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.

Simulation of protected and unprotected loss of flow transients in a WWER-1000 reactor based on the Drift-Flux Model

In view of the importance of studying coolant transient behavior in a nuclear reactor, this work is devoted to the thermal-hydraulic analysis of protected and unprotected loss of flow transients in a WWER-1000 reactor. A series of corresponding mathematical and physical models based on the four-equation Drift-Flux model has been applied. Based on a multi-channel approach, the core has been divided into different regions. Each region has different characteristics as represented in a single fuel pin with its associated coolant channel. Appropriate initial and boundary conditions have been considered and two situations of tripping four and two primary pumps in a protected core in addition to situation of tripping all four pumps in an unprotected core have been analyzed. For each transient, a full range of thermal-hydraulic parameters has been obtained. For verification of the proposed model, the results have been compared with those of the RELAP5/MOD3 and Bushehr nuclear power plant Final Safety Analysis Report (FSAR). A good agreement between results has been attained for the aforementioned transients.

Prevalence of celiac disease in Iranian patients with irritable bowel syndrome: a cross-sectional study

OBJECTIVE

This study was aimed to determine the prevalence of celiac disease (CD) in irritable bowel syndrome (IBS) and its subtypes in a group of Iranian patients.

METHODS

From March 2007 to June 2009, 465 consecutive patients who were referred to the gastroenterology clinic of Jundishapur University of Medical Sciences and fulfilled the Rome III criteria for IBS were included. Immunoglobulin A (IgA) anti-tissue transglutaminase (IgA-tTG) and anti-gliadin antibody (AGA) levels were measured. CD was confirmed by gastroduodenoscopy and biopsy in patients with abnormal antibodies.

RESULTS

Five patients had only elevated IgA-tTG, 26 with only elevated AGA, and in 16 patients abnormal results for both antibodies were reported. Duodenal biopsies from these 47 patients confirmed CD in 13 (2.8%, 95% CI 1.6-4.0%) according to the Marsh criteria. Two CD patients had normal IgA-tTG concentrations while only one patient with normal AGA was proven to have CD. CD was most prevalent in unsubtyped IBS (4.9%, 95% CI 1.1-8.7%), followed by mixed IBS (4.7%, 95% CI 0.3-9.1%). In multiple comparison, CD was less common in diarrhea-predominant IBS than in unsubtyped IBS, although this did not reach statistical significance (1.0% vs. 4.9%, P = 0.057).

CONCLUSIONS

CD in unsubtyped IBS had a growing trend to be more common than in diarrhea-predominant IBS. Evaluation of IBS patients for CD is advisable.