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Renal micrograph (A) and ADC map (B) in a 32-year-old female with no tubular atrophy. No tubular atrophy and moderate mesangial proliferation are shown in the right renal micrograph (A) (periodic acid-Schiff (PAS) stain, × 200). The ADC value of the right kidney was 2.45 × 10⁻³ mm²/s (B)
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PurposeTo investigate the value of diffusion-weighted imaging (DWI) for assessing histopathologic changes observed in chronic kidney disease (CKD). Methods
Fifty-two patients with CKD underwent DWI before renal biopsy. The renal apparent diffusion coefficient (ADC) values and histopathologic changes were analyzed. The pathologic changes were scored...
Citations
... It could develop into kidney failure in the later stage if not diagnosed and treated promptly in the early The inclusion criteria were as follows：The CKD (mild group): (1) All patients met the clinical diagnostic criteria of CKD; (2) Ultrasound examination showed no obvious renal atrophy and severe renal interstitial fibrosis; (3) There was no serious disease of other organs or systems; (4) MRI showed no renal organic lesions. The healthy controls (HCs): (1) No history of kidney disease, diabetes mellitus, hypertension, or gout; (2) Serum creatinine and urea nitrogen were normal;(3) MRI showed no renal organic lesions; (4) No history of taking nephrotoxic drugs in the past 1 year. ...
... In recent years, more and more studies had been conducted on functional magnetic resonance imaging (MRI) in CDK. Mono, IVIM, SEM, and DKI as advanced diffusion models, had been gradually applied to the study of kidney disease, and the results showed that the measures of these models could accurately evaluate the renal function [4][5][6][7]. ...
Objectives
To compare the diagnostic value of histogram features of multiple diffusion metrics in predicting early renal impairment in chronic kidney disease (CKD).
Methods
77 patients with CKD (mild group, eGFR ≥ 60 ml/min/1.73m2) and 30 healthy controls (HCs)were enrolled. Diffusion weighted imaging was performed by using SS-EPI sequence with 13 b values (0, 20, 50, 80, 100, 150, 200, 500, 800, 1000, 1500, 2000 and 2500 sec/mm2). Diffusion models including mono-exponential (Mono), intravoxel incoherent motion (IVIM), stretched-exponential (SEM) and kurtosis (DKI) were calculated, and their histogram features were analyzed. All diffusion models for predicting early renal impairment in CKD were established using logistic regression analysis, and diagnostic efficiency were compared among the models.
Results
All diffusion models had high differential diagnosis efficiency between mild-group and HCs. The areas under the curve (AUCs) of Mono, IVIM, SEM, DKI and the combined diffusion model for predicting early renal impairment in CKD were 0.829, 0.809, 0.760, 0.825, and 0.861 respectively. There were no significant differences in AUCs except SEM and combined model, SEM and DKI model. There were significant correlations between eGFR/SCr and some of histogram features.
Conclusions
Histogram analysis based on multiple diffusion metrics was practicable for the noninvasive assessment of early renal impairment in CKD.
Advances in knowledge
Advanced diffusion models provided microstructural information. Histogram analysis further reflected histological characteristics and heterogeneity. Histogram analysis based on multiple diffusion models could provide an accurate and non-invasive method to evaluate the early renal damage of CKD.
... Multiparametric renal Magnetic Resonance Imaging (MRI) shows great promise as a non-invasive method to assess kidney structure and function without exposure to radiation or gadolinium contrast agents [1,2]. This was highlighted in the COST Action PARENCHIMA [3], which initiated a drive towards standardisation of the renal MRI techniques of Blood Oxygen Level Dependent (BOLD) relaxation time or rate (T 2 * or R 2 *) [4][5][6], longitudinal relaxation time (T 1 ) mapping [7][8][9], Arterial Spin Labeling (ASL) [10], and Diffusion Weighted Imaging (DWI) [11][12][13][14][15][16][17]. ...
