Automatic Urinary Stone Detection System for Abdominal Non-Enhanced CT Images Reduces the Burden on Radiologists.

To develop a fully automatic urinary stone detection system (kidney, ureter, and bladder) and to test it in a real clinical environment. The local institutional review board approved this retrospective single-center study that used non-enhanced abdominopelvic CT scans from patients admitted urology (uPatients) and emergency (ePatients). The uPatients were randomly divided into training and validation sets in a ratio of 3:1. We designed a cascade urinary stone map location-feature pyramid networks (USm-FPNs) and innovatively proposed a ureter distance heatmap method to estimate the ureter position on non-enhanced CT to further reduce the false positives. The performances of the system were compared using the free-response receiver operating characteristic curve and the precision-recall curve. This study included 811 uPatients and 356 ePatients. At stone level, the cascade detector USm-FPNs has the mean of false positives per scan (mFP) 1.88 with the sensitivity 0.977 in validation set, and mFP was further reduced to 1.18 with the sensitivity 0.977 after combining the ureter distance heatmap. At patient level, the sensitivity and precision were as high as 0.995 and 0.990 in validation set, respectively. In a real clinical set of ePatients (27.5% of patients contain stones), the mFP was 1.31 with as high as sensitivity 0.977, and the diagnostic time reduced by > 20% with the system help. A fully automatic detection system for entire urinary stones on non-enhanced CT scans was proposed and reduces obviously the burden on junior radiologists without compromising sensitivity in real emergency data.

Assessment of Transplant Renal Artery Stenosis with Non-contrast-Enhanced Magnetic Resonance Angiography: Comparison with Digital Subtraction Angiography.

RATIONALE AND OBJECTIVES: Early diagnosis of transplant renal artery stenosis (TRAS) is crucial for salvaging kidney function and improving patient prognosis. The purpose of this study was to evaluate image quality of non-contrast-enhanced MR angiography (NCE-MRA) and the value of NCE-MRA in evaluating TRAS compared to DSA. MATERIALS AND METHODS: In 60 patients with TRAS confirmed by DSA, the degree of TRAS was assessed using balanced triggered angiography non-contrast-enhanced (B-TRANCE) MR angiography and was compared to that of DSA. Image quality for NCE-MRA was assessed independently by two radiologists. The Wilcoxon signed-rank test was used to compare NCE-MRA with DSA in assessing TRAS degree. Specificity, sensitivity, accuracy, positive-predictive value (PPV), and negative-predictive value (NPV) of NCE-MRA for the detection of marked (≥50%) TRAS were calculated. RESULTS: The image quality of NCE-MRA based on the B-TRANCE technology of transplanted renal arteries was sufficient (excellent in 81.67%, good in 8.33%, moderate in 6.67%, and non-diagnostic in 3.33%) and had a high inter-observer reproducibility (Kappa=0.836). DSA helped identify severe, moderate, and mild stenosis in 6, 32, and 22 arteries, respectively. No significant difference in the extent of TRAS between NCE-MRA and DSA were observed (P = 0.317). The specificity, sensitivity, accuracy, PPV, and NPV of NCE-MRA in detecting marked (≥50%) TRAS were 90.91%, 100%, 96.55%, 94.74%, and 100%, respectively. CONCLUSION: NCE-MRA based on B-TRANCE technology has shown promising consistency with DSA in evaluating TRAS and yielding high sensitivity, specificity, and accuracy in assessing the severity of TRAS.

Association between renal surface nodularity and increased adverse vascular event risk in patients with arterial hypertension.

OBJECTIVE: To explore the association of renal surface nodularity (RSN) with the increased adverse vascular event (AVE) risk in patients with arterial hypertension. METHODS: This cross-sectional study included patients with arterial hypertension aged 18-60 years who underwent contrasted computed tomography (CT) of kidney from January 2012 to December 2020. The subjects were classified into AVE or not (non-AVE) matched with age (≤5 years) and sex. Their CT images were analyzed using both qualitative (semiRSN) and quantitative RSN (qRSN) methods, respectively. Their clinical characteristics included age, sex, systolic blood pressure (SBP), diastolic blood pressure, hypertension course, diabetes history, hyperlipidemia, and estimated glomerular filtration rate (eGFR). RESULTS: Compared with non-AVE group (n = 91), AVE (n = 91) was at lower age, higher SBP, and fewer rate of diabetes and hyperlipidemia history (all P < .01). Rate of positive semiRSN was higher in AVE than non-AVE (49.45% vs 14.29%, P < .001). qRSN was larger in AVE than non-AVE [1.03 (0.85, 1.33) vs 0.86 (0.75,1.03), P < .001]. The increased AVE was associated with semiRSN (odds ratio = 7.04, P < .001) and qRSN (odds ratio = 5.09, P = .003), respectively. For distinguishing AVE from non-AVE, the area under receiver operating characteristic was bigger in the models combining the clinical characteristics with either semiRSN or qRSN than that of semiRSN or qRSN alone (P ≤.01). CONCLUSION: Among the patients with arterial hypertension aged 18-60 years, CT imaging-based RSN was associated with increased AVE risk.

