高血压与脑小血管病患者磁共振弥散张量成像的相关性研究

目的探讨高血压与脑小血管病(SVD)患者磁共振弥散张量成像(DTI)的关系。方法选择55例SVD患者分为血压正常组19例和高血压组36例。行MRI和DTI检查,观察感兴趣区部分各向异性(FA)及表观扩散系数(ADC)的变化,分析其与血压的相关性。结果与血压正常组比较,高血压组左、右侧半卵圆中心和左侧额叶FA值显著降低(P<0.01);左侧半卵圆中心ADC值显著升高(P<0.05)。Pearson相关分析显示,高血压组左、右侧半卵圆中心FA值与收缩压呈负相关(r=-0.338,P=0.044;r=-0.334,P=0.046);左侧半卵圆中心和左侧额叶FA值与舒张压呈负相关(r=-0.419,P=0.011;r=-0.355,P=0.034);右侧半卵圆中心ADC值与舒张压呈正相关(r=0.336,P=0.045)。结论 DTI能够更敏感地显示高血压对SVD患者脑微观结构的损害,为评价高血压性脑损伤提供研究工具。     

肝性脑病的脑磁共振弥散张量成像特点分析

目的评价脑弥散张量成像(DTI)在肝性脑病(HE)诊断中的价值。方法 39例肝炎后肝硬化患者,其中伴HE18例(HE组),不伴HE 21例(肝硬化组),27例健康成人(正常组)。对三组行颅脑DTI扫描,测量分析DTI图像上脑深部灰质或白质区的各感兴趣区6个测量部位中的平均弥散率(MD)及各向异性分数值(FA)。结果肝硬化组与正常组MD与FA值无显著差异。与肝硬化组比较,HE组2个部位的MD值显著升高(P<0.05),4个部位的FA值显著降低(P<0.05);与正常组比较,HE组4个部位的MD值显著升高(P<0.05),4个部位的FA值显著降低(P<0.05)。结论 HE患者脑细胞外间隙水肿及细胞毒性水肿同时存在,DTI诊断HE有一定价值。     

磁共振弥散张量成像在神经疾病中的应用

磁共振弥散张量成像(DTI)是近几年发展起来的水弥散成像技术,它通过脑水分子的弥散性定量反映脑白质纤维束的完整性。文章简要介绍了DTI的基本概念及其在脑梗死、多发性硬化、癫、Alzheimer病和颅内肿瘤等多种神经疾病中的应用。     

磁共振弥散张量成像在神经疾病中的应用

磁共振弥散张量成像（DT）是近几年发展起来的水弥散成像技术，它通过脑水分子的弥散性定量反映脑白质纤维束的完整性。文章简要介绍了DTI的基本概念及其在脑梗死、多发性硬化、癫痫、Alzheimer病和颅内肿瘤等多种神经疾病中的应用。     

磁共振弥散张量成像在脑小血管病中的应用

<正>脑小血管病(cerebral small vessel disease,SVD)是指脑小血管的各种病变所导致的临床、认知、影像学及病理表现的综合征[1]。包括小动脉、微动脉、毛细血管和小静脉疾病,目前普遍指脑小动脉及微动脉血管病,累及的是直径为30~300μm脑内皮质/穿髓小动脉。在西方国家,SVD占所有缺血性脑卒中的25%。2007~2008年中国国家卒中登记的住院患者中,小动脉闭塞型占17.2%[2]。近十多年的研究发     

线粒体脑肌病:常规MRI与弥散加权成像及弥散张量成像的比较

线粒体脑肌病是主要累及中枢神经系统和骨骼肌且具有遗传异质性的一组疾病。诊断主要根据肌肉的组织病理学检查、极谱法和分光光度计研究以及线粒体或核DNA基因突变分析。常规T_2加权(T_2W)磁共振成像(MRI)可见不按血管分布的灰质和皮层下白质高信号,白质损害可能与小血管缺血和脱髓鞘有关。作者对1例经活检证实为线粒体脑肌病的患者进行磁共振弥散加权成像、弥散张量成像和质子磁共振波谱(MRS)检查。结果表明弥散加权     

