Biomedical subjects

Daniel Dhumeaux

Publications and source records attributed to Daniel Dhumeaux.

At least 19 recordsLinked to original sources

PubMed2006

The nonstructural 5A protein of hepatitis C virus genotype 1b does not contain an interferon sensitivity-determining region.

BACKGROUND: The nonstructural (NS) 5A protein of hepatitis C virus (HCV) has been suggested to contain an interferon (IFN) sensitivity-determining region (ISDR). METHODS: We studied whether the degree of viral decline on day 1 is associated with differences in NS5A amino acid sequences among patients receiving IFN- alpha. RESULTS: Phylogenetic analyses of the full-length protein and of functional domains showed no relationship between the baseline protein sequence and the antiviral response. NS5A quasispecies sequences showed no differences in the number of mutations in the putative ISDR relative to a prototype sequence between responders and nonresponders or according to IFN- alpha antiviral efficacy. No relationship was found between antiviral efficacy at 24 h and the baseline sequence of any NS5A region. Amino acid changes were observed in a few cases at 24 h in both responders and nonresponders, but no consistent pattern of amino acid shifts was observed, ruling out the possibility that IFN- alpha selected IFN-resistant variants. CONCLUSION: Our findings show that there is no ISDR in the HCV genotype 1 NS5A protein and that the NS5A sequence does not influence the capacity of IFN- alpha to block viral replication. The findings do not rule out a role for NS5A in subsequent viral clearance.

Adult↗

PubMed2006

Diagnosis of hepatic fibrosis and cirrhosis by transient elastography in HIV/hepatitis C virus-coinfected patients.

BACKGROUND: Chronic hepatitis C in HIV-infected patients is an increasing cause of death dependent on the development of liver fibrosis, which is currently assessed by liver biopsy despite its limitations. Liver stiffness measurement, a new noninvasive method, allows the evaluation of liver fibrosis. The aim of this prospective study was to assess the accuracy of liver stiffness measurement for the detection of fibrosis and cirrhosis in HIV/hepatitis C virus (HCV)-coinfected patients and to compare its accuracy with other noninvasive methods. METHODS: We studied 72 consecutive HIV patients with chronic hepatitis C who had a simultaneous liver biopsy and liver stiffness measurement by transient elastography (FibroScan; Echosens, Paris, France) for the assessment of liver fibrosis. RESULTS: Liver stiffness values ranged from 3.0 to 46.4 kilopascal. Liver stiffness was significantly correlated to fibrosis stage (Kendall tau-b = 0.48; P < 0.0001). The area under the receiver operating characteristic (AUROC) curve of liver stiffness measurement was 0.72 for F > or = 2 and 0.97 for F = 4. For the diagnosis of cirrhosis, AUROC curves of liver stiffness measurement were significantly higher than those for platelet count (P = 0.02), aspartate aminotransferase (AST)/alanine aminotransferase (ALT) ratio (P = 0.0001), Aspartate aminotransferase-to-Platelet Ratio Index (APRI) (P = 0.01), and FIB-4 (P = 0.004). CONCLUSION: Liver stiffness measurement is a promising noninvasive method for the assessment of fibrosis in HIV-infected patients with chronic HCV infection. Its use for the follow-up of these patients should be further evaluated.

Diagnostic Techniques, Digestive System↗

PubMed2006

Assessment of biliary fibrosis by transient elastography in patients with PBC and PSC.

Noninvasive measurement of liver stiffness with transient elastography has been recently validated for the evaluation of hepatic fibrosis in chronic hepatitis C. The current study assessed the diagnostic performance of liver stiffness measurement (LSM) for the determination of fibrosis stage in chronic cholestatic diseases. One hundred one patients with primary biliary cirrhosis (PBC, n=73) or primary sclerosing cholangitis (PSC, n=28) were prospectively enrolled in a multicenter study. All patients underwent liver biopsy (LB) and LSM. Histological and fibrosis stages were assessed on LB by two pathologists. LSM was performed by transient elastography. Efficiency of LSM for the determination of histological and fibrosis stages were determined by a receiver operating characteristics (ROC) curve analysis. Analysis failed in six patients (5.9%) because of unsuitable LB (n=4) or LSM (n=2). Stiffness values ranged from 2.8 to 69.1 kPa (median, 7.8 kPa). LSM was correlated to both fibrosis (Spearman's rho= 0.84, P < .0001) and histological (0.79, P < .0001) stages. These correlations were still found when PBC and PSC patients were analyzed separately. Areas under ROC curves were 0.92 for fibrosis stage (F) > or =2, 0.95 for F > or =3 and 0.96 for F=4. Optimal stiffness cutoff values of 7.3, 9.8, and 17.3 kPa showed F > or =2, F > or =3 and F=4, respectively. LSM and serum hyaluronic acid level were independent parameters associated with extensive fibrosis on LB. In conclusion, transient elastography is a simple and reliable noninvasive means for assessing biliary fibrosis. It should be a promising tool to assess antifibrotic therapies in PBC or PSC.

