Liver Apparent Diffusion Coefficient Research Articles

MRI features for predicting the pathological grade of HCC in patients undergoing liver transplantation

BackgroundContrast-enhanced magnetic resonance imaging (MRI) plays a crucial role in the diagnosis of hepatocellular carcinoma (HCC). This study aims to assess the performance of MRI features for evaluating hepatocellular carcinoma (HCC) aggressiveness in living liver transplantation in patients.Material and methodsThis retrospective study included patients who underwent liver transplantation in our hospital between 2015 and 2020. Abdominal contrast-enhanced MRIs of these patients were reviewed, and clinical, radiological, and histopathological findings of HCCs were recorded. The prognostic features of HCCs as determined by MRI were compared with Edmondson-Steiner (E-S) grades. Liver parenchyma fibrosis based on an apparent diffusion coefficient (ADC) map was correlated with histological subclassification of cirrhosis using the Laennec staging system.ResultsThe study subjects included 37 men and 8 women with a mean age of 59.56 ± 7.81 (range: 25–72). The mean tumour size was 37.33 ± 22.27 mm (range: 10–118 mm), and nine tumours (23.1%) involved portal vein tumour thrombosis. There was a significant correlation between tumour grade and size (p = 0.007) and intratumoral fat (p = 0.014) even though no significant correlations between grade and mean ADC value, capsule appearance, presence of satellite lesions, smooth margin, imaging of the tumour feeding artery, and corona enhancement of HCC (p > 0.05) were found. There was a statistically significant correlation between mild (stage 4A) and moderate (stage 4B) fibrosis of non-tumorous liver parenchyma and ADC value (p < 0.001).ConclusionOur study found that ADC values can be used to distinguish mild cirrhotic livers from moderate cirrhotic livers. Diffusion MRI might be used to diagnose the degree of liver fibrosis without histopathological analysis. According to our results, only intralesional fat and tumour size correlated with tumour grade, and as such, these parameters could be used as prognostic MRI biomarkers for HCC.

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.

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 Diagnostic Value of Normalized ADC Using Spleen As A Reference Organ In Assessment Of Liver Fibrosis

Abstract Objectives To investigate the value of liver ADC normalization using spleen as a reference organ in liver fibrosis assessment, in comparison with transient elastography (Fibroscan). Materials and methods A total of 60 participants were included,30 HCV positive patients and 30 in the 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. Results No significant difference between spleen ADC values of patient group and control group or in-between different fibrosis stages. A significant negative linear correlation between control and patient groups using ADC (r = -0.900; p = 0.0374) or nADC(r=-1:p&amp;lt;0,001).We also found that the mean liver ADC and nADC value in patients with hepatic fibrosis was significantly lower than that of volunteers (1.53 × 10 − 3 mm2/s vs.1.65 × 10 − 3 mm2/s, p = 0.001 &amp;1.). Liver ADC only could distinguish F0 from F4. After analysis with ROC, there was a statistically significant difference between area under the receiver operating characteristic curve (AUC) of normalized liver ADC and ADC for all groups except for F4 stage. nADC AUC was 0.878 for detection of stage ≥ F2 with sensitivity and specificity of 87% &amp; 80% respectively while ADC AUC was 0.548 with sensitivity and specificity of 62 % &amp; 72% respectively(p = 0.021), ≥ F3 AUC of nADC was0.891 with sensitivity and specificity of 88.7 % &amp; 80% respectively while ADC AUC is 0.603 with sensitivity and specificity of 72% &amp; 72% respectively(p = 0.03), and F4 stage nADC AUC was0.879 for with sensitivity and specificity of 90% &amp; 80% respectively ,while ADC AUC was 0.648 with sensitivity and specificity of 80 % &amp; 72% respectively(p = 0.054) Conclusion Normalized liver ADC using the spleen as a reference organ increases the diagnostic performance of MRI in evaluation of liver fibrosis in comparison to ADC alone.

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.

Magnetic resonance imaging features in 283 patients with primary biliary cholangitis.

