Role of functional magnetic resonance imaging in evaluating renal hypoxic injury in mice with lupus nephritis

To investigate the utility of diffusion weighted imaging (DWI) and blood oxygen level-dependent (BOLD) magnetic resonance imaging (MRI) in the assessment of renal hypoxia in an experimental model of mice with lupus nephritis（LN). Methods MRL/lpr mice (n=13) were studied and C57BL/6 mice (n=10) served as controls. Urinary albumin to creatinine ratio (ACR), serum creatinine (Scr), anti-ds-DNA antibody, and complement C3 levels were measured. The mice underwent coronal echo-planar DWI and BOLD MRI of the kidneys when they were 14-16 weeks old. Hypoxyprobe was administered intraperitoneally to the mice 1 hour before they were sacrificed. The distribution of HypoxyprobeTM-1, hypoxia-inducible factor 1α (HIF-1α) and heme oxygenase-1 (HO-1) in renal tissues was detected by immunohistochemical analysis and Western blotting. Results Urinary ACR, Scr and anti-ds-DNA antibody levels in MRL/lpr mice were significantly higher than that in C57BL/6 mice. It was found that HypoxyprobeTM-1, HIF-1α and HO-1 distributed widely in the renal tissue of MRL/lpr mice, and closely associated with the renal tubulointerstitial lesion. The mean apparent diffusion coefficient (ADC) value of kidneys in MRL/lpr mice was (1.52±0.27) ×10-3 mm2/s, and the mean R2* values of the renal cortex and medulla were (30.95±4.59)/s and (23.43±3.06)/s respectively, all significantly lower than that in C57BL/6 mice (P=0.037, P=0.030 and P=0.043, respectively). The ADC of medulla was negatively correlated with urinary albumin to creatinine ratio (r=-0.364, P=0.032; r=-0.329, P=0.050), the ADC of cortex was negatively correlated with the level of serum creatinine (r=-0.814, P=0.014; r=-0.755, P=0.031) when b value was 500 s/mm2 and 800 s/mm2, and the mean R2* value was negatively correlated with the degree of tubulointerstitial lesions and the expression of hypoxia parameters (all P＜0.05). Conclusions Renal hypoxia may play an important role in renal tubulointerstitial lesion. Functional MRI may be used to monitor renal function changes, pathological injuries and renal hypoxia in LN.     

血氧水平依赖的磁共振成像对早期移植肾排异的诊断和预测作用

目的 探讨血氧水平依赖的功能磁共振成像（BOLD-MRI）在早期移植肾排异中的诊断和预测作用。 方法 纳入2005年12月至2007年3月在浙江大学医学院附属第一医院肾脏病中心首次接受同种异体尸体肾移植患者共103例，分为肾功能正常组82例，急性排异组（病理证实）21例，记录两组的基线资料并测量移植肾皮、髓质磁共振参数R2*。 结果 急性排异组髓质R2*（MR2*）值显著低于肾功能正常组[（14.02±2.68）/s比（16.66±2.82）/s，P < 0.01]；ROC曲线分析显示MR2*值可作为急性排异的辅助诊断指标；肾功能正常组中低水平MR2*值（MR2*<14.9/s，23例）者日后发生急性排异的比例高于高水平MR2*值（MR2*≥14.9/s，59例）者，但差异无统计学意义（17.39％ 比 8.47％，P ＝ 0.259）。 结论 移植肾MR2*值可以作为肾移植术后早期急性排异的辅助诊断指标，并且可能有一定的预测价值。     

Noninvasive evaluation of kidney hypoxia and fibrosis using magnetic resonance imaging

Interstitial fibrosis and hypoxia accelerate the progression of CKD, but clinical tools to quantitate these factors in patients are lacking. Here, we evaluated the use of two magnetic resonance imaging (MRI) techniques, diffusion-weighted (DW)-MRI and blood oxygen level-dependent (BOLD)-MRI, to assess kidney fibrosis and hypoxia of the cortex in 142 patients with either diabetic nephropathy (n = 43), CKD without diabetes (n = 76), or acute kidney injury (AKI) (n = 23). Apparent diffusion coefficient (ADC) values of DW-MRI correlated with estimated glomerular filtration rates (eGFR) in the diabetic nephropathy and CKD groups (r(2) = 0.56 and r(2) = 0.46, respectively). Although the T2* values of BOLD-MRI and eGFR displayed good correlation in the CKD group (r(2) = 0.38), we did not observe a significant correlation between these values in the diabetic nephropathy group, suggesting that factors other than tubulointerstitial alteration determine the degree of hypoxia in the renal cortex. In the AKI group, neither the T2* nor ADC values correlated with eGFR. Renal biopsies from patients with CKD demonstrated that the T2* and ADC MRI values correlated with renal pathology. Taken together, ADC and T2* values appear to serve as accurate indices for evaluating renal tubulointerstitial alterations and parenchymal hypoxia, respectively, in the cortex. Functional MRI can thus contribute to multilateral, noninvasive, in vivo assessment of kidney function.     

