Search

Background Renal surface nodularity (RSN) is a subclinical biomarker of renal injury and may be associated with arterial hypertension. Purpose To explore the association of RSN with arterial hypertension compared to normotensive patients. Material and Methods A total of 205 inpatients with or without high blood pressure (HBP vs. control group) who underwent abdominal computed tomography (CT) scans were included. Their clinical characteristics included age, sex, HBP course, HBP grade, history of diabetes mellitus (DM), and renal function (estimated glomerular filtration rate [eGFR]). The HBP group included HBP/+DM and HBP/–DM based on the presence or absence of DM. The CT-based RSN grade was scored from 0 to 2 by two radiologists, respectively, where RSN grade 0 indicated smooth renal surface, grade 1 was mild RSN, and grade 2 was marked RSN. Results The inter-rater agreement on RSN was good (Kappa = 0.76). The age-specific rate of RSN grade 1–2 was bigger in the HBP group than in the control group (42.86% [40%–49.22%] vs. 2.18% [0.00%–22.5%]; P = 0.005). RSN grade was associated with HBP course ( P 0.05). The eGFR was similar among the RSN grades in HBP or between the HBP and control groups ( P > 0.05). Conclusion RSN was associated with HBP compared to normotensive patients.

Background To explore whole-liver histogram analysis (HA) with blood oxygen level-dependent functional magnetic resonance imaging (BOLD-fMRI) in evaluating and diagnosing hepatic fibrosis (HF) in a CCl4-induced rabbit model. Methods One hundred rabbits were classified as CCl4-induced HF groups (n=80) and control group (n=20), and were scheduled for BOLD-fMRI examination on a 3.0T scanner. Whole-liver HA metrics, including the mean, median, skewness, kurtosis, inhomogeneity, entropy, and nth percentiles, were extracted from the R2* map. Parameters were compared among the different HF stages using receivers operating characteristic analysis and Mann-Whitney U-test. Results In all, 17, 18, 19, 17, and 15 rabbits were pathologically diagnosed as F0, F1, F2, F3, and F4, respectively. HA parameters, including the median, inhomogeneity, entropy, and the 75th and 90th percentiles of the BOLD R2* map, demonstrated significant positive correlations with the fibrosis stage (r=0.226-0.718, P≤0.039). The 75th percentiles demonstrated higher diagnostic efficacy than the other HA parameters in fibrosis staging, with an AUC value of 0.86 for ≥ F1, 0.87 for ≥ F2, 0.87 for ≥ F3, and 0.86 for ≥ F4. Conclusions BOLD-fMRI HA provides increased diagnostic performance in staging HF, especially for the 75th percentiles.

BACKGROUND The diagnostic efficacy of contrast-enhanced magnetic resonance imaging (CEMRI) in diagnosing residual or recurrent hepatocellular carcinoma (HCC) after transarterial chemoembolization (TACE) is currently not completely clear. PURPOSE To investigate the diagnostic efficacy of CEMRI in detecting residual or recurrent HCCs after TACE by meta-analysis. STUDY TYPE Systematic review and meta-analysis. POPULATION A systematic literature search was performed in PubMed, Embase, Web of Science, Ovid, and the Cochrane Library database up to June 2019 to find original studies on diagnosing patients suspected of residual or recurrent HCCs after TACE with CEMRI. Thirteen studies comprising 721 nodules were finally included. FIELD STRENGTH/SEQUENCE 1.5T or 3.0T, CEMRI. ASSESSMENT Quality assessment of the included studies was performed by applying the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. STATISTICAL TESTS Sensitivity and specificity were pooled with a bivariate random-effects model. Heterogeneity was assessed by the chi-square test. The potential sources of heterogeneity were explored by subgroup and publication bias analyses. RESULTS The pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, diagnostic odds ratio, and area under the summary receiver operating characteristic (ROC) curve (AUC) of CEMRI in diagnosing residual or recurrent HCCs after TACE were 91% (95% confidence interval [CI]: 87%-96%), 93% (95% CI: 85%-97%), 12.22 (95% CI: 5.62-26.57), 0.09 (95% CI: 0.05-0.18), 126.99 (95% CI: 34.76-436.99) and 0.97 (95% CI: 0.95-0.98), respectively. Subgroup analysis revealed that CEMRI performed significantly better in prospective studies than in retrospective studies: 0.99 (95% CI: 0.96-1.00) vs. 0.95 (95% CI: 0.92-0.96) with P < 0.05. DATA CONCLUSION Our meta-analysis suggested that CEMRI had high diagnostic efficacy in detecting residual or recurrent HCCs after TACE and may serve as an alternative method for further evaluation after TACE. LEVEL OF EVIDENCE 5 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2020;52:1019-1028.

