Zeitschrift fur Medizinische Physik最新文献_第2页

Development of an MR-only radiotherapy treatment planning workflow using a commercial synthetic CT generator for brain and head & neck tumor patients 使用商用合成CT发生器开发用于脑和头颈部肿瘤患者的仅磁共振放射治疗计划工作流程。

IF 4.2 4区医学 Q2 RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING

Zeitschrift fur Medizinische Physik

Pub Date : 2026-02-01 DOI: 10.1016/j.zemedi.2025.01.003

Martin Buschmann , Harald Herrmann , Manuela Gober , Aleksandra Winkler , Nicole Eder-Nesvacil , Franziska Eckert , Joachim Widder , Dietmar Georg , Petra Trnková

Background

In magnetic resonance (MR)-only radiotherapy (RT) workflows, synthetic computed tomography images (sCT) are needed as a surrogate for a dose calculation. Commercial and certified sCT algorithms became recently available, but many have not been evaluated in a clinical setting, especially in the head and neck tumor (HN) region. In this study, an MRI-only workflow using a commercial sCT generator for photon beam therapy in brain and HN body sites was evaluated in terms of dose calculation accuracy, modelling of immobilization devices, as well as usability for autosegmentation.

Methods

For 13 brain and 10 HN cancer patients, MR scans using T1W mDIXON sequences were retrospectively collected. Four brain and all HN patients were scanned in RT treatment position with immobilization devices. All MRIs were converted to a sCT using the MRCAT algorithm (Philips, Eindhoven, The Netherlands).

All patients underwent standard planning CT (pCT) for clinical segmentation and VMAT treatment planning. The sCT was rigidly registered to the pCT and clinical contours were transferred to the sCT. For dosimetric evaluation of sCT based dose calculation, all VMAT plans were recalculated on the sCT. D_1% and D_mean were compared for all structures between pCT and sCT, but D_95%, D_98% for targets only. For MR-invisible RT immobilization device modelling, MR-visible markers were placed into sCT and a geometric robustness analysis was performed based on the same target dose-volume parameters. For organs-at-risk (OARs) autosegmentation, both pCT and sCT were autosegmented with a clinically established CT-based autocontouring software. The agreement of contours on pCT and sCT was analyzed by similar dose-volume parameters and dice similarity (DSC) and Hausforff distance (HD).

Results

The overall median deviation (± interquartile range) of dosimetric parameters between sCT and pCT including the immobilization model was 1.1 ± 0.4% for brain target volumes, 1.3 ± 1.2% for brain OAR, 0.4 ± 0.7% for HN target volumes and 0.4 ± 0.9% for HN OAR. The median geometric agreement over all sCT autocontours compared to pCT autocontours resulted in DSC = 0.82 for brain OAR and DSC = 0.79 for HN OAR.

Conclusion

MR-only RT planning using MRCAT software package was feasible for brain and HN tumors, with acceptable clinical accuracy. The MR-invisible immobilization devices could be modelled in the planning system and the autosegmentation on sCTs using a CT-based autosegmentation tool was feasible.

背景：在仅磁共振（MR）放射治疗（RT）工作流程中，需要合成计算机断层扫描图像（sCT）作为剂量计算的替代。商业和认证的sCT算法最近可用，但许多尚未在临床环境中进行评估，特别是在头颈部肿瘤（HN）区域。在这项研究中，使用商用sCT发生器在脑和HN体部位进行光子束治疗的mri工作流程在剂量计算精度、固定装置建模以及自动分割的可用性方面进行了评估。方法：回顾性收集13例脑癌和10例HN癌患者的T1W mDIXON序列mri扫描结果。4例和所有HN患者在RT治疗体位用固定装置进行脑部扫描。使用MRCAT算法（Philips, Eindhoven, Netherlands）将所有mri转换为sCT。所有患者均行标准计划CT （pCT）进行临床分割和VMAT治疗计划。将sCT严格注册到pCT，并将临床轮廓转移到sCT。对于基于剂量计算的sCT剂量学评估，在sCT上重新计算所有VMAT计划。pCT和sCT之间所有结构的D1%和Dmean比较，但仅靶的D95%和D98%比较。对于磁共振不可见RT固定装置建模，将磁共振可见标记物置于sCT中，并基于相同的靶剂量-体积参数进行几何稳健性分析。对于危险器官（OARs）的自动分割，pCT和sCT都使用临床建立的基于ct的自动轮廓软件进行自动分割。通过相似剂量-体积参数、骰子相似度（DSC）和Hausforff距离（HD）分析pCT和sCT轮廓的一致性。结果：sCT和pCT包括固定模型的剂量学参数的总体中位偏差（±四分位数范围）为：脑靶体积1.1 ± 0.4%，脑OAR 1.3 ± 1.2%，HN靶体积0.4 ± 0.7%,HN OAR 0.4 ± 0.9%。与pCT自动轮廓相比，所有sCT自动轮廓的中位几何一致性导致脑OAR的DSC = 0.82，HN OAR的DSC = 0.79。结论：采用MRCAT软件包进行脑及HN肿瘤的MR-only RT规划是可行的，临床准确性可接受。磁共振不可见固定装置可以在规划系统中建模，利用基于ct的自动分割工具对sct进行自动分割是可行的。