The use of magnetic resonance to evaluate tissue oxygenation in renal artery stenosis

Vascular occlusive disease poses a threat to kidney viability, but whether the events leading to injury and eventual fibrosis actually entail reduced oxygenation and regional tissue ischemia is unknown. Answering this question has been difficult because of the lack of an adequate method to assess tissue oxygenation in humans. BOLD (blood oxygen-level-dependent) magnetic resonance imaging detects changes in tissue deoxyhemoglobin during maneuvers that affect oxygen consumption, therefore this technique was used to image and analyze cortical and medullary segments of 50 kidneys in 25 subjects undergoing magnetic resonance (MR) angiography to diagnose renal artery stenosis (RAS). Magnetic rate of relaxation (R2*) positively correlates with deoxyhemoglobin levels and was therefore used as a surrogate measure of tissue oxygenation. Furosemide was administered to examine the effect of inhibiting energy-dependent electrolyte transport on tissue oxygenation in subjects with renovascular disease. In 21 kidneys with normal nephrograms, administration of furosemide led to a 20% decrease in medullary R2* (P < 0.01) and an 11.2% decrease in cortical R2*. In normal-size kidneys downstream of high-grade renal arterial stenoses, R2* was elevated at baseline, but fell after furosemide. In contrast, atrophic kidneys beyond totally occluded renal arteries demonstrated low levels of R2* that did not change after furosemide. In kidneys with multiple arteries, localized renal artery stenoses produced focal elevations of R2*, suggesting areas of deoxyhemoglobin accumulation. These results suggest that BOLD MR coupled with a method to suppress tubular oxygen consumption can be used to evaluate regional tissue oxygenation in the human kidney affected by vascular occlusive disease.     

Validation of quantitative BOLD MRI measurements in kidney: application to unilateral ureteral obstruction

BACKGROUND: Blood oxygenation level dependent (BOLD) magnetic resonance imaging (MRI) provides a measure of deoxyhemoglobin content and therefore an indirect measure of the partial oxygen pressure (pO(2)). The main purpose of this study was to examine the relationship between the apparent relaxation rate (R2*) in the pig kidney by BOLD imaging and renal tissue pO(2) levels measured directly by oxygen-sensitive microelectrodes. Second, BOLD imaging was applied to kidneys in pigs subjected to acute unilateral ureteral obstruction (UUO) to examine whether this condition is associated with changes in intrarenal oxygenation. METHODS: Oxygen-sensitive microelectrodes were inserted in the cortex and medulla of pig kidneys (N= 6). Different arterial and intrarenal levels of pO(2) were obtained by stepwise changing the oxygen-to-nitrogen ratio supplied by a respirator. Simultaneous BOLD MRI measurements using an R2*-sensitive Echo Planar Imaging (EPI) sequence were performed on the contralateral kidney. In another group of pigs (N= 3) BOLD imaging was performed following 24 hours of UUO. RESULTS: When the inhaled oxygen fraction was 5% to 70%, R2* was linearly related to pO(2) levels (cortex DeltaR2*/DeltapO(2)=-1.2 ms(-1)kPa(-1), and medulla DeltaR2*/DeltapO2 =-1.7 ms(-1)kPa(-1)). Twenty-four hours of UUO was associated with an increased R2* in the cortex and a decreased R2* in medulla as compared with baseline, which remained augmented after the release of UUO, indicating that pO(2) levels were reduced in the cortex and increased in the medulla during and after release of obstruction. CONCLUSION: BOLD MRI provides noninvasive estimates of regional renal oxygen content and our study demonstrates that this technique may provide a useful tool in UUO which is associated with altered renal oxygen consumption.     

