3 workstation (GE Healthcare)

Planar images were assessed by experienced nuclear medicine physicians. For planar images, precise regions of interest (ROIs) were drawn over the condyles. For planar image, ROI was drawn over one condyle in one lateral planar image and was copied and placed to contralateral condyle to ensure a fixed size of ROI in the planar image (Fig. 2), mean radiotracer count ratio between the condyles was then calculated. All the image interpretations and ROI analyses were performed on a Xeleris 3 workstation (GE Healthcare)