• acute rejection
• chronic allograft nephropathy
• diffusion tensor imaging
• renal function

• Humans
• Kidney Transplantation
• Female
• Male
• Diffusion Tensor Imaging/methods
• Graft Rejection/diagnostic imaging
• Adult
• Prospective Studies
• Middle Aged
• Reproducibility of Results
• Acute Disease
• Chronic Disease
• Allografts/diagnostic imaging
• Sensitivity and Specificity
• Anisotropy
• Creatinine/blood
• ROC Curve
• Kidney/diagnostic imaging
• Kidney Diseases/diagnostic imaging

• LK2021017 Application Fundamental Research Program of the Jiangsu Provincial Health Commission's Elderly Health Project
• UTPIE2023006 Undergraduate Training Program for Innovation and Entrepreneurship, Soochow University

• chromophobe renal cell carcinoma
• diffusion-weighted imaging
• intravoxel incoherent motion
• oncocytoma

• Humans
• Kidney Neoplasms/diagnostic imaging
• Carcinoma, Renal Cell/diagnostic imaging
• Adenoma, Oxyphilic/diagnostic imaging
• Diffusion Magnetic Resonance Imaging/methods
• Diagnosis, Differential
• Female
• Middle Aged
• Male
• Aged
• Adult
• Sensitivity and Specificity
• Retrospective Studies

• YZ2021079 Yangzhou Social Development Fundation

• Diffusion
• Intravoxel incoherent motion
• Kidney
• Respiratory-controlled acquisition

• Humans
• Magnetic Resonance Imaging
• Diffusion Magnetic Resonance Imaging/methods
• Kidney/diagnostic imaging
• Motion
• Respiration

• MR urography
• MRI
• kidney perfusion
• urinary tract

• Cardiovascular magnetic resonance
• Comparison
• Diffusion tensor imaging
• Ex-vivo human heart

To compare the effects of 1.5 T and 3.0 T upper abdominal magnetic resonance diffusion-weighted imaging (DWI) under three acquisition techniques of breath holding, breath triggering, and free breathing, so as to provide a reference for the usage of upper abdominal DWI scanning.

Twenty-one healthy subjects were selected from social volunteers and underwent routine magnetic resonance imaging (MRI) and DWI on 1.5 T and 3.0 T, respectively. DWI included three acquisition methods: breath triggering, breath holding, and free breathing, and b values were 100 and 800. The DWI image artifacts, image quality, apparent diffusion coefficient (ADC), and the signal-to-noise ratio (SNR) obtained through the three acquisition methods were compared.

The 1.5 T free-breathing DWI image quality was the best, while the 3.0 T had the best breath-triggered DWI image quality. The 3.0 T breath-triggered DWI image quality was better than the 1.5 T free-breathing DWI image (P=0.012), and the SNR of free-breathing DWI was the highest. Between the two field intensities, the SNR of the liver in the 3.0 T group was much lower than that in the 1.5 T group, and obvious differences were not observed in ADC values of normal liver, gallbladder, kidney, spleen, and pancreas.

3.0 T respiratory-triggered acquisition can obtain higher quality DWI images. But in the case of only 1.5 T field strength, free-breathing acquisition of DWI images should be selected.

• Diabetes
• Diabetic kidney disease
• Diffusion tensor imaging
• Intravoxel incoherent motion

To evaluate the role of diffusion tensor imaging (DTI) of the liver in children with autoimmune hepatitis (AIH).

A prospective study was done on 42 children with AIH (30 girls and 12 boys, with a mean age of 13 years) and 20 age- and sex-matched healthy control children. They underwent DTI of the liver and laboratory tests. Liver biopsy was done for the patients. The mean diffusivity (MD) and fractional anisotropy (FA) of the liver were calculated and correlated with the pathological results.