Diffusion-weighted MR imaging of normal and abnormal scrotum: preliminary results

Magnetic resonance (MR) imaging of the scrotum represents an important supplemental diagnostic tool in the evaluation of scrotal diseases. Diffusion-weighted (DW) MR imaging is a developing technique, proved to improve tissue characterization. We evaluated the feasibility and diagnostic performance of DW MR imaging in the detection and characterization of scrotal lesions. We retrospectively evaluated 31 scrotal lesions (23 intratesticular and 8 extratesticular) in 26 men. All MR examinations were performed on a 1.5-T unit, using a pelvic-phased array coil. DW sequences were obtained using a single shot, multislice spin echo planar diffusion pulse sequence and a b factor of 0 and 900 s mm⁻². The DW MR characteristics and the apparent diffusion coefficient (ADC) values of normal scrotal contents and scrotal diseases were evaluated. Comparison between the ADC values of normal scrotum, benign lesions and scrotal malignancies was performed. The accuracy of conventional sequences, DW images alone and DW imaging combined with conventional images in differentiating benign from malignant scrotal lesions was calculated. The ADC values of testicular malignancies were different from those of normal testis and benign intratesticular lesions, and the ADC values of benign extratesticular lesions from those of normal epididymis (P<0.05). The overall accuracy of conventional imaging, DW imaging alone and DW MR combined with conventional sequences in the characterization of intratesticular lesions was 91%, 87% and 100%, respectively. Our findings suggest that DW MR imaging and ADC values may provide valuable information in the diagnosis and characterization of scrotal diseases.     

环磷酰胺代谢酶基因多态性与中国汉族难治性狼疮肾炎的相关性

目的探讨中国汉族难治性狼疮肾炎(LN)和环磷酰胺(CTX)代谢酶基因多态性的相关性。 方法对2012年1月至2015年12月在海口市人民医院初发系统性红斑狼疮(SLE)的132例患者进行分析,其中LN组88例,非LN组44例;LN组中难治性LN 46例,非难治性LN 42例。比较各组临床指标差异。采用PCR-RELP检测CTX代谢酶基因,采用单因素方差分析CYP2C19*2、CYP2C19*3、CYP2B6*4、CYP2C9*3和CYP3A5与LN及难治性LN、非难治性LN的相关性。 结果(1)CYP2C19*2、CYP2C19*3、CYP2B6*4和CYP3A5频率分布符合Hardy-Weinberg平衡分布;(2)LN组较非LN组,血肌酐(Scr)(t＝2.68,P＝0.008)和SLEDAI明显升高(t＝4.07,P≤0.001),血红蛋白(Hb)(t＝－2.368,P＝0.019)和血白蛋白(ALB)(t＝－4.514,P＝0.000)明显降低,差异具有统计学意义;(3)单因素方差分析显示LN组CYP2C19*3 GC携带者与CC、GG携带者比较血尿素氮(BUN)显著升高[(13.3±13.02)mmol/L与(6.57±5.22)mmol/L与(7.08±6.11) mmol/L,F＝5.770,P＝0.004];难治性LN组中,GC携带者较CC、GG携带者Scr显著升高：[(436.22±286.38)μmol/L与(161.7±144.33)μmol/L与(66±19.02)μmol/L, F＝8.411, P＝0.001]差异均有统计学意义;(4) CYP3A5*3 GG携带者肾脏受累明显增多(χ²＝6.991,P＝0.03);在难治性LN组中CYP3A5*3 GG基因型Scr较高(F＝0.213,P＝0.81)但差异无统计学意义。 结论CTX代谢酶CYP2C19*3基因多态性对中国汉族难治性LN的疗效可能有影响,GC携带者疗效更差;CYP3A5*3 GG基因型携带者的肾脏受累更多见。     

Renal tissue oxygenation in children with chronic kidney disease due to vesicoureteral reflux

Background

Vesicoureteral reflux (VUR) is a frequent cause of chronic kidney disease (CKD) in children. Using blood oxygenation level-dependent magnetic resonance imaging (BOLD-MRI), we measured cortical and medullary oxygenation in children with CKD due to VUR and compared the results to those obtained on healthy controls.

Method

The study population comprised 37 children (19 with CKD due to VUR and 18 healthy age-matched controls). BOLD-MRI was performed before and after furosemide treatment. MR images were analyzed with the region-of-interest (ROI) technique to assess the mean R2* values (=1/T2*) of the cortex and medulla of each kidney and with the concentric object (CO) technique that divides renal parenchyma in 12 equal layers.

