Liver Apparent Diffusion Coefficient Values Research Articles

Liver parenchymal changes detected by MR elastography and diffusion-weighted imaging after stereotactic body radiotherapy for hepatocellular carcinoma.

Stereotactic body radiotherapy (SBRT) is a local treatment option for hepatocellular carcinoma (HCC). SBRT-induced focal reactions on the liver parenchyma have not been thoroughly evaluated using quantitative magnetic resonance imaging (MRI). To quantitatively evaluate liver parenchymal changes caused by SBRT for HCC using magnetic resonance elastography (MRE) and diffusion-weighted imaging (DWI). We retrospectively evaluated 22 adult patients who received SBRT for HCC and 27 who received locoregional therapy other than SBRT (controls). Liver stiffness by MRE and apparent diffusion coefficient (ADC) values by DWI of the liver parenchyma were measured before and after SBRT. Regions of interest (ROIs) were drawn on the two areas of radiation dose distribution levels, > 30 Gy and ≤ 30 Gy; a ROI was drawn in the control group. The two indices were compared before and after SBRT using a Wilcoxon matched-pairs signed-rank test. Liver stiffness and ADC values were significantly increased after SBRT in the dose areas of > 30 Gy compared with those before SBRT (4.05 vs 4.85 kPa; p < 0.05 in liver stiffness, and 1.10 vs 1.40 ×10-3 s/mm2; p < 0.05 in ADC values). In the dose area of ≦ 30 Gy, liver stiffness showed a significant increase in one reader (p = 0.033) but not in another reader (p = 0.085); ADC value showed no significant difference before and after SBRT as per both readers (p > 0.05). The control group demonstrated no significant differences before and after treatment (p > 0.05). MRE and DWI can be used to detect SBRT-induced liver parenchymal changes.

Diffusion-weighted imaging of the liver in assessing chronic liver disease: effects of fat and iron deposition on ADC values.

This study was designed to evaluate whether fat and iron affect the apparent diffusion coefficient (ADC) values of the liver parenchyma in the settings of fibrosis and inflammation. We evaluated the diffusion-weighted images (DWIs) of 58 patients with chronic liver disease and 48 control subjects. Liver specimens of patients were assessed for fibrosis, necroinflammation, iron, and steatosis. Liver ADCs, spleen ADCs, and normalized liver ADCs (defined as the ratio of the liver ADC to spleen ADC) values were analyzed after stratifying patients with either fibrosis stages or histology activity index (HAI) scores. The relationship between ADC values and histopathological findings was studied using multiple linear regression analysis. The median liver and normalized liver ADC values were significantly lower in higher stages of fibrosis and HAI scores. Compared to the control group, patients with the highest stages of fibrosis and inflammation had significantly higher spleen ADCs. The effect of the fibrosis stage on liver ADC and normalized liver ADC values was significant in the setting of inflammation, whereas the degree of steatosis and iron grade did not affect these ADC values. ADC values can distinguish both later stages of liver fibrosis and inflammation. There is no significant effect of fat and iron on ADC values. Therefore, DWI may be reliable in evaluating liver fibrosis and inflammation.

With 3 Types of Respiratory Acquisition: 3.0 T Respiratory Triggered Acquisition Can Obtain Higher Quality DWI Images of the Upper Abdomen.

Objective 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. Methods 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. Results 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. Conclusion 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.

Comparison of the Efficiency of Conventional Diffusion, Diffusion Tensor Imaging, and Dynamic Susceptibility Contrast-Enhanced Magnetic Resonance Perfusion Imaging in the Evaluation of Liver Fibrosis

