neural blind deconvolution

  • 文章类型: Journal Article
    目的:使用一种新的图像去噪技术和信号与b值曲线的模型无关参数化,以提高体素不相干运动成像(IVIM)磁共振成像(MRI)的质量。方法:在放疗前采集了13例头颈部患者的IVIM图像。还对五名患者进行了放疗后扫描。在参数拟合之前使用神经盲去卷积对图像进行去噪,用神经网络解决盲解卷积数学问题的方法。然后根据几个曲线下面积(AUC)参数对信号衰减曲线进行定量。使用盲图像质量度量来评估图像质量的改善,总变化(TV),腮腺IVIM参数与放疗剂量水平的相关性强度。通过恢复已应用于去噪图像的人工“伪内核”的能力来评估模糊内核预测的准确性。AUC参数与表观扩散系数(ADC)比较,双指数,和三指数模型参数与剂量的相关性,腮腺内外对比噪声(CNR)比,以及通过主成分分析确定的它们的相对重要性。 主要结果:图像去噪改进了盲图像质量度量,平滑了信号对b值的曲线,并加强了IVIM参数与剂量之间的相关性。去噪后,图像TV降低,参数CNR通常增加。与传统IVIM参数相比,AUC参数变化与剂量具有更高的相关性和更高的相对重要性。意义:IVIM参数在文献中具有高度变异性,与灌注相关的参数难以解释。用与模型无关的参数(如AUC)描述信号与b值曲线,并用去噪技术预处理图像可能会在再现性和功能实用性方面使IVIM图像参数化受益。
    Objective. To improve intravoxel incoherent motion imaging (IVIM) magnetic resonance Imaging quality using a new image denoising technique and model-independent parameterization of the signal versusb-value curve.Approach. IVIM images were acquired for 13 head-and-neck patients prior to radiotherapy. Post-radiotherapy scans were also acquired for five of these patients. Images were denoised prior to parameter fitting using neural blind deconvolution, a method of solving the ill-posed mathematical problem of blind deconvolution using neural networks. The signal decay curve was then quantified in terms of several area under the curve (AUC) parameters. Improvements in image quality were assessed using blind image quality metrics, total variation (TV), and the correlations between parameter changes in parotid glands with radiotherapy dose levels. The validity of blur kernel predictions was assessed by the testing the method\'s ability to recover artificial \'pseudokernels\'. AUC parameters were compared with monoexponential, biexponential, and triexponential model parameters in terms of their correlations with dose, contrast-to-noise (CNR) around parotid glands, and relative importance via principal component analysis.Main results. Image denoising improved blind image quality metrics, smoothed the signal versusb-value curve, and strengthened correlations between IVIM parameters and dose levels. Image TV was reduced and parameter CNRs generally increased following denoising.AUCparameters were more correlated with dose and had higher relative importance than exponential model parameters.Significance. IVIM parameters have high variability in the literature and perfusion-related parameters are difficult to interpret. Describing the signal versusb-value curve with model-independent parameters like theAUCand preprocessing images with denoising techniques could potentially benefit IVIM image parameterization in terms of reproducibility and functional utility.
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  • 文章类型: Journal Article
    目的:使用神经盲解卷积同时对前列腺特异性膜抗原(PSMA)正电子发射断层扫描(PET)图像进行模糊和超采样。方法:盲解卷积是一种同时估计假设的“去模糊”图像以及模糊核(与点扩散函数相关)的方法。传统的最大后验盲反褶积方法需要严格的假设,并且会收敛到琐碎的解决方案。一种用独立神经网络对去模糊图像和核建模的方法,被称为“神经盲去卷积”的人在2020年证明了对2D自然图像进行去模糊的成功。在这项工作中,我们采用神经盲反卷积对PSMAPET图像进行PVE校正,同时进行超采样。我们将这种方法与几种插值方法进行比较,使用盲图像质量度量,并通过在将人工“伪内核”应用于去模糊图像后重新运行模型来测试模型预测内核的能力。该方法在30名前列腺患者的回顾性集合以及包含各种体积的球形病变的体模图像上进行了测试。主要结果:神经盲反卷积在盲图像质量度量方面比其他插值方法提高了图像质量,恢复系数,视觉评估。患者之间预测的内核相似,该模型准确地预测了几个人工应用的伪核。去模糊后,幻像球中活动的定位得到了改善,允许更准确地定义小病变。意义:PSMAPET的固有低空间分辨率导致PVE,其负面影响小区域中的摄取定量。所提出的方法可以用来缓解这个问题,并且可以直接适用于其他成像模式。
    Objective. To simultaneously deblur and supersample prostate specific membrane antigen (PSMA) positron emission tomography (PET) images using neural blind deconvolution.Approach. Blind deconvolution is a method of estimating the hypothetical \'deblurred\' image along with the blur kernel (related to the point spread function) simultaneously. Traditionalmaximum a posterioriblind deconvolution methods require stringent assumptions and suffer from convergence to a trivial solution. A method of modelling the deblurred image and kernel with independent neural networks, called \'neural blind deconvolution\' had demonstrated success for deblurring 2D natural images in 2020. In this work, we adapt neural blind deconvolution to deblur PSMA PET images while simultaneous supersampling to double the original resolution. We compare this methodology with several interpolation methods in terms of resultant blind image quality metrics and test the model\'s ability to predict accurate kernels by re-running the model after applying artificial \'pseudokernels\' to deblurred images. The methodology was tested on a retrospective set of 30 prostate patients as well as phantom images containing spherical lesions of various volumes.Main results. Neural blind deconvolution led to improvements in image quality over other interpolation methods in terms of blind image quality metrics, recovery coefficients, and visual assessment. Predicted kernels were similar between patients, and the model accurately predicted several artificially-applied pseudokernels. Localization of activity in phantom spheres was improved after deblurring, allowing small lesions to be more accurately defined.Significance. The intrinsically low spatial resolution of PSMA PET leads to partial volume effects (PVEs) which negatively impact uptake quantification in small regions. The proposed method can be used to mitigate this issue, and can be straightforwardly adapted for other imaging modalities.
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