Results

R2* values were significantly lower (corresponding to higher oxygenation) in the cortex and medulla of kidneys of children with CKD due to VUR than in those of the healthy controls (cortex 16.4?±?1.4 vs. 17.2?±?1.6 s^?1 , respectively; medulla 28.4?±?3.2 vs. 30.3?±?1.9 s^?1 , respectively; P?<?0.05), and furosemide-induced changes in medullary R2* were smaller in the former than in the latter (?5.7?±?3.0 vs. ?6.9?±?3.4 s^?1, respectively; P?<?0.05). Similar results were found with the CO technique. In children with a history of unilateral reflux (n?=?9), the non-affected contralateral kidneys presented similar R2* values as the diseased kidneys, but their response to furosemide was significantly larger (?7.4?±?3.2 vs. ?5.7?±?3.0, respectively; P?=?0.05).

Conclusions

Chronic kidney disease due to VUR is not associated with kidney tissue hypoxia in children. The significantly larger furosemide-induced decrease in medullary R2* levels in the healthy group and unaffected contralateral kidneys of the VUR group points towards more intense renal sodium transport in these kidneys.

     

Noninvasive assessment of early kidney allograft dysfunction by blood oxygen level-dependent magnetic resonance imaging

BACKGROUND: Blood oxygen level-dependent (BOLD) magnetic resonance imaging (MRI) is a noninvasive method to assess tissue oxygen bioavailability, using deoxyhemoglobin as an endogenous contrast agent. We hypothesized that BOLD-MRI could accurately discriminate different types of rejection early after kidney transplantation. METHODS: Twenty-three patients underwent imaging in the first four months posttransplant. Five had normal functioning transplants and 18 had biopsy-proven acute allograft dysfunction (acute tubular necrosis [ATN, n=5] and acute rejection [n=13] including borderline rejection: n=3; IA rejection: n=4; IIA rejection: n=6: C4d(+) rejection: n=9). RESULTS: Mean medullary R2* (MR2*) levels (a measure directly proportional to tissue deoxyhemoglobin levels) were significantly higher in normal functioning allografts (R2*=24.3/s+/-2.3) versus acute rejection (R2*=16.6/s+/-2.1) and ATN (R2*=20.9/s+/-1.8) (P<0.05). The lowest MR2* levels were observed in acute rejection episodes with vascular injury i.e. IIA and C4d (+). Similarly, the lowest medullary to cortical R2* ratios (MCR2*) were present in allografts with IIA (1.24+/-0.05) and C4d(+) rejection (1.26+/-0.06). ROC curve analyses suggested that MR2* and MCR2* values could accurately discriminate acute rejection in the early posttransplant period. CONCLUSIONS: BOLD-MRI demonstrated significant changes in medullary oxygen bioavailability in allografts with biopsy-proven ATN and acute rejection, suggesting that there may be a role for this noninvasive tool to evaluate kidney function early after transplantation.     

Use of diffusion-weighted magnetic resonance imaging in differentiating purulent brain processes from cystic brain tumors

OBJECT: Brain abscesses and other purulent brain processes represent potentially life-threatening conditions for which immediate correct diagnosis is necessary to administer treatment. Distinguishing between cystic brain tumors and abscesses is often difficult using conventional imaging methods. The authors' goal was to study the ability of diffusion-weighted (DW) magnetic resonance (MR) imaging to differentiate between these two pathologies in patients within the clinical setting. METHODS: Diffusion-weighted MR imaging studies and calculation of the apparent diffusion coefficient (ADC) values were completed in a consecutive series of 16 patients harboring surgically verified purulent brain processes. This study group included 11 patients with brain abscess (one patient had an additional subdural hematoma and another also had ventriculitis), two with subdural empyema, two with septic embolic disease, and one patient with ventriculitis. Data from these patients were compared with similar data obtained in 16 patients matched for age and sex, who harbored surgically verified neoplastic cystic brain tumors. In patients with brain abscess, subdural empyema, septic emboli, and ventriculitis, these lesions appeared hyperintense on DW MR images, whereas in patients with tumor, the lesion was visualized as a hypointense area. The ADC values calculated in patients with brain infections (mean 0.68 x 10(3) mm2/sec) were significantly lower than those measured in patients with neoplastic lesions (mean 1.63 x 10(3) mm2/sec; p < 0.05). CONCLUSIONS: Diffusion-weighted MR imaging can be used to identify infectious brain lesions and can help to differentiate between brain abscess and cystic brain tumor, thus making it a strong additional imaging modality in the early diagnosis of central nervous system purulent brain processes.     