Objective: Liver fibrosis is a dynamic, reversible process that can result in liver failure. There has been considerable interest in developing noninvasive methods for diagnosis and staging. To investigate the diffusion and perfusion changes of the fibrotic liver parenchyma with conventional diffusion-weighted imaging (CDI), diffusion tensor imaging (DTI), and T2*weighted dynamic susceptibility contrast-magnetic resonance perfusion imaging (DSC-MRPI) at 3Tesla MR scanner. Methods: Twenty-seven patients with chronic viral hepatitis and 24 volunteers were evaluated, prospectively. The standard MRI protocols of the abdomen, CDI, and DTI were performed. Apparent diffusion coefficient (ADC) maps were obtained, D and FA values were calculated for DTI. Signal Intensity(SI)-time curves were obtained and “blood volume”(BV), “blood flow” (BF), “time to peak”(TTP), “mean transit time”(MTT) were measured. All patients with hepatitis underwent liver biopsy. The efficacy of diffusion and perfusion parameters used in the diagnosis of fibrosis was analyzed with the receiver operating characteristic curve (ROC). Results: Patients had significantly lower liver ADC when compared to the control group, either with CDI and DTI. D values obtained from DTI were lower in patients than those of the normal volunteers, and the difference was statistically significant. On DSC-MRPI; BF, BV, MTT, and TTP of the liver were lower than those of the control group but only BV and MTT values showed statistical significance. Liver ADC, D, and BV values had a negative correlation with fibrosis. Conclusion: The results showed that the D values obtained from DTI, BV, and MTT values obtained from DSC-MRPI can be an efficient diagnostic tool for liver fibrosis in patients with chronic hepatitis.

The correlation between magnetic resonance diffusion parameters and Ki-67 and PCNA in hepatic fibrosis and cirrhosis rats.

The aim of this study was to assess the value of different 1.5 T MRI apparent diffusion coefficient (ADC) and exponential apparent diffusion coefficient (EADC) values in diagnosing the stages of liver cirrhosis. Sprague-Dawley (SD) rats were randomly divided into the experimental group and the control group. The experimental group was injected with thioacetamide intraperitoneally 3 times per week. After routine MR scanning, diffusion-weighted imaging (DWI) was processed by spin echo-echo planar imaging (SE-EPI) to generate the ADC value and EADC image. The liver ADC and EADC values of rats were measured in the control and experimental groups, followed by Masson staining and hematoxylin and eosin staining. Furthermore, immunohistochemistry was performed to detect Ki-67 and PCNA expression in liver tissues. In the control group, the differences in ADC and EADC values between the liver fibrosis and cirrhosis group were different. The ADC values of the liver fibrosis stage I-II, III-IV, and cirrhosis rats in the experimental group were lower than the control group, while the EADC values were higher than the control group. The ADC values of the liver fibrosis stage III-IV group and cirrhosis nodules group were lower than the control group. There were significant differences in EADC values between the cirrhotic nodule groups and the control group. DWI-ADC values showed a negative correlation between SD rat liver fibrosis and cirrhosis pathology classification.

Alkolün Karaciğer Görünür Difüzyon Katsayısı Değerleri Üzerine Etkileri: Tek Merkez Çalışması

Background and Aims: This study aimed to investigate the relationship between liver apparent diffusion coefficient values and potential early-stage liver injury by comparing apparent diffusion coefficient values obtained by liver diffusion-weighted magnetic resonance imaging between individuals with a history of excessive alcohol consumption and healthy volunteers. Materials and Methods: This study enrolled 35 individuals with a history of excessive alcohol consumption and 32 healthy volunteers. In all cases, blood samples were taken to measure biochemical parameters and complete blood count. Upper abdominal magnetic resonance imaging including liver diffusion-weighted imaging was performed. Results: In total, 19 individuals with a history of excessive alcohol consumption and 20 healthy volunteers were included in the study. The mean apparent diffusion coefficient values obtained by high b value (b 1000) diffusion-weighted imaging in individuals with a history of excessive alcohol consumption were lower than those in healthy volunteers. Although no significant difference was observed between the two groups in terms of biochemical parameters, hepatic apparent diffusion coefficient values in both groups were positively correlated with international normalized ratio values and negatively correlated with gamma-glutamyl transferase and alkaline phosphatase levels (r = 0.002, r = −0.007, r = −0.049, respectively). Conclusion: Diffusion-weighted imaging is a noninvasive imaging technique that can be used for the detection and follow-up of liver fibrosis induced by alcohol consumption.

Diffusion-Weighted Imaging for Differentiation of Biliary Atresia and Grading of Hepatic Fibrosis in Infants with Cholestasis.