Background. This study sought to explore the association between quantitative classification of renal surface nodularity (qRSN) based on computed tomography (CT) imaging and early renal injury (ERI) in patients with arterial hypertension. Methods. A total of 143 patients with a history of hypertension were retrospectively enrolled; clinical information (age, sex, hypertension grade, and hypertension course), laboratory tests, and qRSN were collected or assessed. The subjects were divided into an ERI group (n = 60) or a control group (CP, n = 83) according to ERI diagnosis based on the following criteria: cystatin C > 1.02 mg/L. Univariate analysis and multiple logistic regression were used to assess the association between ERI and qRSN. A receiver operating characteristic curve (ROC) was performed to compare multiple logistic regression models with or without qRSN for differentiating the ERI group from the control group. Results. In univariate analysis, hypertension grade, hypertension course, triglycerides (TG), and qRSN were related to ERI in patients with arterial hypertension (all P < 0.1 ), with strong interrater agreement of qRSN. Multiple logistic regression analysis showed an area under the ROC curve of 0.697 in the model without qRSN and 0.790 in the model with qRSN, which was significantly different (Z = 2.314, P = 0.021 ). Conclusion. CT imaging-based qRSN was associated with ERI in patients with arterial hypertension and may be an imaging biomarker of early renal injury.

Objective To explore the association between quantitative classification of renal surface nodularity (qRSN) based on computed tomography (CT) imaging and early renal injury (ERI) in patients with aerial hypertension.Methods A total of 143 patients with a history of hypertension were retrospectively enrolled; clinical information (age, sex, hypertension grade, hypertension course, poorly controlled hypertension), laboratory tests and qRSN were collected or assessed. The subjects were divided into an ERI (n=60) or a control (CP, n=83) group according to ERI diagnosis based on the following criteria: cystatin C > 1.02 mg/L, creatinine ≤ 127 μmol/L, and urea nitrogen ≤ 8.3 mmol/L. Univariate analysis and multiple logistic regression were used to examine the association between ERI and qRSN. A receiver operating characteristic curve (ROC) was produced to compare multiple logistic regression models with or without qRSN for differing the ERI group from the control group.Results In univariate analysis, hypertension grade, poorly controlled hypertension, hypertension course, triglycerides (TG) and qRSN were related to ERI in patients with arterial hypertension (all PZ=2.317, P=0.021).Conclusion CT imaging-based qRSN was associated with ERI in patients with arterial hypertension and may be an imaging biomarker of early renal injury.

Background Mild cognitive impairment (MCI) occurs frequently in many end stage renal disease (ESRD) patients, may significantly worsen survival odds and prognosis. However, the exact neuropathological mechanisms of MCI combined with ESRD are not fully clear. This study examined functional connectivity (FC) alterations of the default-mode network (DMN) in individuals with ESRD and MCI. Methods Twenty–four individuals with ESRD identified as MCI patients were included in this study; of these, 19 and 5 underwent hemodialysis (HD) and peritoneal dialysis (PD), respectively. Another group of 25 age-, sex- and education level-matched subjects were recruited as the control group. All participants underwent resting-state functional MRI and neuropsychological tests; the ESRD group underwent additional laboratory testing. Independent component analysis (ICA) was used for DMN characterization. With functional connectivity maps of the DMN derived individually, group comparison was performed with voxel-wise independent samples t-test, and connectivity changes were correlated with neuropsychological and clinical variables. Results Compared with the control group, significantly decreased functional connectivity of the DMN was observed in the posterior cingulate cortex (PCC) and precuneus (Pcu), as well as in the medial prefrontal cortex (MPFC) in the ESRD group. Functional connectivity reductions in the MPFC and PCC/Pcu were positively correlated with hemoglobin levels. In addition, functional connectivity reduction in the MPFC showed positive correlation with Montreal Cognitive Assessment (MoCA) score. Conclusion Decreased functional connectivity in the DMN may be associated with neuropathological mechanisms involved in ESRD and MCI.

