与模拟PET/CT相比，降低用于数字PET/MR的[镓]镓-DOTA-TATE注射活度。

Reduction of [Ga]Ga-DOTA-TATE injected activity for digital PET/MR in comparison with analogue PET/CT.

作者信息

Cox Christina P W, Brabander Tessa, Vegt Erik, de Lussanet de la Sablonière Quido G, Graven Laura H, Verburg Frederik A, Segbers Marcel

机构信息

Department of Radiology and Nuclear Medicine, Erasmus MC, University Medical Center Rotterdam, Postbus 2040, 3000 CA, Rotterdam, The Netherlands.

出版信息

EJNMMI Phys. 2024 Mar 15;11(1):27. doi: 10.1186/s40658-024-00629-z.

DOI:10.1186/s40658-024-00629-z

PMID:38488989

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC11266332/

Abstract

BACKGROUND

New digital detectors and block-sequential regularized expectation maximization (BSREM) reconstruction algorithm improve positron emission tomography (PET)/magnetic resonance (MR) image quality. The impact on image quality may differ from analogue PET/computed tomography (CT) protocol. The aim of this study is to determine the potential reduction of injected [Ga]Ga-DOTA-TATE activity for digital PET/MR with BSREM reconstruction while maintaining at least equal image quality compared to the current analogue PET/CT protocol.

METHODS

NEMA IQ phantom data and 25 patients scheduled for a diagnostic PET/MR were included. According to our current protocol, 1.5 MBq [Ga]Ga-DOTA-TATE per kilogram (kg) was injected. After 60 min, scans were acquired with 3 (≤ 70 kg) or 4 (> 70 kg) minutes per bedposition. PET/MR scans were reconstructed using BSREM and factors β 150, 300, 450 and 600. List mode data with reduced counts were reconstructed to simulate scans with 17%, 33%, 50% and 67% activity reduction. Image quality was measured quantitatively for PET/CT and PET/MR phantom and patient data. Experienced nuclear medicine physicians performed visual image quality scoring and lesion counting in the PET/MR patient data.

RESULTS

Phantom analysis resulted in a possible injected activity reduction of 50% with factor β = 600. Quantitative analysis of patient images revealed a possible injected activity reduction of 67% with factor β = 600. Both with equal or improved image quality as compared to PET/CT. However, based on visual scoring a maximum activity reduction of 33% with factor β = 450 was acceptable, which was further limited by lesion detectability analysis to an injected activity reduction of 17% with factor β = 450.

CONCLUSION

A digital [Ga]Ga-DOTA-TATE PET/MR together with BSREM using factor β = 450 result in 17% injected activity reduction with quantitative values at least similar to analogue PET/CT, without compromising on PET/MR visual image quality and lesion detectability.

摘要

背景

新型数字探测器和块序贯正则化期望最大化（BSREM）重建算法可提高正电子发射断层扫描（PET）/磁共振（MR）图像质量。其对图像质量的影响可能与模拟PET/计算机断层扫描（CT）协议不同。本研究的目的是确定在使用BSREM重建的数字PET/MR中，在保持至少与当前模拟PET/CT协议相当的图像质量的同时，[镓]Ga-DOTA-TATE注射活度的潜在降低。

方法

纳入NEMA IQ体模数据和25例计划进行诊断性PET/MR检查的患者。根据我们当前的协议，每千克（kg）注射1.5 MBq [镓]Ga-DOTA-TATE。60分钟后，每个床位扫描3（≤70 kg）或4（>70 kg）分钟。使用BSREM和因子β 150、300、450和600对PET/MR扫描进行重建。对计数减少的列表模式数据进行重建，以模拟活度降低17%、33%、50%和67%的扫描。对PET/CT和PET/MR体模及患者数据进行图像质量的定量测量。经验丰富的核医学医师对PET/MR患者数据进行视觉图像质量评分和病变计数。

结果

体模分析表明，当因子β = 600时，注射活度可能降低50%。对患者图像的定量分析显示，当因子β = 600时，注射活度可能降低67%。与PET/CT相比，图像质量均相等或有所提高。然而，根据视觉评分，因子β = 450时最大活度降低33%是可接受的，而病变可检测性分析进一步将其限制为因子β = 450时注射活度降低17%。