Jetstream workstation

All SPECT/CT examinations were performed using a SPECT/CT scanner (Philips Precedence-6, ADAC Laboratories, Milpitas, CA, USA) with dual-head gamma camera system, low-energy high-resolution collimators, and six-slice spiral scanning diagnostic CT. Single-photon emission computed tomography/CT was performed 3 h after intravenous injection of 925 to 1,110 MBq ^99mTc-MDP (Atomic High-Tech Co. Ltd., Guangzhou, China). Computed tomography was initially performed, and the parameters were as follows: tube voltage, 140 kV; tube current, 200 mA; window width, 15%; pitch, 1.25; slice thickness, 5 mm; slice space, 3 mm; and matrices, 512 × 512. Single-photon emission computed tomography acquisition protocol was started after CT, and the parameters were as follows: 128 × 128 matrix, 60° angular steps with a range of 180° per gamma camera head, and 30-s projection. Single-photon emission computed tomography/CT fusion images were obtained by JETStream workstation (Philips Medical Systems, Eindhoven, Netherlands). The transverse, sagittal, and coronal planes of CT, SPECT, and SPECT/CT were evaluated, respectively.

All patients underwent scintigraphy scanning (WBS and SPECT/CT) within 3 months after surgery, using a SPECT/CT scanner (Discovery NM/CT 670 Pro, GE medical systems, Israel) with dual-headed gamma camera system, high-energy collimators and a 16-slice spiral scanning diagnostic CT. The WBS images were acquired 24–48 h after taking orally ¹³¹I (Atomic High-Tech Co. Ltd., Guangzhou, China) of 111–185 MBq, using a high-energy general purpose parallel holes collimator with 364 keV photopeak and 256 × 1024 matrix. Neck hybrid SPECT/CT scanning were routinely performed after WBS acquisition. CT scan was firstly performed and the acquisition parameters were as follows: tube voltage 140 kV, tube current 200 mA and matrices 512 × 512. After CT acquisition, the SPECT acquisition protocol was started, and the parameters were as follows: 128 × 128 matrix, 20% energy windows at 364 keV, 60° angular steps with a range of 180° per gamma camera head. JET stream workstation (Philips Medical Systems) was applied to obtain the fusion images of SPECT/CT.