Assessment of glymphatic dysfunction in pediatric idiopathic intracranial hypertension: insights from quantitative diffusivity and perivascular spaces analysis-a case-control study.

Background: The impaired drainage of cerebrospinal fluid through the glymphatic system is thought to play a role in the idiopathic intracranial hypertension (IIH) pathophysiology. Limited data exist regarding the glymphatic system's involvement in pediatric patients with IIH. Therefore, the study's objective was to quantitatively evaluate alterations in parenchymal diffusivity and magnetic resonance imaging (MRI)-visible dilated perivascular spaces (PVS) as imaging indicators of glymphatic dysfunction in pediatric patients with IIH. Methods: Patients diagnosed with IIH in 2017-2022 in a single tertiary center (Sheba Medical Center, Israel) were retrospectively reviewed. Twenty-four pediatric patients were enrolled. All patients underwent clinical 3-T brain MRI. The control group included 24 age- and gender-matched healthy subjects with a normal-appearing brain on imaging. We used automatic atlas-based diffusion-weighted imaging analysis to determine regional diffusivity of the thalamus, caudate, putamen, globus pallidus, hippocampus, amygdala, and brain stem. PVS were evaluated using a semi-quantitative rating scale on T2-weighted images. Variables were compared using the Mann-Whitney test. Multivariate analysis of covariance was used to test for differences between controls and IIH patients. Results: No significant differences in regional brain diffusivity were observed between individuals with IIH and healthy controls (P=0.14-0.91 for various brain regions). The number of visible PVS was comparable between patients with IIH and the control group across all evaluated sites (P=0.12-0.74 for various brain regions). Conclusions: Pediatric IIH patients exhibited similar patterns of parenchymal diffusivity and PVS compared to age-matched controls. These findings do not support the hypothesis that the glymphatic system may play a role in the pathophysiology of pediatric IIH, although previously postulated. However, employing more sophisticated magnetic resonance (MR) techniques could enhance the sensitivity in uncovering underlying glymphatic dysfunction. Further research is warranted to validate and explore this association in larger cohorts and investigate the underlying mechanisms involved in IIH.

Utility of magnetic resonance spectroscopy and diffusion-weighted imaging for detecting changes in the femoral head in divers with hip pain at risk for dysbaric osteonecrosis.

BACKGROUND: Ischemia before the development of dysbaric osteonecrosis (DON) in femoral heads has never been investigated. We assessed whether quantitative magnetic resonance spectroscopy (MRS) and diffusion weighted imaging (DWI) could detect dysbaric changes in divers with hip pain. METHODS: This IRB-approved exploratory study recruited 17 divers [9 with hip pain (Group 1); 8 asymptomatic (Group 2)] with normal findings on radiographs and conventional magnetic resonance imaging scans were age-, gender- and body-mass-index matched to 17 non-divers as controls (Group 1C, 2C). Apparent diffusion coefficients (ADCs) and MRS spectra were obtained from regions/voxels of interest on the femoral heads of all subjects. LCModel was used to determine water content, lipid composition, and the unsaturation index in bone marrow. Mann-Whitney non-parametric test was used to compare results of quantitative MRS and ADCs of ipsilateral femoral heads between divers and controls. RESULTS: MRS of the ipsilateral femoral heads revealed higher water (peak: 4.7 ppm) content, lower total lipid fraction (TLF), and higher unsaturation index (UI) of lipids in Group 1 than in Group 2 (water: P=0.040; UI: P=0.022) and Group 1C (water: P=0.027; TLF: P=0.039; UI: P=0.009). In contrast, femoral head ADCs were comparable between divers and controls. Five out of nine symptomatic divers were contacted for follow-up MRS and DWI studies, and the mean difference in water content in the femoral heads of patients with osteonecrosis was also higher than that in patients with symptom relief (osteonecrosis: 0.077±0.130 vs. symptom relief: 0.003±0.010). CONCLUSIONS: Dysbaric change in the femoral heads of divers with hip pain can be detected using quantitative MRS, which reveals increases in water content and UI of lipids, and a decrease in TLF.

Outcomes of Mechanical Thrombectomy in Patients with Large Diffusion-Weighted Imaging Lesions.