The mean MD and FA of the liver in children with AIH were 1.42 ± 0.06 × 10^-3 mm²/s and 0.37 ± 0.11; and in the control children they were 1.55 ± 0.07 × 10^-3 mm²/s and 0.25 ± 0.03, respectively. The MD and FA were significantly different in the children with AIH compared to the control children (p = 0.001). The cutoff MD and FA used to differentiate patients from controls were 1.50 × 10^-3 mm²/s, 0.31 with AUC of 0.919 and 0.813, sensitivity of 97.6% and 66.7%, a specificity of 80% and 70%, an accuracy of 94.2% and 67.3%, PPV of 95.3 and 90.3, and NPV of 88.9 and 33.3, respectively. There was significantly lower MD and higher FA of the liver in children with AIH type I (n = 31) than type II (n = 11) (p = 0.001), and patients with (n = 9) and without (n = 33) overlap syndrome (p = 0.005).

We concluded that DTI parameters can help to diagnose AIH, detect its phenotyping, and give clues as to the presence of associated overlap syndrome.

• MR imaging
• autoimmune hepatitis
• diffusion
• fibrosis
• hepatic

• Autosomal-dominant polycystic kidney disease (ADPKD)
• disease progression
• height-adjusted TKV (htTKV)
• imaging classification
• kidney cyst growth
• kidney failure
• prognostic biomarker
• rapid progressor
• renal function trajectory
• renoprotective drug
• review
• tolvaptan
• total kidney volume (TKV)
• vasopressin V(2) receptor antagonist

• distortion correction
• diffusion imaging
• reversed gradient

• Adult
• Diabetic Nephropathies/diagnostic imaging
• Diffusion Tensor Imaging/methods
• Feasibility Studies
• Humans
• Image Interpretation, Computer-Assisted/methods
• Kidney/diagnostic imaging
• Middle Aged
• Young Adult

• P41 EB017183 NIBIB NIH HHS
• R01 CA245671 NCI NIH HHS

• Diffusion tensor imaging
• Fractional anisotropy
• Hypertension
• Hypertensive kidney injury
• Mean diffusivity
• Rats
• T2-mapping

Benign and malignant renal tumors share similar some imaging findings.

Sixty-six patients with clear cell renal cell carcinoma (CCRCC), 13 patients with renal angiomyolipoma with minimal fat (RAMF) and 7 patients with renal oncocytoma (RO) were examined. For diffusion kurtosis imaging (DKI), respiratory triggered echo-planar imaging sequences were acquired in axial plane (3 b-values: 0, 500, 1000s/mm²). Mean Diffusivity (MD), fractional Anisotropy (FA), mean kurtosis (MK), kurtosis anisotropy (KA) and radial kurtosis (RK) were performed.

For MD, a significant higher value was shown in CCRCC (3.08 ± 0.23) than the rest renal tumors (2.93 ± 0.30 for RO, 1.52 ± 0.24 for AML, P < 0.05). The MD values were higher for RO than for AML (2.93 ± 0.30 vs.1.52 ± 0.24, P < 0.05), while comparable MD values were found between CCRCC and RO (3.08 ± 0.23 vs. 2.93 ± 0.30, P > 0.05). For MK, KA and RK, a significant higher value was shown in AML (1.32 ± 0.16, 1.42 ± 0.23, 1.41 ± 0.29) than CCRCC (0.43 ± 0.08, 0.57 ± 0.16, 0.37 ± 0.11) and RO (0.81 ± 0.08, 0.86 ± 0.16, 0.69 ± 0.08) (P < 0.05). The MK, KA and RK values were higher for RO than for CCRCC (0.81 ± 0.08 vs. 0.43 ± 0.08, 0.86 ± 0.16 vs. 0.57 ± 0.16, 0.69 ± 0.08 vs. 0.37 ± 0.11, P < 0.05). Using MD values of 2.86 as the threshold value for differentiating CCRCC from RO and AML, the best result obtained had a sensitivity of 76.1%, specificity of 72.6%. Using MK, KA and RK values of 1.19,1.13 and 1.11 as the threshold value for differentiating AML from CCRCC and RO, the best result obtained had a sensitivity of 91.2, 86.7, 82.1%, and specificity of 86.7, 83.2, 72.8%.

DKI can be used as another noninvasive biomarker for benign and malignant renal tumors’ differential diagnosis.