Background: Multiparametric renal Magnetic Resonance Imaging (MRI) provides a non-invasive method to assess kidney structure and function, but longitudinal studies are limited. Methods: A total of 22 patients with CKD category G3-4 (estimated glomerular filtration rate (eGFR) 15–59 mL/min/1.73 m2) were recruited. Annual 3T multiparametric renal MRI scans were performed, comprising total kidney volume (TKV), longitudinal relaxation time (T1), apparent diffusion coefficient (ADC), Arterial Spin Labelling, and Blood Oxygen Level Dependent relaxation time (T2*), with 15 patients completing a Year 2 scan. CKD progression over 2 years was defined as eGFR_slope ≥ −5 mL/min/1.73 m2/year. Results: At baseline, T1 was higher (cortex p = 0.05, medulla p = 0.03) and cortex perfusion lower (p = 0.015) in participants with subsequent progression versus stable eGFR. A significant decrease in TKV and ADC and an increase in cortex T1 occurred in progressors at Year 1 and Year 2, with a significant decrease in perfusion in progressors only at Year 2. The only decline in the stable group was a reduction in TKV. There was no significant change in cortex or medulla T2* at Year 1 or Year 2 for progressors or stable participants. Conclusion: Lower renal cortex perfusion and higher T1 in the cortex and medulla may predict CKD progression, while renal cortex T1, TKV, and ADC may be useful to monitor progression. This study provides pilot data for future large-scale studies.
... A semiquantitative score was devised to evaluate histopathological changes in major organs. The scores, as described by Bedossa [11] and Xu et al. [12], were as follows: -, no lesions (0-5%); + , mild lesions (5-25%); + + , moderate lesions (25-50%); and + + + , severe lesions (≥ 50%). All tissue sections were scored at the same magnification (40 × , 100 × , 200 × , and 400 ×) by two investigators who were blinded to the study. ...
Arsenic is a valuable component in tumor treatment and traditional Chinese medicine and has seen widespread use in processing, manufacturing, and agriculture. Although rare, arsenic poisoning can occur in forensic practice. Elusive pathological changes, as well as obscure clinical signs, may cause arsenic poisoning to go unrecognized. Here, we report four cases of fatal acute arsenic poisoning, with careful observation of pathological changes and collection of postmortem specimens for arsenic concentration analysis. Additionally, we reviewed six cases of fatal arsenic poisoning in the past 20 years. In the present study, microvesicular steatosis in the peripheral areas of the hepatic lobules and acute splenitis were observed, which are rare findings in acute arsenic poisoning. This study summarizes the histopathological features of arsenic poisoning and presents data on arsenic distribution. Arsenic concentrations in the liver and kidneys can increase the reliability of identifying arsenic poisoning. Furthermore, in traditional Chinese medicine-related deaths, arsenic poisoning needs more attention.
... Texture feature analysis on renal ultrasound and MRI can classify the renal function and the chronic kidney disease progression (24,25). Several studies had confirmed that the decreased ADCs and increased R2* were detected in patients with renal dysfunction (26)(27)(28). The changes in signal intensity on DWI and BOLD were significantly associated with the area of fibrosis and cell density during renal fibrogenesis, and the degree of fibrosis was significantly associated with the status of renal function (28,29). ...
Introduction
Diabetic nephropathy (DN) has become a major public health burden in China. A more stable method is needed to reflect the different stages of renal function impairment. We aimed to determine the possible practicability of machine learning (ML)-based multimodal MRI texture analysis (mMRI-TA) for assessing renal function in DN.
