Search

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 m 2 ), non-severe renal function impairment (non-sRI, eGFR ≥ 30 mL/min/1.73 m 2 , and < 80 mL/min/1.73 m 2 ), or control (CG, eGFR ≥ 80 mL/min/1.73 m 2 ) 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: 0.25Quantile DWI , 0.5Quantile DWI , Homogeneity DWI , Entropy BOLD , Skewness SWI , and Correlation SWI . Three features derived from DWI (0.25Quantile DWI , 0.5Quantile DWI , and Homogeneity DWI ) were smaller in sRI than in non-sRI; Entropy BOLD and Correlation SWI were smaller in non-sRI than in CG (p < 0.05). 0.25Quantile DWI , 0.5Quantile DWI , and Homogeneity DWI showed similar capacities for differentiating sRI from non-sRI. Similarly, Entropy BOLD and Correlation SWI 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.

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]