Grenier N, Trillaud H, Combe C, Degrèze P, Jeandot R, Gosse P, Douws C, Palussière J
Service de Radiologie, Groupe Hospitalier Pellegrin, Bordeaux, France.
AJR Am J Roentgenol. 1996 Apr;166(4):835-43. doi: 10.2214/ajr.166.4.8610560.
Angiotensin-converting enzyme inhibitors may decrease glomerular filtration rate when a significant renal artery stenosis is present. The purpose of this preliminary study is to evaluate the feasibility of captopril-sensitized, dynamic MR imaging of the kidney in a series of patients with a high suspicion of renovascular hypertension and to compare the results with those of captopril scintigraphy.
Fifteen hypertensive patients with renal artery stenosis shown by angiography were studied with sequential gadolinium-enhanced MR imaging after oral administration of 50 mg of captopril, an inhibitor of angiotensin-converting enzyme. Symmetry of onset and evolution of tubular phases between the two kidneys were analyzed, and medullary signal intensity time curves were drawn for each kidney. When asymmetry between kidneys was noted, the same dynamic study was repeated 24 hr later, without captopril sensitization. All patients also underwent renal scintigraphy after administration of captopril to compare captopril-induced changes in both techniques. Three-dimensional time-of-flight MR angiography was also performed on all patients.
MR imaging with normal and symmetric tubular phases showed that 11 patients had no impairment of glomerular filtration after administration of captopril. MR imaging showed that four had impairment of glomerular filtration: studies without captopril were symmetric (n = 2) or slightly asymmetric (n = 2), but administration of captopril induced severe functional impairment on the side of stenosis--that is, a delayed tubular phase with late corticomedullary decrease of signal intensity in the first two patients and absence of tubular phase in the other two. The results of scintigraphy were concordant in all but one case, in which the segmental distribution of filtration impairment, shown by MR imaging, was not shown by scintigraphy. The renal artery stenosis was shown by MR angiography in 10 of 15 patients (67%).
Captopril-sensitized dynamic MR imaging of the kidney is feasible in patients with renovascular hypertension. However, captopril-induced changes are not present in all patients proven to have the disease. Scintigraphy provides similar results but may ignore segmental functional involvement.
当存在显著肾动脉狭窄时，血管紧张素转换酶抑制剂可能会降低肾小球滤过率。本初步研究的目的是评估卡托普利激发的动态肾脏磁共振成像在一系列高度怀疑肾血管性高血压患者中的可行性，并将结果与卡托普利闪烁扫描的结果进行比较。
对15例经血管造影显示有肾动脉狭窄的高血压患者，口服50mg血管紧张素转换酶抑制剂卡托普利后，进行序贯钆增强磁共振成像研究。分析两肾之间肾小管期起始和演变的对称性，并为每个肾脏绘制髓质信号强度时间曲线。当发现两肾不对称时，24小时后在未用卡托普利激发的情况下重复相同的动态研究。所有患者在服用卡托普利后也接受了肾脏闪烁扫描，以比较两种技术中卡托普利引起的变化。所有患者还进行了三维时间飞跃磁共振血管造影。
肾小管期正常且对称的磁共振成像显示，11例患者服用卡托普利后肾小球滤过无损害。磁共振成像显示4例有肾小球滤过损害：未用卡托普利的研究结果对称（2例）或稍不对称（2例），但服用卡托普利后狭窄侧出现严重功能损害，即前2例患者肾小管期延迟，皮质髓质信号强度后期降低，另2例患者无肾小管期。除1例病例外，闪烁扫描结果均一致，该病例中磁共振成像显示的滤过损害节段分布在闪烁扫描中未显示。15例患者中有10例（67%）通过磁共振血管造影显示有肾动脉狭窄。
卡托普利激发的肾脏动态磁共振成像在肾血管性高血压患者中是可行的。然而，并非所有经证实患有该病的患者都会出现卡托普利引起的变化。闪烁扫描提供了类似的结果，但可能会忽略节段性功能受累情况。