磁共振弥散张量成像在脑梗死诊断中的价值

目的分析脑梗死患者磁共振弥散张量成像(DTI)的特点,探讨DTI在不同时期对脑梗死患者诊断的价值。方法分别对40例不同时期脑梗死患者和40名健康志愿者行MR I检查,包括T1、T2加权成像、弥散加权成像及DTI,重建部分各向异性(FA)图,对梗死区、健侧相应部位及正常对照组相应部位进行FA值、表观弥散系数(ADC)值测量。结果①DTI显示的梗死灶范围较常规MR I成像更加准确、清晰。②脑梗死组患者梗死区及梗死同侧内囊后肢、大脑脚、皮质脊髓束的FA值分别为0.12±0.01、0.29±0.03、0.36±0.12及0.35±0.04,低于对侧相应部位的0.35±0.08、0.50±0.13、0.53±0.14、0.56±0.07,差异均具有显著性(P<0.05);脑梗死患者健侧ADC、FA值与正常对照组相应部位对比,差异无显著性(P>0.05)。③脑梗死后脑组织FA值、ADC值随梗死时间呈一定规律性变化,在超早期患侧FA值较对侧无一致性变化,可轻度升高或轻度降低,随后(急性期、亚急性期、慢性期)降低;患侧ADC值随梗死时间延长呈明显减低、逐渐恢复正常、继而又升高的规律。结论DTI检查有助于明确脑梗死是否累及白质纤维束,ADC值与FA值联合能更精确对脑梗死进行临床分期和定位。     

慢性肾脏病患者肾功能状态与冠状动脉病变的关系

目的：探讨慢性肾脏病（ CKD）合并冠心病患者冠状动脉病变的严重程度,分析不同肾功能状态与冠状动脉病变的相关性。方法选取396例疑诊冠心病的CKD患者,根据估算的肾小球滤过率（ eGFR）水平分为eG-FR正常、轻度降低、中度降低和重度降低4组,探讨不同肾功能状态对冠状动脉病变狭窄严重程度的影响和相关性。结果冠状动脉造影提示,eGFR降低组的冠心病发病率显著高于eGFR正常组,且病变支数更多、3支病变率显著增高及Gensini积分显著增多（P均＜0．01）。冠心病发病率随肾功能降低而明显增高（P＜0．05）。 CKD与冠心病存在显著关联（OR＝1．38,95％CI为1．23～1．86,P＜0．01）。结论 CKD合并冠心病患者冠状动脉狭窄程度严重,且肾功能降低与冠状动脉狭窄程度呈独立正相关,CKD是冠心病的独立危险因素。     

弥漫性轴索损伤磁共振弥散张量成像研究进展

弥漫性轴索损伤在临床工作中常见,诊断及治疗困难,预后不佳.弥散张量成像是能定性定量显示组织结构完整性、病理改变及功能变化的新技术,在DAI的诊断、疗效观察及预后评估各方面意义重大.     

The diagnostic efficacy of diffusion tensor imaging generated by gadolinium-based magnetic resonance imaging for patients with chronic kidney disease