OBJECTIVE: Despite many advancements in endovascular treatment, the benefits of mechanical thrombectomy (MT) in patients with large infarctions remain uncertain due to hemorrhagic complications. Therefore, we aimed to investigate the efficacy and safety of recanalization via MT within 6 hours after stroke in patients with large cerebral infarction volumes (>70 mL). METHODS: We retrospectively reviewed the medical data of 30 patients with large lesions on initial diffusion-weighted imaging (>70 mL) who underwent MT at our institution within 6 hours after stroke onset. Baseline data, recanalization rate, and 3-month clinical outcomes were analyzed. Successful recanalization was defined as a modified treatment in cerebral ischemia score of 2b or 3. RESULTS: The recanalization rate was 63.3%, and symptomatic intracerebral hemorrhage occurred in six patients (20%). The proportion of patients with modified Rankin Scale (mRS) scores of 0-3 was significantly higher in the recanalization group than in the non-recanalization group (47.4% vs. 9.1%, p=0.049). The mortality rate was higher in the non-recanalization group, this difference was not significant (15.8% vs. 36.4%, p=0.372). In the analysis of 3-month clinical outcomes, only successful recanalization was significantly associated with mRS scores of 0-3 (90% vs. 50%, p=0.049). The odds ratio of recanalization for favorable outcomes (mRS 0-3) was 9.00 (95% confidence interval, 0.95-84.90; p=0.055). CONCLUSION: Despite the risk of symptomatic intracerebral hemorrhage, successful recanalization via MT 6 hours after stroke may improve clinical outcomes in patients with large vessel occlusion.

Diffusion-Weighted Magnetic Resonance Imaging in the Diagnosis of Cerebral Venous Thrombosis : A Meta-Analysis.

OBJECTIVE: A role of diffusion-weighted imaging (DWI) in the diagnosis of cerebral venous thrombosis (CVT) is not wellunderstood. This study evaluates the effectiveness of DWI in the diagnosis of CVT. METHODS: Literature search was conducted in electronic databases for the identification of studies which reported the outcomes of patients subjected to DWI for CVT diagnosis. Random-effects meta-analyses were performed to achieve overall estimates of important diagnostic efficiency indices including hyperintense signal rate, the sensitivity and specificity of DWI in diagnosing CVT, and the apparent diffusion coefficient (ADC) of DWI signal areas and surrounding tissue. RESULTS: Nineteen studies (443 patients with 856 CVTs; age 40 years [95% confidence interval (CI), 33 to 43]; 28% males [95% CI, 18 to 38]; symptom onset to DWI time 4.6 days [95% CI, 2.3 to 6.9]) were included. Hyperintense signals on DWI were detected in 40% (95% CI, 26 to 55) of the cases. The sensitivity of DWI for detecting CVT was 22% (95% CI, 11 to 34) but specificity was 98% (95% CI, 95 to 100). ADC values were quite heterogenous in DWI signal areas. However, generally the ADC values were lower in DWI signal areas than in surrounding normal areas (mean difference-0.33×10-3 mm2/s [95% CI, -0.44 to -0.23]; p<0.00001). CONCLUSION: DWI has a low sensitivity in detecting CVT and thus has a high risk of missing many CVT cases. However, because of its high specificity, it may have supporting and exploratory roles in CVT diagnosis.

Diffusion-weighted magnetic resonance imaging (MRI) without susceptibility artifacts: single-shot stimulated echo acquisition mode (STEAM) MRI with iterative reconstruction and spatial regularization.

This work describes a new method for diffusion-weighted (DW) magnetic resonance imaging (MRI) without susceptibility artifacts. The technique combines a DW spin-echo module and a single-shot stimulated echo acquisition mode (STEAM) MRI readout with undersampled radial trajectories and covers a volume by a gapless series of cross-sectional slices. In a first step, optimal coil sensitivities for all slices are obtained from a series of non-DW acquisitions by nonlinear inverse reconstruction with regularization to the image and coil sensitivities of a directly neighboring slice. In a second step, these coil sensitivities are used to compute all series of non-DW and DW images by linear inverse reconstruction with spatial regularization to a neighboring image. Proof-of-principle applications to the brain (51 sections) and prostate (31 sections) of healthy subjects were realized for a protocol with two b-values and 6 gradient directions at 3 T. Including averaging the measuring times for studies of the brain at 1.0×1.0×3.0 mm3 resolution (b =1,000 s mm-2) and prostate at 1.4×1.4×3.0 mm3 resolution (b =600 s mm-2) were 2.5 min and 4.5 min, respectively. All reconstructions were accomplished online with use of a multi-GPU computer integrated into the MRI system. The resulting non-DW images, mean DW images averaged across directions and maps of the apparent diffusion coefficient confirm the absence of geometric distortions or false signal alterations and demonstrate diagnostic image quality. The novel method for DW STEAM MRI of a volume without susceptibility artifacts warrants extended clinical trials.