BACKGROUND: Susceptibility weighted imaging (SWI) could reflect tissue blood oxygen levels, and then whether it could be used to evaluate renal injury remains to be further studied. This study aimed to examine the performance of SWI parameters and SWI-based texture features in evaluating renal dysfunction of type 2 diabetes mellitus (T2DM). METHODS: Forty-five patients with T2DM were included. With the estimated glomerular filtration rate (eGFR), the patients were divided into non-moderate-severe renal injured group (non-msRI, eGFR >60 mL/min/1.73 m(2)) and moderate-severe renal injured group (msRI, eGFR ≤60 mL/min/1.73 m(2)). The 3 SWI parameters and 16 SWI-based texture features between non-msRI and msRI were compared. The correlation between the parameters and BUN, Scr was analyzed. RESULTS: The signal intensity ratio of the medulla to psoas muscle (MPswi) was significantly lower than the signal intensity ratio of the cortex to psoas muscle (CPswi) in non-msRI and msRI group (t=8.619, 3.483, respectively, P0.05), and AUCs were 0.703–0.854. CMswi was an independent protective factor for msRI (OR =0.026, P=0.003). MPswi and CMswi were correlated with BUN (r=0.416, −0.545, P

Introduction Sclerostin has been reported to be a novel biomarker associated with the bone-vascular axis. In this study, we determined the relationships between serum sclerostin and all-cause mortality, the prevalence of cardiovascular events (CVEs), and coronary artery calcifications (CACs) in dialysis patients. Methods A total of 165 dialysis patients (84 hemodialysis [HD] and 81 peritoneal dialysis [PD]) were enrolled in this study. We performed multivariable linear regression analysis to test the relationships between serum sclerostin levels and demographics and clinical parameters. We also performed Cox proportional hazard regression analysis to determine independent predictors of overall survival and CVEs. Results The median serum sclerostin level was 250.9 pg/mL in dialysis patients. Kaplan–Meier analysis showed that both overall and CVE-free survival rates were significantly lower in the high serum sclerostin group (serum sclerostin level >250.9 pg/mL) compared to the low serum sclerostin group (serum sclerostin level ≤250.9 pg/mL) in patients with PD (p 0.05). Conclusions A low serum sclerostin was associated with better overall survival and lower prevalence of CVEs in patients with PD, but had no relationships in patients with HD. We found that serum sclerostin level was not correlated with CACs in either patients with HD or PD.

To investigate the value of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) in diagnosing residual hepatocellular carcinoma (HCC) after drug-eluting bead transarterial chemoembolization (DEB-TACE).Sixty-two patients (50 men, 12 women; mean age, 56.8 ± 1.4 years) with 74 HCCs who underwent Gd-EOB-DTPA-enhanced MRI and DWI in 1-2-month intervals after DEB-TACE were retrospectively studied. Imaging features derived from Gd-EOB-DTPA-enhanced MRI and DWI were analyzed and compared between residual HCCs and necrotic tumors. The sensitivity and specificity of Gd-EOB-DTPA-enhanced MRI and DWI with quantitative apparent diffusion coefficient (ADC) values in diagnosing residual HCCs were calculated and compared, based on the reference standard of pathology and/or angiography.Thirty-three residual HCCs and 41 necrotic tumors were diagnosed. Residual HCCs presented characteristics of arterial hypervascularity (90.91%) and DWI hyperintensity (78.78%), which were of importance in differentiating necrotic tumors (p0.05). DWI showed lower sensitivity (78.79% vs. 96.97%, p0.001) and specificity (78.05% vs. 100%, p0.001) than Gd-EOB-DTPA-enhanced MRI in diagnosing residual HCCs after DEB-TACE. Residual HCCs had a significantly higher mean ADC value than necrotic tumors (1.30 ± 0.32 × 10Gd-EOB-DTPA-enhanced MRI is superior to DWI in diagnosing residual HCCs after DEB-TACE, and arterial hypervascularity and DWI hyperintensity are important imaging features in distinguishing residual HCCs from necrotic tumors.

