Xeleris 4

Bone scintigraphy was conducted before MOWHTO and at the time of the plate removal. The delayed image was obtained 3 to 4 hours after the injection of 925 MBq 99mTc-methylene diphosphonate (MDP) using a dual-head gamma camera (Discovery NM 630, GE, USA) equipped with a low-energy high-resolution collimator. The spot images centered on the knee were subsequently acquired in a 256 x 256 matrix up to 300,000 counts. The tracer count measurement within the ROIs was analyzed by the vendor-provided software (Xeleris 4.0, GE, USA). For reference measurement, a standard region of interest (ROI) with a diameter of 2 cm was positioned centrally in the distal femur 10 cm above the joint space [21 (link)]. BTU was calculated by dividing maximal tracer uptake in the ROI of each region by the average tracer uptake in the reference ROI for quantification [15 (link)]. Routine analysis of bone scintigraphy were evaluated in the department of nuclear medicine.

We used the NM/CT 870 CZT device equipped with a whole‐body CZT detector (GE Healthcare, Waukesha, WI, USA; Fig. 1), and the E.CAM device equipped with an NaI scintillation detector (Canon Medical Systems Tokyo, Japan). WEHR (C‐SPECT_WEHR) and MEHRS (C‐SPECT_MEHRS) were used as collimators for the C‐SPECT device. A low‐energy high‐resolution (LEHR) collimator (A‐SPECT_LEHR) for ^99mTc and a low‐medium‐energy general purpose (LMEGP) collimator (A‐SPECT_LMEGP) for ¹²³I were used on the A‐SPECT device, while keeping clinical practice in mind. The design parameters of the WEHR, MEHRS, LEHR, and LMEGP collimators are shown in Table 1. Although the parameters of LMEGP were not disclosed, the system spatial resolution and sensitivity were LEHR × 0.70 and LEHR × 1.71 at the manufacturing stage respectively. Xeleris 4.0 (GE Healthcare) and E‐Soft (Canon Medical Systems) were used as image‐processing devices. For image analysis, we used the general image‐processing software Prominence Processor Version 3.1¹² (Nihon Medi‐Physics Co Ltd, Tokyo, Japan), ImageJ (National Institutes of Health, MD, USA), and Demon Research Image Processor Version 3.01 (FUJIFILM Toyama Chemical Co., Tokyo, Japan). Radionuclide, ^99mTc‐incardronate (Nihon Medi‐Physics Co Ltd, Tokyo, Japan) and ¹²³I‐IMP perfuzamine (Nihon Medi‐Physics Co Ltd, Tokyo, Japan).