ObjectiveTo determine whether the values of hepatic apparent diffusion coefficient (ADC) can differentiate biliary atresia (BA) from non-BA or be correlated with the grade of hepatic fibrosis in infants with cholestasis.Materials and MethodsThis retrospective cohort study included infants who received liver MRI examinations to evaluate cholestasis from July 2009 to October 2017. Liver ADC, ADC ratio of liver/spleen, aspartate aminotransferase to platelet ratio index (APRI), and spleen size were compared between the BA and non-BA groups. The diagnostic performances of all parameters for significant fibrosis (F3–4) were obtained by receiver-operating characteristics (ROCs) curve analysis.ResultsAltogether, 227 infants (98 males and 129 females, mean age = 57.2 ± 36.3 days) including 125 BA patients were analyzed. The absolute ADC difference between two reviewers was 0.10 mm2/s for both liver and spleen. Liver ADC value was specific (80.4%) and ADC ratio was sensitive (88.0%) for the diagnosis of BA with comparable performance. There were 33 patients with F0, 15 with F1, 71 with F2, 35 with F3, and 11 with F4. All four parameters of APRI (τ = 0.296), spleen size (τ = 0.312), liver ADC (τ = −0.206), and ADC ratio (τ = −0.288) showed significant correlation with fibrosis grade (all, p < 0.001). The cutoff values for significant fibrosis (F3–4) were 0.783 for APRI (area under the ROC curve [AUC], 0.721), 5.9 cm for spleen size (AUC, 0.719), 1.044 × 10−3 mm2/s for liver ADC (AUC, 0.673), and 1.22 for ADC ratio (AUC, 0.651).ConclusionLiver ADC values and ADC ratio of liver/spleen showed limited additional diagnostic performance for differentiating BA from non-BA and predicting significant hepatic fibrosis in infants with cholestasis.

The diagnostic value of normalized ADC using spleen as reference organ in assessment liver fibrosis

BackgroundTo investigate the value of liver ADC normalization using spleen as a reference organ in liver fibrosis assessment compared to Fibroscan.A total of 60 participants were included, 30 HCV positive patients and 30 in control group. We calculated mean spleen apparent diffusion coefficient (ADC), liver mean ADC, and normalized liver ADC (defined as the ratio of liver ADC to spleen ADC) which were compared between cirrhotic patients and the control group. Data was analyzed, and ROC was used to evaluate the performance of nADC.ResultsNo significant difference between spleen ADC values of patient and control groups or in-between different fibrosis stages. A negative correlation between liver ADC and nADC values with increasing fibrosis stages. We also found that the mean liver ADC and nADC value in patients with hepatic fibrosis were significantly lower than that of control group (1.53 × 10−3 mm2/s vs 1.65 × 10−3 mm2/s). After analysis with ROC, nADC shows higher diagnostic performance compared to liver ADC. nADC area under the curve (AUC) was 0.878 for detection of stage ≥ F2 with sensitivity and specificity of 87% and 80% respectively while ADC AUC was 0.548 with sensitivity and specificity of 62% and 72% respectively (p = 0.021); ≥ F3 AUC of nADC was 0.891 with sensitivity and specificity of 88.7% and 80% respectively while ADC AUC is 0.603 with sensitivity and specificity of 72% and 72% respectively (p = 0.023), and F4 stage nADC AUC was 0.879 for with sensitivity and specificity of 90% and 80% respectively, while ADC AUC was 0.648 with sensitivity and specificity of 80% and 72% respectively (p = 0.054).ConclusionNormalized liver ADC using the spleen as reference organs increases the diagnostic performance of MR in evaluation liver fibrosis compared to ADC alone.

