弥散加权体素内不相干运动成像与肾肿瘤的组织病理学相关性。

Diffusion-weighted intravoxel incoherent motion imaging of renal tumors with histopathologic correlation.

机构信息

Department of Radiology, New York University Langone Medical Center, New York, NY10016, USA.

出版信息

Invest Radiol. 2012 Dec;47(12):688-96. doi: 10.1097/RLI.0b013e31826a0a49.

DOI:10.1097/RLI.0b013e31826a0a49

PMID:22996315

Abstract

PURPOSE

The aim of this study was to use intravoxel incoherent motion diffusion-weighted imaging to discriminate subtypes of renal neoplasms and to assess agreement between intravoxel incoherent motion (perfusion fraction, fp) and dynamic contrast-enhanced magnetic resonance imaging (MRI) metrics of tumor vascularity.

SUBJECTS AND METHODS

In this Health Insurance Portability and Accountability Act-compliant, institutional review board-approved prospective study, 26 patients were imaged at 1.5-T MRI using dynamic contrast-enhanced MRI with high temporal resolution and diffusion-weighted imaging using 8 b values (range, 0-800 s/mm). Perfusion fraction (fp), tissue diffusivity (Dt), and pseudodiffusivity (Dp) were calculated using biexponential fitting of the diffusion data. Apparent diffusion coefficient (ADC) was calculated with monoexponential fit using 3 b values of 0, 400, and 800 s/mm. Dynamic contrast-enhanced data were processed with a semiquantitative method to generate model-free parameter cumulative initial area under the curve of gadolinium concentration at 60 seconds (CIAUC60). Perfusion fraction, Dt, Dp, ADC, and CIAUC60 were compared between different subtypes of renal lesions. Perfusion fraction was correlated with CIAUC60.

RESULTS

We examined 14 clear cell, 4 papillary, 5 chromophobe, and 3 cystic renal cell carcinomas (RCCs). Although fp had higher accuracy (area under the curve, 0.74) for a diagnosis of clear cell RCC compared with Dt or ADC, the combination of fp and Dt had the highest accuracy (area under the curve, 0.78). The combination of fp and Dt diagnosed papillary RCC and cystic RCC with 100% accuracy, and clear cell RCC and chromophobe RCC, with 86.5% accuracy. There was significant strong correlation between fp and CIAUC60 (r = 0.82; P < 0.001).

CONCLUSION

Intravoxel incoherent motion parameters fp and Dt can discriminate renal tumor subtypes. Perfusion fraction demonstrates good correlation with CIAUC60 and can assess degree of tumor vascularity without the use of exogenous contrast agent.

摘要

目的

本研究旨在利用体素内不相干运动扩散加权成像来区分肾肿瘤亚型，并评估体素内不相干运动（灌注分数，fp）与肿瘤血管生成的动态对比增强磁共振成像（MRI）指标之间的一致性。

材料与方法

在这项符合《健康保险流通与责任法案》、机构审查委员会批准的前瞻性研究中，26 名患者在 1.5-T MRI 上进行成像，使用高时间分辨率的动态对比增强 MRI 和 8 个 b 值的扩散加权成像（范围：0-800 s/mm）。使用双指数拟合扩散数据计算灌注分数(fp)、组织扩散系数(Dt)和假性扩散系数(Dp)。使用 3 个 b 值（0、400 和 800 s/mm）的单指数拟合计算表观扩散系数(ADC)。使用半定量方法处理动态对比增强数据，生成 60 秒时钆浓度累积初始曲线下面积的无模型参数（CIAUC60）。比较不同肾病变亚型之间的灌注分数、Dt、Dp、ADC 和 CIAUC60。相关性分析灌注分数与 CIAUC60 的相关性。

结果

我们检查了 14 个透明细胞癌、4 个乳头状癌、5 个嫌色细胞癌和 3 个囊性肾细胞癌（RCC）。尽管与 Dt 或 ADC 相比，fp 对透明细胞 RCC 的诊断具有更高的准确性（曲线下面积，0.74），但 fp 和 Dt 的组合具有最高的准确性（曲线下面积，0.78）。fp 和 Dt 的组合对乳头状 RCC 和囊性 RCC 的诊断准确率为 100%，对透明细胞 RCC 和嫌色细胞 RCC 的诊断准确率为 86.5%。fp 与 CIAUC60 之间存在显著的强相关性（r=0.82；P<0.001）。