In Vivo Quantification of Water Diffusion, Stiffness, and Tissue Fluidity in Benign Prostatic Hyperplasia and Prostate Cancer
In Vivo Quantification of Water Diffusion, Stiffness, and Tissue Fluidity in Benign Prostatic Hyperplasia and Prostate Cancer
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DOI：
10.1097/rli.0000000000000685
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发表时间：
2020-08-01
影响因子：
6.7
通讯作者：
Sack, Ingolf
中科院分区：
文献类型：
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作者：
Asbach, Patrick;Ro, Sa-Ra;Sack, Ingolf
目的水扩散、组织硬度和粘度表征肿瘤的生物物理行为。然而，很少有人知道这些参数如何在前列腺癌（PCa）相关。因此，我们将前列腺弹性断层成像与弥散敏感磁共振成像配对，用于良性前列腺增生（BPH）和PCa生物物理参数的定量映射。材料与方法使用外部压缩空气驱动器在60、70和80 Hz下进行多频磁共振成像弹性成像和断层弹性成像处理。分析剪切波速度（SWS）和损失角（phi）作为正常外周区（PZ）、增生性移行区（TZ）（与BPH一致）和PCa病变中硬度和粘度相关流动性的替代标志物。SWS和phi与标准化表观扩散系数（nADC）相关。结果39名男性（中位年龄/范围，67/49-88岁），25名BPH患者和14名活检证实的PCa患者前瞻性入选本机构审查委员会批准的研究。PCa的SWS（3.1 +/- 0.6 m/s）高于TZ（2.8 +/- 0.3 m/s，P= 0.004）或倾向于高于PZ（2.8 +/- 0.4 m/s，P= 0.025）。同样，Phi在PCa中（1.1 +/- 0.1 rad）高于TZ（0.9 +/- 0.2 m/s，P< 0.001）和PZ PCa的nADC值（1.3 ± 0.3）低于TZ（2.2 ± 0.4，P <0.001）和PZ（3.1 ± 0.7，P < 0.001）。合并nADC值与phi呈负相关（R=-0.6，P < 0.001），但与SWS无相关性。TZ和PZ仅在nADC方面存在差异（P< 0.001），但在粘弹性方面没有差异。通过曲线下面积大于0.9来评估PCa与正常前列腺组织的诊断区分，使用nADC和phi是可行的，但SWS不行。结论弹性断层成像可提供前列腺组织力学参数的定量图像。前列腺癌的特征在于僵硬的组织性质和减少的水扩散，而同时，组织流动性增加，表明病变内的机械摩擦更大。这种生物物理特征与已知的组织病理学特征相关，包括细胞密度增加和纤维蛋白积聚。
Objectives Water diffusion, tissue stiffness, and viscosity characterize the biophysical behavior of tumors. However, little is known about how these parameters correlate in prostate cancer (PCa). Therefore, we paired tomoelastography of the prostate with diffusion-sensitive magnetic resonance imaging for the quantitative mapping of biophysical parameters in benign prostatic hyperplasia (BPH) and PCa. Materials and Methods Multifrequency magnetic resonance imaging elastography with tomoelastography processing was performed at 60, 70, and 80 Hz using externally placed compressed-air drivers. Shear-wave speed (SWS) and loss angle (phi) were analyzed as surrogate markers of stiffness and viscosity-related fluidity in the normal peripheral zone (PZ), hyperplastic transition zone (TZ), which is consistent with BPH, and PCa lesions. The SWS and phi were correlated with the normalized apparent diffusion coefficient (nADC). Results Thirty-nine men (median age/range, 67/49-88 years), 25 with BPH and 14 with biopsy-proven PCa, were prospectively enrolled in this institutional review board-approved study. The SWS in PCa (3.1 +/- 0.6 m/s) was higher than in TZ (2.8 +/- 0.3 m/s,P= 0.004) or tended to be higher than in PZ (2.8 +/- 0.4 m/s,P= 0.025). Similarly, phi in PCa (1.1 +/- 0.1 rad) was higher than in TZ (0.9 +/- 0.2 m/s,P< 0.001) and PZ (0.9 +/- 0.1 rad,P< 0.001), whereas nADC in PCa (1.3 +/- 0.3) was lower than in TZ (2.2 +/- 0.4,P< 0.001) and PZ (3.1 +/- 0.7,P< 0.001). Pooled nADC was inversely correlated with phi (R= -0.6,P< 0.001) but not with SWS. TZ and PZ only differed in nADC (P< 0.001) but not in viscoelastic properties. Diagnostic differentiation of PCa from normal prostate tissues, as assessed by area under the curve greater than 0.9, was feasible using nADC and phi but not SWS. Conclusions Tomoelastography provides quantitative maps of tissue mechanical parameters of the prostate. Prostate cancer is characterized by stiff tissue properties and reduced water diffusion, whereas, at the same time, tissue fluidity is increased, suggesting greater mechanical friction inside the lesion. This biophysical signature correlates with known histopathological features including increased cell density and fibrous protein accumulation.