Background:Chronic kidney disease (CKD) can lead to systemic inflammatory responses and other cardiovascular disease. Diffusion tensor imaging findings generated by gadolinium-based MRI (DTI-GBMRI) is regarded as a standard method for assessing the pathology of CKD. To evaluate the diagnostic value of DTI-GBMRI for renal histopathology and renal efficiency, renal fibrosis and damage, noninvasive quantification of renal blood flow (RBF) were investigated in patients with CKD.Methods:CKD patients (n = 186) were recruited and underwent diagnosis of renal diffusion tensor imaging findings generated by MRI (DTI-MRI) or DTI-GBMRI to identify the pathological characteristics and depict renal efficiency. The cortical RBFs and estimated glomerular filtration rate were compared in CKD patients undergone DTI-GBMRI (n = 92) or DTI-MRI (n = 94).Results:Gadolinium enhanced the diagnosis generated by DTI-MRI in renal fibrosis, renal damage, and estimated glomerular filtration rate. The superiority in sensitivity and accuracy of the DTI-GBMRI method in assessing renal function and evaluating renal impairment was observed in CKD patients compared with DTI-MRI. Outcomes demonstrated that DTI-GBMRI had higher accuracy, sensitivity, and specificity than DTI-MRI in diagnosing patients with CKD.Conclusion:In conclusion, DTI-GBMRI is a potential noninvasive method for measuring renal function, which can provide valuable information for clinical CKD diagnosis.     

Use of renin angiotensin system inhibitors in patients with chronic kidney disease

Current guidelines recommend renin angiotensin system inhibitors (RASI) as key components of treatment of hypertension in patients with chronic kidney disease (CKD), because of their effect on reducing the future rate of loss of glomerular filtration rate (GFR). A common risk of RASI in CKD is a haemodynamically mediated, and reversible, fall in GFR of varying severity and duration, any time after commencement of the Inhibitors. A benefit of the acute reduction in filtration rate with RASI may be a reduction in the future rate of loss in GFR: the greatest benefit likely to be in those patients with a greater rate of loss of GFR prior to, and a lesser acute loss of GFR after, introduction of RASI; and in those patients with significant proteinuria. An acute loss of GFR of >25% following the introduction of RASI is an indication to cease the RASI. An acute loss of GFR < 25% requires consideration of the likely risks of the lower GFR and benefits of any future reduced rate of loss of GFR. A fall in GFR in patients while on RASI is usually associated with a remediable cause. When the cause for the fall in GFR is not revealed, and the fall is less than 25%, hopeful expectancy is recommended. Hyperkalaemia in patients with CKD on RASI is more common with more severe disease, potassium retaining diuretics and hypoaldosteronism. Treatment should be modified to maintain a plasma potassium <6 mmol/L.     

Chronic kidney disease: A likely underestimated component of multimorbidity in older patients with chronic obstructive pulmonary disease

The coexistence of chronic kidney disease and chronic obstructive pulmonary disease, two age‐related conditions, has important clinical and prognostic implications. Respiratory failure is associated with important changes in glomerular and tubulointerstitial function. In contrast, renal failure can affect lung function, mainly by adding a restrictive component or causing complications, such as uremic pulmonary edema and pleural effusion. The effect of age on renal and pulmonary function adds to the complexity of the interplay between the kidney and the lung in these patients. Chronic kidney disease also represents an important risk factor for adverse drug reactions in older chronic obstructive pulmonary disease patients in which multimorbidity and polypharmacy are highly prevalent. Finally, an additive effect of chronic kidney disease and chronic obstructive pulmonary disease might also contribute to the pathophysiology of sarcopenia. Nevertheless, several gaps in our knowledge of the lung–kidney interplay still exist, thus suggesting further basic and clinical research on this topic. Geriatr Gerontol Int 2017; 17: 1770–1788.     

脑白质小血管缺血性病变的MRS、DTI研究

目的应用磁共振波谱（MRS）与磁共振弥散张量成像（DTI）,分析脑白质小血管缺血性病变的微观改变。方法选取发生在半卵圆中心、放射冠区的脑白质小血管缺血性病变患者作为研究对象,其中急性腔隙性梗死组（腔梗组）病灶12例,缺血性脑白质疏松组（疏松组）病灶20例,并设置15例正常志愿者作为对照组,行半卵圆中心、放射冠区T1WI、T2WI、T2FLAIR、DWI、MRS、DTI扫描。测量N-乙酰天门冬氨酸（NAA）、胆碱（Cho）、肌酸（Cr）值,测量平均弥散系数（MD）值,各向异性分数（FA）值。比较各组间的差异。结果与对照组比较,腔梗组与疏松组NAA、FA值均显著降低（P〈0.01）,腔梗组与疏松组之间,NAA、FA值没有明显差异（P〉0.05）。结论在脑白质小血管缺血性病变中,NAA、FA值显著降低,共同反映了神经轴突髓鞘结构和功能的损伤、破坏;联合应用MRS、DTI分析评价脑白质小血管缺血性病变,将有助于全面认识其发病机制及病理改变。     