To evaluate magnetic resonance imaging (MRI) features of the liver in primary biliary cholangitis (PBC). We conducted a multicenter retrospective review on 283 patients with PBC who underwent an MRI between 2007 and 2018. Patients with overlap syndromes were excluded. MRI studies were independently reviewed by two abdominal radiologists for liver morphology, signal intensity, postcontrast enhancement, and decompensation. Liver and spleen volumes and normalized liver apparent diffusion coefficient (nlADC) were also calculated. MRI features were correlated with fibrosis stage among a subset of patients who had a liver biopsy within 6months (n = 72). The study population was comprised of 283 patients (89% females) and a mean ± SD age of 59.4 ± 11.8years. Lymphadenopathy (78.1%), periportal hyperintensity (36.7%), and periportal halo sign (27.6%) were the most common features. A positive correlation was found between fibrosis stage and spleen size (r= 0.457, p < 0.001), spleen volume (r = 0.557, p < 0.001) and portal vein diameter (r = 0.287, p = 0.013), and a negative correlation with nlADC (r= - 0.332, p = 0.011). Fibrosis stage also correlated with the presence of surface nodularity (p < 0.001), periportal halo sign (p = 0.04), collaterals (p = 0.033), and splenomegaly (p = 0.002). No significant differences in nlADC values were found in different fibrosis stages. Spleen size and volume were significantly higher in patients with ascites and collaterals (< 0.001). The periportal halo sign was present only in patients with significant fibrosis. None of the MRI features significantly correlated with inflammation grade. In PBC, presence of periportal halo sign correlates with significant fibrosis. Heterogeneous T2W intensity, heterogeneous postcontrast enhancement, collaterals, spleen size, and spleen volume correlate with fibrosis stage and may be useful for predicting advanced fibrosis. • The presence of periportal halo sign is indicative for significant fibrosis in primary biliary cholangitis. • Liver parenchymal heterogeneous T2 signal intensity, heterogeneous postcontrast enhancement, collaterals, spleen size, and spleen volume correlate with fibrosis stages in PBC and may be useful for predicting advanced fibrosis.

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.

Liver Fibrosis Assessment with Diffusion-Weighted Imaging: Value of Liver Apparent Diffusion Coefficient Normalization Using the Spleen as a Reference Organ.

Liver fibrosis staging is of great clinical importance because it is used to assess the severity of the underlying chronic liver disease. Among various imaging-based methods, apparent diffusion coefficient (ADC) measurement using diffusion-weighted imaging (DWI) has the potential to be used as an imaging biomarker for liver fibrosis assessment. In this study, we investigated the usefulness of liver ADC normalization using the spleen as a reference organ in liver fibrosis staging with 66 patients who underwent liver magnetic resonance imaging (MRI), transient elastography (TE), and surgical resection of a hepatic mass. ADC values of the liver (ADCliver) and spleen were analyzed, and the spleen was used for ADCliver normalization (nADCliver). ADCliver showed a weak negative correlation with TE (r = −0.246; p = 0.047) and fibrosis stage (r = −0.269; p = 0.029), while n ADCliver showed a moderate negative correlation with TE (r = −0.504; p < 0.001) and fibrosis stage (r = −0.579; p < 0.001). AUC values for nADCliver (0.777–0.875) were higher than those for ADCliver for each stage of fibrosis (0.596–0.713, p = 0.037–0.157). AUC values for TE (0.726–0.884) and nADCliver were not statistically different. In conclusion, normalized liver ADC can be useful in diagnosing liver fibrosis stage in patients with variable DWI acquisitions.

