Takayuki Shibutani1, Kenichi Nakajima2, Hiroto Yoneyama3, Takahiro Konishi3, Koichi Okuda4, Masahisa Onoguchi5, Seigo Kinuya6. 1. Department of Quantum Medical Technology, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, 5-11-80, Kodatsuno, Kanazawa, Ishikawa, Japan. iwsb03100621@staff.kanazawa-u.ac.jp. 2. Department of Functional Imaging and Artificial Intelligence, Kanazawa University, Kanazawa, Ishikawa, 920-8641, Japan. 3. Department of Radiological Technology, Kanazawa University Hospital, Kanazawa, Ishikawa, 920-8641, Japan. 4. Department of Physics, Kanazawa Medical University, Uchinada, Kahoku, Japan. 5. Department of Quantum Medical Technology, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, 5-11-80, Kodatsuno, Kanazawa, Ishikawa, Japan. 6. Department of Nuclear Medicine, Kanazawa University Hospital, Kanazawa, Japan.
Abstract
AIMS: 123I-labeled meta-iodobenzylguanidine (MIBG) has used a planar image to measure the heart-to-mediastinum ratio (HMR). However, planar images are not available from IQ-SPECT with SMARTZOOM collimator due to its multi-focal collimation. Since we created the planar-equivalent (IQ-planar) images by adding all slices of the IQ-SPECT coronal image. The aim of this study was to demonstrate the utility of the new method for calculating HMR. METHODS: The planar image and transverse images of IQ-SPECT with attenuation and scatter corrections (ACSC) and without ACSC (NC) were obtained. Multi-planar reconstruction and ray-summation processing were applied to create IQ-planar images with NC and ACSC. Linear regression between the measured HMR from the planar image and the mathematically calculated HMR was used to calibrate HMR to standardized values. RESULTS: Scatterplots and linear regression lines between planar and IQ-planar HMRs before and after cross-calibration showed systematic differences in both NC and ACSC conditions. The IQ-planar HMR with NC and ACSC was significantly higher compared with that of the conventional planar image. However, the IQ-planar HMR with NC and ACSC after cross-calibration was similar to the standardized HMR calculated by planar image. CONCLUSION: The IQ-planar HMR using the new ray-summation processing method could be used along with the conventional planar HMR.
AIMS: 123I-labeled meta-iodobenzylguanidine (MIBG) has used a planar image to measure the heart-to-mediastinum ratio (HMR). However, planar images are not available from IQ-SPECT with SMARTZOOM collimator due to its multi-focal collimation. Since we created the planar-equivalent (IQ-planar) images by adding all slices of the IQ-SPECT coronal image. The aim of this study was to demonstrate the utility of the new method for calculating HMR. METHODS: The planar image and transverse images of IQ-SPECT with attenuation and scatter corrections (ACSC) and without ACSC (NC) were obtained. Multi-planar reconstruction and ray-summation processing were applied to create IQ-planar images with NC and ACSC. Linear regression between the measured HMR from the planar image and the mathematically calculated HMR was used to calibrate HMR to standardized values. RESULTS: Scatterplots and linear regression lines between planar and IQ-planar HMRs before and after cross-calibration showed systematic differences in both NC and ACSC conditions. The IQ-planar HMR with NC and ACSC was significantly higher compared with that of the conventional planar image. However, the IQ-planar HMR with NC and ACSC after cross-calibration was similar to the standardized HMR calculated by planar image. CONCLUSION: The IQ-planar HMR using the new ray-summation processing method could be used along with the conventional planar HMR.
Authors: Mariano Pontico; Gabriele Brunotti; Miriam Conte; Ferdinando Corica; Laura Cosma; Cristina De Angelis; Maria Silvia De Feo; Julia Lazri; Antonio Matto; Melissa Montebello; Arianna Di Rocco; Viviana Frantellizzi; Alessio Farcomeni; Giuseppe De Vincentis Journal: J Nucl Cardiol Date: 2021-01-13 Impact factor: 3.872