Association of renal surface nodularity with arterial hypertension compared to normotensive patients.

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 < 0.02). The rates of RSN grade 1-2 and of RSN grade 2 were bigger in the HBP/+DM group than those in the HBP/-DM group (48.84% vs. 37.84%, and 18.61% vs. 1.35%, respectively; all P = 0.001). Neither HBP course nor HBP grade correlated with rate of RSN grade (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.

Association between Quantitative Classification of Renal Surface Nodularity and Early Renal Injury in Patients with Arterial Hypertension.

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.

Whole-liver histogram analysis of blood oxygen level-dependent functional magnetic resonance imaging in evaluating hepatic fibrosis.

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.

Value of Gd-EOB-DTPA-Enhanced MRI and Diffusion-Weighted Imaging in Detecting Residual Hepatocellular Carcinoma After Drug-Eluting Bead Transarterial Chemoembolization.

RATIONALE AND OBJECTIVES: 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). MATERIALS AND METHODS: 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. RESULTS: 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 (p< 0.05). DWI showed lower sensitivity (78.79% vs. 96.97%, p< 0.001) and specificity (78.05% vs. 100%, p< 0.001) 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 × 10-3 mm2/s vs. 1.55 ± 0.50 × 10-3 mm2/s, p< 0.001). Receiver operating characteristic curve analysis for identifying residual HCCs demonstrated that the threshold ADC value of 1.25 × 10-3 mm2/s had 84.85% sensitivity and 87.80% specificity. CONCLUSION: Gd-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.

Association of sclerostin with cardiovascular events and mortality in dialysis patients.

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). In patients with HD, only CVE-free survival rates notably declined in the high serum sclerostin group compared to the low serum sclerostin group (p = 0.029). However, serum sclerostin level was only an independent predictor of all-cause mortality and CVEs in patients with PD after adjusting for confounding factors (p < 0.05), and therefore was not an independent predictor for patients with HD (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.

Susceptibility weighted imaging (SWI) for evaluating renal dysfunction in type 2 diabetes mellitus: a preliminary study using SWI parameters and SWI-based texture features.

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 m2) and moderate-severe renal injured group (msRI, eGFR ≤60 mL/min/1.73 m2). 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, P<0.05). MPswi was higher, and the signal intensity ratio of the cortex to the medulla (CMswi), Skewness, Correlation were lower in msRI than in non-msRI (P<0.05). These parameters showed similar diagnostic efficacies for msRI (P>0.05), 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<0.05). CMswi and Correlation were correlated with Scr (r=-0.645, -0.411, P<0.05). CONCLUSIONS: SWI was valuable for assessing renal dysfunction, which may be helpful for the evaluation of moderate-severe renal injured patients with T2DM.

Diagnostic Efficacy of Contrast-Enhanced MRI in Detecting Residual or Recurrent Hepatocellular Carcinoma After Transarterial Chemoembolization: A Systematic Review and Meta-analysis.

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.

Alterations of default mode functional connectivity in individuals with end-stage renal disease and mild cognitive impairment.

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.

Uterine arteriovenous malformation combined with iliac arteriovenous malformation diagnosed by contrast-enhanced ultrasound: A case report and review of the literature.

 Uterine arteriovenous malformation (AVM) is an extremely rare condition characterized by abnormal connections between veins and arteries. The atypical clinical manifestations and relatively low morbidity of AVM are conducive to missed diagnosis. The present study describes a case of a 47-year-old female patient with congenital uterine AVM followed by iatrogenic AVM. The diagnosis was established by contrast-enhanced ultrasound combined with contrast-enhanced CT (CECT). Because the symptom of vaginal bleeding was severe, trophoblastic disease or neoplasia could be preferred. The manifestations on various imaging examinations were carefully assessed, and the relevant literature was also reviewed.

