Tatsuyuki Tonan

Diffusion-weighted imaging of soft tissue tumors: usefulness of the apparent diffusion coefficient for differential diagnosis.

PurposeWe evaluated the efficacy of using the apparent diffusion coefficient (ADC) to differentiate soft tissue tumors.Materials and methodsWe examined 88 histologically proven tumors (44 benign, 8 intermediate, 36 malignant) using diffusion-weighted magnetic resonance images. Images of the tumors were obtained using a single-shot, spin-echo type echo-planar imaging sequence. The tumors were classified histologically as myxoid or nonmyxoid. We then compared the ADC values of the myxoid and nonmyxoid tumors; the benign and malignant myxoid tumors; and the benign, intermediate, and malignant nonmyxoid tumors.ResultsThe mean ADC value of the myxoid tumors (2.08 ± 0.51 × 10−3 mm2/s) was significantly greater than that of the nonmyxoid tumors (1.13 ± 0.40 × 10−3 mm2/s) (P < 0.001). There was no significant difference in the mean ADC values between benign myxoid tumors (2.10 ± 0.50 × 10−3 mm2/s) and malignant myxoid tumors (2.05 ± 0.58 × 10−3 mm2/s). The mean ADC value of benign nonmyxoid tumors (1.31 ± 0.46 × 10−3 mm2/s) was significantly higher than that of malignant nonmyxoid tumors (0.94 ± 0.25 × 10−3 mm2/s) (P < 0.001).ConclusionThe ADC value might be useful for diagnosing the malignancy of nonmyxoid soft tissue tumors.

Evaluation of the mean and entropy of apparent diffusion coefficient values in chronic hepatitis C: Correlation with pathologic fibrosis stage and inflammatory activity grade

PURPOSE To determine whether mean and entropy apparent diffusion coefficient (ADC) values obtained at diffusion-weighted (DW) magnetic resonance (MR) imaging can help detect and stage histopathologic liver fibrosis and grade inflammation activity in patients with chronic hepatitis C. MATERIALS AND METHODS This retrospective study was approved by the institutional review board, and the requirement for informed consent was waived. The study included 55 patients with focal hepatic lesions and either chronic hepatitis C (n = 43) or normal hepatic function (control subjects) (n = 12). Mean and entropy of volume histograms were generated in four cubic regions of interest placed in the right hepatic lobe of ADC map images, which were obtained at echo-planar DW MR imaging (gradient factor b values of 0 and 1000 sec/mm(2)). These two parameters (mean and entropy ADC) were compared by using METAVIR histopathologic liver fibrosis and inflammatory activity scores. Statistical analysis was performed with the Kruskal-Wallis test and receiver operating characteristic curves. RESULTS The mean ADC decreased with an increase in the fibrosis stage or inflammatory activity grade, and the entropy ADC increased with an increase in the fibrosis stage or inflammatory activity grade (P < .001 for all comparisons, Kruskal-Wallis test). The area under the receiver operating characteristic curve (A(z)) for the mean ADC was statistically significant in the differentiation of fibrosis stage or inflammatory activity grade (A(z), 0.807-0.926; P < .001 for all comparisons). Entropy of ADC was helpful for classifying normal from abnormal fibrosis stage or inflammatory activity grade (A(z) for both parameters, 0.937; P < .001). CONCLUSION Assessment of a combination of mean ADC and entropy ADC in patients with chronic hepatitis C is more accurate for predicting pathologic hepatic fibrosis stage and inflammatory activity grade and helpful for detecting early fibrotic or inflammatory activity when compared with assessment of mean ADC alone.

