Abteilung für Nephrologie, II. Medizinische Klinik, Klinikum rechts der Isar der TU Munich, Munich, Germany.
Clin Hemorheol Microcirc. 2010;46(2-3):139-48. doi: 10.3233/CH-2010-1340.
Until recently clinical diagnosis of chronic renal allograft dysfunction could only be established invasively by renal biopsy. Given the risks of that procedure, a non-invasive, diagnostic test would be very advantageous. Novel ultrasound-based elasticity tools, using "Acoustic Radiation Force Impulse (ARFI)" technology are now available. Previously this technique has been utilised to quantify liver fibrosis. First results of these studies are promising. The purpose of our study was to investigate correlation between stiffness values obtained by ARFI-quantification and histological fibrosis score in renal transplants.
We employed "Virtual Touch™ tissue quantification" (Siemens Acuson, S2000) to quantitatively measure tissue stiffness in the cortex of transplant kidneys. Eighteen patients were included in this prospective study, recording close temporal ARFI-quantification and fibrosis measurements. All patients undergoing renal transplant biopsy were examined with ARFI-quantification (15 measurements per transplant kidney). Resistive indices were also calculated from pulsed-wave Doppler ultrasound. Transplant biopsies were histologically evaluated by a reference nephropathologist and graded according to the percentage of fibrosis and to the BANFF-score. Due to the non-normal distribution of the data the Spearman-correlation-coefficient (rho) was used to assess the bivariate relationship of ARFI and fibrosis in the transplant kidney.
There was a significant positive moderate correlation between mean ARFI-values and the grade of fibrosis (rho = +0.465; p = 0.026). This correlation was also valid for the mean ARFI-values and the BANFF-category (rho = +0.468; p = 0.025). There was no significant correlation between the mean ARFI-values and the resistive indices in the transplant kidney (rho = +0.034; p = 0.904). Nevertheless, a positive correlation between the mean RI-values of the kidney and the grade of fibrosis was established (rho = +0.563; p = 0.015).
The mean values of ARFI measurements and the resistive indices are potentially independent explanation variables for evaluating the grade of fibrosis in transplant kidneys.
直到最近，慢性肾移植功能障碍的临床诊断只能通过肾活检进行有创性诊断。鉴于该手术的风险，非侵入性的诊断测试将非常有利。目前已经有了基于新型超声的弹性工具，使用“声辐射力脉冲（ARFI）”技术。该技术以前曾用于量化肝纤维化。这些研究的初步结果很有希望。我们研究的目的是探讨 ARFI 定量获得的硬度值与移植肾组织纤维化评分之间的相关性。
我们采用“虚拟触诊组织定量技术（Siemens Acuson，S2000）”定量测量移植肾皮质的组织硬度。本前瞻性研究纳入 18 例患者，记录了 ARFI 定量和纤维化测量的时间接近。所有接受肾移植活检的患者均接受 ARFI 定量检查（每个移植肾 15 次测量）。还从脉冲波多普勒超声计算了阻力指数。移植活检由参考肾病理学家进行组织学评估，并根据纤维化百分比和 BANFF 评分进行分级。由于数据呈非正态分布，因此使用 Spearman 相关系数（rho）评估 ARFI 与移植肾纤维化之间的双变量关系。
平均 ARFI 值与纤维化程度呈显著正中度相关（rho = +0.465；p = 0.026）。这种相关性对于平均 ARFI 值和 BANFF 类别也是有效的（rho = +0.468；p = 0.025）。平均 ARFI 值与移植肾的阻力指数之间无显著相关性（rho = +0.034；p = 0.904）。然而，确立了肾平均 RI 值与纤维化程度之间的正相关（rho = +0.563；p = 0.015）。
ARFI 测量的平均值和阻力指数是评估移植肾纤维化程度的潜在独立解释变量。