Methods
For this retrospective study, 70 patients (between 1 January 2013 and 1 January 2020) were included and randomly assigned to the training cohort ( n 1 = 49) and the testing cohort ( n 2 = 21). According to the estimated glomerular filtration rate (eGFR), patients were assigned into the normal renal function (normal-RF) group, the non-severe renal function impairment (non-sRI) group, and the severe renal function impairment (sRI) group. Based on the largest coronal image of T2WI, the speeded up robust features (SURF) algorithm was used for texture feature extraction. Analysis of variance (ANOVA) and relief and recursive feature elimination (RFE) were applied to select the important features and then support vector machine (SVM), logistic regression (LR), and random forest (RF) algorithms were used for the model construction. The values of area under the curve (AUC) on receiver operating characteristic (ROC) curve analysis were used to assess their performance. The robust T2WI model was selected to construct a multimodal MRI model by combining the measured BOLD (blood oxygenation level-dependent) and diffusion-weighted imaging (DWI) values.
Results
The mMRI-TA model achieved robust and excellent performance in classifying the sRI group, non-sRI group, and normal-RF group, with an AUC of 0.978 (95% confidence interval [CI]: 0.963, 0.993), 0.852 (95% CI: 0.798, 0.902), and 0.972 (95% CI: 0.995, 1.000), respectively, in the training cohort and 0.961 (95% CI: 0.853, 1.000), 0.809 (95% CI: 0.600, 0.980), and 0.850 (95% CI: 0.638, 0.988), respectively, in the testing cohort.
Discussion
The model built from multimodal MRI on DN outperformed other models in assessing renal function and fibrosis. Compared to the single T2WI sequence, mMRI-TA can improve the performance in assessing renal function.
... The renal ADC had a negative correlation with histological fibrosis score [14,15] The ADC values of the patients with histologically proven evidence of acute rejection were lower than those with stable allograft function [16] DTI Cortex FA decreased in the early stage of renal fibrosis in rat models with diabetic nephropathy [17]; ...
... Furthermore, a similar result was found in patients after kidney transplantation [16,60]. Besides renal allografts, several studies have demonstrated that ADC is also effective in assessing fibrosis of native kidneys [14,15,26,[61][62][63]. A latest prospective study of DWI involving patients with CKD or kidney allograft, found that the cortico-medullary difference of ADC is a more excellent predictor of interstitial fibrosis and kidney function decline than ADC in the cortex or medulla alone [64]. ...
As a sign of chronic kidney disease (CKD) progression, renal fibrosis is an irreversible and alarming pathological change. The accurate diagnosis of renal fibrosis depends on the widely used renal biopsy, but this diagnostic modality is invasive and can easily lead to sampling error. With the development of imaging techniques, an increasing number of noninvasive imaging techniques, such as multipara meter magnetic resonance imaging (MRI) and ultrasound elastography, have gained attention in assessing kidney fibrosis. Depending on their ability to detect changes in tissue stiffness and diffusion of water molecules, ultrasound elastography and some MRI techniques can indirectly assess the degree of fibrosis. The worsening of renal tissue oxygenation and perfusion measured by blood oxygenation level-dependent MRI and arterial spin labeling MRI separately is also an indirect reflection of renal fibrosis. Objective and quantitative indices of fibrosis may be available in the future by using novel techniques, such as photoacoustic imaging and fluorescence microscopy. However, these imaging techniques are susceptible to interference or may not be convenient. Due to the lack of sufficient specificity and sensitivity, these imaging techniques are neither widely accepted nor proposed by clinicians. These obstructions must be overcome by conducting technology research and more prospective studies. In this review, we emphasize the recent advancement of these noninvasive imaging techniques and provide clinicians a continuously updated perspective on the assessment of kidney fibrosis.
... Emre et al. revealed that ADC values of renal parenchyma could be used for early diagnosis and clinical staging of patients with kidney disease [39]. Xu et al. found a negative correlation between renal parenchymal ADC values and the degree of interstitial fibrosis [40]. ...
Objectives:
Our study aims to determine the patterns of renal oxygenation changes and microstructural changes by BOLD and DTI with deteriorating kidney function in patients with diabetic kidney disease (DKD).