Periostin, a matrix protein, has potential as a novel serodiagnostic marker for cholangiocarcinoma

Differentiating intrahepatic cholangiocarcinoma (CCA) from other hepatic malignancies is crucial in deciding on treatment modalities and predicting clinical outcomes in patients. Periostin is a secreted protein from stromal cells and regulates the development of cancer cells through interaction with the extracellular matrix. Given that proliferation of fibrous stromal cells is a pathological feature of CCA, we examined the potential use of periostin as a serodiagnostic marker for this disease. Our study enrolled a total of 79 patients including liver cirrhosis (n=26), hepatocellular carcinoma (HCC, n=24), CCA (n=8), other hepatic malignancies (n=13) and histologically normal livers (normal control, n=8). Periostin expression was evaluated using immunohistochemistry and serum periostin level was determined via enzyme-linked immunoassay. The diagnostic performance of serum periostin levels for distinguishing CCA patients from others was also assessed. Strong expression of periostin was noted only in the fibrous stroma of CCA tissue. Serum periostin levels (median) were significantly higher in patients with CCA (513 ng/ml) compared to those patients with normal liver, liver cirrhosis, HCC and other malignancies (120, 146, 155, 213 ng/ml, respectively, all P<0.05). The area under receiver operating characteristics curve of serum periostin level was 0.94 [95% confidence interval (CI), 0.85-1.00, P<0.001]. With optimal cut-off value of 302 ng/ml, diagnostic performances for CCA were as follows: sensitivity, 0.88 (95% CI, 0.47-0.99); specificity, 0.92 (0.83-0.96); accuracy, 0.91 (0.83-0.96); positive predictive value, 0.54 (0.25-0.81); negative predictive value, 0.98 (0.92-0.99); positive-likelihood ratio, 10.4 (4.8-13.4); and negative-likelihood ratio, 0.13 (0.03-0.49). We demonstrated increased expression of periostin in the stroma of CCA tissue. Serum periostin levels were significantly elevated in patients with CCA and enable distinction between CCA and other hepatic malignancies.

CD14 expression and Kupffer cell dysfunction in non-alcoholic steatohepatitis: Superparamagnetic iron oxide-magnetic resonance image and pathologic correlation

Background and Aim:  Kupffer cell (KC) function and CD14 expression contributes to pathogenesis of non‐alcoholic steatohepatitis (NASH). However, these relationships remain unclear. We investigated the relationship of KC function with superparamagnetic iron oxide‐enhanced magnetic resonance imaging (SPIO‐MRI), histopathological severity of NASH, and number of CD14‐positive KCs in NASH.

Diffusion-weighted magnetic resonance imaging predicts malignant potential in small hepatocellular carcinoma

BACKGROUND Poor differentiation and microvascular invasion are indicators of poor outcome after hepatectomy for patients with small hepatocellular carcinoma (HCC). AIMS We investigated whether gadoxetic acid-enhanced and diffusion-weighted magnetic resonance imaging (MRI) could predict these factors before hepatectomy. METHODS Between July 2008 and April 2012, 75 patients who underwent hepatectomy for small HCCs (diameter: ≤3cm, tumor number: ≤3) were consecutively enrolled. In gadoxetic acid-enhanced MRI, the signal intensity in the tumor was corrected to that in the paraspinous muscles, and the relative enhancement was calculated. In diffusion-weighted imaging, we measured the apparent diffusion coefficient (ADC). We then investigated the correlations between relative enhancement or ADC and histological grade, microvascular invasion and recurrence-free survival. RESULTS Poorly differentiated HCCs showed significantly lower ADC than well-differentiated and moderately differentiated HCCs. There was no significant difference in the hepatobiliary phase. Only ADC was an independent predictor of microvascular invasion, and the best cut-off point of its prediction was 1.175×10(-3)mm(2)/s. Additionally, the recurrence-free survival was significantly shorter in low-ADC group than in high-ADC group. CONCLUSION ADC is useful for predicting poorly differentiated HCCs and microvascular invasion, and low ADC is associated with increased recurrence risk for small HCCs after hepatectomy.

