[Imaging diagnosis for fatty liver: a systematic review]

OBJECTIVE

To systematically assess imaging diagnostic tests for fatty liver and provide a decision-making basis for clinical diagnosis and screening.

METHODS

Electronic searches were conducted on the Chinese Biomedical Database, PubMed, and EMBASE, combining with manually searching of Chinese literature. All searches were completed until November 2002. All studies which evaluated imaging diagnostic test of human fatty liver were included. Data of diagnostic accuracy in the included studies were extracted, and methodological quality of the studies was assessed independently by two reviewers according to the established quality standard. Quantitative analysis or qualitative description were performed based on available data.

RESULTS

Of 13 studies that met the eligibility criteria, 10 studies evaluated the diagnostic accuracy of B-mode ultrasound, 3 studies evaluated contrast-enhanced (helical) CT. To assess 7 diagnostic test studies for fatty liver that used liver biopsy as reference test: the pooled sensitivity of B-mode ultrasound was 0.89 (95% confidence interval 0.87-0.92), specificity was 0.94 (95% confidence interval 0.92-0.96) and the Q value was 0.90 by adjusted SROC method. To assess 2 diagnostic test studies for fatty liver that used CT as reference test: the pooled sensitivity, specificity, and Q value were 0.92 (95% confidence interval 0.89-0.96), 0.88 (95% confidence interval 0.84-0.92), and 0.90 respectively by adjusted SROC method.

CONCLUSIONS

B-mode ultrasound method can be regarded as an effective method for fatty liver diagnosis and screening. The methodologic quality of diagnostic test needs to be improved.

Beneficial effects of tumor necrosis factor-alpha inhibition by pentoxifylline on clinical, biochemical, and metabolic parameters of patients with nonalcoholic steatohepatitis

BACKGROUND

Tumor necrosis factor-alpha (TNF-alpha) has been incriminated to play an important role in the pathogenesis of nonalcoholic steatohepatitis (NASH). Pentoxifylline, a TNF-alpha inhibitor could prove useful in treating patients with NASH.

METHODS

Eighteen patients (mean age, 34 +/- 7.8 yr) with histologically proven NASH and with persistently elevated ALT (>1.5 times) were given pentoxifylline at a dosage of 400 mg t.i.d. for 6 months. No lipid-lowering agent or antioxidants were concurrently advised.

RESULTS

Impaired fasting glycemia, impaired glucose tolerance, diabetes mellitus, and hypertriglyceridemia were noted in 6, 35, 17, and 53% of the patients, respectively. After 6 months of therapy, fatigue improved (55.6 vs 20%, p= 0.016), but serum triglyceride (182 +/- 66 vs 160 +/- 55 mg/dl, p= 0.397), cholesterol (173 +/- 46 vs 162 +/- 40 mg/dl, p= 0.440), and body mass index (BMI) (27.3 +/- 3.1 vs 26 +/- 3.1 kg/m(2), p= 0.087) remained unchanged. Mean AST (66 +/- 29 vs 33 +/- 11 IU/l, p < 0.0001) and ALT (109 +/- 44 vs 47 +/- 20 IU/l, p < 0.0001) reduced significantly. ALT normalized in 23% at month 1 (p= 0.125), 35% at month 2 (p= 0.125), and 60% at month 6 (p= 0.008) of treatment. The insulin resistance index assessed by homeostatic metabolic assessment (HOMA(IR)) improved (5.1 +/- 3.4 vs 2.6 +/- 2, p = 0.046) and the serum TNF-alpha reduced significantly after therapy (22.15 +/- 2.49 vs 17 +/- 2.58 pg/ml, p = 0.011). The drug was well tolerated.

CONCLUSIONS

In patients with NASH, pentoxifylline therapy effectively achieved significant clinical and biochemical improvement with reduction in HOMA(IR). These benefits are possibly mediated through suppression of TNF-alpha.

Pregnancy-associated severe liver dysfunction

Determining the cause of liver disease in pregnancy can present a difficult challenge for clinicians. Minor elevations in aminotransferases may be a harbinger of life-threatening processes, such as acute fatty liver of pregnancy (AFLP) or hemolysis, elevated liver enzyme levels, low platelet count (HELLP) syndrome. Preeclampsia, HELLP syndrome, and AFLP form a spectrum of disease that ranges from involving mild symptoms to severe life-threatening multiorgan system dysfunction. They have been shown to be the primary causes of severe hepatic dysfunction during pregnancy. This article attempts to define the clinical and diagnostic features, pathophysiology, and treatment options of these diseases.