• Anisotropy
• Differential diagnosis
• Diffusion magnetic resonance imaging
• Kidney
• Renal neoplasms

Kidney transplantation is the treatment of choice for patients with end-stage renal disease, as it extends survival and increases quality of life in these patients. However, chronic allograft injury continues to be a major problem, and leads to eventual graft loss. Early detection of allograft injury is essential for guiding appropriate intervention to delay or prevent irreversible damage. Several advanced MRI techniques can offer some important information regarding functional changes such as perfusion, diffusion, structural complexity, as well as oxygenation and fibrosis. This review highlights the potential of multiparametric MRI for noninvasive and comprehensive assessment of renal allograft injury.

• Allograft dysfunction
• Allograft fibrosis
• Functional MRI
• Kidney transplantation
• Multiparametric magnetic resonance imaging

Blood oxygenation level-dependent magnetic resonance imaging (BOLD-MRI) and diffusion tensor imaging (DTI) are useful methods for investigating the morphology and function of the kidneys, including revealing unilateral renal damage. Nevertheless, these techniques have not yet been applied for bilateral renal function. The aim of this study was to investigate whether the combination of DTI and BOLD could be used to examine different degrees of contrast-induced acute kidney injury (CI-AKI) in bilateral kidneys compared to standard methods such as serum creatinine (SCr) detection.

Forty-Two New Zealand white rabbits were divided into two groups: the experimental group and the control group. Physiological saline and iodine contrast agent (iohexol, 1.0 g iodine/kg, 1.0 ml/sec) were injected via the right renal artery. DTI and BOLD-MR data were acquired longitudinally at the baseline and 1, 24, 48, and 72 h after high-pressure syringe injection to measure the apparent diffusion coefficient (ADC), fractional anisotropy (FA) and relative transverse relaxation rate (R2*). After the MR scan at each time point, three rabbits in each group were sacrificed, and changes in SCr and hypoxia-inducible factor-1α (HIF-1α) were analyzed using histopathology and immunochemistry.

Twenty-four hours after iohexol administration, the values of ADC and FA decreased significantly (P < 0.05), while R2* values increased (P < 0.05) in the renal cortex (CO), outer medulla (OM) and inner medulla (IM). Besides, significant negative correlations were observed among ADC, FA, and R2* in CO, OM, and IM (all P < 0.001, r = − 0.654–0.828).

DTI and BOLD can simultaneously and non-invasively assess different degrees of CI-AKI in bilateral kidneys.

• Contrast-induced acute kidney injury (CI-AKI)
• Diffusion tensor imaging (DTI)
• Magnetic resonance blood oxygen level-dependent imaging (MR-BOLD)

• Diffusion-weighted imaging
• diffusion kurtosis imaging
• estimated glomerular filtration rate
• hyperuricemia
• kidney injury

Background: Magnetic resonance relaxometry (MRR) offers highly reproducible pixel-wise parametric maps of T1 and T2 relaxation times, reflecting specific tissue properties, while diffusion-tensor imaging (DTI) is a promising technique for the characterization of microstructural changes, depending on the directionality of molecular motion. Both MMR and DTI may be used for non-invasive assessment of parenchymal changes caused by kidney injury or graft dysfunction. Methods: We examined 46 patients with kidney transplantation and 16 healthy controls, using T1/T2 relaxometry and DTI at 3 T. Twenty-two early transplants and 24 late transplants were included. Seven of the patients had prior renal biopsy (all of them dysfunctional allografts; 6/7 with tubular atrophy and 7/7 with interstitial fibrosis). Results: Compared to healthy controls, T1 and T2 relaxation times in the renal parenchyma were increased after transplantation, with the highest T1/T2 values in early transplants (T1: 1700 ± 53 ms/T2: 83 ± 6 ms compared to T1: 1514 ± 29 ms/T2: 78 ± 4 ms in controls). Medullary and cortical ADC/FA values were decreased in early transplants and highest in controls, with medullary FA values showing the most pronounced difference. Cortical renal T1, mean medullary FA and corticomedullary differentiation (CMD) values correlated best with renal function as measured by eGFR (cortical T1: r = −0.63, p < 0.001; medullary FA: r = 0.67, p < 0.001; FA CMD: r = 0.62, p < 0.001). Mean medullary FA proved to be a significant predictor for tubular atrophy (p < 0.001), while cortical T1 appeared as a significant predictor of interstitial fibrosis (p = 0.003). Conclusion: Cortical T1, medullary FA, and FA CMD might serve as new imaging biomarkers of renal function and histopathologic microstructure.