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引用次数: 0

DeepSMCP – Deep-learning powered denoising of Monte Carlo dose distributions within the Swiss Monte Carlo Plan 深度学习驱动的蒙特卡罗剂量分布在瑞士蒙特卡罗计划去噪。

IF 4.2 4区医学 Q2 RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING

Zeitschrift fur Medizinische Physik

Pub Date : 2026-02-01 DOI: 10.1016/j.zemedi.2025.02.004

Hannes A. Loebner , Raphael Joost , Jenny Bertholet , Stavroula Mougiakakou , Michael K. Fix , Peter Manser

This work demonstrated the development of a fast, deep-learning framework (DeepSMCP) to mitigate noise in Monte Carlo dose distributions (MC-DDs) of photon treatment plans with high statistical uncertainty (SU) and its integration into the Swiss Monte Carlo Plan (SMCP). To this end, a two-channel input (MC-DD and computed tomography (CT) scan) 3D U-net was trained, validated and tested (80%/10%/10%) on high/low-SU MC-DD-pairs of 106 clinically-motivated VMAT arcs for 29 available CTs, augmented to 3074 pairs. The model was integrated into SMCP to enable a “one-click” workflow of calculating and denoising MC-DDs of high SU to obtain MC-DDs of low SU. The model accuracy was evaluated on the test set using Gamma passing rate (2% global, 2 mm, 10% threshold) comparing denoised and low-SU MC-DD. Calculation time for the whole workflow was recorded. Denoised MC-DDs match low-SU MC-DDs with average (standard deviation) Gamma passing rate of 82.9% (4.7%). Additional application of DeepSMCP to 12 unseen clinically-motivated cases of different treatment sites, including treatment sites not present during training, resulted in an average Gamma passing rate of 91.0%. Denoised DDs were obtained on average in 35.1 s, a 340-fold efficiency gain compared to low-SU MC-DD calculation. DeepSMCP presented a first seamlessly integrated promising denoising framework for MC-DDs.

这项工作展示了一种快速、深度学习框架（DeepSMCP）的发展，以减轻具有高统计不确定性（SU）的光子处理计划的蒙特卡罗剂量分布（mc - dd）中的噪声，并将其集成到瑞士蒙特卡罗计划（SMCP）中。为此，一个双通道输入（MC-DD和计算机断层扫描（CT）扫描）3D U-net在高/低su MC-DD对106个临床动机VMAT弧上进行训练、验证和测试（80%/10%/10%），用于29个可用的CT，增加到3074对。将该模型集成到SMCP中，实现高SU的MC-DD计算和去噪以获得低SU的MC-DD的“一键式”工作流。在测试集上使用Gamma通过率（2%全局，2 mm， 10%阈值）比较去噪和低SU的MC-DD，评估模型精度。记录整个工作流程的计算时间。降噪后的mc - dd与低su的mc - dd相匹配，平均（标准差）Gamma通过率为82.9%（4.7%）。将DeepSMCP额外应用于12个未见的临床动机病例的不同治疗地点，包括训练期间未出现的治疗地点，导致平均Gamma通过率为91.0%。平均在35.1 秒内获得去噪的dd，与低su MC-DD计算相比，效率提高了340倍。DeepSMCP提出了首个无缝集成的mc - dd去噪框架。

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引用次数: 0

Patente in der Medizinphysik am Beispiel der Magnetresonanztomographie 以磁共振成像为例的医学物理专利。

IF 4.2 4区医学 Q2 RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING

Zeitschrift fur Medizinische Physik

Pub Date : 2026-02-01 DOI: 10.1016/j.zemedi.2025.09.002

Oliver Koppel

引用次数: 0

Systematizing the risk management process in clinical radiotherapy practice: Recommendations of the working group on risk management of the DGMP 将临床放射治疗实践中的风险管理过程系统化：DGMP 风险管理工作组的建议。

IF 4.2 4区医学 Q2 RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING

Zeitschrift fur Medizinische Physik

Pub Date : 2025-11-01 DOI: 10.1016/j.zemedi.2024.11.001

Dominik Kornek , Cordelia Hoinkis , Natasa Milickovic , Ailine Lange , Alena Knak , Manuel März , Mieke L. Möller , Markus Buchgeister

Purpose

The Deutsche Gesellschaft für Medizinische Physik [German Society of Medical Physics] has recently published two coherent reports, No. 25 and No. 28, detailing the design and implementation of a risk management (RM) process for German radiotherapy (RT) departments. This study offers an overview and background of the efforts behind these reports.

