TY - JOUR T1 - <strong>Image characteristics of brain perfusion SPECT/CT using a new multi-focal collimator: Comparison with conventional SPECT with LEHR collimator</strong> JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 4116 LP - 4116 VL - 63 IS - supplement 2 AU - Takayuki Shibutani AU - Masahisa ONOGUCHI AU - Tomoki Nishiyama AU - Alexander Hans Vija AU - Francesc Massanes AU - Takeshi Shimizu AU - Hiroto Yoneyama AU - Takahiro Konishi AU - Shintaro Saito AU - Kenichi Nakajima Y1 - 2022/06/01 UR - http://jnm.snmjournals.org/content/63/supplement_2/4116.abstract N2 - 4116 Introduction: A new multi-focal SMARTZoom class collimator with a suitable high resolution and extended magnification volume (SZHRX) is applied to cardiology and neurology. We evaluated the image characteristics of brain perfusion imaging with the SZHRX collimator in comparison to conventional low-energy high-resolution (LEHR) collimator with a single-photon emission computed tomography (SPECT) device.Methods: A Hoffman phantom was filled with 99mTc solution of 280 kBq/mL. A calibrated Symbia Intevo 16 (Siemens) SPECT/CT scanner was equipped with LEHR and SZHRX collimators. The conventional SPECT data with LEHR collimator were acquired with 128&amp;times;128 matrices, 1.45x zoom, 3.3 mm pixel size, with a circular brain centered orbit radius of 15 cm, and 4&amp;deg; angular step, while the continuous rotation with list-mode data using SZHRX collimator on a circular brain centered orbit radius of 26 cm and 28 cm, and 3&amp;deg; angular step yielding a 256&amp;times;256matrices, 2.4 mm pixel size. The SPECT image with LEHR and SZHRX collimators were reconstructed with Flash3D (LEHR) and a prototype quantitative xSPECT using the ordered subset conjugate gradient method (OSCGM) including system modeling, attenuation, and scatter corrections (SZHRX). A Gaussian filter with a full width at half-maximum of 7.2 mm was used as a post-filter. The conventional SPECT images with LEHR collimator were compared with xSPECT images with SZHRX collimator of the radius with 26 cm and 28 cm using the percent contrast (%contrast) of gray and white matters and the percent -coefficient of variation (%CV) of thalamus and cerebellum.Results: The %contrast of LEHR and SZHRX collimator with the radius of 26 cm and 28 cm was 36.2%, 42.2% and 36.7%, respectively. The xSPECT with SZHRX collimator showed a slightly higher %contrast compared with conventional SPECT with LEHR collimator, and the %contrast of SZHRX collimator had no difference between the radius of 26 cm and 28 cm. The %CV of LEHR and SZHRX collimator with the radius of 26 cm and 28 cm was 8.0%, 6.2% and 5.1% for the right thalamus, 6.1%, 6.4% and 5.0% for the left thalamus, and 7.5%, 8.3% and 7.6% for the cerebellum, respectively. The %CV of xSPECT with SZHRX collimator was equivalent or lower than conventional SPECT with LEHR collimator. Furthermore, the SZHRX collimator with the radius of 26 cm was a high %CV compared with those of 28 cm.Conclusions: The new multi-focal SZHRX collimator demonstrated equivalent image quality as assessed by %contrast and %CV compared with conventional SPECT with LEHR collimator. ER -