Association between liver diffusion-weighted imaging apparent diffusion coefficient values and other measures of liver disease in pediatric autoimmune liver disease patients

Multiple quantitative magnetic resonance imaging (MRI) methods have been described to noninvasively detect and characterize liver fibrosis, including diffusion-weighted imaging (DWI). To evaluate associations between liver MRI DWI apparent diffusion coefficient (ADC) values and clinical factors and other quantitative liver MRI metrics in pediatric patients with autoimmune liver disease (AILD). Fifty-seven research liver MRI examinations performed from January 2017 to August 2018 for pediatric AILD registry participants were evaluated. Liver DWI ADC values, liver and spleen stiffness (kPa), and iron-corrected T1 (cT1; Perspectum Diagnostics) were measured at four anatomic levels. Participant age, sex, and laboratory data (alanine aminotransferase [ALT], total bilirubin, alkaline phosphatase, gamma-glutamyl transferase [GGT]) were recorded. Spearman's rank-order correlation (rho) and multiple linear regression were used to evaluate the associations between liver ADC values and predictor variables. Mean (SD) participant age was 14.8 (4.0) years, 45.6% (26/57) were girls. Mean liver DWI ADC value was 1.34 (0.14 × 10-3) mm2/s. Liver ADC values showed weak to moderate correlations with liver stiffness (r = - 0.42, p = 0.001), spleen stiffness (r = - 0.34; p = 0.015), whole-liver mean cT1 (r = - 0.39; p = 0.007), ALT (r = - 0.50; p = 0.0001), and GGT (r = - 0.48; p = 0.0004). Multiple linear regression showed liver stiffness (p = 0.0009) and sex (p = 0.023) to be independent predictors of liver ADC values. Liver DWI ADC values are significantly associated with liver and spleen stiffnesses, liver cT1, ALT, GGT, and participant sex, with liver stiffness and sex remaining significant at multivariable regression. Liver ADC ultimately may play a role in multi-parametric prediction of chronic liver disease/fibrosis severity.

Quantitative liver MR imaging with DWI sequence and Normalized ADC in diagnosis and staging of hepatitis C virus liver fibrosis and cirrhosis, a comparative study with transient elastography (Fibroscan) in egyptian patients

Abstract Purpose To evaluate the diagnostic efficacy of quantitative liver MR imaging using diffusion-weighted imaging (DWI) and normalized apparent diffusion coefficient (ADC) in diagnosis and staging of liver fibrosis and cirrhosis in egyptian patients with hepatitis C virus (HCV) infection and compare the results with transient elastography (FibroScan). Materials and Methods Twenty-five patients known to have hepatitis C virus were enrolled after fulfilling inclusion and exclusion criteria.. Quantification of liver, spleen and muscle ADC values was done using MRI DWI sequences using 4 different b-values (0, 200, 400, 800). Normalized ADC was calculated as the ratio of liver ADC to spleen ADC.. Post processing was performed using 3D synapse ADC viewer Tool. Results Liver ADC failed to distinguish different stages of fibrosis, except between stages 2 and 3 (p = 0.016). Normalized liver ADC distinguished between individual groups of fibrosis , with significant differences between mild stages (stage 0/1) and sever stages of fibrosis (stages 3) and between stages 0/1 and cirrhosis (stage 4). There were significant differences between stages 0–2 and 3–4 using normalized liver ADC. There was a statistically significant moderate correlation between fibrosis stage and normalized liver ADC (r = −0.403; p = 0.009). ROC analysis revealed higher performance using normalized liver ADC compared with liver ADC, with higher AUC, sensitivity, and specificity for detection of cirrhosis (stage 0 vs 4 and stages 0–3 vs 4), moderate-to-advanced fibrosis (stages 2–4), and advanced fibrosis and cirrhosis (stages 3–4), reaching significance for all comparisons except for diagnosis of stage 4 (cirrhosis). Conclusion Our results suggest that normalizing liver ADC with spleen ADC improves diagnostic accuracy for detection of liver fibrosis and cirrhosis in egyptian population when using breath-hold diffusion-weighted imaging.

The clinical value of the apparent diffusion coefficient of liver magnetic resonance images in patients with liver fibrosis compared to healthy subjects.