Methods and Materials

For three years, up to nine medical physicists (MPs) with practical RM experience held weekly meetings to develop recommendations for a clinical RM process. Care was taken to ensure that the recommendations were equally applicable to RT departments of various sizes. A process-based method derived from the failure mode and effects analysis (FMEA) was created to identify and address risks from unintentional radiation exposure. This method was applied to exemplarily analyze the hazardous scenarios in breast RT using surface guidance and deep inspiration breath hold (DIBH) techniques. Three common criticality methods—risk matrix, risk priority number, and action priority—were applied, and each step was schematically explained for first-time users. Each report was peer-reviewed by two radiation oncologists and 11 MPs.

Results

In report No. 25, basic requirements were outlined for running the RM process, conducting risk assessments, and monitoring clinical procedures. A three-year plan-do-check-act cycle was proposed for continuous improvement. In report No. 28, general process lists for external beam radiotherapy (EBRT), brachytherapy, and radionuclide therapy were designed. Based on the EBRT process list, 45 hazardous scenarios in the surface-guided breast RT in DIBH were identified. Two scenarios were used to illustrate handling instructions for the three criticality methods.

Conclusions

The recommendations provide clinical MPs and other health professionals with a pragmatic approach to RM, balancing both the needs of smaller practices and larger clinics in Germany. The risk of unintended exposures of patients is viewed acceptable once it has been lowered to a state that is as low as reasonably achievable.

目的：德国医学物理学会（Deutsche Gesellschaft für Medizinische Physik）最近发布了两份连贯的报告（第 25 号和第 28 号），详细介绍了德国放射治疗（RT）部门风险管理（RM）流程的设计和实施。本研究概述了这些报告背后的努力和背景：在三年的时间里，多达九名具有风险管理实践经验的医学物理学家（MPs）每周召开一次会议，为临床风险管理流程提出建议。我们注意确保这些建议同样适用于不同规模的 RT 部门。从故障模式和影响分析（FMEA）中衍生出一种基于流程的方法，用于识别和解决无意辐照带来的风险。该方法被应用于使用表面引导和深吸气屏气（DIBH）技术对乳腺 RT 中的危险情况进行示例分析。应用了三种常用的临界值方法--风险矩阵、风险优先级编号和行动优先级，并为初次使用者示意性地解释了每个步骤。每份报告都经过了两名放射肿瘤专家和 11 名宪兵的同行评审：第 25 号报告概述了运行 RM 流程、进行风险评估和监控临床程序的基本要求。报告提出了一个持续改进的三年计划-执行-检查-行动周期。在第 28 号报告中，设计了体外放射治疗 (EBRT)、近距离放射治疗和放射性核素治疗的一般流程清单。根据 EBRT 流程表，确定了 DIBH 表面引导乳腺 RT 中的 45 种危险情况。用两个场景说明了三种临界方法的处理说明：这些建议为临床医生和其他卫生专业人员提供了一种实用的RM方法，同时兼顾了德国小型诊所和大型诊所的需求。一旦患者意外暴露的风险降低到可合理实现的最低水平，这种风险是可以接受的。

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引用次数: 0

Explorative study using ultrasound time-harmonic elastography for stiffness-based quantification of skeletal muscle function 利用超声时谐弹性成像技术对骨骼肌功能进行基于硬度的量化的探索性研究。

IF 4.2 4区医学 Q2 RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING

Zeitschrift fur Medizinische Physik

Pub Date : 2025-11-01 DOI: 10.1016/j.zemedi.2024.03.001

Yang Yang , Mehrgan Shahryari , Tom Meyer , Stephan Rodrigo Marticorena Garcia , Steffen Görner , Mahsa Salimi Majd , Jing Guo , Jürgen Braun , Ingolf Sack , Heiko Tzschätzsch

Time-harmonic elastography (THE) is an emerging ultrasound imaging technique that allows full-field mapping of the stiffness of deep biological tissues. THE's unique ability to rapidly capture stiffness in multiple tissues has never been applied for imaging skeletal muscle. Therefore, we addressed the lack of data on temporal changes in skeletal muscle stiffness while simultaneously covering stiffness of different muscles.