Nonalcoholic fatty liver disease: is all the fat bad?

Nonalcoholic fatty liver disease is now a major cause of liver disease in developed countries, largely as a result of an epidemic of obesity, diabetes and sedentary lifestyles. This has resulted in raised clinical awareness and diagnostic refinement. The entity encompasses several histologic patterns from benign steatosis to nonalcoholic steatohepatitis, the latter having a significant risk of progressive fibrosis and the development of cirrhosis. Laboratory tests and imaging are not able to distinguish steatosis from steatohepatitis, which requires liver biopsy. However following an assessment of several risk factors, patients can be stratified for the potential risk of fibrosis, allowing the rational use of liver biopsy. This review will describe the various patterns of nonalcoholic fatty liver disease and relate this to disease pathogenesis and progression. Strategies for management, including experimental interventions, will be discussed.

[Subcapsular fatty infiltration of the liver in peritoneal dialysis patients treated with intraperitoneal insulin: US and CT features (case report)]

In recent years a characteristic subcapsular and periligamentous fatty infiltration of the liver has been reported in diabetic patients on intraperitoneal insulin treatment by continuous ambulatory peritoneal dialysis. The finding is unique to these patients on continuous ambulatory peritoneal dialysis and has not been defined in diabetics using subcutaneous insulin. We present characteristic US and CT findings in two such patients with focal subcapsular fatty infiltration of the liver.

Hepatic Pseudotumor Due To Nodular Fatty Sparing: The Diagnostic Role of Opposed-Phase MRI

OBJECTIVE

We sought to describe the role of opposed-phase MRI in the diagnosis of nodular fatty sparing in the liver.

CONCLUSION

Nodular fatty sparing of the liver displays characteristic findings on opposed-phase MRI. Because the lesion may otherwise mimic a hepatic tumor, knowledge of these findings may prevent unnecessary biopsy or inappropriate treatment.

Should a liver biopsy be done in patients with subclinical chronically elevated transaminases?

In 10% of the patients with chronic abnormal alanine aminotransferase (ALT) levels no cause is found. The prognosis of this liver disease, the increased risk of liver fibrosis regardless of the types of histological lesions and the need for a liver biopsy are unknown. Nearly 50% of these cases are explained by non-alcoholic steatohepatitis (NASH). The aim of this study was to evaluate, in patients with accidentally detected chronically elevated ALT levels, the prevalence of fibrosis and NASH, and the clinical and biological factors associated with each entity. Retrospectively, 67 patients (mean age, 46.6 +/- 12.1 years; 45 males) were included. All patients had a liver biopsy and were hepatitis B virus, hepatitis C virus, human immunodeficiency virus seronegative without alcohol, drug, autoimmune or genetically induced liver disease, with ALT > N (the upper limit of normal). NASH was evaluated according to necroinflammatory lesions and fibrosis. Fibrosis was evaluated according to the METAVIR score. Statistical analyses were performed using Student's t test, the Mann-Whitney rank-sum test and the chi-square test. Fibrosis scores were: F0, 37.3%; F1, 32.8%; F2, 26.9%; F3, 1.5%; and F4, 1.5%. NASH was absent in 59.7% and present in 40.3%. Significant differences were observed between F < 2 and F > or = 2 fibrosis patients for aspartate aminotransferase (AST) and ALT and between patients with NASH or without for body mass index. Overall, the risk of F > or = 2 fibrosis was increased in patients with AST > N, ALT > 2N or AST > N and ALT > 2N. The prevalence of F > or = 2 fibrosis and NASH in patients with unexplained chronic abnormal ALT are 30% and 40%, respectively. Since the risk of F > or = 2 fibrosis is significantly increased in patients with AST > N and/or ALT > 2N, liver biopsy should be performed only in patients with AST > N or ALT > 2N.

Hepatocellular carcinoma with nonalcoholic steatohepatitis

Nonalcoholic steatohepatitis (NASH) was originally believed to be a benign disease. However, it has been recently revealed that NASH could lead to irreversible liver disease in some patients. We report an unusual case of hepatocellular carcinoma (HCC) in a 76-year-old man with NASH. He had no history of alcohol consumption, drug use, or blood transfusion. He was negative for all serological viral markers and autoantibodies. In addition, he was obese (body mass index [BMI], 30.75 kg/m(2)) and had type 2 diabetes mellitus. A liver biopsy specimen showed moderate steatosis with necroinflammatory changes, ballooning degeneration, Mallory bodies, pericellular fibrosis, and evidence of nodular regeneration. He was diagnosed with NASH with cirrhosis. Simultaneously, a liver tumor, measuring 19 mm in diameter, was detected in segment 6. A tumor biopsy specimen revealed well-differentiated HCC, and imaging modalities confirmed the characteristics of HCC. To our knowledge, ten patients who had HCC with NASH were reported. In all patients with NASH and HCC, cirrhosis was present. Patients with NASH and cirrhosis may progress to HCC, and regular screening, based on tumor markers and imaging modalities, is needed to detect HCC in patients with NASH and cirrhosis.