Diffusion‐weighted magnetic resonance imaging in the differentiation of angiomyolipoma with minimal fat from clear cell renal cell carcinoma

The aim of the present study was to evaluate diffusion‐weighted (DW) magnetic resonance imaging (MRI) in differentiating between minimal fat angiomyolipoma (MFAML) and clear cell renal cell carcinoma (CCRCC). Forty‐one solid renal tumors without visible macroscopic fat on unenhanced computed tomography images were evaluated by MRI, including DW‐MRI, and were diagnosed pathologically as CCRCC (n = 36) or MFAML (n = 5). To evaluate the heterogeneity of diffusion in each tumor, the signals of the tumors on DW‐MRI were analyzed subjectively and the apparent diffusion coefficient (ADC) values and histograms assessed objectively. Thirty‐three of 36 CCRCC (92%) exhibited a heterogeneous signal on DW‐MRI and several peaks in the ADC value histogram, whereas four of five MFAML exhibited a homogeneous signal on DW‐MRI and a single prominent peak in the histogram. The standard deviations of the ADC values were significantly smaller for MFAML than for CCRCC (P = 0.0015). In conclusion, DW‐MRI can be considered a useful and noninvasive addition to the preoperative differentiation of CCRCC and MFAML.     

Initial experience of functional imaging of upper urinary tract neoplasm by diffusion-weighted magnetic resonance imaging

Objectives: Diffusion‐weighted (DW) magnetic resonance imaging (MRI) provides functional information widely used in the diagnosis of acute cerebral stroke. We reported our initial experience of this imaging technique of upper urinary tract (UUT) urothelial carcinoma (UC). Methods: Diffusion‐weighted magnetic resonance imaging was carried out in 10 consecutive patients with suspected UUT UC. With conventional imaging, seven were diagnosed as having renal pelvic tumors and two were highly suspected of having UUT UC. These nine patients were diagnosed histopathologically as having renal pelvic UC by subsequent operation. The last patient was confirmed as experiencing benign stenosis. DW MRI was obtained with a 1.5‐T MR imager without a breath‐holding sequence. The apparent diffusion coefficient (ADC) values of renal parenchyma, dilated collecting system, and tumor were calculated. The differences were analyzed using Wilcoxon t‐test. Results: On DW MRI, all nine tumors showed hyperintensity with negligible urinary intensity. Two cases of highly suspected UUT UC with unclear conventional MRI had high signal intensity and contrast. The case of benign stenosis had negative DW MRI. The median (range) ADC value of the tumor (0.803 [0.412–0.958] × 10^?3 mm²/s) was significantly lower than those of the dilated collecting system (2.19 [1.42–2.40] × 10^?3) and renal parenchyma (1.28 [0.922–1.45] × 10^?3, respectively (P < 0.01 and P < 0.01). Conclusions: This is the first report on the application of DW MRI for a series of UUT UC. With this technique, a clear demonstration of UUT UC could be obtained. Moreover, this imaging technique is potentially useful to identify small lesions if they have a low diffusion coefficient.     

3.0T MR扩散加权成像对直肠癌盆腔淋巴结转移的诊断价值

目的探讨3.0T MR扩散加权成像对直肠癌盆腔淋巴结转移的诊断价值。 方法回顾性分析经手术病理证实的53例直肠癌患者的临床资料、术前常规MRI及扩散加权成像(DWI)资料,以病理结果为参照,将淋巴结分为转移性和非转移性两组,分别测量定量参数ADC值,采用SPSS19.0软件包进行统计学处理,诊断效能采用ROC曲线分析,确定诊断转移性淋巴结的最佳临界点,计算诊断的敏感度、特异度和准确度。以P<0.05认为差异具有统计学意义。 结果116枚淋巴结中,转移性淋巴结47枚(40.5%),非转移性淋巴结69枚(59.5%)。转移性淋巴结的ADC值为(0.81±0.10)×10^－3mm²/s明显低于非转移性淋巴结ADC值(1.06±0.13)×10^－3mm²/s,差异具有显著统计学意义(t＝10.47, P<0.01);ROC曲线分析显示ADC值用于诊断转移性淋巴结的最佳临界点为0.95×10^－3mm²/s,其敏感度为91.5%,特异度为78.3%,准确度为83.6%。 结论3.0T MR扩散加权成像ADC值对直肠癌盆腔淋巴结转移具有较高的鉴别诊断价值,可为患者手术方案的选择和预后的评估提供更多的参考。     