Purpose To compare the predictive models that can incorporate a set of CT image features for preoperatively differentiating the high grade (Fuhrman III–IV) from low grade (Fuhrman I–II) clear cell renal cell carcinoma (ccRCC). Material and methods One hundred and fourteen patients with ccRCC treated with a partial or radical nephrectomy were enrolled in the training cohort. The six non-texture features, including Pseudocapsule, Round mass, maximal tumor diameter (Diametermax), intratumoral artery (Arterytumor), enhancement value of the tumor (TEV) and relative TEV (rTEV), were assessed for each tumor. The texture features were extracted from the CT images of the section with the largest area of renal mass at both corticomedullary and nephrographic phases. The least absolute shrinkage and selection operator (LASSO) was used to screen the most valuable texture features to calculate a texture score (Texture-score) for each patient. A logistic regression model was used in the training cohort to discriminate the high from low grade ccRCC at nephrectomy. The predictors would include all non-texture features in Model 1, all non-texture features and Texture-score in Model 2, and Texture-score in Model 3. The performance of the predictive models were tested and compared in an independent validation cohort composed of 92 cases with ccRCC. Results Inter-rater agreement was good for each non-texture feature and Texture-score (the concordance correlation coefficient or Kappa coefficient > 0.70). The Texture-score was calculated via a linear combination of the 4 selected texture features. The three models shown good discrimination of the high from low grade ccRCC in the training cohort and the area under receiver operating characteristic curve (AUC) was 0.826 in Mode 1, 0.878 in Model 2 and 0.843 in Model 3, and a significant different AUC was found between Model 1 and Model 2. Application of the predictive models in the validation cohort still gave a discrimination (AUC > 0.670), and the Texture-score based models with or without the non-texture features (Model 2 and 3) showed a better discrimination of the high from low grade ccRCC (P Conclusion This study presented the Texture-score based models can facilitate the preoperative discrimination of the high from low grade ccRCC.

Preparation of small molecule based dual-modality probes remains a challenging task due to the complicated synthetic procedure. In this study, a novel concise and generic strategy for preparing dual-modality optical/PET imaging probes via photo-click chemistry was developed, in which the diazole photo-click linker functioned not only as a bridge between the targeting-ligand and the PET imaging moiety, but also as the fluorophore for optical imaging. A dual-modality AE105 peptidic probe was successfully generated via this strategy and subsequently applied in the fluorescent staining of U87MG cells and the (68)Ga based PET imaging of mice bearing U87MG xenograft. In addition, dual-modality monoclonal antibody cetuximab has also been generated via this strategy and labeled with (64)Cu for PET imaging studies, broadening the application of this strategy to include the preparation of macromolecule based imaging probes.

The aim of the study was to investigate the potential of T2* histogram (HIST) in the analysis of blood oxygen level-dependent magnetic resonance imaging for differentiating a renal dysfunction group from a control group.This study consisted of 13 control subjects and 20 patients with renal dysfunction. T2* maps were analyzed using both HIST and the conventional method. For the HIST, each region of interest covering renal parenchyma was applied to T2* map to generate a T2* HIST. The T2* HISTs were classified into type 1, 2, 3, and 4 on the basis of their morphologies. In each T2* HIST, the parameters were acquired from the peak with the smallest mean T2* values, which acted as the medullary T2* values, and from the peak with largest mean T2* values, which acted as the cortical T2* values. For the conventional method, small regions of interest were placed in the cortex and medulla for the quantitative analysis of the cortical and medullary T2* values, respectively.The type distribution of the T2* HISTs was significantly different between the 2 groups (control group: type 1, 0; 2, 4; 3, 5; and 4, 17 vs renal dysfunction group: type 1, 4; 2, 1; 3, 33; and 4, 2; P0.05). The medullary T2* values measured using both methods were significantly higher in the renal dysfunction group than that in the control group (29.38 [6.44] vs 22.79 [4.22] milliseconds for HIST, 30.61 [8.65] vs 21.37 [4.88] milliseconds for conventional method; P0.05). The area under the receiver operating characteristic curve for the medullary T2* measured using HIST was not greater than that using the conventional method (0.89 vs 0.82, P0.05).Histogram can automatically characterize the T2* map of renal parenchyma, thereby reducing the tediousness of placing ROIs and making it comparable with the conventional method in its ability to distinguish the renal dysfunction group from the control group.