Methods:
Seventy-two patients with type 2 diabetes mellitus (DM) and twenty healthy controls (HCs) underwent laboratory examinations, and renal BOLD and DTI images were obtained on a 3T-MRI machine. R2 ∗ , fractional anisotropy (FA), and average diffusion coefficient (ADC) values were evaluated. DM patients were divided into three subgroups (Group-DI/DII/DIII, based on urinary albumin-creatinine ratio (UACR)) and a nondiabetic kidney disease group (Group-NDKD). D-value and MCR of R2 ∗ and FA were proposed to evaluate the differentiation between medulla and cortex of the individual kidney among HCs and three subgroups for reducing individual differences. Comparisons were made between NDKD and kidney function-matched DKD patients. Correlations between MRI parameters and renal clinical indices were analyzed.
Results:
Compared with Group-HC/DI, medullary R2 ∗ and FA values were significantly different in Group-DII/III. The D-value of R2 ∗ and FA in Group-III were significantly smaller than that in Group-HC. However, only MCR of R2 ∗ in Group-III was significantly smaller than that in HCs. Medullary R2 ∗ and FA were negatively associated with serum creatinine (SCr) and cystatin C (Cys C) and positively associated with eGFR.
Conclusions:
With renal function declining, BOLD and DTI could capture alterations including the first rising and then falling medullary R2 ∗ , continuously declining medullary FA, and apparent cortex-medullary differentiation in DKD patients. The MRI parameters showed renal changes accompanied by varying degrees of albuminuria, sharing common involvement in DKD and NDKD patients, but it was hard to distinguish between them. BOLD seemed more sensitive than DTI in identifying renal cortex-medullary differentiation.
... The necessity to assess fibrosis noninvasively and accurately led to studies involving various imaging techniques, including ultrasound and magnetic resonance imaging (MRI) [10]. While multiple MRI techniques have been studied in order to assess fibrosis [11][12][13][14][15][16][17][18][19][20][21], magnetic resonance elastography (MRE) seems to hold promise [5,[22][23][24][25][26][27]. MRE combines MRI with the assessment of acoustic waves for the quantitative determination of viscoelastic properties of tissues based on their response to external mechanical vibration and was originally developed to assess liver fibrosis [28]. ...
Background
Renal parenchymal fibrosis is the most important determinant of kidney disease progression and it is determined via biopsy. The aim of this study is to evaluate the renal stiffness noninvasively by magnetic resonance elastography (MRE) and to compare it with clinicopathologic parameters in glomerulonephritis and AA amyloidosis patients.
Methods
Thirty-four patients with glomerular filtration rate (GFR) over 20 ml/min/1.73m² had non-contrast MRE prospectively. Kidney stiffness values were obtained from whole kidney, cortex, and medulla. Values were correlated with GFR, albuminuria, proteinuria, and degree of fibrosis that are assessed via renal biopsy. Patients were grouped clinicopathologically to assess the relation between stiffness and chronicity.
Results
Mean whole kidney, cortex, and medulla stiffnesses were 3.78 (± 1.26), 3.63 (± 1.25), and 4.77 (± 2.03) kPa, respectively. Mean global glomerulosclerosis was 22% (± 18%) and median segmental glomerulosclerosis was 4% (min–max: 0%–100%). Extent of tubulointerstitial fibrosis was less than 25% in 26 of the patients (76.5%), 25%–50% in 6 of the patients (17.6%), and higher than 50% in 2 of the patients (5.9%). Fourteen patients were defined to have chronic renal parenchymal injury. MRE-derived stiffness values correlated negatively with parameters of fibrosis. Lower stiffness values were observed in patients with chronic renal injury compared to those without (P < 0.05 for whole kidney and medulla MRE-derived stiffness).
Conclusion
MRE-derived stiffness values were lower in patients with chronic injury. Stiffness decreases as glomerulosclerosis and tubulointerstitial fibrosis progresses in patients with primary glomerulonephritis and AA amyloidosis. With future studies, there may be a role for MRE to assess renal function in concert with conventional markers.