肾移植术后早期移植肾动脉狭窄的诊断与治疗

目的总结肾移植术后早期发生移植肾动脉狭窄(TRAS)受者诊疗经验。 方法回顾性分析2014年1月1日至2018年8月31日复旦大学附属中山医院肾移植术后并发TRAS的16例受者(TRAS组)临床资料,并选取同期16例未发生TRAS的肾移植受者作为对照组。采用配对t检验比较两组受者介入治疗前年龄、等待移植时间、血清肌酐、估算肾小球滤过率(eGFR)、收缩压/舒张压、移植肾动脉峰值流速(PSV)和段间动脉阻力指数(RI),以及TRAS组治疗后与TRAS组治疗前、对照组治疗后血清肌酐、eGFR、收缩压/舒张压、移植肾动脉PSV、段间动脉RI的差异。采用χ²检验比较两组受者性别、供肾来源、透析方式、供肾侧别、供肾动脉吻合方式及移植肾功能延迟恢复发生情况;采用Fisher确切概率法比较两组受者移植前糖尿病、高血压和急性排斥反应发生情况。P<0.05为差异有统计学意义。 结果TRAS组受者中13例行球囊扩张,2例置入球扩支架。随访至2018年8月31日,期间除1例受者因慢性排斥反应行移植肾切除术外,余15例受者移植肾功能均稳定。两组受者年龄、性别、移植前糖尿病、移植前高血压、等待移植时间、供肾来源、透析方式、供肾侧别、供肾动脉吻合方式、移植前血清肌酐、移植肾功能延迟恢复及急性排斥反应发生情况差异均无统计学意义(P均>0.05)。介入治疗前,TRAS组受者平均血清肌酐、收缩压及移植肾动脉PSV分别为(5.6±3.5)mg/dL、(144±9)mmHg(1 mmHg＝0.133 kPa,下同)和(3.4±1.6)m/s,均高于对照组[(1.9±0.8)mg/dL、(130±19)mmHg和(1.3±0.5)m/s],差异均有统计学意义(t＝3.94、2.35和4.73,P均<0.05);TRAS组受者平均eGFR和段间动脉RI分别为(18±15)mL/min和0.5±0.1,均低于对照组[(49±20)mL/min和0.6±0.1],差异均有统计学意义(t＝－4.84和－3.88,P均<0.05)。介入治疗后,TRAS组受者平均血清肌酐、收缩压、舒张压和移植肾动脉PSV分别为(3.2±1.5)mg/dL、(128±16)mmHg、(76±8)mmHg和(2.0±1.0)m/s,较治疗前均有所下降,差异均有统计学意义(t＝3.63、4.40、3.72和3.03,P均<0.05),但平均血清肌酐高于仍高于对照组[(1.5±0.5)mg/dL],差异有统计学意义(t＝3.93,P<0.05)。TRAS组受者平均eGFR和段间动脉RI分别为(26±13)mL/min和0.6±0.1,均高于治疗前,差异均有统计学意义(t＝－4.65和－3.25,P均<0.05);但平均eGFR仍低于对照组[(58±17)mL/min],差异有统计学意义(t＝－5.75,P<0.05)。 结论对于肾移植术后怀疑发生TRAS的受者应先进行彩色多普勒血流显像检查,然后再根据血管动脉造影进行确诊。介入治疗可有效改善TRAS受者移植肾功能。     

Diffusion-weighted magnetic resonance imaging in patients selected for radical cystectomy: detection rate of pelvic lymph node metastases

Study Type – Diagnostic (exploratory cohort) Level of Evidence 3a What's known on the subject? and What does the study add? Preoperative imaging of nodal status in patients undergoing radical cystectomy for bladder cancer lacks diagnostic accuracy. This is the first study that has investigated nodal metastates in bladder cancer using DW‐MRI. ADC derived from DW‐MRI may be used to differentiate metastatic from non‐metastatic lymph nodes.

OBJECTIVE

? To evaluate whether DW‐MRI improves the detection of pelvic lymph nodes metastates in patients with bladder cancer undergoing radical cystectomy.