Adolescent↗

PubMed2006

Accuracy of liver stiffness measurement for the diagnosis of cirrhosis in patients with chronic liver diseases.

A proper diagnosis of cirrhosis is essential for the management of patients with chronic liver diseases. We assessed the accuracy of liver stiffness measurement by Fibroscan for the diagnosis of cirrhosis in 1,257 patients with chronic liver diseases of various causes enrolled in a prospective multicenter study as well as clarified causes of discrepancies between liver histology and Fibroscan. One hundred thirty-two patients had unsuitable biopsy specimens, and 118 had unreliable liver stiffness measurements. Because 232 patients overlapped with a previous study, analysis was performed in the 775 new patients then derived in the whole population (1,007; 165 cirrhosis). Diagnostic accuracy was assessed by receiver operator curve (ROC) analysis. Liver samples were re-analyzed in case of discrepancies. The area under the ROC (AUROC) was 0.95 (95% CI, 0.93-0.96) for the diagnosis of cirrhosis in either 775 or 1,007 patients. The cutoff value with optimal diagnosis accuracy was 14.6 kPa in 1,007 patients (positive and negative predictive values, 74% and 96%) with discrepancies among the etiological groups. Eighty patients were misclassified: (1) among 45 patients without cirrhosis with liver stiffness 14.6 kPa or greater, 27 (60%) had extensive fibrosis and 10 (22%) significant perisinusoidal fibrosis; and (2) among 35 patients with cirrhosis and liver stiffness less than 14.6 kPa, 10 (29%) had a macronodular pattern and 25 (71%) either none or mild activity. In conclusion, Fibroscan is a reliable method for the diagnosis of cirrhosis in patients with chronic liver diseases, better at excluding than at predicting cirrhosis using a threshold of 14.6 kPa. False-negatives are mainly attributable to inactive or macronodular cirrhosis.

Adult↗

PubMed2006

Molecular epidemiology of hepatitis C virus subtype 3a in injecting drug users.

Hepatitis C virus subtype 3a (HCV-3a) originates from Asia and has spread widely among injecting drug users as well as other patient groups in industrialized countries. HCV subtype 3a infection remains highly prevalent and frequently transmitted in the population of intravenous drug users. The objective of this study was to understand better the mechanisms of the worldwide HCV-3a epidemics in drug users. Ninety-three sera from HCV-3a-infected IDUs from France, the United States, Brazil, Argentina, and Australia were studied. Phylogenetic analyses of the non-structural 5B region showed no specific clustering according to the continent of the patient's origin. Non-exclusive clusters of viral sequences from South America, Australia, and California were observed, but topologies were not supported by strong bootstrap values. The results suggest that HCV-3a has been transmitted from a common origin through a unique worldwide epidemic that rapidly spread among drug users. Regional transmission occurred in the recent past, leading to an embryonic genetic diversification of HCV-3a among local injecting drug user population.

Argentina↗

PubMed2006

Laparoscopic liver resection for peripheral hepatocellular carcinoma in patients with chronic liver disease: midterm results and perspectives.