Reliability and Reproducibility of the Diameters Method in Rapid Determination of Acute Infarct Volume in Magnetic Resonance Diffusion-Weighted Imaging.

BACKGROUND: In acute ischemic stroke, diffusion-weighted imaging (DWI) volume is an independent predictive factor of poor outcome and an exclusion criterion for thrombolytic treatment. A simplified diameters method (ABC/2, orthogonal diameter [OD], and the maximum diameter [MD]) was proposed to replace the conventional measuring method and overcome the tedious and time-consuming defects, but its accuracy remains to be determined. OBJECTIVE: The objective of this study is to clarify the reliability and reproducibility of the diameter-based estimations in the infarct volume in DWI (Vol-DWI) measured by automated software. METHODS: Data of 316 patients with acute ischemic stroke who underwent MRI within 72 h at Jinling Hospital were retrospectively reviewed. Subgroup analysis by the location (cortex, white matter and deep gray nuclei, and combined) and volume (<70 and >70 mL) of cerebral infarction was evaluated. Relationship and consistency between the diameters methods and Vol-DWI were determined using Spearman rank correlation, Wilcoxon signed-rank test, and Bland-Altman plots. The OD and MD thresholds indicating infarct size >15, 70, and 100 mL were determined by generating receiver-operating characteristic (ROC) curves. Interobserver reliability was established using intraclass correlation coefficient and Bland-Altman plot. RESULTS: There was a strong positive correlation between the diameters and the Vol-DWI (ABC/2: r = 0.992, OD: r = 0.984, MD: r = 0.970, p < 0.001). Infarct volumes measured using the ABC/2 formula were significantly lower than those measured with Vol-DWI (Wilcoxon signed-rank test, z = 6.476, p < 0.001). Bland-Altman plot showed that the agreement of the volume <70 mL group, and white matter and deep gray nuclei groups was better than that of the other subgroups. For infarct volumes >15, 70, and 100 mL, the cutoff value for the MD was identified at 5, 6.9, and 8.4 cm, and the OD was identified at 12.47, 26.4, and 36.4 cm2, respectively, with a sensitivity and specificity >90%. CONCLUSIONS: The MD method was the best for achieving a rapid and excellent interobserver reliability for estimating infarct volume. Both OD and MD methods can quickly screen patients suitable for recanalization treatment and predict poor prognosis through threshold evaluation.

The diagnostic accuracy of 1.5 T versus 3 T non-echo-planar diffusion-weighted imaging in the detection of residual or recurrent cholesteatoma in the middle ear and mastoid.

PURPOSE AND BACKGROUND: This study retrospectively compares diagnostic performance of 1.5 T versus 3 T non-echo planar diffusion weighted imaging with or without additional T1 and T2 sequences in the detection of residual and/or recurrent cholesteatoma. METHODS: Patients with clinically suspected recurrent cholesteatoma or postoperative routine survey MR who subsequently underwent surgical procedure were retrospectively included (135 patients, 164 operated ears) from a large database. Patients underwent 1.5 T (128 ears) or 3 T MRI (36 ears), with non-echo planar DWI, T1 and T2 acquisitions. Two radiologists independently reassessed the images. Definitive surgical diagnosis was used as gold standard. Sensitivity, specificity and diagnostic odds ratio were evaluated. RESULTS: According to surgical diagnosis a cholesteatoma was present in 124 of 164 ears, corresponding with a prevalence of 75%. Sensitivity and specificity were lower for 3 T compared to 1.5 T, irrespective of whether additional T1 and T2-weighted sequences were used or not. Diagnostic odds ratios were higher for 1.5 T (34 and 12 for reader 1 and 2, respectively) compared to 3 T (3 and 4 for reader 1 and 2, respectively). Adding T1 and T2 sequences lowers sensitivity but increases specificity. CONCLUSION: Non-epi DWI for the detection of residual/recurrent cholesteatoma is preferably performed on 1.5 T scanners over 3 T. The use of additional sequences regarding detection of cholesteatoma is debatable as it lowers sensitivity but increases specificity. However, these sequences may also be of use in diagnosing complications and planning surgical procedures in some hospitals.