Acquiring repeated THE scans every five seconds we quantified shear-wave speed (SWS) as a marker of stiffness of the long head (LHB) and short head (SHB) of biceps brachii and of the brachialis muscle (B) in ten healthy volunteers. SWS was continuously acquired during a 3-min isometric preloading phase, a 3-min loading phase with different weights (4, 8, and 12 kg), and a 9-min postloading phase. In addition, we analyzed temporal SWS standard deviation (SD) as a marker of muscle contraction regulation.

Our results (median [min, max]) showed both SWS at preloading (LHB: 1.04 [0.94, 1.12] m/s, SHB: 0.86 [0.78, 0.94] m/s, B: 0.96 [0.87, 1.09] m/s, p < 0.001) and the increase in SWS with loading weight to be muscle-specific (LHB: 0.010 [0.002, 0.019] m/s/kg, SHB: 0.022 [0.017, 0.042] m/s/kg, B: 0.039 [0.019, 0.062] m/s/kg, p < 0.001). Additionally, SWS during loading increased continuously over time by 0.022 [0.004, 0.051] m/s/min (p < 0.01). Using an exponential decay model, we found an average relaxation time of 27 seconds during postloading. Analogously, SWS SD at preloading was also muscle-specific (LHB: 0.018 [0.011, 0.029] m/s, SHB: 0.021 [0.015, 0.027] m/s, B: 0.024 [0.018, 0.037] m/s, p < 0.05) and increased by 0.005 [0.003, 0.008] m/s/kg (p < 0.01) with loading. SWS SD did not change over loading time and decreased immediately in the postloading phase.

Taken together, THE of skeletal muscle is a promising imaging technique for in vivo quantification of stiffness and stiffness changes in multiple muscle groups within seconds. Both the magnitude of stiffness changes and their temporal variation during isometric exercise may reflect the functional status of skeletal muscle and provide additional information to the morphological measures obtained by conventional imaging modalities.

时谐弹性成像（THE）是一种新兴的超声成像技术，可对深层生物组织的硬度进行全场测绘。时谐弹性成像技术具有快速捕捉多种组织刚度的独特能力，但从未应用于骨骼肌成像。因此，我们解决了骨骼肌僵硬度时间变化数据缺乏的问题，同时涵盖了不同肌肉的僵硬度。通过每五秒重复采集 THE 扫描，我们量化了剪切波速度（SWS），将其作为十名健康志愿者肱二头肌长头（LHB）和短头（SHB）以及肱二头肌（B）僵硬度的标记。在 3 分钟的等长预加载阶段、3 分钟的不同重量（4、8 和 12 千克）加载阶段以及 9 分钟的加载后阶段，我们连续采集了 SWS。此外，我们还分析了作为肌肉收缩调节标志的时间 SWS 标准偏差（SD）。我们的结果（中位数 [最小，最大]）显示，加载前的 SWS（LHB：1.04 [0.94, 1.12] m/s，SHB：0.86 [0.78, 0.94] m/s，B：0.96 [0.87, 1.09] m/s，p

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引用次数: 0

Comparison of iterative reconstruction implementations for multislice helical CT 多层螺旋 CT 迭代重建实现方法的比较。

IF 4.2 4区医学 Q2 RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING

Zeitschrift fur Medizinische Physik

Pub Date : 2025-11-01 DOI: 10.1016/j.zemedi.2024.04.001

Zsolt Adam Balogh , Zsofia Barna , Eva Majoros

The most mature image reconstruction algorithms in multislice helical computed tomography are based on analytical and iterative methods. Over the past decades, several methods have been developed for iterative reconstructions that improve image quality by reducing noise and artifacts. In the regularization step of iterative reconstruction, noise can be significantly reduced, thereby making low-dose CT. The quality of the reconstructed image can be further improved by using model-based reconstructions. In these reconstructions, the main focus is on modeling the data acquisition process, including the behavior of the photon beams, the geometry of the system, etc.

In this article, we propose two model-based reconstruction algorithms using a virtual detector for multislice helical CT. The aim of this study is to compare the effect of using a virtual detector on image quality for the two proposed algorithms with a model-based iterative reconstruction using the original detector model. Since the algorithms are implemented using multiple GPUs, the merging of separately reconstructed volumes can significantly affect image quality. This issue is often referred to as the ”long object” problem, for which we also present a solution that plays an important role in the proposed reconstruction processes.

The algorithms were evaluated using mathematical and physical phantoms, as well as patient cases. The SSIM, MS-SSIM and

L_{1}

metrics were utilized to evaluate the image quality of the mathematical phantom case. To demonstrate the effectiveness of the algorithms, we used the CatPhan 600 phantom. Additionally, anonymized patient scans were used to showcase the improvements in image quality on real scan data.

