Improved prostate cancer diagnostics and treatment planning with Magnetic ResonanceElastography (MRE), Diffusion Tensor Imaging (DTI) and Chemical Exchange Saturation Transfer (CEST): ex-vivo imaging and translation to an in-vivo application for patients

动机：在德国，前列腺癌(PCA)是男性最常见的肿瘤。尽管多参数磁共振成像(MpMRI)在评价前列腺癌方面取得了成功，但仍存在明显的局限性，如鉴别良性前列腺增生症和恶性肿瘤的特异性低，检测前列腺外肿瘤扩散的敏感性低，放射科医生阅读器间的可信度中等。该项目建立在先前研究的基础上，也旨在改进非侵入性PCA诊断。该项目的创新包括扩展和加速诊断方法以及将其转化为体内应用。方法：将研究三种新的MRI技术，这些技术将提供有关前列腺的粘弹性特性(磁共振弹性成像，MRE)、结构组织(扩散张量成像，DTI)和生理(化学交换饱和转移，CEST)的定量信息。此外，还将首次同时采集前列腺的DTI和MRE，即所谓的DTI-MRE。随后，可以加速检查时间，并且可以减少体内应用的伪影，例如，由于非自愿的肠道运动。这些技术首先在超高场9.4特斯拉核磁共振扫描仪上对10例前列腺癌患者的前列腺癌切除标本进行了体外研究。之后，将在临床3Tesla磁共振扫描仪上对10名健康志愿者和10名PCA患者进行体内应用程序的转换。为了评估诊断的准确性，将结果与病理作为参考标准。此外，利用定量数据开发了用于主成分分析概率确定的三维可视化软件和预测性多变量Logistic回归模型。假设和目的：我们假设，在现有的标准mpMRI方案中增加一个时间效率高的DTI-MRE和CEST序列，可以改善PCa的检测、分级和治疗计划，而不会对临床常规产生显著的额外影响。未来，患者可能会从这种非侵入性方法中受益，因为经直肠活检的并发症，如感染和直肠出血，以及不必要的前列腺切除术及其风险，如大小便失禁和阳萎，都可以避免。此外，我们假设定量数据的实施增加了放射科医生在阅读器之间的可靠性。为了使这些信息可用于临床实践，我们将可视化地将量化数据与当前标准的mpMRI和病理学相结合。

Motivation:In Germany, prostate cancer (PCa) is the most common tumor in men. Despite the success of multiparametric magnetic resonance imaging (mpMRI) in evaluating PCa, there are significant limitations such as the low specificity for distinguishing benign prostatic hyperplasia and malignant tumors, low sensitivity for detecting extraprostatic tumor extension and moderate inter-reader reliability of radiologists. This project builds on the previous study and also aims to improve non-invasive PCa diagnostics. The innovation of this project consists of expansion and acceleration of diagnostic methods as well as translation to an in-vivo application for patients.Methods:A total of three new MRI techniques will be investigated which will provide quantitative information on viscoelastic properties (magnetic resonance elastography, MRE), structural organization (diffusion tensor imaging, DTI) and physiology (chemical exchange saturation transfer, CEST) of the prostate. Additionally, for the first time, a simultaneous acquisition of DTI and MRE of the prostate will be performed - the so-called DTI-MRE. Subsequently, the examination times can be accelerated and artifacts, e.g., due to involuntary bowel movements, can be reduced for in-vivo applications. These techniques are first studied ex-vivo on ten resected prostatectomy specimens from patients with PCa on an ultra-high-field 9.4 Tesla MRI scanner. Afterwards, a translation to an in-vivo application with ten healthy volunteers and ten patients with PCa on a clinical 3 Tesla MRI scanner will be performed. To evaluate the diagnostic accuracy, results are compared with pathology as the reference standard. Furthermore, the quantitative data is used to develop a 3D visualization software and predictive multivariable logistic regression model for PCa probability determination. Hypothesis and aims:We hypothesize that the addition of a time-efficient DTI-MRE and CEST sequence to current standard mpMRI protocols improves the detection, grading and treatment planning of PCa without a significant additional effort for clinical routine. In the future, patients may benefit from this non-invasive method because complications of transrectal biopsies, such as infections and rectal bleedings, but also unnecessary surgical prostatectomy and its risks, such as incontinence and impotence, can be avoided. Moreover, we hypothesize that the implementation of quantitative data increases the inter-reader reliability of radiologists. In order to make this information actionable for clinical practice, we will visually integrate quantitative data with current standard mpMRI and pathology.