Microvascular changes at different stages of chronic kidney disease

Patients with progressing chronic kidney disease (CKD) are more likely to experience cardio‐ and cerebrovascular events than progressing to end‐stage renal disease. The authors explored whether retinal microvascular calibers differed with the degree of renal impairment and between the standard and extended optic disk and may serve as a simple additional tool for risk stratification in this highly vulnerable patient cohort. The authors analyzed central retinal arteriolar and venular equivalent calibers (CRAE, CRVE) at different retinal zones (zone B&C) using digital retinal imaging in hypertensive patients with stage 2 (n = 66) or stage 3 CKD (n = 30). Results were adjusted for age, sex, HbA1c, and 24‐hour diastolic blood pressure. Mean eGFR was 77.7 ± 8.9 and 48.8 ± 7.9 ml/min/1.73 m² for stage 2 and 3 CKD, respectively. CRAE and CRVE in zones B and C were significantly lower in patients with stage 3 CKD compared to patients with stage 2 CKD (CRAE‐B:141.1 ± 21.4 vs. 130.5 ± 18.9 µm, p = .030; CRAE‐C:137.4 ± 19.4 vs 129.2 ± 18.2 µm, p = .049; CRVE‐B:220.8 ± 33.0 vs. 206.0 ± 28.4 µm, p = .004; and CRVE‐C:215.9 ± 33.0 vs. 201.2 ± 25.1µm, p = .003). In patients with stage 2 CKD, CRAE‐B was higher than CRAE‐C (141.1 ± 21.4 vs. 137.4 ± 19.4µm, p < .001). In contrast, such a difference was not found in patients with stage 3 CKD. CRAE of both retinal zones correlated with eGFR for the entire cohort. In patients with stage 3 CKD, retinal narrowing is more pronounced compared to patients with stage 2 CKD. Whether the novel observation of difference in arteriolar caliber between zones B and C in stage 2 CKD could serve as an early marker of CKD progression warrants further investigation.     

Assessing the prevalence, monitoring and management of chronic kidney disease in patients with diabetes compared with those without diabetes in general practice.

AIMS: To compare rates of chronic kidney disease (CKD) in patients with diabetes and management of risk factors compared with people without diabetes using general practice computer records, and to assess the utility of serum creatinine and albuminuria as markers of impaired renal function. METHODS: The simplified Modification of Diet in Renal Disease (MDRD) equation was used to estimate glomerular filtration rate (eGFR) and stage of CKD. Further data were extracted to assess how effectively impaired renal function was being identified and how well potentially modifiable risk factors were being managed. The setting was 17 practices in Surrey, Kent and Greater Manchester (2003-2004). Participants were all patients with serum creatinine (SCr) recorded. RESULTS: Of the total population of 162 113, 5072 were recorded as having a diagnosis of diabetes, giving a prevalence of 3.1%. Of patients with diabetes, 31% had clinically significant CKD (defined as eGFR < 60 ml/min per 1.73 m(2); CKD stages 3-5) compared with 6.9% of those without diabetes. Only 33% of patients with diabetes at CKD stage 3 had serum creatinine > 120 micromol/l. Of patients with diabetes with eGFR < 60 ml/min per 1.73 m(2), 63% had normoalbuminuria. Considering those with eGFR 30-60 ml/min per 1.73 m(2), 42% of people with diabetes were on an ACE inhibitor compared with 25% of those without diabetes; 32% of patients with diabetes who had any record of micro- or macroalbuminuria at CKD stage 3 were taking an ACE inhibitor. Of people with diabetes and hypertension (BP > 140/80 mmHg), 26% were not prescribed any hypertensive medication, regardless of level of CKD. CONCLUSIONS: CKD is common in people with diabetes living in the community in the UK. The study found a similar rate of stage 3-5 CKD to that found previously in the USA. Currently used measures of renal function fail to identify CKD as effectively as eGFR. Risk factors for CKD and its progression are suboptimally managed.     

