Akihiko Takahashi, K. Himuro, K. Funada, M. Sasaki, S. Baba
{"title":"准直器对DaT-SPECT成像的影响:蒙特卡罗模拟研究","authors":"Akihiko Takahashi, K. Himuro, K. Funada, M. Sasaki, S. Baba","doi":"10.31487/j.rdi.2019.04.06","DOIUrl":null,"url":null,"abstract":"Aim: The purpose of this study was to assess the impact of the collimator in viewing the dopamine\ntransporter, using 123I ioflupane single-photon emission computed tomography (DaT-SPECT) images\nutilizing a Monte Carlo simulation.\nMethods: For the purpose of this study, the Monte Carlo simulation of electrons and photons (MCEP)-\nSPECT was used. A numerical phantom was created from a real basal ganglia phantom and installed within\nthe code. The specific binding ratios (SBRs) were 5.03 and 2.01 for the background concentration of 7.44\nkBq/mL or 7.04 and 3.03 for a background concentration of 5.56 kBq/mL. The simulated images were\nevaluated using a recovery coefficient (RC). Initially, we simulated the performance of 14 collimators\nwithout resolution correction to investigate the impact of the collimator dimension. The effects of two\nresolution correction methods (collimator broad correction (CBC) and three-dimensional frequency–\ndistance relationship (3D-FDR)) on two reconstruction methods (Ordered-Subsets Expectation\nMaximization (OSEM) and Filtered back projection (FBP)) was assessed for collimators that demonstrated\na better RC value.\nResults: Five low-energy high-resolution (LEHR) collimators and one medium-energy general-purpose\n(MEGP) collimator demonstrated superior RC values. These collimators had a high aspect ratio (holelength/hole-diameter). The maximum RC value without resolution correction was 64.9% when the image\nwas reconstructed with OSEM. The RC value improved to 79.7% when the resolution correction of CBC\nwas applied. When the resolution collection was applied, the RCs improved by approximately 1.2 times\nwhen compared against those without the resolution correction. In terms of the reconstruction method, the\nRC obtained using OSEM was statistically insignificant when compared to the RC using FBP. The\ndifference in the RC value with collimators decreased according to resolution correction.\nConclusion: The LEHR collimator with a high aspect ratio, and the OSEM with spatial resolution correction\nwere confirmed to be appropriate for DaT-SPECT imaging. In terms of the reconstruction method, CBC\nwas more favourable than FDR.","PeriodicalId":308916,"journal":{"name":"Radiology and Medical Diagnostic Imaging","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2020-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"2","resultStr":"{\"title\":\"Impact of Collimator on DaT-SPECT Imaging: Monte Carlo Simulation Study\",\"authors\":\"Akihiko Takahashi, K. Himuro, K. Funada, M. Sasaki, S. Baba\",\"doi\":\"10.31487/j.rdi.2019.04.06\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Aim: The purpose of this study was to assess the impact of the collimator in viewing the dopamine\\ntransporter, using 123I ioflupane single-photon emission computed tomography (DaT-SPECT) images\\nutilizing a Monte Carlo simulation.\\nMethods: For the purpose of this study, the Monte Carlo simulation of electrons and photons (MCEP)-\\nSPECT was used. A numerical phantom was created from a real basal ganglia phantom and installed within\\nthe code. The specific binding ratios (SBRs) were 5.03 and 2.01 for the background concentration of 7.44\\nkBq/mL or 7.04 and 3.03 for a background concentration of 5.56 kBq/mL. The simulated images were\\nevaluated using a recovery coefficient (RC). Initially, we simulated the performance of 14 collimators\\nwithout resolution correction to investigate the impact of the collimator dimension. The effects of two\\nresolution correction methods (collimator broad correction (CBC) and three-dimensional frequency–\\ndistance relationship (3D-FDR)) on two reconstruction methods (Ordered-Subsets Expectation\\nMaximization (OSEM) and Filtered back projection (FBP)) was assessed for collimators that demonstrated\\na better RC value.