Comparative Study between 18F FDG-PET/CT and Whole Body MRI DWIBS in Assessment of Recurrent Breast Cancer (Prospective, Comparative, Cross-sectional Study Design).

AIM: This study aims to assess the diagnostic performance of 18F-fluorodeoxyglucose-positron emission tomography/computerized tomography (18FDG-PET/CT) compared to whole body (WB) magnetic resonance diffusion-weighted imaging (DWI) with background body signal suppression (MR/DWIBS) in lesions detection in patients with recurrent breast cancer. MATERIALS AND METHODS: Twenty-three female patients with suspected breast cancer recurrence by clinical, laboratory, or conventional imaging underwent both 18FDG-PET/CT and WB MR/DWIBS. WB 18FDG-PET/CT was performed using the standard technique. WB MR/DWIBS acquired sequences were WB DWI with short tau inversion recovery (STIR), coronal T1, and coronal STIR. Both 18FDG-PET/CT and WB-magnetic resonance imaging/DWIBS were independently interpreted using visual qualitative and quantitative analysis. Pathological findings and combined clinical/radiological follow-up data were used as a reference standard. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall accuracy were calculated for both techniques. RESULTS: PET/CT demonstrated higher specificity and sensitivity indices than MR/DWIBS in the detection of the nodal and distant lesions, while the latter displayed higher sensitivity in the detection of local breast lesions. The overall sensitivity, specificity, NPV, PPV, and accuracy of PET/CT were 84.8%, 86.3%, 90.4%, 78.7%, and 85.4% versus 82.1%, 78.0%, 85.2%, 74.0%, and 80.5% for MR/DWIBS. A high degree of agreement existed between PET/CT and MR-DWIBS. CONCLUSION: 18FDG-PET/CT is more sensitive and has superiority in the assessment of nodal and distant lesions than DWIBS that has a potential superior role in the assessment of local breast lesions. DWIBS has a promising and helpful complementary tool for 18FDG-PET/CT in the evaluation of patients with proven malignancies.

Comparative Study of Transrectal Real-time Tissue Elastography and Magnetic Resonance Diffusion-Weighted Imaging in the Diagnosis and Guided Biopsy of Prostate Cancer / 中山大学学报(医学科学版)

@#【Objectives】 To comparatively analyze the diagnostic performance of transrectal real- time elastography（TRTE）and magnetic resonance diffusion- weighted imaging （DWI）in differentiating benign from malignant prostatic lesions，to evaluate the value of the two methods in guided prostate biopsy，and to investigate the correlation between the two methods and Gleason scores. 【Methods】 A total of 126 patients with suspected prostate cancer underwent prostate biopsy. Preoperative tests of TRTE and DWI were performed in all of the included patients. Combined with pathological results，the diagnostic efficacy of TRTE and DWI for prostate cancer and the effects of prostate biopsy guided by the two methods were compared ，and the relationship between the elastography score and ADC value and Gleason scores were also evaluated.【Results】 The sensitivity，specificity，accuracy of diagnosing prostate cancer by TRTE were 78.8% ，78.3% ，78.6% ，the sensitivity，specificity，accuracy of diagnosing prostate cancer by DWI were 87.9% ，90% ，88.9% ， there was no significant difference of sensitivity and specificity between the two groups（P > 0.05），and the accuracy was statistically different（P < 0.05）. The AUC of elastography score and ADC value were 0.859 and 0.906，the accuracy of the diagnosis of benign and malignant prostate lesions by ADC value method was higher than elastography score ，but there was no statistically significant difference （P > 0.05）. A significant positive correlation was found between elastography score and Gleason scores，while a significant negative correlation was found between ADC value and Gleason scores.【Conclusions】TRTE and DWI is valuable in diagnosis of prostatic lesions. Biopsy guided by the two methods can improve the detection rate of prostate cancer and can provide indicative evidence for tumor differentiation analysis.