Value of whole-liver apparent diffusion coefficient histogram analysis for quantification of liver fibrosis stages

To explore whether volumetric acquisition of histogram analysis of apparent diffusion coefficient (ADC) maps could quantify liver fibrosis stages. 84 patients underwent MRI exams including DWI before surgery or liver biopsy were included. Histogram analysis of whole liver ADC maps were performed and parameters including ADC mean, ADC median, ADC skewness, ADC kurtosis, ADC standard deviation (SD), ADC 5th, 10th, 25th, 75th, 90th and 95th percentiles were calculated. The correlations between different histopathologic grades and histogram analysis parameters were determined. For the significant parameters, receiver operating characteristics (ROC) analyses were further established to evaluate the potential diagnostic performance for differentiating liver fibrosis stages. The ADC mean and ADC median, ADC SD, ADC5th, 10th, 25th, 75th, 90th and 95th percentile were significantly lower with the increasing grade of liver fibrosis (rho: from − 0.580 to − 0.230). ADC skewness and ADC kurtosis were significantly higher with the increasing grade of liver fibrosis (rho: 0.243, 0.347, respectively). Areas under the ROC curve (AUC) of ADC mean and ADC 75th percentile for identification liver fibrosis (F1–F4), moderate to advanced liver fibrosis (F2–F4), advanced liver fibrosis (F3–F4), cirrhosis (F4) were 0.87, 0.83, 0.82, 0.76 and 0.88, 0.82, 0.80, 0.74, respectively. Histogram analysis of volumetric acquisition of liver ADC maps has a potential value for quantifying liver fibrosis grades.

Application of intravoxel incoherent motion diffusion weighted imaging in inflammation activity of chronic hepatitis B

Objective To discuss the diagnostic value of intravoxel incoherent motion (IVIM) DWI in the inflammation activity of chronic hepatitis B. Methods One hundred and seventy-five patients with chronic hepatitis B were prospectively collected as inflammation group, and 15 healthy volunteers with no history of hepatitis and normal liver function as control group. All subjects were performed MR plan scans for liver and IVIM tests. The liver apparent diffusion coefficient (ADC), the diffusion coefficient of the true water molecule (D), microcirculation perfusion coefficient (D*) and perfusion fraction (f) were measured. After MRI examination, the inflammation group received liver biopsy within two days, and obtained the pathological hepatitis activity grades. According to the degree of inflammation activity (G), the inflammation group was divided into G1, G2 and G3+G4 groups. The independent sample t test was used for the parameter values between the inflammation group and the control group. A single factor variance analysis was used to compare the parameters among different levels of inflammation group. Spearman correlation analysis was used to evaluate the correlation between inflammation activity grades and IVIM parameters. ROC curve was used to evaluate each parameter in the diagnosis of hepatitis activity pathology classification efficiency. Results The values of ADC, D, D*, f between control group and inflammation group were statistically significant (P 0.05). ADC, D* and f values were correlated negatively with low, moderate and low levels of inflammation activity (r=-0.377,-0.434,-0.226, P 0.05). Areas of ADC, D* and ADC combined with D* values under ROC curves to diagnose ≥G2 grade inflammation activity were 0.732, 0.748, 0.837 respectively. Areas of f values under ROC curve to diagnose ≥G3+G4 grade inflammation activity was 0.600. Conclusion ADC and D* values help to identify ≥G2 grade inflammation activity, and ADC combined with D* value has the highest diagnostic performance, and has certain reference value for clinical treatment. Key words: Hepatitis B, Chronic; Magnetic resonance imaging; Intravoxel incoherent motion; Inflammation activity

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.

Postmortem MR diffusion-weighted imaging of the liver: time-behavior of the hepatic apparent diffusion coefficient in the early death interval.

The objective of this study is to assess postmortem changes of the hepatic apparent diffusion coefficient (ADC) at multiple time points in the time interval of 16hours postmortem in comparison to in vivo controls and to literature data. Hepatic diffusion-weighted imaging (DWI) was repeatedly performed at 1.5Tesla (b values 50, 400, and 800s/mm2) in 2-hourly steps within 16hours postmortem in 19 cases (male to female 13:6, mean age 68.5±12.2years) and 5 in vivo controls. The core body temperature was measured rectally prior to every scan. Mean ADC values were calculated from regions of interest (ROIs) and compared to in vivo healthy controls and to literature data of normal liver parenchyma. Spearman rank correlation and Levenberg-Marquardt algorithm were used to assess a relationship between postmortem core body temperature and ADC values. Mean hepatic ADC values were significantly lower in postmortem cases than in in vivo controls (52.0±15.0·10-5mm2/s vs. 111.0±15.7·10-5mm2/s, p<0.0001). The ex vivo liver ADC correlated inversely to calculated liver temperature (-3.5±0.8)·10-5mm2/s/°C, r=-0.44, p<0.0001. At low calculated liver temperature (<30°C), the ADC described an average increase of (22±10)·10-5mm2/s/°C. Hepatic ADC values show a characteristic change in the immediate 16hours postmortem, which is influenced by the postmortem liver temperature change. With the knowledge of characteristic postmortem liver changes, diffusion-weighted imaging could be added to conventional postmortem MRI for virtual autopsy.