• multiparametric MRI
• quantitative tissue analysis
• renal biopsy
• renal pathology
• transplantation

• DWI
• FA map
• PGSE
• STEAM
• kidney
• renal DTI

Standardization is an important milestone in the validation of DWI-based parameters as imaging biomarkers for renal disease. Here, we propose technical recommendations on three variants of renal DWI, monoexponential DWI, IVIM and DTI, as well as associated MRI biomarkers (ADC, D, D*, f, FA and MD) to aid ongoing international efforts on methodological harmonization.

Reported DWI biomarkers from 194 prior renal DWI studies were extracted and Pearson correlations between diffusion biomarkers and protocol parameters were computed. Based on the literature review, surveys were designed for the consensus building. Survey data were collected via Delphi consensus process on renal DWI preparation, acquisition, analysis, and reporting. Consensus was defined as ≥ 75% agreement.

Correlations were observed between reported diffusion biomarkers and protocol parameters. Out of 87 survey questions, 57 achieved consensus resolution, while many of the remaining questions were resolved by preference (65–74% agreement). Summary of the literature and survey data as well as recommendations for the preparation, acquisition, processing and reporting of renal DWI were provided.

The consensus-based technical recommendations for renal DWI aim to facilitate inter-site harmonization and increase clinical impact of the technique on a larger scale by setting a framework for acquisition protocols for future renal DWI studies. We anticipate an iterative process with continuous updating of the recommendations according to progress in the field.

The online version of this article (10.1007/s10334-019-00790-y) contains supplementary material, which is available to authorized users.

• ADC
• Biomarker
• DTI
• DWI
• IVIM

Diffusion tensor imaging (DTI) is particularly suitable for kidney studies due to tubules, collector ducts and blood vessels in the medulla that produce spatially restricted diffusion of water molecules, thus reflecting the high grade of anisotropy detectable by DTI. Kidney DTI is still a challenging technique where the off-resonance susceptibility artefacts and subject motion can severely affect the reproducibility of results. The aim of this study is to design a reliable processing pipeline by assessing different image processing approaches in terms of reproducibility and image artefacts correction. The results of four different processing pipelines (eddy: correction of eddy-currents and motion between DTI volume; eddy-s2v: eddy and within DTI volume motion correction; topup: eddy and geometric distortion correction; topup-s2v: topup and within DTI volume motion correction) are compared in terms of reproducibility by test-retest analysis in 14 healthy subjects. Within-subject coefficient of variation (wsCV) and intra-class correlation coefficient (ICC) are measured to assess the reproducibility and Dice similarity index is evaluated for the spatial alignment between DTI and anatomical images. Topup-s2v pipeline provides highest reproducibility (wsCV = 0.053, ICC = 0.814) and best correction of image distortion (Dice = 0.83). This study definitely provides a recipe for data processing, enabling for a clinical suitability of kidney DTI.

• MRI
• autosomal dominant polycystic kidney disease
• total kidney volume

• Diffusion
• intravoxel incoherent motion
• kidney
• tumor

• Children
• Diffusion tensor imaging
• Magnetic resonance imaging
• Magnetic resonance urography
• Ureteropelvic junction obstruction
• Urinary tract

• Adolescent
• Anisotropy
• Child
• Child, Preschool
• Diagnosis, Differential
• Diffusion Tensor Imaging/methods
• Feasibility Studies
• Female
• Humans
• Image Interpretation, Computer-Assisted
• Infant
• Male
• Pilot Projects
• Retrospective Studies
• Ureteral Obstruction/diagnostic imaging
• Ureteral Obstruction/surgery

• Functional MRI
• Renal allografts
• Renal function
• Transplanted kidneys

To investigate the utility of renal diffusion tensor imaging (DTI) to detect early renal damage in patients with type 2 diabetes.