OBJECTIVE: Report the midterm results of laparoscopic resection for hepatocellular in chronic liver disease (CLD). SUMMARY BACKGROUND DATA: Surgical resection for hepatocellular carcinoma (HCC) in chronic liver disease (CLD) remains controversial because of high morbidity and recurrence rates. Laparoscopic resection of liver tumors has recently been developed and could reduce morbidity. METHODS: From 1998 to 2003, patients with HCC and CLD were considered for laparoscopic liver resection. Inclusion criteria were chronic hepatitis or Child's A cirrhosis, solitary tumor < or =5 cm in size, and location in peripheral segments of the liver. Mortality, morbidity, recurrence rates, and survival were analyzed. RESULTS: A total of 27 patients were included. Liver resections included anatomic resection in 17 cases and non anatomic resection in 10. Seven conversions to laparotomy (26%) occurred for moderate hemorrhage in 5 cases and technical difficulties in 2 cases. Mortality and morbidity rates were 0% and 33%, respectively. Postoperative ascites and encephalopathy occurred in 2 patients (7%) who both had undergone conversion to laparotomy. Mean surgical margin was 11 mm (range, 1-47 mm). After a mean follow-up of 2 years (range, 1.1-4.7), 8 patients (30%) developed intrahepatic tumor recurrence of which one died. Treatment of recurrence was possible in 4 patients (50%), including orthotopic liver transplantation, right hepatectomy, radiofrequency ablation, and chemoembolization in 1 case each. There were no adhesions in the 2 reoperated patients. Overall and disease-free 3-year survival rates were 93% and 64%, respectively. CONCLUSION: Our study shows that laparoscopic liver resection for HCC in selected patients is a safe procedure with very good midterm results. This approach could have an impact on the therapeutic strategy of HCC complicating CLD as a treatment with curative intent or as a bridge to liver transplantation.

Adult↗

PubMed2006

Dynamics of hepatitis B virus resistance to lamivudine.

Lamivudine was the first approved inhibitor of hepatitis B virus (HBV) reverse transcriptase (RT). Lamivudine resistance develops in 53% to 76% of patients after 3 years of treatment. We extensively characterized the dynamics of HBV quasispecies variant populations in four HBV-infected patients who developed lamivudine resistance. Virological breakthrough was preceded by 2 to 4 months by the emergence of quasispecies variants bearing amino acid substitutions at RT position 204, i.e., within the YMDD catalytic motif (rtM204V/I). Three patients had a gradual switch from a YMDD variant population at baseline to a 100% lamivudine-resistant variant population, whereas the remaining patient had a fluctuating pattern of resistance variant dynamics. Careful analysis of amino acid substitutions located outside domain C of HBV RT, including those known to partially restore replication capacities in vitro, showed that the in vivo replication of HBV variants is driven by multiple forces, including intrinsic replicative advantages conferred by mutations accumulating outside domain C and the changing environment in which these variants replicate. Our findings also suggest that individual treatment optimization will require sensitive methods capable of detecting the emergence of viral resistance before the relevant variants acquire optimal replicative capacities.

Adult↗

PubMed2005

Noninvasive assessment of liver fibrosis by measurement of stiffness in patients with chronic hepatitis C.

Liver fibrosis is the main predictor of the progression of chronic hepatitis C, and its assessment by liver biopsy (LB) can help determine therapy. However, biopsy is an invasive procedure with several limitations. A new, noninvasive medical device based on transient elastography has been designed to measure liver stiffness. The aim of this study was to investigate the use of liver stiffness measurement (LSM) in the evaluation of liver fibrosis in patients with chronic hepatitis C. We prospectively enrolled 327 patients with chronic hepatitis C in a multicenter study. Patients underwent LB and LSM. METAVIR liver fibrosis stages were assessed on biopsy specimens by 2 pathologists. LSM was performed by transient elastography. Efficiency of LSM and optimal cutoff values for fibrosis stage assessment were determined by a receiver-operating characteristics (ROC) curve analysis and cross-validated by the jack-knife method. LSM was well correlated with fibrosis stage (Kendall correlation coefficient: 0.55; P < .0001). The areas under ROC curves were 0.79 (95% CI, 0.73-0.84) for F > or =2, 0.91 (0.87-0.96) for F > or =3, and 0.97 (0.93-1) for F=4; for larger biopsies, these values were, respectively, 0.81, 0.95, and 0.99. Optimal stiffness cutoff values of 8.7 and 14.5 kPa showed F > or =2 and F=4, respectively. In conclusion, noninvasive assessment of liver stiffness with transient elastography appears as a reliable tool to detect significant fibrosis or cirrhosis in patients with chronic hepatitis C.