PATIENTS AND METHODS

? 36 patients with CT scan negative for nodal metastates underwent DW‐MRI before surgery. Diagnostic accuracy of DW‐MRI was compared with histopathological findings.

RESULTS

? Mean ADC value was 0.85 × 10^?3 mm³/s in the nodal metastatic group and 1 × 10^?3 mm³/s in the nodal non‐metastatic group (P = 0.02). ? The ADC cut‐off value, obtained by the ROC curve was 0.86 × 10^?3 mm³/s. ? Patient‐based sensitivity, specificity and positive and negative predictive values were 76.4%, 89.4%, 26.6%, and 71.4%, respectively.

CONCLUSION

? DW‐MRI may be used to differentiate metastatic from non‐metastatic lymph nodes in patients with high‐grade bladder cancer.     

3.0T磁共振扩散加权成像诊断肾血管 平滑肌脂肪瘤

目的探讨MR扩散加权成像（DWI）及相应的表观扩散系数（ADC）对肾血管平滑肌脂肪瘤（AML）的诊断价值。方法收集经手术病理证实的肾脏AML患者15例,其中典型AML 10例,不典型AML 5例;正常对照组15名,对病变区域行DWI及常规MRI,测量b=50～1000 s/mm^2时肾脏AML及正常对照组的ADC值。结果肾脏典型AML、不典型AML及正常对照组的ADC值（×10^-3mm^2/s）分别为（0.87±0.08）、（1.55±0.34）、（1.82±0.18）,差异有统计学意义（P〈0.05）。结论3.0T磁共振DWI及ADC值测定可为诊断肾脏AML提供帮助。     

mito-KATP通道在缺血后处理减轻大鼠肾缺血再灌注损伤中的作用

目的 评价线粒体ATP敏感性钾通道(mito-KATP通道)在缺血后处理减轻大鼠肾缺血再灌注损伤中的作用.方法 健康成年雄性SD大鼠35只,体重250～280 g,随机分为5组(n=7):假手术组(S组)仅分离双侧肾蒂,暴露45 min不夹闭;肾缺血再灌注组(I/R组)夹闭双侧肾蒂缺血45 min,再灌注6 h制备大鼠肾缺血再灌注模型;缺血后处理组(Ipo组)夹闭双侧肾蒂缺血45 min,再灌注10 s,缺血10 s,反复3次,再灌注6 h;mito-KATP通道阻断剂5-羟葵酸+I/R组(5-HD+I/R组)缺血前30 min腹腔注射5-HD 10 mg/kg,余处理同I/R组;缺血后处理+5-HD组(5-HD+Ipo组)缺血前30 min腹腔注射5-HD 10 mg/kg,余处理同Ipo组.于再灌注6 h时采集心脏血样,取肾并分离肾小管上皮细胞,测定血清Cr和BUN的浓度、肾小管上皮细胞线粒体膜电位、细胞内活性氧(ROS)含量和游离Ca2+浓度.结果 与S组比较,I/R组、Ipo组、5-HD+I/R组和5-HD+Ipo组血清Cr和BUN的浓度、肾小管上皮细胞内游离Ca2+浓度和ROS含量升高,线粒体膜电位降低(P＜0.05);与I/R组比较,Ipo组血清Cr和BUN的浓度、肾小管上皮细胞内游离Ca2+浓度和ROS含量降低,线粒体膜电位升高(P＜0.05),5-HD+I/R组和5-HD+Ipo组上述指标差异无统计学意义(P＞0.05);与Ipo组比较,5-HD+I/R组和5-HD+Ipo组血清Cr和BUN浓度、肾小管上皮细胞内游离Ca2+浓度和ROS含量升高,线粒体膜电位降低(P＜0.05).结论 mito-KATP通道的开放参与了缺血后处理减轻大鼠肾缺血再灌注损伤的过程.     