Twenty-six diabetic patients (12 with microalbuminuria (MAU), and 14 with normoalbuminuria) and fourteen healthy volunteers were prospectively included in this study. Renal DTI on 3.0 T MR was performed, and estimated glomerular filtration rate (eGFR) was recorded for each subject. Mean cortical and medullary fractional anisotropy (FA) values were calculated by placing multiple representative regions of interest. Mean FA values were statistically compared among groups. Correlations between FA values and eGFR were evaluated.

Both cortical and medullary FA were significantly reduced in diabetic patients compared to healthy controls (0.403 ± 0.064 vs 0.463 ± 0.047, P = 0.004, and 0.556 ± 0.084 vs 0.645 ± 0.076, P = 0.002, respectively). Cortical FA was significantly lower in diabetic patients with NAU than healthy controls (0.412 ± 0.068 vs 0.463 ± 0.047, P = 0.02). Medullary FA in diabetic patients with NAU and healthy controls were similar (0.582 ± 0.096 vs 0.645 ± 0.076, P = 0.06). Both cortical FA and medullary FA correlated with eGFR (r = 0.382, P = 0.015 and r = 0.552, P = 0.000, respectively).

FA of renal parenchyma on DTI might serve as a more sensitive biomarker of early diabetic nephropathy than MAU.

• Renal diffusion tensor imaging
• Fractional anisotropy
• Diabetic nephropathy
• Microalbuminuria
• Estimated GFR
• Correlation

• diffusion tensor imaging
• longitudinal MRI
• medulloblastoma
• regional analysis
• tissue volumes

Functional magnetic resonance imaging (MRI) provided critical functional information in addition to the anatomic profiles offered by conventional MRI, and has been enormously used in the initial diagnosis and followed evaluation of various diseases. Diffusion tensor imaging (DTI) is a newly developed and advanced technique that measures the diffusion properties including both diffusion motion and its direction in situ, and has been extensively applied in central nerve system with acknowledged success. Technical advances have enabled DTI in abdominal and pelvic organs. Its application is increasing, yet remains less understood. A systematic overview of clinical application of DTI in abdominal and pelvic organs such as liver, pancreas, kidneys, prostate, uterus, etc., is therefore presented. Exploration of techniques with less artifacts and more normative post-processing enabled generally satisfactory image quality and repeatability of measurement. DTI appears to be more valuable in the evaluation of diffused diseases of organs with highly directionally arranged structures, such as the assessment of function impairment of native and transplanted kidneys. However, the utility of DTI to diagnose focal lesions, such as liver mass, pancreatic and prostate tumor, remains limited. Besides, diffusion of different layers of the uterus and the fiber structure disruption can be depicted by DTI. Finally, a discussion of future directions of research is given. The underlying heterogeneous pathologic conditions of certain diseases need to be further differentiated, and it is suggested that DTI parameters might potentially depict certain pathologic characterization such as cell density. Nevertheless, DTI should be better integrated into the current multi-modality evaluation in clinical practice.

• Functional magnetic resonance imaging
• Diffusion tensor imaging
• Abdomen
• Pelvis
• Kidney

• DTI
• FA
• MRI
• abdominal organs
• diffusion
• diffusion tensor imaging

• Abdomen/anatomy & histology
• Abdomen/diagnostic imaging
• Diffusion Tensor Imaging/methods
• Evidence-Based Medicine
• Humans
• Image Enhancement/methods
• Reproducibility of Results
• Sensitivity and Specificity
• Viscera/anatomy & histology
• Viscera/diagnostic imaging

• Crohn's Disease
• MR imaging
• MR-enterography
• diffusion weighted imaging
• imaging techniques
• inflammatory bowel disease

• Crohn Disease/diagnostic imaging
• Crohn Disease/pathology
• Diffusion Magnetic Resonance Imaging/methods
• Evidence-Based Medicine
• Humans
• Image Enhancement/methods
• Image Interpretation, Computer-Assisted/methods
• Reproducibility of Results
• Sensitivity and Specificity

AIM: To investigate feasibility of a quantitative study of prostate cancer using three dimensional (3D) fiber tractography.

