磁共振成像测量肾动脉血流和肾体积能否预测经皮腔内肾血管成形术的结果？

Can MR measurement of renal artery flow and renal volume predict the outcome of percutaneous transluminal renal angioplasty?

作者信息

Binkert C A, Debatin J F, Schneider E, Hodler J, Ruehm S G, Schmidt M, Hoffmann U

机构信息

Department of Radiology, University Hospital Zurich, Switzerland.

出版信息

Cardiovasc Intervent Radiol. 2001 Jul-Aug;24(4):233-9. doi: 10.1007/s00270-001-0005-y.

DOI:10.1007/s00270-001-0005-y

PMID:11779012

Abstract

PURPOSE

Predicting therapeutic benefit from percutaneous transluminal renal angioplasty (PTRA) in patients with renal artery stenosis (RAS) remains difficult. This study investigates whether magnetic resonance (MR)-based renal artery flow measurements relative to renal parenchymal volume can predict clinical outcome following PTRA.

METHODS

The data on 23 patients (13 men, 10 women; age range 47-82 years, mean age 64 years) were analyzed. The indication for treatment was hypertension (n = 18) or renal insufficiency (n = 5). Thirty-four cases of RAS were identified: bilateral disease was manifest in 11 and unilateral disease in 12 patients. The MR imaging protocol included a breath-hold, cardiac-gated cine phase-contrast sequence for renal flow measurement and a fast multiplanar spoiled gradient-echo sequence for renal volume measurement. MR measurements were performed on the day prior to and the day following PTRA. Clinical success was defined as (a) a reduction in diastolic blood pressure > 15% or (b) a reduction in serum creatinine > 20%. Kidneys were categorized as normal volume or low volume. A renal flow index (RFI) was calculated by dividing the renal flow (ml/min) by the renal volume (cm3).

RESULTS

Clinical success was observed in patients. Twelve patients did not benefit from angioplasty. Normal kidney volume was seen in 10 of 11 responders and in 8 of 12 nonresponders, resulting in a sensitivity of 91%, specificity of 33%, a positive predictive value (PPV) of 56% and a negative predictive value (NPV) of 80%. A RFI below a threshold of 1.5 ml/min/cm3 predicted successful outcome with 100% sensitivity, 33% specificity, 58% PPV, and 100% NPV. The combination of normal renal volume and a RFI below 1.5 ml/min/cm3 identified PTRA responders with a sensitivity of 91%, a specificity of 67%, a PPV of 71%, and a NPV of 89%. PTRA resulted in a greater increase in renal flow in responders compared with nonresponders (p < 0.001).

CONCLUSION

A combination of cine phase-contrast MR renal flow and parenchymal volume measurements enables identification of patients benefiting from PTRA with a high sensitivity and NPV, but only moderate specificity and PPV.

摘要

目的

预测经皮腔内肾血管成形术（PTRA）对肾动脉狭窄（RAS）患者的治疗效果仍然困难。本研究调查基于磁共振（MR）的肾动脉血流测量相对于肾实质体积是否能预测PTRA后的临床结果。

方法

分析了23例患者（13例男性，10例女性；年龄范围47 - 82岁，平均年龄64岁）的数据。治疗指征为高血压（n = 18）或肾功能不全（n = 5）。共识别出34例RAS病例：11例为双侧病变，12例为单侧病变。MR成像方案包括用于肾血流测量的屏气、心脏门控电影相位对比序列和用于肾体积测量的快速多平面扰相梯度回波序列。在PTRA前一天和后一天进行MR测量。临床成功定义为：（a）舒张压降低> 15%或（b）血清肌酐降低> 20%。肾脏分为正常体积或低体积。肾血流指数（RFI）通过将肾血流（ml/min）除以肾体积（cm³）计算得出。

结果

观察到患者有临床成功情况。12例患者未从血管成形术中获益。11例有反应者中有10例肾体积正常，12例无反应者中有8例肾体积正常，敏感性为91%，特异性为33%，阳性预测值（PPV）为56%，阴性预测值（NPV）为80%。RFI低于1.5 ml/min/cm³的阈值预测成功结果的敏感性为100%，特异性为33%，PPV为58%，NPV为100%。肾体积正常且RFI低于1.5 ml/min/cm³的组合识别PTRA有反应者的敏感性为91%，特异性为67%，PPV为71%，NPV为89%。与无反应者相比，PTRA使有反应者的肾血流增加更大（p < 0.001）。