Apparent diffusion coefficient normalization of normal liver: Will it improve the reproducibility of diffusion-weighted imaging at different MR scanners as a new biomarker?

Apparent diffusion coefficient (ADC) measurement in diffusion-weighted imaging (DWI) has been reported to be a helpful biomarker for detection and characterization of lesion. In view of the importance of ADC measurement reproducibility, the aim of this study was to probe the variability of the healthy hepatic ADC values measured at 3 MR scanners from different vendors and with different field strengths, and to investigate the reproducibility of normalized ADC (nADC) value with the spleen as the reference organ. Thirty enrolled healthy volunteers received DWI with GE 1.5T, Siemens 1.5T, and Philips 3.0T magnetic resonance (MR) systems on liver and spleen (session 1) and were imaged again after 10 to 14 days using only GE 1.5T MR and Philips 3.0T MR systems (session 2). Interscan agreement and reproducibility of ADC measurements of liver and the calculated nADC values (ADCliver/ADCspleen) were statistically evaluated between 2 sessions. In session 1, ADC and nADC values of liver were evaluated for the scanner-related variability by 2-way analysis of variance and intraclass correlation coefficients (ICCs). Coefficients of variation (CVs) of ADCs and nADCs of liver were calculated for both 1.5 and 3.0-T MR system. Interscan agreement and reproducibility of ADC measurements of liver and related nADCs between 2 sessions were found to be satisfactory with ICC values of 0.773 to 0.905. In session 1, the liver nADCs obtained from different scanners were consistent (P = 0.112) without any significant difference in multiple comparison (P = 0.117 to >0.99) by using 2-way analysis of variance with post-hoc analysis of Bonferroni method, although the liver ADCs varied significantly (P < 0.001). nADCs measured by 3 scanners were in good interscanner agreements with ICCs of 0.685 to 0.776. The mean CV of nADCs of both 1.5T MR scanners (9.6%) was similar to that of 3.0T MR scanner (8.9%). ADCs measured at 3 MR scanners with different field strengths and vendors could not be compared directly. Normalization of ADCs, however, may provide better reproducibility by overcoming these potential issues.

Assessment of the liver and spleen in children with Gaucher disease type I with diffusion-weighted MR imaging

PurposeTo assess hepatic and splenic apparent diffusion coefficient (ADC) in children with Gaucher disease type I with diffusion-weighted MR imaging and to correlate hepatic and splenic ADC with parameters of disease severity. Subjects and methodsProspective study was conducted upon 25 children (11 treated and 14 untreated) with Gaucher disease and 12 age and sex matched control children. They underwent diffusion-weighted MR imaging of abdomen. Hepatic and splenic ADC and volume were calculated. ResultsThere was statistically difference in hepatic and splenic apparent diffusion coefficient (P=0.001) between patients and controls. The cutoff ADC of liver and spleen used to differentiate patients from controls were 0.47 and 0.39×10−3mm2 with area and curve of 0.947 and 0.886 respectively. There was significant difference in hepatic and splenic ADC between untreated and treated patients (P=0.003 and 0.001). Hepatic ADC correlated with splenic volume (r=−0.721), hepatic volume (r=−0.555) and chitotriosidase (r=−0.413). Splenic ADC correlated with splenic volume (r=−0.652), hepatic volume (r=−0.544) and chitotriosidase (r=−0.355). ConclusionHepatic and splenic ADC can detect hepatic and splenic infiltration in Gaucher disease and correlated with some parameters of disease severity.

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.