Nonalcoholic fatty liver disease and the epidemic of obesity

Nonalcoholic fatty liver disease (NAFLD) is common in patients with the metabolic syndrome, and it is expected to become more common in countries where obesity, one of the components of the metabolic syndrome, is increasing.

[The trace element status in patients with chronic hepatic diseases]

Despite of the achievements of pharmacology it is very actually to improve the diagnosis and therapy of different chronic hepatic diseases. The purpose of the investigation is to study trace element (TE) status in patients with chronic hepatic diseases for estimating the possibility of therapy efficiency improvement. 102 patients with chronic hepatic diseases, aged from 19 to 60 were clinically and laboratory investigated. Group 1 (36 patients) suffered from alcoholic liver cirrhosis, group 2 (35 patients) had chronic alcoholic steatohepatitis and group 3 (31 patients) had non-alcoholic steatohepatitis (NASH). Multielement blood plasma analysis by ICP-MS and ICP-OES was perfomed in the Center of Biotic Medicine (Moscow). The results showed the significant changes in TE status in patients with chronic hepatic diseases that proves the expediency of studying both the essential and toxic element in such patients to improve the diagnosis and to optimize the treatment. Patients with chronic hepatic diseases are characterized by changing of such elements as Al, Ca, Cu, K, Se, Zn, that leads to necessity of using them for diagnosis.

The clinical features, diagnosis and natural history of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) has emerged as the most common chronic liver disease in the United States. The histologic spectrum of NAFLD ranges from steatosis liver alone to nonalcoholic steatohepatitis (NASH), which is the most serious form of NAFLD. NASH is a progressive fibrotic disease, in which cirrhosis and liver-related death occur in up to 20% and 12%, respectively, over a 10-year period. NASH-associated cirrhosis also can develop into subacute liver failure, progress to hepatocellular carcinoma, and reoccur post-transplantation. In contrast, steatosis alone has a more benign clinical course, although progression to cirrhosis has occurred in 3% of these patients. The major risk factors for fibrosis include diabetes or obesity, an aspartate aminotransferase/alanine aminotransferase ratio of greater than 1, age older than 50, and hepatic histology.

[Is non alcoholic steatohepatitis (NASH) part of the metabolic syndrome?]

The metabolic syndrome is one of the most common disease of our era that may cause numerous complications. There are some studies showing the need to take attention to the hepatic manifestation of the metabolic syndrome besides its already well-known consequences. In most of the cases there are histopathological evidences for the presence of fatty liver and mainly non alcoholic steatohepatitis. These conditions can lead to hepatic cirrhosis, hepatic failure or even to hepatocellular carcinoma. The risk of these consequences is the greater the more severe the metabolic syndrome is and the more components of it are included. All these emphasise the importance of examining the hepathological status of the patients suffering from the metabolic syndrome.

Detection of hepatocellular carcinoma using double-echo FLASH sequence during the hepatic arterial phase

PURPOSE

The purpose of this study was to compare the performance of in-phase and opposed-phase gradient-recalled echo (GRE) pulse sequences in paramagnetic contrast-enhanced magnetic resonance (MR) imaging of hepatocellular carcinomas (HCCs) during the hepatic arterial phase.

MATERIAL AND METHODS

Thirty-four patients with 84 lesions with known or suspected HCCs, nine of whom had a fatty liver, were examined with double-echo GRE techniques under 1.5T before and 30 s after injection of gadopentenate dimeglumine at a dose of 0.1 mmol/kg. Echo times were 2.4 ms (opposed phase) and 5.0 ms (in phase). Contrast enhancement of the HCC detected in both in-phase and opposed-phase images was evaluated. The liver signal-to-noise ratio (SNR), lesion-liver contrast-to-noise ratio (CNR), and enhancement ratio (ER) were calculated for the largest lesion of each patient.