A comparative analysis of diffusion-weighted magnetic resonance imaging and contrast-enhanced CT in target volume delineation for pancreatic cancer / 中华放射肿瘤学杂志

Objective To investigate the differences in tumor volume and metastatic tumors of the liver and regional lymph nodes between contrast-enhanced computed tomography (CT) and diffusion-weighted magnetic resonance imaging (DWMRI) through a comparative analysis,as well the useful information for target volume delineation,and to guide radiotherapy in clinical practice.Methods A total of 40 patients with pancreatic cancer were enrolled and underwent contrast-enhanced CT and DWMRI in the same position.The target volume was delineated,the major axis of the maximum tumor section was measured,and the numbers of liver metastatic tumors and metastatic tumors of the lymph nodes with a diameter of 5-8 mm or＞8 mm were measured based on the CT and DWMRI images.The analysis was performed by using paired t-test or paired Wilcoxon rank sum test.Results The mean gross tumor volume (GTV) delineated by contrast-enhanced CT and DWMRI was 54.95 cm3 and 41.67 cm3(P =0.000),and the mean value-different value was 13.28 cm3.The major axis of the maximum tumor section measured by contrast-enhanced CT and DWMRI were 4.18 cm and 3.94 cm (P=0.000),respectively,and in two patients,dCT was smaller than dDWMRI.A total of 83 liver metastatic tumors were identified by contrast-enhanced CT,and 112 were identified by DWMRI;the liver metastatic tumors detected by contrast-enhanced CT accounted for 74％ of those detected by DWMRI.As for the metastatic tumors of the lymph nodes with a diameter of 5-8 mm or＞8 mm,103 or 46 were detected by contrast-enhanced CT,and 200 or 56 were detected by DWMRI,and the tumors detected contrast-enhanced CT accounted for 52％ or 82％ of those detected by DWMRI.There were significant differences in all data between contrast-enhanced CT and DWMRI.Conclusions GTV and the major axis of the maximum tumor section measured by DWMRI are lower than those measured by contrast-enhanced CT,and contrast-enhanced CT is sensitive in detecting the metastatic tumors of the liver and lymph nodes.However,it is necessary to conduct further controlled experiments with reference to pathology.

Findings of MRI in Cervical Spinal Cord Injury without Fracture and Dislocation and Correlation between Apparent Diffusion Coefficient of Foci and Severity of Injuries / 中国康复理论与实践

@#Objective To study the MRI of cervical spinal cord injury without fracture and dislocation and explore of the apparent diffusion coefficient (ADC) of injured site related to the severity of injury. Methods 46 patients with cervical spinal cord injury without fracture and dislocation and 20 healthy controls were scaned with routine MRI and diffusion weighted imaging. The ADC value of site of injury and grades of Frankel's classification were analyze with the correlation. Results There were 22 cases with spinal cord edema, 8 cases with intramedullary hemorrhage, 14 cases with edema and hemorrhage, 2 cases without abnormal finding. The ADC of controls and patients were (1.05±0.12)×10-3 mm2/s, (1.21±0.23)×10-3 mm2/s (t=0.704, P<0.05). The ADC values positively correlated with the grades of Frankel's classification (r=0.407, P<0.05). Conclusion MRI may help to find the cervical cord injury in those without fracture and dislocation, and the ADC may be resposible to the severity of injury.

脑转移瘤磁共振弥散加权像与原发肿瘤病理学相关性初步探讨 / 中国康复理论与实践

@#ObjectiveTo study the application of magnetic resonance imaging (MRI) diffusion-weighted imaging (DWI) in brain metastases, and the relationship between DWI results and the primary tumor pathology. Methods76 cases with brain metastases were grouped according to the primary cancer pathology. The apparent diffusion coefficient (ADC) of tumor parenchyma, capsule area, edema around tumors and normal parenchyma were determined; the ratio of high signal on the DWI were calculated (namely diffusion limited) in different tumor. ResultsThe ADC was (1.1364±0.310)×10-3 mm2/s in tumor parenchyma, (2.167±0.472)×10-3 mm2/s in capsule, (1.597±0.238)×10-3 mm2/s in edema and (0.812±0.158)×10-3 mm2/s in normal parenchyma (P<0.05). 15 cases appeared diffusion limited (19.7%), in which the primary tumors were lung cancer in 10 patients (66.6%) (including 5 cases with small cell lung cancer, 5 cases with none small cell lung cancer), breast cancer in 3 cases, and the other 2 cases were colon cancer and teratocarcinoma of testis (P>0.05). The minimum ADC were (0.72±0.16)×10-3 mm2/s in tumor parenchyma with diffuse limited metastases and (0.78±0.21)×10-3 mm2/s without diffuse limited (P=0.325). ConclusionDWI can respond to brain metastases to the microstructure change, but diffusion limited may not be related with the primary histopathology.