多层螺旋计算机断层扫描中最成熟的图像重建算法是基于分析和迭代方法。在过去几十年中，已开发出多种迭代重建方法，通过减少噪声和伪影提高图像质量。在迭代重建的正则化步骤中，可以显著降低噪声，从而实现低剂量 CT。使用基于模型的重建可进一步提高重建图像的质量。在这些重建中，重点是对数据采集过程进行建模，包括光子束的行为、系统的几何形状等。在本文中，我们提出了两种基于模型的重建算法，使用虚拟探测器进行多层螺旋 CT 重建。本研究的目的是比较使用虚拟探测器与使用原始探测器模型的基于模型迭代重建两种算法对图像质量的影响。由于这些算法是使用多个 GPU 实现的，因此合并单独重建的体量会严重影响图像质量。这个问题通常被称为 "长物体 "问题，我们也提出了一个解决方案，它在拟议的重建过程中发挥了重要作用。我们使用数学和物理模型以及患者病例对这些算法进行了评估。我们利用 SSIM、MS-SSIM 和 L1 指标来评估数学模型的图像质量。为了证明算法的有效性，我们使用了 CatPhan 600 模型。此外，我们还使用匿名患者扫描数据来展示真实扫描数据对图像质量的改善。

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引用次数: 0

Advancing risk management in nuclear medicine diagnostic and therapy through incident-driven risk management tools 通过事件驱动的风险管理工具推进核医学诊断和治疗的风险管理。

IF 4.2 4区医学 Q2 RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING

Zeitschrift fur Medizinische Physik

Pub Date : 2025-11-01 DOI: 10.1016/j.zemedi.2025.03.004

Lidia Strigari , David Menichelli , Elisa Lodi Rizzini , Arber Golemi , Gian Mauro Sacchetti , Lucia Leva , Cristina Nanni , Paolo Castelucci , Stefano Fanti , Alessio Giuseppe Morganti , Roberta Matheoud

Accidental or unintended exposures in nuclear medicine present significant risks, demanding proactive and systematic risk management strategies. This study explores the development and implementation of a novel software tool that integrates Failure Modes and Effects Analysis (FMEA) and Fault Tree Analysis (FTA) into a unified platform tailored for nuclear medicine. The tool addresses the complexities of risk assessment across diagnostic and therapeutic workflows, offering customizable templates and a streamlined process for identifying, prioritizing, and mitigating failure modes.

A multicenter study involving nuclear medicine departments of various sizes demonstrated the tool’s efficacy in standardizing risk analysis and enhancing interdisciplinary collaboration. Key scenarios, such as errors in radiopharmaceutical preparation and administration, were assessed, with rankings assigned based on a refined Risk Priority Number (RPN) system.

The results underscore the transformative potential of combining FMEA and FTA in nuclear medicine, addressing the limitations of standalone methodologies. This approach improves workflow efficiency and ensures a robust framework for patient safety. Future directions include expanding the tool’s applications, refining templates, and fostering a proactive culture of risk assessment. These advancements pave the way for safer, more efficient practices in nuclear medicine, benefiting patients and professionals alike.

核医学中的意外或意外暴露会带来重大风险，需要采取主动和系统的风险管理战略。本研究探索了一种新的软件工具的开发和实现，该软件工具将故障模式和影响分析（FMEA）和故障树分析（FTA）集成到一个为核医学量身定制的统一平台中。该工具解决了诊断和治疗工作流程中风险评估的复杂性，提供了可定制的模板和简化的流程，用于识别、优先排序和减轻故障模式。一项涉及不同规模核医学部门的多中心研究证明了该工具在标准化风险分析和加强跨学科合作方面的功效。评估了关键情况，如放射性药物制备和给药中的错误，并根据改进的风险优先级编号（RPN）系统进行了排名。结果强调了FMEA和FTA结合在核医学中的变革潜力，解决了独立方法的局限性。这种方法提高了工作流程效率，并确保了患者安全的健全框架。未来的方向包括扩展工具的应用，精炼模板，以及培养一种前瞻性的风险评估文化。这些进步为更安全、更有效的核医学实践铺平了道路，使患者和专业人员都受益。

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引用次数: 0

High-energy X-ray diffraction experiment employing a compact synchrotron X-ray source based on inverse Compton scattering 利用基于反康普顿散射的紧凑型同步辐射 X 射线源进行高能 X 射线衍射实验。