RESULTS

In dynamic gadolinium-enhanced images of the 84 HCCs, 81 (96.4%) were detected in both in-phase and opposed-phase images, two (2.4%) were detected in only in-phase images, and one (1.2%) was detected only in opposed-phase images. The liver SNR, CNR, and ER were 46.7+/-16.1, 15.2+/-10.3, and 0.637+/-0.268 for in-phase images, and 48.9+/-16.9, 16.3+/-11.8, and 0.647+/-0.309 for opposed-phase images, respectively. In patients with a fatty liver, the SNR, CNR, and ER were 46.0+/-18.1, 21.7+/-17.9, and 0.525+/-0.231 for in-phase images, and 44.3+/-18.7, 26.0+/-21.3, and 0.793+/-0.124 for opposed-phase images, respectively. No significant statistical differences were found between the in-phase and opposed-phase images.

CONCLUSION

Opposed-phase GRE imaging is equivalent to in-phase GRE sequences in patients with or without fatty liver for detection of HCC in dynamic gadolinium-enhanced images.

Hypertransaminasemia and severe hepatic steatosis without inflammation. A case report

Nonalcoholic fatty liver disease (NAFLD) is a medical condition that may progress to end-stage liver disease. The spectrum of NAFLD is wide and ranges from simple fat accumulation in hepatocytes (steatosis), to fat accumulation plus necroinflammatory activity with or without fibrosis (steatohepatitis). In addition, NAFLD is the most common cause of abnormal liver-test results among adults with a prevalence of 13%-23%. This case report is an example of a patient with asymptomatic hypertransaminasemia and severe hepatic steatosis without inflammation in which the diagnosis was made by liver biopsy.

Beyond insulin resistance in NASH: TNF-alpha or adiponectin?

Adiponectin has antilipogenic and anti-inflammatory effects, while tumor necrosis factor alpha (TNF-alpha) reduces insulin sensitivity and has proinflammatory effects. We examined (1) the extent to which hypoadiponectinemia and TNF-alpha activation are features of nonalcoholic steatohepatitis (NASH) and (2) whether serum levels of these markers correlate with the severity of histological changes in 109 subjects with nonalcoholic fatty liver disease (NAFLD), including 80 with NASH and 29 with simple steatosis. By multivariate analysis, subjects with NASH had reduced adiponectin level and increased TNF-alpha and soluble TNF receptor 2 (sTNFR2)-but not leptin levels, compared with controls matched by age, sex, and body mass index; these differences were independent of the increased insulin resistance (by homeostasis model [HOMA-IR]) in NASH. When compared with simple steatosis, NASH was associated with lower adiponectin levels and higher HOMA-IR, but there were no significant differences in the levels of TNF-alpha and sTNFR2. The majority of subjects with steatohepatitis (77%) had adiponectin levels less than 10 microg/mL and HOMA-IR greater than 3 units, but only 33% of those with pure steatosis had these findings. HOMA-IR and low serum adiponectin were also independently associated with increased grades of hepatic necroinflammation. In conclusion, hypoadiponectinemia is a feature of NASH independent of insulin resistance. Reduced adiponectin level is associated with more extensive necroinflammation and may contribute to the development of necroinflammatory forms of NAFLD.

[Nonalcoholic steatohepatitis in children]

Nonalcoholic steatohepatitis (NASH) occurs not only in adults but also in children. NASH is diagnosed in obese children with increased aminotranspherases, characteristic ultrasonography and typical percutneous liver biopsy (fat vacuoles in hepatocytes, different stages of inflammation with or without liver fibrosis) when other possible causes of steatosis are excluded. It is important to diagnose NASH and start the treatment as early as possible in order to prevent irreversible liver damage. The first line therapy consists of reduction of body weight by low-calorie diet and exercising. Ursodeoxycholic acid has been used as adjuvant therapy mainly in adults, and vitamin E also in children. We presented 5 cases with NASH (2 girls, 3 boys; age 11-15 years). All were obese and had increased transaminases, and ultrasonography and liver biopsy typical for NASH. With low-calorie diet in all our patients BMI declined, symptoms vanished and transaminases decreased (in two patients transaminases normalized).