\\nResults: Five low-energy high-resolution (LEHR) collimators and one medium-energy general-purpose\\n(MEGP) collimator demonstrated superior RC values. These collimators had a high aspect ratio (holelength/hole-diameter). The maximum RC value without resolution correction was 64.9% when the image\\nwas reconstructed with OSEM. The RC value improved to 79.7% when the resolution correction of CBC\\nwas applied. When the resolution collection was applied, the RCs improved by approximately 1.2 times\\nwhen compared against those without the resolution correction. In terms of the reconstruction method, the\\nRC obtained using OSEM was statistically insignificant when compared to the RC using FBP. The\\ndifference in the RC value with collimators decreased according to resolution correction.\\nConclusion: The LEHR collimator with a high aspect ratio, and the OSEM with spatial resolution correction\\nwere confirmed to be appropriate for DaT-SPECT imaging. In terms of the reconstruction method, CBC\\nwas more favourable than FDR.\",\"PeriodicalId\":308916,\"journal\":{\"name\":\"Radiology and Medical Diagnostic Imaging\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2020-01-21\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"2\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Radiology and Medical Diagnostic Imaging\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.31487/j.rdi.2019.04.06\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Radiology and Medical Diagnostic Imaging","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.31487/j.rdi.2019.04.06","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 2
摘要
目的:本研究的目的是利用蒙特卡罗模拟的123I碘氟烷单光子发射计算机断层扫描(pat - spect)图像,评估准直仪对观察多巴胺转运体的影响。方法:采用Monte Carlo simulation of electron and photon (MCEP)-SPECT进行研究。从真实的基底神经节幻像中创建了一个数值幻像,并将其安装在代码中。背景浓度为7.44kBq/mL时,特异性结合比分别为5.03和2.01,背景浓度为5.56 kBq/mL时,特异性结合比分别为7.04和3.03。利用恢复系数(RC)对模拟图像进行评价。首先,我们模拟了14个没有分辨率校正的准直器的性能,以研究准直器尺寸的影响。研究了两种分辨率校正方法(准直器宽校正(CBC)和三维频率-距离关系(3D-FDR))对两种重建方法(有序子集期望最大化(OSEM)和滤波后投影(FBP))的影响,并对具有较好RC值的准直器进行了评估。结果:5个低能量高分辨率(LEHR)准直器和1个中等能量通用型(MEGP)准直器显示出优越的RC值。这些准直器具有很高的纵横比(孔长/孔直径)。在不进行分辨率校正的情况下,用OSEM重建图像的最大RC值为64.9%。采用cbc分辨率校正后,RC值提高到79.7%。当应用分辨率收集时,与没有分辨率校正的RCs相比,RCs提高了约1.2倍。在重建方法方面,与使用FBP的RC相比,使用OSEM获得的theRC在统计学上不显著。随着分辨率的修正,准直器的RC值差异减小。结论:高宽高比的LEHR准直器和空间分辨率校正的OSEM适合于pet - spect成像。在重建方法上,cbc优于FDR。
Impact of Collimator on DaT-SPECT Imaging: Monte Carlo Simulation Study
Aim: The purpose of this study was to assess the impact of the collimator in viewing the dopamine
transporter, using 123I ioflupane single-photon emission computed tomography (DaT-SPECT) images
utilizing a Monte Carlo simulation.
Methods: For the purpose of this study, the Monte Carlo simulation of electrons and photons (MCEP)-
SPECT was used. A numerical phantom was created from a real basal ganglia phantom and installed within
the code. The specific binding ratios (SBRs) were 5.03 and 2.01 for the background concentration of 7.44
kBq/mL or 7.04 and 3.03 for a background concentration of 5.56 kBq/mL. The simulated images were
evaluated using a recovery coefficient (RC). Initially, we simulated the performance of 14 collimators
without resolution correction to investigate the impact of the collimator dimension. The effects of two
resolution correction methods (collimator broad correction (CBC) and three-dimensional frequency–
distance relationship (3D-FDR)) on two reconstruction methods (Ordered-Subsets Expectation
Maximization (OSEM) and Filtered back projection (FBP)) was assessed for collimators that demonstrated
a better RC value.
Results: Five low-energy high-resolution (LEHR) collimators and one medium-energy general-purpose
(MEGP) collimator demonstrated superior RC values. These collimators had a high aspect ratio (holelength/hole-diameter). The maximum RC value without resolution correction was 64.9% when the image
was reconstructed with OSEM. The RC value improved to 79.7% when the resolution correction of CBC
was applied. When the resolution collection was applied, the RCs improved by approximately 1.2 times
when compared against those without the resolution correction. In terms of the reconstruction method, the
RC obtained using OSEM was statistically insignificant when compared to the RC using FBP. The
difference in the RC value with collimators decreased according to resolution correction.
Conclusion: The LEHR collimator with a high aspect ratio, and the OSEM with spatial resolution correction
were confirmed to be appropriate for DaT-SPECT imaging. In terms of the reconstruction method, CBC
was more favourable than FDR.