IF 4.2 4区医学 Q2 RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING

Zeitschrift fur Medizinische Physik

Pub Date : 2025-11-01 DOI: 10.1016/j.zemedi.2024.03.003

Johannes Melcher , Martin Dierolf , Benedikt Günther , Klaus Achterhold , Daniela Pfeiffer , Franz Pfeiffer

X-ray diffraction (XRD) is an important material analysis technique with a widespread use of laboratory systems. These systems typically operate at low X-ray energies (from 5 keV to 22 keV) since they rely on the small bandwidth of K-lines like copper. The narrow bandwidth is essential for precise measurements of the crystal structure in these systems. Inverse Compton X-ray source (ICS) could pave the way to XRD at high X-ray energies in a laboratory setting since these sources provide brilliant energy-tunable and partially coherent X-rays. This study demonstrates high-energy XRD at an ICS with strongly absorbing mineralogical samples embedded in soft tissue. A quantitative comparison of the measured XRD patterns with calculations of their expected shapes validates the performance of ICSs for XRD. This analysis was performed for two types of kidney stones of different materials. Since these stones are not isolated in a human body, the influence of the surrounding soft tissue on the XRD pattern is investigated and a correction for this soft tissue contribution is introduced.

x射线衍射（XRD）是一种重要的材料分析技术，在实验室系统中得到广泛应用。这些系统通常在低x射线能量下运行（从5 keV到22 keV），因为它们依赖于像铜一样的k线的小带宽。在这些系统中，窄带宽对于精确测量晶体结构是必不可少的。逆康普顿x射线源（ICS）可以提供明亮的能量可调和部分相干x射线，为在实验室环境中实现高x射线能量的XRD铺平了道路。本研究在具有强吸收矿物样品嵌入软组织的ICS上展示了高能XRD。通过对测量到的x射线衍射图与预期形状的计算进行定量比较，验证了ics的x射线衍射性能。该分析是针对两种不同材料的肾结石进行的。由于这些石头在人体中不是孤立的，因此研究了周围软组织对x射线衍射图的影响，并介绍了对软组织贡献的修正。

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引用次数: 0

An automated pipeline for computation and analysis of functional ventilation and perfusion lung MRI with matrix pencil decomposition: TrueLung 利用矩阵铅笔分解计算和分析功能性通气和灌注肺磁共振成像的自动管道：TrueLung.

IF 4.2 4区医学 Q2 RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING

Zeitschrift fur Medizinische Physik

Pub Date : 2025-11-01 DOI: 10.1016/j.zemedi.2024.08.001

Orso Pusterla , Corin Willers , Robin Sandkühler , Simon Andermatt , Sylvia Nyilas , Philippe C. Cattin , Philipp Latzin , Oliver Bieri , Grzegorz Bauman

Purpose

To introduce and evaluate TrueLung, an automated pipeline for computation and analysis of free-breathing and contrast-agent free pulmonary functional magnetic resonance imaging.

Materials and Methods

Two-dimensional time-resolved ultra-fast balanced steady-state free precession acquisitions were transferred to TrueLung, which included image quality checks, image registration, and computation of perfusion and ventilation maps with matrix pencil decomposition. Neural network whole-lung and lobar segmentations allowed quantification of impaired relative perfusion (R_Q) and fractional ventilation (R_FV). TrueLung delivered functional maps and quantitative outcomes, reported for clinicians in concise documents.

We evaluated the pipeline using 1.5T data from 75 children with cystic fibrosis by assessing the feasibility of functional MR imaging, average scan time, and the robustness of the functional outcomes. Whole-lung and lobar segmentations were manually refined when necessary, and the impact on R_Q and R_FV was quantified.

Results

Functional imaging was feasible in all included CF children without any dropouts. On average, 7.9 ± 1.8 (mean±SD) coronal slice positions per patient were acquired, resulting in a mean scan time of 6min 20s per patient. The whole pipeline required 20min processing time per subject. TrueLung delivered the functional maps of all the subjects for radiological assessment. Quality controlling maps and segmentations lasted 1min 12s per patient. The automated segmentations and quantification of whole-lung defects were satisfying in 88% of patients (97% of slices) and the lobar quantification in 73% (93% of slices). The segmentations refinements required 16s per patient for the whole-lung, and 2min 10s for the lobe masks.

The relative differences in R_FV and R_Q between fully-automated and manually refined data were 0.7% (1.2%) and 2.0% (2.9%) for whole-lung quantification (median, [third quartile]), and excluding two outliers, 1.7% (3.9%) and 1.2% (3.8%) for the lobes, indicating the refinements could be potentially omitted in several patients.