To explore the value of texture analysis based on diffusion-weighted imaging (DWI), blood oxygen level–dependent MRI (BOLD), and susceptibility-weighted imaging (SWI) in evaluating renal dysfunction. Seventy-two patients (mean age 53.72 ± 13.46 years) underwent MRI consisting of DWI, BOLD, and SWI. According to their estimated glomerular filtration rate (eGFR), the patients were classified into either severe renal function impairment (sRI, eGFR

Background: Blood oxygen level-dependent (BOLD)-MRI is a novel and noninvasive tool that can assess renal oxygenation. The R2* value is a parameter of tissue deoxyhemoglobin concentration detected by BOLD-MRI. The purpose of the current study was to determine the relationships between renal R2* values and clinical parameters and to determine whether renal R2* values were associated with the risk for progression of chronic kidney disease (CKD). Methods: Sixty patients with CKD were enrolled in this prospective observational study in China from March 2013 to August 2014. A region of interest-based BOLD-MRI was performed to obtain cortical and medullary R2* (CR2* and MR2*) values. Data on demographics and clinical characteristics were collected. The primary end point (CKD progression) was defined as an absolute 30% decline in the estimated glomerular filtration rates (eGFR; CKD-Epidemiology Collaboration equations) or initiation of dialysis during follow-up. Results: The CR2* and MR2* values in patients with CKD were significantly higher compared with those of healthy controls. The CR2* levels were positively associated with 24-h urinary protein excretion, blood urea nitrogen, creatinine, and uric acid but negatively associated with baseline eGFR, 24-h creatinine clearance, eGFR slope, serum albumin, and the use of angiotensin II type 1 receptor blockade. The CR2* levels had the highest areas under the curve during follow-up compared with the MR2* levels and medullary cortical ratios. The Kaplan-Meier survival analysis showed that patients with CKD in the lowest tertile of the CR2* levels had the best prognosis compared with the other 2 tertiles. Moreover, baseline eGFR and CR2* tertiles were associated with the progression of CKD in Cox proportional hazard regression models. Only CR2* tertiles correlated negatively with the eGFR slope. Conclusion: We have demonstrated that the clinical feasibility of BOLD-MRI to evaluate renal oxygenation and cortex hypoxia aggravates with the decline of renal function, and cortex hypoxia was a prognostic marker in the progression of CKD.

Objective To assess the feasibility of susceptibility-weighted imaging (SWI) while monitoring changes in renal oxygenation level after water loading. Materials and Methods Thirty-two volunteers (age, 28.0 ± 2.2 years) were enrolled in this study. SWI and multi-echo gradient echo sequence-based T2* mapping were used to cover the kidney before and after water loading. Cortical and medullary parameters were measured using small regions of interest, and their relative changes due to water loading were calculated based on baseline and post-water loading data. An intraclass correlation coefficient analysis was used to assess inter-observer reliability of each parameter. A receiver operating characteristic curve analysis was conducted to compare the performance of the two methods for detecting renal oxygenation changes due to water loading. Results Both medullary phase and medullary T2* values increased after water loading (p < 0.001), although poor correlations were found between the phase changes and the T2* changes (p > 0.05). Interobserver reliability was excellent for the T2* values, good for SWI cortical phase values, and moderate for the SWI medullary phase values. The area under receiver operating characteristic curve of the SWI medullary phase values was 0.85 and was not different from the medullary T2* value (0.84). Conclusion Susceptibility-weighted imaging enabled monitoring changes in the oxygenation level in the medulla after water loading, and may allow comparable feasibility to detect renal oxygenation level changes due to water loading compared with that of T2* mapping.

Background End-stage renal disease and dialysis patients have a higher incidence of renal cell carcinoma (RCC) than the general population. Preoperatively evaluating the biological behavior of RCC plays an important role in treatment decision-making. Susceptibility-weighted imaging (SWI) can visualize the distribution of microvenous structures and hemorrhage without contrast materials. Purpose To evaluate the feasibility of SWI in grading clear cell RCCs (CRCC) and compare the ability of SWI and necrosis for grading CRCCs. Material and Methods Retrospective reviews of 35 patients with pathologically-proven CRCCs were performed. All patients underwent both conventional magnetic resonance imaging (MRI) and SWI examinations. The morphology of the intratumoral susceptibility signal intensities (ITSS) was classified into hemorrhage and microvessels. The differences of ITSSs on SWI and necrosis between low- and high-grade CRCCs were assessed. The diagnostic values of ITSSs and necrosis in differentiating low- from high-grade CRCCs were compared by receiver-operating characteristics. Results ITSSs were seen in 31 of 35 patients. No ITSSs were seen in four patients with low-grade CRCCs. Mean scores of ITSSs on SWI were significantly lower for low-grade CRCCs (1.24 ± 0.72) than that for the high-grade CRCCs (2.70 ± 0.48). No significant necrosis was seen in 10 patients with low-grade CRCCs. There was a significant difference of the presence of intratumoral necrosis between low- and high-grade CRCCs. Sensitivity, specificity, positive (PPV) and negative predictive values (NPV) were for ITSSs: 70%, 100%, 100%, and 89.3%, respectively; for necrosis: 100%, 40%, 40%, and 100%. Conclusion SWI can evaluate ITSSs without contrast materials and can be an alternative to grading CRCCs preoperatively for some special patients.

