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arXiv 2411.01351cs.CVcs.AI

用于脑室增大分割的、基于潜扩散模型的带标签脑部MRI数据引导合成

Guided Synthesis of Labeled Brain MRI Data Using Latent Diffusion Models for Segmentation of Enlarged Ventricles

University of Copenhagen (UCPH)(哥本哈根大学);Rigshospitalet(哥本哈根大学医院( Rigshospitalet));DEPICT, Centre for AI and Medical Imaging(DEPICT AI与医学影像中心)

Tim Ruschke, Jonathan Frederik Carlsen, Adam Espe Hansen, Ulrich Lindberg, Amalie Monberg Hindsholm, Martin Norgaard, Claes Nøhr Ladefoged

AI总结:

本研究针对医学深度学习数据稀缺等问题,采用两个潜扩散模型引导合成带标签的脑部MRI数据,提升了脑室增大的分割性能,部分指标优于现有最优模型SynthSeg。

摘要:

医学场景下的深度学习模型面临数据稀缺、异质性和隐私问题等挑战。本研究聚焦于利用合成数据改进脑部MRI图像中的脑室分割任务。我们采用了两个潜扩散模型(LDMs):一个是使用10000个掩码训练的掩码生成器,另一个是使用6881次扫描优化的对应SPADE图像生成器,用于生成以3D脑部掩码为条件的MRI图像。通过将掩码生成器以脑室体积为条件,结合无分类器引导,我们能够控制生成的合成图像的脑室体积分布。随后,我们使用三个nnU-Net分割模型测试了合成数据的性能,这三个模型分别在真实数据、增强数据和纯合成数据上训练。我们在一个完全独立的、由脑室增大患者组成的留存数据集上测试了所得模型的性能,以人工勾勒的脑室作为真值。在真实数据上训练的模型预测脑室体积的平均绝对误差(MAE)为9.09 ± 12.18 mL,而在合成数据和增强数据上训练的模型的MAE分别为7.52 ± 4.81 mL和6.23 ± 4.33 mL。合成模型和增强模型的表现也都优于当前最优模型SynthSeg——SynthSeg因在大脑室体积病例中性能有限,MAE为7.73 ± 12.12 mL,标准差是前两者的3倍。在增强数据上训练的模型取得了最高的Dice分数,为0.892 ± 0.05,略优于SynthSeg,与在真实数据上训练的模型表现相当。合成模型的表现与SynthSeg相近。综上,我们证明了利用LDMs引导合成带标签的脑部MRI数据能够改进脑室增大的分割效果,且性能优于现有的最优分割模型。

英文摘要:

Deep learning models in medical contexts face challenges like data scarcity, inhomogeneity, and privacy concerns. This study focuses on improving ventricular segmentation in brain MRI images using synthetic data. We employed two latent diffusion models (LDMs): a mask generator trained using 10,000 masks, and a corresponding SPADE image generator optimized using 6,881 scans to create an MRI conditioned on a 3D brain mask. Conditioning the mask generator on ventricular volume in combination with classifier-free guidance enabled the control of the ventricular volume distribution of the generated synthetic images. Next, the performance of the synthetic data was tested using three nnU-Net segmentation models trained on a real, augmented and entirely synthetic data, respectively. The resulting models were tested on a completely independent hold-out dataset of patients with enlarged ventricles, with manual delineation of the ventricles used as ground truth. The model trained on real data showed a mean absolute error (MAE) of 9.09 \pm 12.18 mL in predicted ventricular volume, while the models trained on synthetic and augmented data showed MAEs of 7.52 \pm 4.81 mL and 6.23 \pm 4.33 mL, respectively. Both the synthetic and augmented model also outperformed the state-of-the-art model SynthSeg, which due to limited performance in cases of large ventricular volumes, showed an MAE of 7.73 \pm 12.12 mL with a factor of 3 higher standard deviation. The model trained on augmented data showed the highest Dice score of 0.892 \pm 0.05, slightly outperforming SynthSeg and on par with the model trained on real data. The synthetic model performed similar to SynthSeg. In summary, we provide evidence that guided synthesis of labeled brain MRI data using LDMs improves the segmentation of enlarged ventricles and outperforms existing state-of-the-art segmentation models.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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