Conclusions

TrueLung quickly delivers functional maps and quantitative outcomes in an objective and standardized way, suitable for radiological and pneumological assessment with minimal manual input. TrueLung can be used for clinical research in cystic fibrosis and might be applied across various lung diseases.

目的：介绍并评估用于计算和分析自由呼吸和无造影剂肺功能磁共振成像的自动化管道 TrueLung：将二维时间分辨超快平衡稳态自由前驱采集图像传输到TrueLung，其中包括图像质量检查、图像配准以及利用矩阵铅笔分解计算灌注和通气图。神经网络全肺和肺叶分割可量化受损的相对灌注（RQ）和分数通气（RFV）。TrueLung 可提供功能图和定量结果，并以简洁的文档形式报告给临床医生。我们使用 75 名囊性纤维化患儿的 1.5T 数据对该管道进行了评估，评估了功能磁共振成像的可行性、平均扫描时间和功能结果的稳健性。必要时对全肺和肺叶分割进行人工细化，并量化对 RQ 和 RFV 的影响：结果：所有被纳入研究的 CF 儿童都能进行功能成像，无一辍学。平均每位患者采集了 7.9 ± 1.8（平均值±SD）个冠状切片位置，每位患者的平均扫描时间为 6 分 20 秒。每个受试者的整个管道处理时间为 20 分钟。TrueLung 提供了所有受试者的功能图，用于放射学评估。质量控制图和分割每个患者需要 1 分 12 秒。88%的患者（97%的切片）和73%的患者（93%的切片）对全肺缺陷的自动分割和量化结果表示满意，肺叶量化结果也令人满意。每位患者的全肺分割细化需要 16 秒，肺叶掩膜需要 2 分 10 秒。全自动和手动细化数据的 RFV 和 RQ 的相对差异为：全肺量化为 0.7% (1.2%) 和 2.0% (2.9%)（中位数，[第三四分位数]），排除两个异常值后，肺叶为 1.7% (3.9%) 和 1.2% (3.8%)，这表明在一些患者中可能会省略细化：TrueLung能以客观、标准化的方式快速提供功能图谱和定量结果，适用于放射学和肺学评估，只需极少的人工输入。TrueLung 可用于囊性纤维化的临床研究，也可应用于各种肺部疾病。

{"title":"An automated pipeline for computation and analysis of functional ventilation and perfusion lung MRI with matrix pencil decomposition: TrueLung","authors":"Orso Pusterla , Corin Willers , Robin Sandkühler , Simon Andermatt , Sylvia Nyilas , Philippe C. Cattin , Philipp Latzin , Oliver Bieri , Grzegorz Bauman","doi":"10.1016/j.zemedi.2024.08.001","DOIUrl":"10.1016/j.zemedi.2024.08.001","url":null,"abstract":"<div><h3>Purpose</h3><div>To introduce and evaluate TrueLung, an automated pipeline for computation and analysis of free-breathing and contrast-agent free pulmonary functional magnetic resonance imaging.</div></div><div><h3>Materials and Methods</h3><div>Two-dimensional time-resolved ultra-fast balanced steady-state free precession acquisitions were transferred to TrueLung, which included image quality checks, image registration, and computation of perfusion and ventilation maps with matrix pencil decomposition. Neural network whole-lung and lobar segmentations allowed quantification of impaired relative perfusion (R<sub>Q</sub>) and fractional ventilation (R<sub>FV</sub>). TrueLung delivered functional maps and quantitative outcomes, reported for clinicians in concise documents.</div><div>We evaluated the pipeline using 1.5T data from 75 children with cystic fibrosis by assessing the feasibility of functional MR imaging, average scan time, and the robustness of the functional outcomes. Whole-lung and lobar segmentations were manually refined when necessary, and the impact on R<sub>Q</sub> and R<sub>FV</sub> was quantified.</div></div><div><h3>Results</h3><div>Functional imaging was feasible in all included CF children without any dropouts. On average, 7.9 ± 1.8 (mean±SD) coronal slice positions per patient were acquired, resulting in a mean scan time of 6min 20s per patient. The whole pipeline required 20min processing time per subject. TrueLung delivered the functional maps of all the subjects for radiological assessment. Quality controlling maps and segmentations lasted 1min 12s per patient. The automated segmentations and quantification of whole-lung defects were satisfying in 88% of patients (97% of slices) and the lobar quantification in 73% (93% of slices). The segmentations refinements required 16s per patient for the whole-lung, and 2min 10s for the lobe masks.</div><div>The relative differences in R<sub>FV</sub> and R<sub>Q</sub> between fully-automated and manually refined data were 0.7% (1.2%) and 2.0% (2.9%) for whole-lung quantification (median, [third quartile]), and excluding two outliers, 1.7% (3.9%) and 1.2% (3.8%) for the lobes, indicating the refinements could be potentially omitted in several patients.</div></div><div><h3>Conclusions</h3><div>TrueLung quickly delivers functional maps and quantitative outcomes in an objective and standardized way, suitable for radiological and pneumological assessment with minimal manual input. TrueLung can be used for clinical research in cystic fibrosis and might be applied across various lung diseases.</div></div>","PeriodicalId":54397,"journal":{"name":"Zeitschrift fur Medizinische Physik","volume":"35 4","pages":"Pages 452-469"},"PeriodicalIF":4.2,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142305511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Safety in MR-enhanced daily adaptive SBRT Radiotherapy using a conventional C-arm linear accelerator: An FMEA approach 使用常规c臂直线加速器的mr增强每日适应性SBRT放疗的安全性：FMEA方法。