Value of MR Diffusion-Weighted Imaging for Differentiating Pancreatic Carcinoma from Chronic Focal Pancreatitis on 3.0 T MR System / 中国普外基础与临床杂志

Objective To investigate the value of MR diffusion-weighted imaging (DWI) in differentiating pancreatic carcinoma from chronic focal pancreatitis on 3.0 T MR system. Methods Thirteen patients with proved pancreatic carcinoma, 7 patients with confirmed chronic focal pancreatitis, and 14 healthy volunteers, were included in this study. MR examination including the routine abdomen scanning protocol and DWI was performed for both patients and volunteers. The SE-EPI sequence and ASSET technique were used for DWI. The b values of 400, 600, 800 and 1 000 s/mm2 were selected to acquire the DWI. The corresponding apparent diffusion coefficient (ADC) values were measured in each designated region of interest and statistically analyzed. Results ①DWI of the healthy volunteers showed intermediate signals of pancreas. ②DWI of pancreatic tumor masses showed homogenous high signal intensity relative to the surrounding pancreatic tissue with clear boundary. Under different b values, the tumor ADC values were (1.63?0.235)?10-3 mm2/s, (1.42?0.126)?10-3 mm2/s, (1.36?0.170)?10-3 mm2/s and (1.26?0.178)?10-3 mm2/s respectively, which were significantly lower than those of non-tumor region (2.11?0.444)?10-3 mm2/s, (1.83?0.230)?10-3 mm2/s, (1.81?0.426)?10-3 mm2/s, (1.60?0.230)?10-3 mm2/s and of the normal pancreas (1.85?0.350)?10-3 mm2/s, (1.69?0.290)?10-3 mm2/s, (1.67?0.268)?10-3 mm2/s, (1.42?0.221)?10-3 mm2/s, P

Relationship between Duration of Transient Ischemic Attacks and Prognosis:36 Case Report / 中国康复理论与实践

@#ObjectiveTo explore the relationship between the duration, MRI characters and prognosis in transient ischemic attack (TIA). Methods36 TIA cases were retrospectively analyzed according to the duration and Magnetic Resonance Imaging Diffusion Weighted Imaging(MRI-DWI). They were divided into two groups, Group A (13 cases) in which TIA continued within 1 h and Group B (23cases) in which TIA continued for 1～24 h. The patients were followed up 3 months and 12 months later. ResultsMRI abnormalities could be found with MRI-DWI in 2 cases in Group A, but 17 cases in group B(χ2=11.416,P=0.001). 1 case in Group A and 14 cases in Group B occurred cerebral infarction within a year(χ2=9.663,P=0.004). ConclusionThe longer TIA duration, the worse the prognosis.

Diagnostic Value of Average Apparent Diffusion Coefficient of Diffusion-Weighted Imaging for Leukoencephalopathy in Neonates and Children / 实用儿科临床杂志

Objective To explore the diagnostic merits of the average apparent diffusion coefficient(ADCav) for leukoencephalopathy in neonates and children.Methods One hundred and fifty-six neonates and children with central nervous system signs or symptoms were classified into 6 groups according to their ages(1 d-0.05).Contrast to the normal,the ADCav of leukoencephalopathy in neonates and children decreased.With increasing age,there showed a linear downtrend in each group.Conclusions The ADCav rises in neonates and children with leukoencephalopathy.The ADCav variation precedes changes in routine MRI.

Relationship of Magnetic Resonance Diffusion-Weighted Imaging to Histology in Chronic Viral Hepatitis / 中国普外基础与临床杂志

Objective To investigate the relationship of magnetic resonance diffusion-weighted imaging (DWI) to histology in the patients of chronic viral hepatitis. Methods Thirty-five patients of chronic viral hepatitis who received liver biopsy and 10 healthy volunteers were included in this study. All of them underwent DWI on a 3.0T MRI device. Apparent diffusion coefficient (ADC) of the liver were measured respectively when b value were set as 100, 400, 600 and 800 s/mm~2. Biopsy specimens were scored for fibrosis and necroinflammation according to the Knodell histology activity index (HAI). Results When b value was set as 800 s/mm~2, statistical difference was showed between the fibrosis group and the non-fibrosis group, statistical difference was also shown among the different degrees of necroinflammation and fibrosis. Conclusion DWI is a valuable method for grading and staging of chronic viral hepatitis.