Rationale and Objectives To assess whether r 2 * values can be used to determine the nuclear grade of clear cell renal cell carcinomas (CRCC). Materials and Methods A total of 26 patients with pathologically proven CRCCs underwent blood oxygen level-dependent magnetic resonance imaging. r 2 * values were determined for the solid components of CRCC lesions. Histological nuclear grade was determined for each lesion. All patients were divided into low- and high-grade groups. r 2 * values were compared between different grades and between low- and high- grade groups. Receiver operating characteristic curve was drawn to establish the cutoff point for r 2 * values. The correlation between r 2 * values and pathological groups was assessed. Results Low-grade group (grades I + II) contained 17 cases and high-grade group (grades III + IV) contained nine cases. The intraclass correlation coefficient for r 2 * values was 0.89. Significant difference was seen between different grades ( P r 2 * values of the high-grade group were higher than the low-grade group ( P −1 . r 2 * values directly correlated with pathological groups ( P Conclusion r 2 * values of CRCCs could be employed as a noninvasive biomarker to help classify the nuclear grade of CRCC.

Multivalent and multimodal imaging probes are rapidly emerging as powerful chemical tools for visualizing various biochemical processes. Herein, we described a bifunctional chelator (BFC)-based scaffold that can be used to construct such promising probes concisely. Compared to other reported similar scaffolds, this new BFC scaffold demonstrated two major advantages: (1) significantly simplified synthesis due to the use of this new BFC that can serve as chelator and linker simultaneously; (2) highly efficient synthesis rendered by using either click chemistry and/or total solid-phase synthesis. In addition, the versatile utility of this molecular scaffold has been demonstrated by constructing several multivalent/multimodal imaging probes labeled with various radioisotopes, and the resulting radiotracers demonstrated substantially improved in vivo performance compared to the two individual monomeric counterparts.

To investigate whether low b-factors-based apparent diffusion coefficient (ADC) is helpful in assessing renal dysfunction.Forty-four subjects were recruited, and classified as having severe renal injury group (sRI) or not (non-sRI) according to a threshold of estimated glomerular filtration rate (eGFR) = 30 ml/min/1.73 m(2). A free-breathing DWI with 7 b-factors (0, 20, 40, 80, 200, 400, and 800 s/mm(2)) was performed. After choosing an anatomical section that covered the largest part of right kidney, the regions of interest covered the renal parenchyma. For each subject, two apparent diffusion coefficients based on all b-factors less than 400 s/mm(2) (ADC0-400) and 800 s/mm(2) (ADC0-800) were calculated by fitting the signal intensity at different b-factors to a mono-exponential decay, respectively. It was found that the examination time of the free-breathing DWI sequence in this study can be reduced from 3.27 to 2.55 min if the b-factor (800 s/mm(2)) is removed.ADC0-400 was larger than ADC0-800 in each group (P0.05). Both ADC0-400 and ADC0-800 were smaller in the sRI group than those in the non-sRI group (P0.01), and they were linearly related with eGFR (P0.05). While a significant difference was not found between the two coefficients to differentiate sRI from non-sRI participants (P0.05), a strong correlation was present between ADC0-400 and ADC0-800 (r = 0.856, P0.001).The low b-factors-based ADC was an economical option for reducing the examination time without sacrificing its diagnostic performance.

Background Because renal dysfunction is a worldwide problem, accurate assessment is required for planning treatment and follow-up. Intra-voxel incoherent motion (IVIM) can isolate fast from slow water motion in well-perfused organs and may be helpful in assessing renal dysfunction. Purpose To determine the clinical value of IVIM in the assessment of renal dysfunction compared with a mono-exponential model. Material and Methods Fifty-four consecutive participants (mean age, 53.13 ± 13.96 years) were recruited into this study. The estimated glomerular filtration rate (eGFR) was calculated to classify the participants as having severe renal injury (sRI, eGFR ≤ 30 mL/min/1.73 m2) or not (non-sRI). DWI with seven b-factors was performed. Image analysis was performed by a radiologist to generate an apparent diffusion coefficient map (ADCmon) by mono-exponential model, diffusion coefficient (Dslow and Dfast), and fraction of fast diffusion (Ffast) maps by IVIM. The circular regions of interest were placed at the interface between the cortex and medulla for parameter measurements. Results The ADCmon, Dslow, Dfast, and Ffast were less in sRI than non-sRI ( P mon and Dslow were positively related with eGFR ( P 0.05). Furthermore, the correlation was 0.93 between ADCmon and Dslow, followed by 0.57 between Dfast and Ffast, 0.48 between ADCmon and Dfast, and 0.34 between ADCmon and Ffast ( P Conclusion The IVIM model contributed little to improving the assessment of renal dysfunction compared with a mono-exponential model.

