Impact of contrast-enhanced ultrasound in patients with renal function impairment

AIMTo investigate the role of contrast enhanced ultrasound (CEUS) in evaluating patients with renal function impairment (RFI) showing: (1) acute renal failure (ARF) of suspicious vascular origin; or (2) suspicious renal lesions.METHODSWe retrospectively evaluated patients addressed to CEUS over an eight years period to rule-out vascular causes of ARF (first group of 50 subjects) or assess previously found suspicious renal lesions (second group of 41 subjects with acute or chronic RFI). After preliminary grey-scale and color Doppler investigation, each kidney was investigated individually with CEUS, using 1.2-2.4 mL of a sulfur hexafluoride-filled microbubble contrast agent. Image analysis was performed in consensus by two readers who reviewed digital clips of CEUS. We calculated the detection rate of vascular abnormalities in the first group and performed descriptive statistics of imaging findings for the second group.RESULTSIn the first group, CEUS detected renal infarction or cortical ischemia in 18/50 patients (36%; 95%CI: 23.3-50.9) and 1/50 patients (2%; 95%CI: 0.1-12), respectively. The detection rate of infarction was significantly higher (P = 0.0002; McNemar test) compared to color Doppler ultrasonography (10%). No vascular causes of ARF were identified in the remaining 31/50 patients (62%). In the second group, CEUS detected 41 lesions on 39 patients, allowing differentiation between solid lesions (21/41; 51.2%) vs complex cysts (20/41; 48.8%), and properly addressing 15/39 patients to intervention when feasible based on clinical conditions (surgery and cryoablation in 13 and 2 cases, respectively). Cysts were categorized Bosniak II, IIF, III and IV in 8, 5, 4 and 3 cases, respectively. In the remaining two patients, CEUS found 1 pseudolesion and 1 subcapsular hematoma.CONCLUSIONCEUS showed high detection rate of renal perfusion abnormalities in patients with ARF, influencing the management of patients with acute or chronic RFI and renal masses throughout their proper characterization.

Effect of Data Augmentation of Renal Lesion Image by Nine-layer Convolutional Neural Network in Kidney CT

Artificial Intelligence(AI)becomes one hotspot in the field of the medical images analysis and provides rather promising solution.Although some research has been explored in smart diagnosis for the common diseases of urinary system,some problems remain unsolved completely A nine-layer Convolutional Neural Network(CNN)is proposed in this paper to classify the renal Computed Tomography(CT)images.Four group of comparative experiments prove the structure of this CNN is optimal and can achieve good performance with average accuracy about 92.07±1.67%.Although our renal CT data is not very large,we do augment the training data by affine,translating,rotating and scaling geometric transformation and gamma,noise transformation in color space.Experimental results validate the Data Augmentation(DA)on training data can improve the performance of our proposed CNN compared to without DA with the average accuracy about 0.85%.This proposed algorithm gives a promising solution to help clinical doctors automatically recognize the abnormal images faster than manual judgment and more accurately than previous methods.

Effect of Adhesion Molecule P-selectin and Dendritic Cells on Tubulointerstitial Lesions in IgA Nephropathy

To observe the expression of P-selectin and the localization of dendritic cells (DCs) in human kidney with IgA nephropathy, and to evaluate their function in human renal tubulointerstitial lesions and renal dysfunction, 45 biopsy specimens of patients with IgA nephropathy were divided into 3 groups according to the degree of renal tubulointerstitial lesions: i. e. mild group ( n =29), moderate group ( n =10), severe group ( n =6). Ten normal renal tissues severed as control. The expression of P-selectin was analysed by immunohistochemistry. CD1a +CD80 +DCs were investigated by double immunostaining method and the images were analyzed with Axioplan 2 microscopy. The experimental results showed that (1) P-selectin was not expressed in normal controls, but presented mainly in renal tubular epithelial cells, which was greater in severe group than mild and moderate groups. The expression of P-selectin was associated with the degree of renal tubulointerstitial lesions. (2) CD1a +CD80 +DCs were hardly observed in nomal renal tissues, but in renal tissues of patients with IgA nephropathy, CD1a +CD80 +DCs were mostly found in renal tubulointerstitium. Also the distribution area, number and density of CD1a +CD80 +DCs in severe group was much more than other groups, which was associated with the degree of renal tubulointerstitial lesions and the lever of serum creatine. The distribution of CD1a +CD80 +DCs was associated with the expression of P-selectin in patient′s renal tubulointerstitium. The present study demonstrated that P-selectin and DCs might play an important role in renal tubulointerstitial lesions of IgA nephropathy, and DCs recruited into the renal tissues with IgA nephropathy might be mediated by P-selectin.

Differentiation of Renal Oncocytoma and Renal Clear Cell Carcinoma Using Relative CT Enhancement Ratio

Background：The difference between renal oncocytomas （RO） and renal clear cell carcinomas （RCCs） presents the greatest diagnostic challenge.The aim of this study was to retrospectively determine ifRO and RCCs could be differentiated on computed tomography （CT） images on the basis of their enhancement patterns with a new enhancement correcting method.Methods：Forty-six patients with a solitary renal mass who underwent total or partial nephrectomy were included in this study.Fourteen of those were RO and 32 were RCCs.All patients were examined with contrast-enhanced CT.The pattern and degree of enhancement were evaluated.We selected the area that demonstrated the greatest degree of enhancement of the renal lesion in the corticomedullary nephrographic and excretory phase images.Regions of interest （ROI） were also placed in adjacent normal renal cortex for normalization.We used the values of the normal renal cortex that were measured at the same time as divisors.The ratios of lesion-to-renal cortex enhancement were calculated for all three phases.The Student＆#39;s t-test and Pearson＆#39;s Chi-square test were used for statistical analyses.Results：All RCCs masses showed contrast that appeared to be better enhanced than RO on all contrast-enhanced phases of CT imaging,but there was no significant difference in absolute attenuation values between these two diseases （P 〉 0.05）.The ratio of lesion-to-cortex attenuation in the corticomedullary phase showed significantly different values between RO and RCCs.The degree of contrast enhancement in RCCs was equal to or greater than that of the normal renal cortex,but it was less than that of the normal cortex in RO in the corticomedullary phase.The ratio of lesion-to-cortex attenuation in the corticomedullary phase was higher than the cut off value of 1.0 in most RCCs （84%,27/32） and lower than 1.0 in most RO （93%,13/14） （P 〈 0.05）.In the nephrographic phase,the ratio of lesion-to-cortex attenuation was higher than that in the corticomedullary phase in most RO （71%,10/14）,showing a prolonged enhancement pattern; and was lower than that in most RCCs （97%,31/32）,showing an early washout pattern （P 〈 0.05）.In the differentiation of RO from RCCs,the sensitivity was 93%,specificity 84%,positive predictive value 72%,negative predictive value 84%,and accuracy for RO was 87,if the ratio of lesion-to-cortex attenuation in a cortex phase was lower than the cutoff value of 1.0.The sensitivity was 71%,specificity was 97%,positive predictive value was 91%,negative predictive value was 91%,and accuracy for RO was 89%,if the ratio of lesion-to-cortex attenuation in nephrographic phase was higher than that in the corticomedullary phase.Conclusions：The ratios of renal lesion-to-cortex attenuation ratios may be helpful in differentiating RO from RCCs.