Discovery nm 630

Using the Discovery NM/CT 670 or Discovery NM 630 (GE Healthcare, Milwaukee, WI) mounted with a FAN beam collimator, SPECT images were acquired 3 h after the injection of ¹²³I-Ioflupane (185 MBq). The imaging parameters were as follows: matrix size, 128 × 128; pixel size, 4.4 mm; slice thickness, 4.4 mm; and energy window, 159 keV ± 10%. The projection data acquired for 30 min were reconstructed on a Xeleris workstation (GE Healthcare). The ordered-subset expectation maximization method (iterations, three; subset, ten) and a Butterworth filter (critical frequency, 0.5; power, 10.0) were applied to the SPECT images. Both data with and without attenuation correction were generated (no correction [NC]; attenuation correction [AC]). Scatter correction was not used.

Bone SPECT imaging was performed after an intravenous injection of 555 MBq Tc-99 m HMDP (Clearbone® 99mTc-HMDP; Nihon Medi-Physics Co., Ltd., Tokyo, Japan) using a SPECT dual-head gamma camera system (Discovery NM630; GE Healthcare, Chicago, IL, USA). The SPECT images were acquired using the following parameters: a low-energy high-resolution collimator; step-and-shoot mode with 30 s per step and 72 steps per detector; 360-degree view; matrix size of 128 × 128; pixel size of 3.32 mm; and energy window of 140.5 keV ± 10%. The interval between the injection of Tc-99 m-HMDP and the start of acquisition of the first SPECT image was 2 h, and that for the second image was 3 h, which have been referred to as the 2-h and 3-h image uptake times, respectively. When there were multiple lesions in the jawbone, the site with the highest SUVmax was used as the representative value for the patient.

¹²³I-MIBG scans were performed with a two-detector single-photon emission computerized tomography (SPECT) camera (Discovery NM 630, GE Healthcare) equipped with extended low-energy general-purpose (ELEGP) collimators. ELEGP is optimal for ¹²³I imaging due to its high sensitivity and low septal penetration. A 10% energy window was used on the 159-keV photopeak. Planar images were obtained using a 256 × 256 matrix. Scan 1 (30 × 2 s + 40 × 6 s + 75 × 20 s, total 30 min) was started immediately after a bolus injection of 111 MBq of ¹²³I-MIBG. Scan 2 (3 × 300 s) and scan 3 (3 × 300 s) were started 90 and 180 min, respectively, after the injection.

All SPECT images were acquired 3 h after the injection of ¹²³I-Ioflupane (185 MBq) using the Discovery NM 630 or Discovery NM/CT 670 (GE Healthcare, Milwaukee, WI) with a FAN beam collimator. The imaging parameters were as follows: matrix size, 128 × 128; pixel size, 4.4 mm; slice thickness, 4.4 mm; and energy window, 159 keV ± 10%. The projection data acquired for 30 min were reconstructed on a Xeleris workstation (GE Healthcare). The ordered-subset expectation maximization (OSEM) method (iterations, 3; subset, 10) and a Butterworth filter setting with a critical frequency of 0.5 and power of 10.0 were applied for DaTView software. The OSEM (iterations, 2; subset, 10) and a Butterworth filter setting with a critical frequency of 0.6 and power of 10.0 were applied for DaTQUANT. Neither attenuation correction nor scatter correction was used. These settings were determined based on the manufacturer’s recommended settings.

According to our standard procedure, all patients underwent a single-day stress-rest sequence with a gap of ≥2 h between the administrations of 180 and 500 MBq of ^99mTc-Sestamibi, respectively. Imaging was performed 30 min after radiotracer administration, with scan duration set at 35 and 25 s per view for stress and rest acquisition, respectively. In all cases, single photon computerized tomography (SPECT) was acquired using a dual-head SPECT gamma camera (Discovery NM630, GE Healthcare, Chicago, IL, USA) equipped with parallel hole low-energy high-resolution collimators.
The energy window (10%) was centered over the 140 keV ^99mTc photopeak. An automated body-contour orbit was used, with image acquisition every 3 degrees, through a 180 degrees arc starting from 45 degrees right anterior oblique to 45 degrees left posterior oblique view, with heads configured in L mode. No attenuation or motion correction was applied. According to the current guidelines (Hesse et al., 2005 (link)), SPECT scans were performed using both non-gated and gated protocols. Acquisition matrix was 64 × 64, while for EKG-gating cardiac cycle was divided into 12 frames. In all scans, at least the cranial half of spleen was included allowing the analysis of average tracer content in these organs.