Serum albumin level is a notable profiling factor for non-B, non-C hepatitis virus-related hepatocellular carcinoma: A data-mining analysis

Various factors are underlying for the onset of non‐B, non‐C hepatitis virus‐related hepatocellular carcinoma (NBNC‐HCC). We aimed to investigate the independent risk factors and profiles associated with NBNC‐HCC using a data‐mining technique.

Quantification of hepatic iron concentration in chronic viral hepatitis: Usefulness of T2-weighted single-shot spin-echo echo-planar MR imaging

Objective To investigate the usefulness of single-shot spin-echo echo-planar imaging (SSEPI) sequence for quantifying mild degree of hepatic iron stores in patients with viral hepatitis. Methods This retrospective study included 34 patients with chronic viral hepatitis/cirrhosis who had undergone histological investigation and magnetic resonance imaging with T2-weighted gradient-recalled echo sequence (T2-GRE) and diffusion-weighted SSEPI sequence with b-factors of 0 s/mm2 (T2-EPI), 500 s/mm2 (DW-EPI-500), and 1000 s/mm2 (DW-EPI-1000). The correlation between the liver-to-muscle signal intensity ratio, which was generated by regions of interest placed in the liver and paraspinous muscles of each sequence image, and the hepatic iron concentration (µmol/g dry liver), which was assessed by spectrophotometry, was analyzed by linear regression using a spline model. Akaike information criterion (AIC) was used to select the optimal model. Results Mean ± standard deviation of the hepatic iron concentration quantified by spectrophotometry was 24.6±16.4 (range, 5.5 to 83.2) µmol/g dry liver. DW-EPI correlated more closely with hepatic iron concentration than T2-GRE (R square values: 0.75 for T2-EPI, 0.69 for DW-EPI-500, 0.62 for DW-EPI-1000, and 0.61 for T2-GRE, respectively, all P<0.0001). Using the AIC, the regression model for T2-EPI generated by spline model was optimal because of lowest cross validation error. Conclusion T2-EPI was sensitive to hepatic iron, and might be a more useful sequence for quantifying mild degree of hepatic iron stores in patients with chronic viral hepatitis.

Supplement improves nutrition and stresses caused by examination-associated fasting in patients with liver cirrhosis

Aim:  Cirrhotic patients tend to develop malnutrition by fasting, yet the importance of nutritional care during examination‐associated fasting has not been investigated. This study aimed to examine the effects of a nutritional supplement on nutrition and stresses caused by examination‐associated fasting in cirrhotic patients.

Glycogenic hepatopathy and non-alcoholic fatty liver disease in type 1 diabetes patients

Patients with type 1 diabetes mellitus (T1DM) sometimes have hepatomegaly and increased transaminase. This is usually due to non-alcoholic fatty liver disease (NAFLD) or, rarely, glycogenic hepatopathy (GH). A 13-year-old boy with NAFLD who was diagnosed with T1DM at 8 years of age, and a 13-year-old girl with GH who was found to have T1DM at 9 years of age were observed to have hepatomegaly and elevation of transaminase (aspartate aminotransferase [reference value, 12–30 IU/mL]/ alanine aminotransferase [reference value: 3–18 IU/mL]: 48/100 and 181/191, respectively). Their blood glucose levels had been poorly controlled for the last few years (HbA1c 11–12%). Lowdensity liver on computed tomography (CT) is usually seen in NAFLD, but sometimes, in early stage NAFLD, low-density liver is not seen on CT. Gradient dual-echo magnetic resonance imaging (MRI) can effectively discriminate glycogen from fat in the liver (Fig. 1). Therefore, we believe that gradient dual-echo MRI is a powerful tool to distinguish GH from NAFLD in T1DM with hepatomegaly and elevated transaminase.

Chronic Hepatitis and Cirrhosis on MR Imaging

This article focuses on the current role of magnetic resonance imaging in the detection and characterization of chronic hepatitis and cirrhosis. In particular, the characteristic MR imaging features of morphologic changes and focal manifestations of chronic liver disease are highlighted.