Comparison of prediction equations to estimate glomerular filtration rate in Chinese patients with chronic kidney disease

Aim: We sought to evaluate the applicability of formulae based on serum creatinine (SC) levels in Chinese patients with chronic kidney disease (CKD). Materials and methods: Three hundred and twenty‐seven patients with CKD who had undergone ^99mTc‐DTPA glomerular filtration rate (GFR) estimation were enrolled. The Cockcroft–Gault equation, SC‐reciprocal equation, Gate equation, Hull equation, Jelliffe‐1973 equation, Jelliffe‐1971 equation, Mawer equation, Bjornsson equation, reexpressed 6‐variable MDRD equation and reexpressed 4‐variable MDRD equation were compared. Using the ^99mTc‐DTPA GFR as the standard GFR (sGFR), the accuracy of estimated GFR was compared with sGFR in various stages of CKD. Results: Median per cents of the absolute difference ranged from 28.16% to 39.39%, accuracy with a deviation less than 30% ranging from 39.4% to 53.5%, accuracy with a deviation less than 50% ranging from 63.0% to 80.7%. None of the equations had accuracy up to the 70% level with a deviation less than 30% from sGFR. Bland–Altman analysis demonstrated that mean difference ranged from ?2.42 to 16.39 mL/min/1.73 m², whereas precision ranged from 82.66 to 106.15 mL/min/1.73 m². However, the agreement limits of all the equations exceeded the prior acceptable tolerances defined as 60 mL/min/1.73 m². Linear regression showed that the slopes of regression line ranged from 0.37 to 0.54 and intercepts ranged from ?12.10 to 3.86. When the overall performance as well as bias and accuracy were compared in different stages of CKD, GFR estimated by Jelliffe‐1973 equation, Cockcroft–Gault equation and Bjornsson equation showed promising results. Conclusion: When SC was measured by the enzymatic method, GFR estimation equations showed great bias in Chinese CKD patients. At present, the Jelliffe‐1973 equation and Cockcroft–Gault equation may be more accurate in the Chinese ethnic group.     

The high prevalence of unrecognized anaemia in patients with diabetes and chronic kidney disease: a population-based study

Background Anaemia occurs early in the course of diabetes-related chronic kidney disease (CKD). There is little evidence about the prevalence of anaemia in people with diabetes. The aim of this study was to assess the prevalence of anaemia, by stage of CKD, in the general diabetic population. Methods Haemoglobin (Hb) was measured on all glycated haemoglobin (HbA_1c) samples and the most recent (< 4 months) estimated glomerular filtration rate (eGFR) was obtained. Anaemia (at treatment level) was defined as Hb < 110 g/l or the use of erythropoetic stimulating agents (ESA). Results Twelve per cent (10–14%) of people had Hb < 110 g/l. The prevalence of anaemia increased progressively with worsening CKD. People with CKD stage 3 accounted for the largest number of people with anaemia; 18% (95% CI 13–24%) had Hb < 110 g/l. Those with eGFR < 60 ml/min/1.73 m² and not on ESA or dialysis were four (2–7) times more likely than patients with better renal function to have Hb < 110 g/l. The relation between Hb and eGFR became approximately linear below an eGFR of 83 ml/min/1.73 m², where, for every 1 ml/min/1.73 m² fall in eGFR, there was a 0.4 (0.3–0.5) g/l fall in haemoglobin. Conclusions This study demonstrates that anaemia, at levels where treatment is indicated, occurs commonly in people with diabetes and CKD stage 3 or worse. The screening for anaemia in current diabetes management should be extended.