To explore the influence of signal noise ratio (SNR) on analysis of clear cell renal cell carcinoma (CCRCC) using DWI with multi-b values.The images of 17 cases with CCRCC were analyzed, including 17 masses and 9 pure cysts. The signal intensity of the cysts and masses was measured separately on DWI for each b value. The minimal SNR, as the threshold, was recorded when the signal curve manifest as the single exponential line. The SNR of the CCRCC was calculated on DWI for each b value, and compared with the threshold by independent Two-sample t Test.The signal decreased on DWI with increased b factors for both pure cysts and CCRCC. The threshold is 1.29 ± 0.17, and the signal intensity of the cysts on DWI with multi-b values shown as a single exponential line when b ≤ 800 s/mm(2). For the CCRCC, the SNR is similar to the threshold when b = 1 000 s/mm(2) (t = 0.40, P = 0.69), and is lower when b = 1 200 s/mm(2) (t = -2.38, P = 0.03).The SNR should be sufficient for quantitative analysis of DWI, and the maximal b value is 1000 s/mm(2) for CCRCC.

BACKGROUND: Intratumoral hemorrhage is a frequent occurrence in renal cell carcinoma and is an indicator of tumor subtype. We hypothesize that susceptibility weighted imaging (SWI) is sensitive to hemorrhage in renal cell carcinoma and can give a more diagnostic image when compared to conventional imaging techniques. MATERIALS AND METHODS: A retrospective review of 32 patients with clear cell renal cell carcinoma was evaluated. All patients underwent magnetic resonance imaging (MRI) and 22 out of 32 patients also underwent a computed tomography (CT) scan. Hemorrhage was classified into 3 different categories according to shape and distribution. Histopathology was obtained from all masses by radical nephrectomy. The ability to detect the presence of hemorrhage using CT, non-contrast conventional MRI and SWI was evaluated, and the patterns of hemorrhage were compared. RESULTS: Using pathologic results as the gold standard, the sensitivities of non-contrast conventional MRI, SWI and CT in detecting hemorrhage in clear cell renal cell carcinoma were 65.6%, 100% and 22.7%, respectively. Accuracy of non-contrast conventional MRI and SWI in evaluating hemorrhagic patterns were 31.3% and 100%, respectively. CONCLUSION: These results demonstrate that SWI can better reveal hemorrhage and characterize the pattern more accurately than either non-contrast conventional MRI or CT. This suggests that SWI is the technique of choice for detecting hemorrhagic lesions in patients with renal cancer.

Background Multiple treatment options exist for the management of renal cell carcinomas. Preoperative evaluation of clear cell renal cell carcinoma (CRCC) grades is important for deciding upon the appropriate method of therapy. We hypothesize that susceptibility weighted imaging (SWI) is sensitive enough to detect intratumoral microvessles and microbleeding in renal cell carcinoma, which can be used to grade CRCC. Material and Methods Retrospective reviews of 37 patients with pathologically proven CRCCs were evaluated. All patients underwent SWI examinations. The characteristics of intratumoral susceptibility signal intensity (ITSS) includes the likelihood of the presence of ITSS, morphology of ITSS, dominant structure of ITSS and ratio of ITSS area to tumor area, which were all assessed on SWI. The results were compared using the nonparametric Mann-Whitney test. Results ITSS was seen in all patients except 4 patients with low-grade CRCCs. There was no significant difference between low and high-grade CRCCs when looking at the likelihood of the presence of ITSS. There was a significant difference in the mean score of dominant structures between low and high-grade CRCCs. Specifically, more dominant vascular structures and less hemorrhage were seen in low-grade tumors (2.15±1.05) compared to high-grade tumors (1.27±0.47) (P