Shibutani Takayuki, Nakajima Kenichi, Yoneyama Hiroto, Konishi Takahiro, Okuda Koichi, Onoguchi Masahisa, Kinuya Seigo
Department of Quantum Medical Technology, Institute of Medical, Pharmaceutical and Health Sciences, Kanazawa University, 5-11-80, Kodatsuno, Kanazawa, Ishikawa, Japan.
Department of Functional Imaging and Artificial Intelligence, Kanazawa University, Kanazawa, Ishikawa, 920-8641, Japan.
J Nucl Cardiol. 2021 Dec;28(6):2569-2577. doi: 10.1007/s12350-020-02081-9. Epub 2020 Feb 26.
I-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.
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.
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.
The IQ-planar HMR using the new ray-summation processing method could be used along with the conventional planar HMR.
I标记的间碘苄胍（MIBG）已用于通过平面图像测量心纵隔比（HMR）。然而，由于其多焦点准直，使用SMARTZOOM准直器的IQ-SPECT无法获得平面图像。由于我们通过添加IQ-SPECT冠状图像的所有切片创建了平面等效（IQ平面）图像。本研究的目的是证明计算HMR的新方法的实用性。
获取带有衰减和散射校正（ACSC）和不带有ACSC（NC）的IQ-SPECT的平面图像和横断面图像。应用多平面重建和射线求和处理来创建带有NC和ACSC的IQ平面图像。使用从平面图像测量的HMR与数学计算的HMR之间的线性回归将HMR校准为标准化值。
交叉校准前后平面和IQ平面HMR之间的散点图和线性回归线在NC和ACSC条件下均显示出系统差异。带有NC和ACSC的IQ平面HMR明显高于传统平面图像。然而，交叉校准后带有NC和ACSC的IQ平面HMR与通过平面图像计算的标准化HMR相似。
使用新的射线求和处理方法的IQ平面HMR可与传统平面HMR一起使用。