... With MR techniques and clinical applications' developments, it is possible to make a noninvasive assessment of renal pathology types by fMR imaging in patients with kidney diseases. However, at present, there is little evidence directly from kidney histopathology [28][29][30][31]. In this study, DW and BOLD MRI parameters of TIN kidneys were acquired and compared between ATIN and CTIN. ...
Abstract Background Diffusion-weighted (DW) and blood oxygen level-dependent (BOLD) magnetic resonance imaging are classical sequences of functional MR, but the exploration in non-transplanted kidney disease is limited. Objects: To analyze the characteristics of apparent diffusion coefficient (ADC) and R2* value using DW and BOLD imaging in tubulointerstitial nephritis (TIN). Methods Four acute TIN, thirteen chronic TIN patients, and four controls were enrolled. We used multiple gradient-echo sequences to acquire 12 T2*-weighted images to calculate the R2* map. DW imaging acquired ADC values by combining a single-shot spin-echo echo-planar imaging pulse sequence and the additional motion probing gradient pulses along the x,y, z-axes with two b values:0 and 200, as well as 0 and 800 s/mm2. ATIN patients performed DW and BOLD magnetic resonance at renal biopsy(T0) and the third month(T3). We assessed the pathological changes semiquantitatively, and conducted correlation analyses within functional MR, pathological and clinical indexes. Results In ATIN, ADCs were significantly lower(b was 0,200 s/mm2, 2.86 ± 0.19 vs. 3.39 ± 0.11, b was 0,800 s/mm2, 1.76 ± 0.12 vs. 2.16 ± 0.08, P
... Since the molecular motion of water is not free but is hindered by many obstacles, including cell membranes and interstitial matrices, the apparent diffusion coefficient (ADC) has been used for data from biological tissues to account for these influences. Although there have been more published investigations regarding the correlation of ADC values with renal pathological changes in recent years [12,13], such studies focusing on LN patients have been limited. To the best of our best knowledge, aside from our previous study [10], only three similar studies have been published [12,14,15]. ...
... Xu et al. explored the relationship between renal ADC values and histopathologic changes in 52 patients with CKD. They found negative correlations between renal ADC values and scores of tubulointerstitial lesions and severity of interstitial fibrosis [13]. Inoue et al. detected the ADC values in 142 patients with either diabetic nephropathy, CKD without diabetes, or acute-kidney injury. ...
Background:
Lupus nephritis (LN) is one of most common types of secondary glomerulonephritis, which is characterized by longitudinal pathological changes. Microstructural lesions of LN will impact the motion of water molecules, which can be detected by diffusion-weighted imaging (DWI). There are few reported measurements of water diffusion in patients with LN, and the nature of water diffusion across the entire depth of the renal parenchyma remains largely unknown.
Methods:
Twenty adult patients with LN and 11 healthy volunteers underwent DWI inspection. Renal biopsy samples were characterized based on the revised ISN/RPS 2003 classification. The apparent-diffusion coefficient (ADC) was calculated via fitting into a mono-exponential model. To compare the ADC level across the entire renal parenchyma between the two groups, repeated-measures analysis of variance (RM-ANOVA) was performed. ADC data derived from DWI pictures were transformed into tridimensional maps by MATLAB software.
Results:
Compared with data from healthy volunteers, lower average ADC values with major undulatory magnitudes were found in patients with LN, especially in the cortical zone. Tridimensional maps of patients with LN displayed geographic terrain-like canyons and/or valleys that were different from the corresponding terrain-like flatlands and/or plateaus in healthy volunteers. A heterogeneity of ADC values was found in bilateral kidneys. Left kidneys predominated higher ADC values in patients with LN. The ADC values across the entire renal parenchyma exhibited statistically significant differences among the three identified pathological subclasses (P < 0.001).
Conclusions:
Analysis of the motion of water molecules across the entire renal parenchyma may be helpful for better understanding the pathological conditions of LN, for which microstructural and functional heterogeneity may be detected and visualized via DWI.