Clinical spectrum and natural history of non-alcoholic steatohepatitis with normal alanine aminotransferase values

Non-alcoholic fatty liver disease (NAFLD) including nonalcoholic steatohepatitis (NASH) is a well-established cause for chronic liver disease. In most studies on NASH, elevation in alanine aminotransferase (ALT) is taken as one of the diagnostic criteria. However, the clinical and histological spectrum and natural history of NAFLD with normal ALT are not well explored. This study was planned to define the clinical spectrum and natural history of patients with NAFLD with normal ALT, and to compare them with NAFLD with abnormal ALT. A prospective study including 81 consecutive patients with ahistological diagnosis ofNAFLD was planned during the period from 1999 to 2003. Consecutive (n=81) patients with the histological diagnosis of NAFLD were included in the study. In all the patients, clinical, anthropometric, laboratory, histological and imaging features were noted at the baseline. All these patients were followed up regularly at 6-month intervals. Of the 81 cases, 25 patients (including 60% cirrhotics) had persistently normal enzyme, whereas 56 (including 23% cirrhotics) had abnormal ALT. Both the groups were comparable with respect to distribution of age, gender, ethnicity, clinical features, imaging features, histological severity and laboratory features; except a higher incidence of diabetes and higher occurrence of advanced liver disease at baseline in NAFLD with normal ALT. Natural history of NAFLD was better in patients without cirrhosis irrespective of baseline ALT levels than in patients with cirrhosis; except for a higher incidence of decompensation in cirrhotics with normal ALT. The entire clinical and histological spectrum of NAFLD is seen in patients with normal ALT and is not different from patients with abnormal ALT. In patients with diabetes and hepatomegaly in the absence of other obvious liver diseases, even normal ALT may not rule out advanced liver disease, and liver biopsy may be necessary to identify the severity of liver disease.

[Obesity and non-alcoholic steatohepatitis]

Obesity is the most important risk factor associated with non-alcoholic steatohepatitis, which is caused by to impaired insulin activity, overflow of portal triglycerides, and production of inflammatory cytokines; all of these are deleterious to hepatocytes. These phenomena facilitate disruptions in hepatic physiology, as observed in alcoholic hepatitis; however, consumption of this substance is absent. Non-alcoholic steatohepatitis has had a great impact due to the fact that previously, main cases of cryptogenic cirrhosis actually were attributed to this disease. Despite advances in understanding the pathophysiologic process of the disease, there is no better treatment than weight reduction (a combination of diet and exercise). In this issue, we describe the most important topics with regard to non-alcoholic steatohepatitis and the obesity-related process.

Fatty liver disease in children

NAFLD/NASH is now recognised as an increasing clinical problem in children and adolescents. Risk factors include obesity, insulin resistance, and hypertriglyceridaemia. Drug hepatoxicity and genetic or metabolic diseases that can cause hepatic steatosis must be excluded. Affected children are usually asymptomatic although a few may complain of malaise, fatigue, or vague recurrent abdominal pain. Liver biopsy is the gold standard for diagnosis, and is important in determining disease severity and prognosis. The natural history of childhood NASH may be progressive liver disease for a significant minority. Long term follow up studies in this population are still lacking. The mainstay of treatment is weight reduction. The use of pharmacological therapy, though promising, ideally needs further evaluation in well designed randomised controlled studies in children.

[Non alcoholic steatohepatitis: an emergent and potentially serious pathology]

Nonalcoholic steatohepatitis is an acquired liver disease, usually metabolic characterised by histologic lesions with steatosis, intralobular necrosis and inflammatory infiltrates. Liver biopsy findings are identical to those seen in alcoholic hepatitis. Nonalcoholic steatohepatitis is increasingly reported in industrial countries because of an increase of the prevalence of obesity and diabetes which are the most common risk factors of this disease. The diagnosis of nonalcoholic steatohepatitis is based on a confrontation between clinical and anatomic data and an exclusion of an excessive intake of alcohol and other hepatic disease. Liver biopsy has a prognosis and histologic benefit especially when there is risk factors of fibrosis. This disease is potentially severe with a potential risk for progression to cirrhosis. Progress in pathogenesis is noted but no definite therapy exist. The aim of this review is to indicate current knowledge for the gravity of nonalcoholic steatohepatitis and its consequence and to understand the pathogenesis to prevent cirrhosis.

Steatohepatitis and unsuspected micronodular cirrhosis in Dorfman-Chanarin syndrome with documented ABHD5 mutation

Mutation in ABHD5 causes Dorfman-Chanarin syndrome (DCS), a multisystem triglyceride storage disorder. Ultrastructural study of leukocytes confirmed DCS in a child homozygous for a novel ABHD5 mutation, with ichthyosis, developmental delay, and steatohepatitis with cirrhosis, manifest only as elevated aminotranferase levels. We recommend early assessment for liver disease in DCS.