METHODS: In this institutional review board approved retrospective study, 24 men with biopsy proven prostate cancer underwent prostate magnetic resonance imaging (MRI) with an endorectal coil on a 1.5 T MRI scanner. Single shot echo-planar diffusion weighted images were acquired with b = 0.600 s/mm², six gradient directions. Open-source available software TrackVis and its Diffusion Toolkit were used to generate diffusion tensor imaging (DTI) map and 3D fiber tracts. Multiple 3D spherical regions of interest were drawn over the areas of tumor and healthy prostatic parenchyma to measure tract density, apparent diffusion coefficient (ADC) and fractional anisotropy (FA), which were statistically analyzed.

RESULTS: DTI tractography showed rich fiber tract anatomy with tract heterogeneity. Mean tumor region and normal parenchymal tract densities were 2.53 and 3.37 respectively (P < 0.001). In the tumor, mean ADC was 0.0011 × 10^-3 mm²/s vs 0.0014 × 10^-3 mm²/s in the normal parenchyma (P < 0.001). The FA values for tumor and normal parenchyma were 0.2047 and 0.2259 respectively (P = 0.3819).

CONCLUSION: DTI tractography of the prostate is feasible and depicts congregate fibers within the gland. Tract density may offer new biomarker to distinguish tumor from normal tissue.

• Prostate cancer
• Tract density
• Diffusion tensor imaging
• Tractography
• Magnetic resonance imaging

• DTI
• diffusion
• kidney
• motion correction
• nonrigid image registration
• respiratory triggering

• Apparent diffusion coefficient
• Apparent diffusion coefficient reproducibility
• Cancer imaging
• Diffusion-weighted magnetic resonance imaging
• Extra-cranial organs

• Acute Kidney Injury/diagnostic imaging
• Acute Kidney Injury/pathology
• Contrast Media/chemistry
• Gadolinium/chemistry
• Humans
• Kidney/diagnostic imaging
• Kidney/pathology
• Magnetic Resonance Imaging/methods

• delayed graft function
• diffusion tensor imaging
• diffusion weighted magnetic resonance imaging
• fibrosis
• kidney transplantation

To investigate the value of apparent diffusion coefficient (ADC) and fractional anisotropy (FA) in differentiating clear-cell renal cell carcinoma (CCRCC) from low-fat renal angiomyolipomas (RAML), and to obtain the optimal b value. Fifty patients, including 30 cases of CCRCC and 20 cases of low-fat RAML, were retrospectively recruited to participate in this study. Before renal nephrectomy, all subjects underwent functional magnetic resonance imaging. For diffusion tensor imaging (DTI), a respiratory-triggered coronal echo planar imaging sequence was performed with three groups of different b values (0 and 400, 600, and 800). The ADC and FA of kidneys were analyzed and compared between different b values using analysis of variance. Receiver operation characteristic analysis was computed to assess the diagnostic performance of ADC and FA in differentiating low-fat RAML from CCRCC and to determine the optimal b values. With either CCRCC or low-fat RAML, the ADC values decreased with increased b values and significant differences were observed (F = 11.34, 23.15, P < 0.05), while the FA values were not significantly different (F = 0.28, 2.80, P > 0.05). The statistical differences in ADC, and the FA values for CCRCC and low-fat RAML were significantly different (P < 0.05). When the b value was 0.800 s/mm², the cutoff FA value for differentiating CCRCC from low-fat RAML was 0.254 × 10.3 mm²/s, and had a sensitivity of 100 %, and a specificity of 73.3 %. MR-DTI can be used to differentiate CCRCC from low-fat RAML.

• Clear cell renal cell carcinomas
• Diffusion tensor imaging
• Fractional anisotropy
• Renal angiomyolipomas

• Arterial Spin Labeling
• BOLD imaging
• Diffusion-tensor imaging (DTI)
• Diffusion-weighted imaging (DWI)
• Functional renal MRI
• Perfusion imaging

• diffusion-weighted imaging (DWI)
• liver cirrhosis
• renal function

• Adult
• Aged
• Carcinoma, Pancreatic Ductal/pathology
• Diffusion Tensor Imaging/methods
• Female
• Humans
• Magnetic Resonance Imaging
• Male
• Middle Aged
• Pancreas/pathology
• Pilot Projects