Background:Fibrotic tissue forms following chronic inflammation in the liver, which may progress over time to cirrhosis. Liver biopsy is the gold standard for the diagnosis of liver fibrosis, and there has been a considerable interest in developing noninvasive methods.Objectives:In the present study, we evaluated the efficacy of the apparent diffusion coefficient (ADC) of the liver in the diagnosis and staging of liver fibrosis.Patients and Methods:This case–control study was conducted on 40 patients with chronic liver disease and 31 healthy controls who were subjected to diffusion-weighted magnetic resonance imaging (MRI). Diagnostic values for different stages of fibrosis were determined using receiver-operating characteristic (ROC) curves based on the sensitivity and specificity.Results:Of 37 patients in the case group, 12 were males (32.4%) and 25 (67.5%) were females, whereas in the control group of 31 patients, 11 were males (35.5%) and 20 (64.5%) were females. In the ROC analysis, area under the curve separating stage one or lower fibrosis from stage two or greater fibrosis groups with a b-value of 600 s/mm2 was 0.893 (98% confidence interval (CI): 0.795–0.955), and that with a b-value of 1000 s/mm2 was 0.946 (98% CI: 0.813–0.946).Conclusion:Our results are in line with the previous studies, which showed that liver ADC values could be considered as a method for the diagnosis and staging of liver fibrosis.

Evaluation of upper abdominal organs with DWI in patients with familial Mediterranean fever

To investigate the diagnostic efficiency of diffusion-weighted magnetic resonance imaging (DWI) for the evaluation of functional changes that can occur in upper abdominal organs in patients with familial Mediterranean fever (FMF). The study included 50 controls, 45 patients with FMF, and 14 patients with FMF who had accompanying proteinuria. Measurement of apparent diffusion coefficient (ADC) was performed using DWI sections obtained from liver, spleen, kidney, and pancreas parenchyma with 1.5T MRI using b=500 and b=1000s/mm2 values both in patients and control groups. Mean ADC values were compared between patient and control groups. Renal ADC values were lower in the patient groups compared to the control group. Additionally, renal ADC values showed further decrease in the patient group in the presence of accompanying proteinuria, when compared to the FMF group without proteinuria (p<0.001). Based on the ROC analysis, calculated cutoff values for the determination of FMF and FMF accompanied by proteinuria were 2.26×10-3 and 2.04×10-3mm2/s, respectively. Liver, spleen, and pancreas ADC values did not show remarkable change between patient and control groups. Present findings indicate that the presence of FMF and its clinical progression expressed by proteinuria can be differentially determined with renal DWI.

Simultaneous multi-slice echo planar diffusion weighted imaging of the liver and the pancreas: Optimization of signal-to-noise ratio and acquisition time and application to intravoxel incoherent motion analysis

PurposeTo optimize and test a diffusion-weighted imaging (DWI) echo-planar imaging (EPI) sequence with simultaneous multi-slice (SMS) excitation in the liver and pancreas regarding acquisition time (TA), number of slices, signal-to-noise ratio (SNR), image quality (IQ), apparent diffusion coefficient (ADC) quantitation accuracy, and feasibility of intravoxel incoherent motion (IVIM) analysis. Materials and methodsTen healthy volunteers underwent DWI of the upper abdomen at 3T. A SMS DWI sequence with CAIPIRINHA unaliasing technique (acceleration factors 2/3, denoted AF2/3) was compared to standard DWI-EPI (AF1). Four schemes were evaluated: (i) reducing TA, (ii) keeping TA identical with increasing number of averages, (iii) increasing number of slices with identical TA (iv) increasing number of b-values for IVIM. Acquisition schemes i-iii were evaluated qualitatively (reader score) and quantitatively (ADC values, SNR). ResultsIn scheme (i) no differences in SNR were observed (p=0.321−0.038) with reduced TA (AF2 increase in SNR/time 75.6%, AF3 increase SNR/time 102.4%). No SNR improvement was obtained in scheme (ii). Increased SNR/time could be invested in acquisition of more and thinner slices or higher number of b-values. Image quality scores were stable for AF2 but decreased for AF3. Only for AF3, liver ADC values were systematically lower. ConclusionSMS-DWI of the liver and pancreas provides substantially higher SNR/time, which either may be used for shorter scan time, higher slice resolution or IVIM measurements.