Glioblastoma multiforme with diffusion-weighted magnetic resonance imaging characteristics mimicking primary brain lymphoma. Case report

The authors report on the first case of corpus callosum glioblastoma multiforme (GBM) with diffusion-weighted (DW) magnetic resonance (MR) imaging findings that mimicked those for lymphoma but with MR spectroscopy results absent of lymphoma characteristics. This 68-year-old man presented with rapid, progressive impairment in short-term memory as well as slow responses and a change in his personality within 3 weeks of admission. Results of cranial computed tomography revealed a slightly hyperdense corpus callosum tumor with bihemispheric involvement. Magnetic resonance images showed a homogeneous mass with strong enhancement. The mass showed water restriction on DW MR images and apparent diffusion coefficient (ADC) maps but no markedly elevated lipid resonance on MR spectroscopy. The patient underwent tumor resection. Results of pathological studies with immunohistochemical analysis confirmed that the lesion was GBM. Diffusion-weighted MR imaging together with ADC mapping and MR spectroscopy was reported to be useful in differentiating GBM and primary brain lymphoma. The lymphomas were hyperintense to gray matter on DW MR images and isointense to hypointense on ADC maps because of water restriction. In contrast, the GBMs were hyperintense to gray matter on both DW MR images and ADC maps because of the T2 shine-through effect. On MR spectroscopy, lipid resonance was markedly elevated in lymphoma but only slightly elevated in GBM.     

维持性血液透析患者血氨基末端脑钠肽前体水平与肾性贫血的相关性

目的探讨维持性血液透析(MHD)患者发生肾性贫血的危险因素,分析其与血氨基末端脑钠肽前体(NT⁃proBNP)的相关关系。方法选取2018年8月至2018年11月期间在复旦大学附属华山医院接受MHD 3个月以上、病情稳定的患者为研究对象。按照血红蛋白(Hb)水平分为贫血组和非贫血组。回顾性收集患者一般资料、观察期内实验室检查及透析相关资料。Pearson相关分析法分析贫血指标与透析相关指标、血NT⁃proBNP水平的相关性;逐步多元线性回归法分析MHD患者发生贫血的危险因素。结果共160例MHD患者入选本研究,年龄(63.11±11.35)岁,男79例(49.4%),女81例(50.6%)。患者透析龄(118.01±82.32)个月,血红蛋白(110.09±13.48)g/L,NT⁃proBNP水平中位数为3985 ng/L。贫血组73例(45.6%),非贫血组87例(54.4%),贫血组血NT⁃proBNP水平显著高于非贫血组(t=-3.714,P<0.001)。MHD患者血红蛋白水平与每周透析时间(r=0.228)和血白蛋白(r=0.349)呈正相关,与血NT⁃proBNP水平呈负相关(r=-0.318);血细胞比容与每周透析时间(r=0.283)、血清钙(r=0.317)、血磷(r=0.264)、白蛋白(r=0.513)呈正相关(均P<0.05)。逐步多元线性回归分析结果显示,低血白蛋白、高NT⁃proBNP水平是MHD患者发生肾性贫血的独立危险因素。结论MHD患者NT⁃proBNP水平升高与血红蛋白水平降低相关,低血白蛋白、高NT⁃proBNP是MHD患者发生贫血的危险因素。提示肾性贫血的治疗需要考虑改善营养不良和高容量等因素。     

Relationship of angiotensin II type 1 receptor autoantibody and renal cell apoptosis induced by caspase-12 in diabetic nephropathy rats

Objective To study the relationship of angiotensin II type 1 receptor (AT1R) autoantibody (AT1-AA) and renal cell apoptosis induced by caspase-12 in diabetic nephropathy (DN) rats. Methods High-sucrose and high-fat diet and intraperitoneal injection of streptozotocin (35 mg/kg) were utilized to establish DN rat model. Serum AT1-AA was detected by enzyme-linked immunosorbent assay (ELISA) and renal cell apoptosis was detected by TUNEL staining. Furthermore, the mRNA levels of the endoplasmic reticulum stress (ERS) chaperone protein glucose regulated protein 78 (GRP78) and ERS-associated apoptosis protein caspase-12 were measured by real-time quantitative PCR. Additionally, the levels of GRP78 and caspase-12 protein were measured by Western blotting. Results The renal cell apoptosis rate in DN group was increased significantly (P＜0.01), and the renal cells apoptosis rate in AT1-AA positive DN group was higher than that in AT1-AA negative DN group [(20.05±1.71)% vs (13.24±4.93)%, P＜0.01]. The mRNA expressions of GRP78 and caspase-12 in DN group, in comparison to NC group, were increased significantly (P＜0.01), as well as the proteins (P＜0.01). And the expression of these mRNA and proteins had significant increment in AT1-AA positive DN rats when compared with AT1-AA negative DN rats (P＜0.05). Conclusions AT1-AA can induce ERS in the renal tissue of DN rats, and promote renal cell apoptosis likely via the modulation of caspase-12 signaling pathway.