Evaluation of renal dysfunction using texture analysis based on DWI, BOLD, and susceptibility-weighted imaging.

OBJECTIVE: 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. METHODS: 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 < 30 mL/min/1.73 m2), non-severe renal function impairment (non-sRI, eGFR ≥ 30 mL/min/1.73 m2, and < 80 mL/min/1.73 m2), or control (CG, eGFR ≥ 80 mL/min/1.73 m2) groups. Thirteen texture features were extracted and then were analyzed to select the most valuable for discerning the three groups with each imaging method. A ROC curve was performed to compare the capacities of the features to differentiate non-sRI from sRI or CG. RESULTS: Six features proved to be the most valuable for assessing renal dysfunction: 0.25QuantileDWI, 0.5QuantileDWI, HomogeneityDWI, EntropyBOLD, SkewnessSWI, and CorrelationSWI. Three features derived from DWI (0.25QuantileDWI, 0.5QuantileDWI, and HomogeneityDWI) were smaller in sRI than in non-sRI; EntropyBOLD and CorrelationSWI were smaller in non-sRI than in CG (p < 0.05). 0.25QuantileDWI, 0.5QuantileDWI, and HomogeneityDWI showed similar capacities for differentiating sRI from non-sRI. Similarly, EntropyBOLD and CorrelationSWI showed equal capacities for differentiating non-sRI from CG. CONCLUSION: Texture analysis based on DWI, BOLD, and SWI can assist in assessing renal dysfunction, and texture features based on BOLD and SWI may be suitable for assessing renal dysfunction during early stages. KEY POINTS: • Texture analysis based on MRI techniques allowed for assessing renal dysfunction. • Texture features based on BOLD and SWI, but not DWI, may be suitable for assessing renal function impairment during early stages. • SWI exhibited a similar capacity to BOLD for assessing renal dysfunction.

Renal Hypoxia: An Important Prognostic Marker in Patients with Chronic Kidney Disease.

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.

CT-based radiomic model predicts high grade of clear cell renal cell carcinoma.

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 < 0.05). CONCLUSION: This study presented the Texture-score based models can facilitate the preoperative discrimination of the high from low grade ccRCC.

Novel Strategy for Preparing Dual-Modality Optical/PET Imaging Probes via Photo-Click Chemistry.

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.

Universal Molecular Scaffold for Facile Construction of Multivalent and Multimodal Imaging Probes.

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.

Assessment of Blood Oxygen Level-Dependent Magnetic Resonance Imaging for Differentiating Renal Dysfunction From Control Group: Comparing T2* Histogram With Conventional Method.

OBJECTIVE: 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. METHODS: 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. RESULTS: 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; P < 0.05). 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; P < 0.05). 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, P > 0.05). CONCLUSIONS: 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.

Is low b-factors-based apparent diffusion coefficient helpful in assessing renal dysfunction?

PURPOSE: To investigate whether low b-factors-based apparent diffusion coefficient (ADC) is helpful in assessing renal dysfunction. MATERIALS AND METHODS: 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. RESULTS: ADC0-400 was larger than ADC0-800 in each group (P < 0.05). Both ADC0-400 and ADC0-800 were smaller in the sRI group than those in the non-sRI group (P < 0.01), and they were linearly related with eGFR (P < 0.05). While a significant difference was not found between the two coefficients to differentiate sRI from non-sRI participants (P > 0.05), a strong correlation was present between ADC0-400 and ADC0-800 (r = 0.856, P < 0.001). CONCLUSION: The low b-factors-based ADC was an economical option for reducing the examination time without sacrificing its diagnostic performance.

Assessment of renal dysfunction with diffusion-weighted imaging: comparing intra-voxel incoherent motion (IVIM) with a mono-exponential model.

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 m(2)) 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 < 0.05). ADCmon and Dslow were positively related with eGFR (P < 0.05). For differentiating sRI from non-sRI, receiver operating characteristic curve indicated no significant difference between the two methods (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 < 0.05). CONCLUSION: The IVIM model contributed little to improving the assessment of renal dysfunction compared with a mono-exponential model.