Diffusion-weighted imaging (DWI) of the liver in assessing chronic liver disease: effects of the presence and the degree of ascites on ADC values

The aim of this study was to determine the correlation between the liver and spleen apparent diffusion coefficient (ADC) values of patients with chronic liver disease and the presence and the degree of ascites. In this retrospective study, we assessed 107 patients with chronic liver disease and 39 control subjects who underwent upper abdominal MR imaging including echo-planar diffusion-weighted imaging (DWI). Among the 107 cirrhotic patients, 56 were classified as group 1, 25 as group 2, and 26 as group 3 according to the absence, the presence of minimal, and the presence of massive ascites, respectively. The scores of model for end-stage liver disease (MELD) were matched between groups as the standard reference. The liver ADC, spleen ADC, and normalized liver ADC values were compared between the control group and patients' groups. Patients with massive ascites had significantly higher MELD score compared with the other groups. The MELD score was also significantly higher in patient groups than in control group. The liver and normalized liver ADCs of patients' groups were significantly lower than that of the control group. With some overlap among groups, the measured ADC values decreased as the amount of the ascites increased, and these relationships were statistically significant. Furthermore, compared to control group, patients with massive ascites had significantly higher spleen ADCs. Our results indicate that the ADC value of the liver and spleen correlates with the presence and the degree of ascites in patients with chronic liver disease, and merits further study.

The diagnostic efficacy of quantitative liver MR imaging with diffusion-weighted, SWI, and hepato-specific contrast-enhanced sequences in staging liver fibrosis--a multiparametric approach.

To assess the diagnostic efficacy of multiparametric MRI using quantitative measurements of the apparent diffusion coefficient (ADC) of the liver parenchyma on diffusion-weighted imaging (DWI), signal intensity (SI) on susceptibility-weighted imaging (SWI), and gadoxetic acid-enhanced T1-weighted imaging during the hepatobiliary phase for the staging of liver fibrosis. Seventy-seven patients underwent a 3T MRI examination, including DWI/SWI sequences and gadoxetic acid-enhanced T1-weighted MRI. Liver fibrosis according to liver biopsy was staged using the Metavir fibrosis score: F0 (n = 21, 27.3%); F1 (n = 7, 9.1%); F2 (n = 8, 10.4%); F3 (n = 12, 15.6%); and F4 (n = 29, 37.7%). SI of the liver was defined using region-of-interest measurements to calculate the ADC values, the relative enhancement (RE) in the hepatobiliary phase, and the liver-to-muscle ratio (LMR) measurements for SWI. The values of RE, LMR, and ADC measurements were statistically significantly different among the five fibrosis stages (p < 0.004). Combining the three parameters in a multiparametric approach, the AUC for detecting F1 stage or greater (≥ F1) was 94%, for F2 or greater (≥F2) was 95%, for F3 or greater (≥F3) was 90%, and for stage F4 was 93%. Multiparametric MRI is an efficient non-invasive diagnostic tool for the staging of liver fibrosis. • Multiparametric MRI has high accuracy in predicting moderate or greater liver fibrosis. • Relative enhancement post- gadoxetic acid is an independent predictor of liver fibrosis. • Liver SWI signal intensity and ADC values enhance the diagnostic ability.

Assessment of Liver Fibrosis with Diffusion-Weighted Magnetic Resonance Imaging Using Different b-values in Chronic Viral Hepatitis

