Precedence spect ct

To block the thyroid gland, all subjects were administered compound iodine solution starting 3 days prior to imaging. On the day of imaging, an intravenous injection of ¹³¹I-MIBG with a radioactivity of 111 MBq was given. SPECT/CT images of the major salivary glands and the heart were obtained at 30 min for the early images and at 4 h for the delayed images after the injection on a dual-head gamma camera and multidetector (16-row) spiral CT (Precedence SPECT/CT; Philips Healthcare, Amsterdam, Netherlands). The spiral CT examination from head to thorax was performed with the parameters of 100 mAs, 120 keV, and 5-mm section width. SPECT followed a CT scan from head to thorax with a 15% energy window centred on a 364-keV photopeak. Acquisition parameters for SPECT included a 64 × 64 matrix with 64 frames (15 s/frame) over 360°. SPECT data were reconstructed using Astonish methods incorporating photon attenuation correction based on the X-ray transmission map and scatter correction through AutoSPECT+ software. Then the reconstructed SPECT data and CT data were fused and analysed on an EBW workstation, providing the transverse, sagittal, and coronal slices of SPECT, CT, and fused SPECT/CT data.

Lymphoscintigraphy (LSG) and SPECT/CT were performed using a dual head SPECT/CT camera (Precedence SPECT/CT, Philips Healthcare, The Netherlands) in a 60-min scanning protocol. Immediately after tracer injection, a dynamic LSG in anterior and lateral projection was acquired followed by a static LSG 15 min postinjection to identify the temporal order of SN identification. Then, SPECT/CT was performed and images were generated. If the first scanning session did not identify any SN, a second late LSG and SPECT/CT was performed 120 min postinjection. Images were interpreted by a specialist in nuclear medicine, and the localization of the SN was depicted in an anatomical chart of the neck divided into neck levels as proposed by AHNS.18 (link) The number of SNs detected on LSG and SPECT/CT was recorded. A lymph node clearly visible on LSG or SPECT/CT was considered a SN.