IF 4.2 4区医学 Q2 RADIOLOGY, NUCLEAR MEDICINE & MEDICAL IMAGING

Zeitschrift fur Medizinische Physik

Pub Date : 2025-11-01 DOI: 10.1016/j.zemedi.2025.05.002

Lotte Wilke, Sebastian M. Christ, Riccardo Dal Bello, Elizabeth Denney, Silvia Fabiano, Hubert S. Gabryś, Klara Kefer, Michael Mayinger, Ina Nilo, Sophie Perryck, Jens von der Grün, Matthias Guckenberger, Stephanie Tanadini-Lang

Background and Purpose

MR-guided adaptive Radiotherapy has the potential to compensate for interfractional changes in patient anatomy. Modern hybrid devices, which combine MR and linear accelerator technologies, have been clinically implemented but their costs may prevent broad adoption. To accelerate the adoption of MR-guided adaptive radiotherapy, we developed a workflow for MR-enhanced daily adaptive Radiotherapy on a C-arm linac using a dedicated MR simulator and a patient transfer shuttle system. A failure mode and effects analysis (FMEA) was performed to identify possible risks in this newly developed workflow.

Materials and Methods

A workflow for MR-enhanced daily adaptive SBRT (MEDAS) on a Varian Truebeam linac was developed using a stand-alone 1.5T MR-simulator and patient transfer using a shuttle system. The different process steps were conceptualized in a multidisciplinary team and an FMEA of the different process steps was performed as well as measures for mitigation of possible risks were discussed.

Results

The FMEA identified 23 failure modes across eight process steps, with the majority occurring during base plan preparation and adaptive planning. Seventeen (74%) failure modes were classified as low risk, while six (26%) were assessed as medium risk. No high-risk failure modes were identified. Risk mitigation measures, including workflow automation and checklist enhancements, successfully reduced all failure modes to low risk while not introducing new risks

Conclusion

We developed a workflow for MEDAS on a conventional C-Arm linac. In this process, an FMEA was performed in a multidisciplinary team. The FMEA identified and addressed six medium-risk failure modes within the MEDAS workflow. Through further automation and adaption of existing checklists, the occurrence- and discover probability was successfully reduced, such that these failure modes are decreased to a low risk.

背景和目的：磁共振引导下的适应性放疗有可能补偿患者解剖结构的分节间变化。结合了磁共振和线性加速器技术的现代混合设备已经在临床上实施，但其成本可能会阻碍其广泛采用。为了加速采用核磁共振引导的自适应放疗，我们开发了一套在c臂直线机上使用专用核磁共振模拟器和病人转移穿梭系统的核磁共振增强日常自适应放疗工作流程。进行了失效模式和影响分析（FMEA）以识别新开发的工作流程中可能存在的风险。材料和方法：利用独立的1.5T磁共振模拟器和穿梭系统进行患者转移，在瓦里安Truebeam直线加速器上开发了磁共振增强每日自适应SBRT （MEDAS）的工作流程。在一个多学科团队中对不同的过程步骤进行了概念化，并对不同过程步骤进行了FMEA，并讨论了减轻可能风险的措施。结果：FMEA确定了8个过程步骤中的23种失效模式，其中大多数发生在基本计划准备和适应性计划期间。17种（74%）失效模式被归类为低风险，而6种（26%）被评估为中等风险。未发现高风险失效模式。风险缓解措施，包括工作流程自动化和检查表增强，成功地将所有故障模式降低到低风险，同时没有引入新的风险。在此过程中，在一个多学科团队中执行了FMEA。FMEA确定并解决了MEDAS工作流程中的六种中等风险失效模式。通过进一步的自动化和对现有检查表的适应，成功地降低了发生和发现的概率，从而将这些故障模式降低到低风险。

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引用次数: 0