Objective: To examine the effectiveness of apparent diffusion coefficient (ADC) values and to compare the reliability of different b-values in detecting and identifying significant liver fibrosis. Subjects and Methods: There were 44 patients with chronic viral hepatitis (CVH) in the study group and 30 healthy participants in the control group. Diffusion-weighted magnetic resonance imaging (DWI) was performed before the liver biopsy in patients with CVH. The values of ADC were measured with 3 different b-values (100, 600, 1,000 s/mm²). In addition, liver fibrosis was classified using the modified Ishak scoring system. Liver fibrosis stages and ADC values were compared using areas under the receiver-operating characteristic (ROC) curve. Results: The study group's mean ADC value was not statistically significantly different from the control group's mean ADC value at b = 100 s/mm² (3.69 ± 0.5 × 10^-3 vs. 3.7 ± 0.3 × 10^-3 mm²/s) and b = 600 s/mm² (2.40 ± 0.3 × 10^-3 vs. 2.5 ± 0.5 × 10^-3 mm²/s). However, the study group's mean ADC value (0.99 ± 0.3 × 10^-3 mm²/s) was significantly lower than that of the control group (1.2 ± 0.1 × 10^-3 mm²/s) at b = 1,000 s/mm². With b = 1,000 s/mm² and the cutoff ADC value of 0.0011 mm²/s for the diagnosis of liver fibrosis, the mean area under the ROC curve was 0.702 ± 0.07 (p = 0.0015). For b = 1,000 s/mm² and the cutoff ADC value of 0.0011 mm²/s to diagnose significant liver fibrosis (Ishak score = 3), the mean area under the ROC curve was 0.759 ± 0.07 (p = 0.0001). Conclusion: Measurement of ADC values by DWI was effective in detecting liver fibrosis and accurately identifying significant liver fibrosis when a b-value of 1,000 s/mm² was used.

Diffusion-weighted perinatal postmortem magnetic resonance imaging as a marker of postmortem interval.

ObjectiveTo evaluate perinatal body organ apparent diffusion coefficient (ADC) values at postmortem magnetic resonance imaging (PMMR) in order to evaluate postmortem changes.MethodsPostmortem diffusion-weighted imaging (DWI) of the thorax and abdomen were performed with diffusion gradient values b = 0, 500, and 1000 s/mm2 on 15 foetal and childhood cases (mean 33.3 ± 7.8 weeks gestation) compared to 44 live infants (mean age 75.5 ± 53.4 days). Mean ADC values were calculated from regions of interest (ROIs) for the lungs, liver, spleen and renal cortex, compared to normative live infantile body ADC values of similar gestational age.ResultsMean ADC values were significantly lower in postmortem cases than in normal controls for liver (0.88 10-3 mm2/s ± SD 0.39 vs. 1.13 ± 0.13; p < 0.05) and renal cortex (0.85 ± 0.26 vs. 1.19 ± 0.13; p < 0.05) but not spleen or muscle. Mean lung ADC values were significantly higher than normal controls (1.06 ± 0.18 vs. 0 ± 0; p < 0.001), and there was a significant correlation between postmortem interval and lung ADC (R2 = 0.55).ConclusionLung PMMR ADC values are related to postmortem interval, making them a potential marker of time since death. Further research is needed to understand the organ-specific changes which occur in the postmortem period.Key Points • Liver and spleen PM ADC values were lower than controls. • Lung ADC changes correlate with PM interval. • These findings may be useful in medicolegal cases.

Apparent diffusion coefficient (ADC) in liver fibrosis: Usefulness of normalized ADC using the spleen as reference organ

ObjectiveThe purpose of the current study was to determine the usefulness of the usage of the spleen as a reference organ to normalize liver ADC to improve the diagnostic performance of diffusion weighted imaging (DWI) for assessing liver fibrosis. Materials and methodsForty-nine subjects, 34 patients with liver disease and 15 control subjects were assessed with diffusion-weighted imaging. Liver ADC and normalized liver ADC (defined as the ratio of liver ADC to spleen ADC) were compared between patients and the control groups as well as among patients with different stages of fibrosis. Receiver operating characteristic (ROC) analysis was used to determine the performance of ADC and normalized liver ADC for prediction of liver fibrosis and cirrhosis. ResultsThere was no significant difference between spleen ADC values among patients in comparison to control (1.107±0.07×10−3mm2/s vs. 1.12±0.068×10−3mm2/s, p=0.998) or among patients with different stages of fibrosis (p=0.59–0.89). The mean liver ADC and mean normalized liver ADC values were significantly lower in patients with hepatic fibrosis compared to volunteers (P=0.01,<0.001 respectively), however liver ADC could not significantly differentiate different stages of fibrosis except between stages 0 and 4. The mean normalized liver ADC was significantly different between stage 0 and stages 2, 3, and 4 as well as between stage 1 and stage 4. In addition, it had a trend toward significance between stage 0 and 1, stage 2 and 4 as well as stage 3 and 4. Both liver ADC and normalized liver ADC had a significant negative correlation with the grade of fibrosis, however it was more powerful for normalized liver ADC in comparison to liver ADC (r=−0.694 vs. −0.361, p=0.01 vs. 0.05). ROC analysis showed higher performance using normalized liver ADC in comparison to liver ADC, with higher AUC, sensitivity, and specificity for detection of fibrotic stages ⩾2 (0.88, 92.5% and 76.2% Vs 0.72, 82.1%, and 57.1% respectively). The corresponding values for stages ⩾3 were 0.83, 100%, and 55% vs. 0.69, 77.3%, and 44.4% respectively), while the corresponding values for cirrhosis (stage 4) were 0.87, 81.8%, and 81.8% for normalized liver ADC vs. 0.74, 69.2%, 72.2%.for ADC liver. ConclusionThe utility of using the spleen as a reference organ could improve the diagnostic performance of ADC measurement for the diagnosis of liver fibrosis. The application of this technique for the evaluation of liver fibrosis is promising.