... Diffusion-weighted imaging (DWI) is beneficial in the evaluation of kidney transplants, allowing a noninvasive means of kidney allograft functional characterization (3). Prior studies have consistently found that the apparent diffusion coefficient (ADC) calculated from DWI with a monoexponential model correlated significantly with interstitial fibrosis (4,5). Nonetheless, monoexponential ADC does not consider the physiological process of microcapillary perfusion. ...
... However, the capability of DWI parameters derived from both monoexponential and bi-exponential models to assess kidney allograft pathologic changes has not been compared, and it remains unclear which model is superior for categorizing kidney transplant pathologic changes. Moreover, earlier studies have focused on evaluating kidney fibrosis (4)(5)(6)(7)(8), but few have explored the capability of DWI to evaluate acute pathologic changes. ...
... Interstitial fibrosis is an irreversible lesion that has received considerable attention in the literature in regards to the native kidneys. At least a dozen studies have explored the utility of DWI for assessing interstitial fibrosis either in animal models or human subjects (4)(5)(6)(7)(8)13,(21)(22)(23)(24)(25)(26)(27). However, the diagnostic performances of mono-exponential and biexponential models, to the best of our knowledge, have been scarcely compared. ...
Background:
Diffusion-weighted imaging (DWI) can noninvasively assess renal allograft pathologic changes that provide useful information for clinical management and prognostication. However, it is still unknown whether the bi-exponential model analysis of DWI signals is superior to that of the mono-exponential model.
Methods:
Pathologic and DWI data from a total of 47 allografts were prospectively collected and analyzed. Kidney transplant interstitial fibrosis was quantified digitally. The severity of acute and chronic pathologic changes was semi-quantified by calculating the acute composite scores (ACS) and chronic composite score (CCS). Mono-exponential total apparent diffusion coefficient (ADCT), and the bi-exponential parameters of true diffusion (D) and perfusion fraction (fp) were acquired. The diagnostic performances of both mono-exponential and bi-exponential parameters were assessed and compared by calculating the area under the curve (AUC) from receiver-operating characteristic (ROC) curve analysis.
Results:
ADCT, D, and fp were all significantly correlated with interstitial fibrosis, ACS, and CCS. Cortical fp discriminated mild from moderate and severe ACS with the largest AUC of 0.89 [95% confidence interval (CI), 0.77-0.96]. Noticeably, only cortical fp could differentiate severe ACS from mild-to-moderate ACS (P<0.001) with an AUC of 0.80 (95% CI, 0.65-0.90) and a sensitivity of 100% (95% CI, 66.4-100%). Strikingly, the joint use of D and fp in either the cortex or the medulla could achieve a sensitivity of 100% for identifying either mild or severe interstitial fibrosis. Meanwhile, the serial use of cortical D and cortical fp showed the largest specificity for identifying both mild [88.9% (95% CI, 70.8-97.6%)] and severe [84.4% (95% CI, 67.2-94.7%)] interstitial fibrosis. For identifying mild CCS, the AUC of medullary ADCT (0.90, 95% CI, 0.78-0.97) was similar to that of cortical D (0.81, 95% CI, 0.67-0.91) and fp (0.86, 95% CI, 0.73-0.94), but statistically larger than that of medullary D (P=0.005) and fp (P=0.01). Furthermore, the parallel use of cortical D and cortical fp could increase the sensitivity to 95.0% (95% CI, 75.1-99.9%), whereas serial use of medullary D and medullary fp could increase the specificity to 100% (95% CI, 87.2-100%). The AUCs for differentiating severe from mild and moderate CCS were statistically insignificant among all parameters in the cortex and medulla (P≥0.15).
Conclusions:
Cortical fp was superior to the ADCT for identifying both mild and severe acute pathologic changes. Nevertheless, ADCT was equal to or better than single D or fp for evaluating chronic pathologic changes. Thus, both monoexponential and bi-exponential analysis of DWI images are complementary for evaluating kidney allograft pathologic changes, and the combined use of D and fp can increase the sensitivity and specificity for discriminating allograft pathologic changes severity.