The use of DWI to assess spleen and liver quantitative ADC changes in the detection of liver fibrosis stages in chronic viral hepatitis

This study aimed to evaluate the changes in spleen and liver diffusion-weighted magnetic resonance imaging (DWI) in chronic viral hepatitis patients.The study comprised 47 patients and 30 healthy volunteers. DWIs were obtained. Apparent Diffusion Coefficient (ADC) measurements were made by transferring the images to the workstation. The measurements of value b 1000 were made from a total of five points of the liver and three points of the spleen. Liver biopsy was performed on the 47 patients. The fibrosis stages of the patients were defined according to the METAVIR scoring system. Student's t-test was used in the comparison of mean ages, liver and spleen ADC values between the patient and the control group. Kruskal–Wallis followed by Mann–Whitney U Test with Bonferroni adjustment was performed in the comparison of mean ADC values of the patients at different stages and the control group.A statistically significant difference was determined between the patient and control group in respect of liver and spleen mean ADC values (P<0.05). F3 group showed a significant difference compared to control and F1 and F4 group showed a significant difference compared to control, F1, F2 and F3 group in terms of the mean liver ADC value (P<0.01). F3 and F4 group showed a significant difference compared to control and F1 group in terms of the mean spleen ADC value (P<0.01).As a result we believe that the measurement of liver and spleen ADC values may be an indicator in the determination of the level of fibrosis.

Diagnostic performance of conventional diffusion weighted imaging and diffusion tensor imaging for the liver fibrosis and inflammation

ObjectiveTo evaluate the diagnostic accuracy of liver apparent diffusion coefficient (ADC) measured with conventional diffusion-weighted imaging (CDI) and diffusion tensor imaging (DTI) for the diagnosis of liver fibrosis and inflammation. Materials and methodsThirty-seven patients with histologic diagnosis of chronic viral hepatitis and 34 healthy volunteers were included in this prospective study. All patients and healthy volunteers were examined by 3T MRI. CDI and DTI were performed using a breath-hold single-shot echo-planar spin echo sequence with b factors of 0 and 1000s/mm2. ADCs were obtained with CDI and DTI. Histopathologically, fibrosis of the liver parenchyma was classified with the use of a 5-point scale (0–4) and inflammation was classified with use of a 4-point scale (0–3) in accordance with the METAVIR score. Quantitatively, signal intensity and the ADCs of the liver parenchyma were compared between patients stratified by fibrosis stage and inflammation grade. ResultsWith a b factor of 1000s/mm2, the signal intensity of the cirrhotic livers was significantly higher than those of the normal volunteers. In addition, ADCs reconstructed from CDI and DTI of the patients were significantly lower than those of the normal volunteers. Liver ADC values inversely correlated with fibrosis and inflammation but there was only statistically significant for inflammatory grading. CDI performed better than DTI for the diagnosis of fibrosis and inflammation. ConclusionADC values measured with CDI and DTI may help in the detection of liver fibrosis. They may also give contributory to the inflammatory grading, particularly in distinguishing high from low grade.