Adult↗

PubMed2005

Daily cannabis smoking as a risk factor for progression of fibrosis in chronic hepatitis C.

Cannabinoids present in Cannabis sativa (marijuana) exert biological effects via cannabinoid receptors CB1 and CB2. We recently demonstrated that CB1 and CB2 receptors regulate progression of experimental liver fibrosis. We therefore investigated the impact of cannabis smoking on fibrosis progression rate in patients with chronic hepatitis C (CHC). Two hundred seventy consecutive untreated patients with CHC of known duration undergoing liver biopsy were studied. Demographic, epidemiological, metabolic, and virological data were recorded, and detailed histories of cannabis, alcohol, and tobacco use over the span of hepatitis C virus infection were obtained. Fibrosis stage, steatosis, and activity grades were scored according to Metavir system. Patients were categorized as noncannabis users (52.2%), occasional users (14.8%), or daily users (33.0%), and the relationship between cannabis use and fibrosis progression rate (FPR) or fibrosis stage was assessed. On multivariate analysis, six factors were independently related to a FPR greater than 0.074 (median value of the cohort): daily cannabis use (OR = 3.4 [1.5-7.4]), Metavir activity grade A2 or higher (OR = 5.4 [2.9-10.3]), age at contamination of more than 40 years (OR = 10.5 [3.0-37.1]), genotype 3 (OR = 3.4 [1.5-7.7]), excessive alcohol intake (OR = 2.2 [1.1-4.5]), and steatosis (OR = 2.0 [1.0-4.1]). Daily cannabis use was also an independent predictor of a rapid FPR (>0.15) (OR = 3.6 [1.5-7.5]). Finally, severe fibrosis (> or =F3) was also predicted by daily cannabis use (OR = 2.5 [1.1-5.6]; P = .034), independently of Metavir activity grade, excessive alcohol intake, age at liver biopsy, steatosis, and tobacco smoking. In conclusion, daily cannabis smoking is significantly associated with fibrosis progression during CHC. Patients with ongoing CHC should be advised to refrain from regular cannabis use.

Adult↗

PubMed2005

Impact of pretransplantation transarterial chemoembolization on survival and recurrence after liver transplantation for hepatocellular carcinoma.

The actual impact of transarterial chemoembolization before liver transplantation (LT) for hepatocellular carcinoma (HCC) on patient survival and HCC recurrence is not known. Between 1985 and 1998, 479 patients with HCC in 14 French centers were evaluated for LT. Among these 479 patients, this case-control study included 100 patients who received transarterial chemoembolization before LT (TACE group) and 100 control patients who did not receive chemoembolization (no-TACE group). Patients and controls were matched for the pre-LT tumor characteristics, the period of transplantation, the time spent on the waiting list, and pre- and posttransplantation treatments. Kaplan-Meier estimates were calculated 5 years after LT and were compared with the log-rank test. The mean waiting time before LT was 4.2 +/- 3.2 months in the TACE group and 4.3 +/- 4.4 months in the no-TACE group. The median number of TACE procedures was 1 (range: 1-12). Demographic data, median alpha-fetoprotein level (21.6 ng/mL and 22.0 ng/mL, respectively), and pre- and post-LT morphologic characteristics of the tumors did not differ in the TACE and no-TACE groups. Overall 5-year survival was 59.4% with TACE and 59.3% without TACE (ns). Survival rates did not differ significantly between the two groups with respect to the time on the waiting list, the tumor diameter, or the type of TACE (selective or nonselective). In the TACE group, 30 patients had tumor necrosis > or =80% on the liver explant with a 5-year survival rate of 63.2%, compared with 54.2% among their matched controls (P = 0.9). In conclusion, with a mean waiting period of 4.2 months and 1 TACE procedure, pre-LT TACE does not influence post-LT overall survival and disease-free survival.

Carcinoma, Hepatocellular↗

PubMed2005

Predicting sustained virological responses in chronic hepatitis C patients treated with peginterferon alfa-2a (40 KD)/ribavirin.

BACKGROUND/AIMS: Prediction of sustained virological response (SVR) during treatment would allow clinicians to identify patients most likely to benefit from therapy. METHODS: Retrospective analysis of data from 1121 adults with chronic hepatitis C treated for 48 weeks with peginterferon alfa-2a (40 KD) 180 microg/week plus placebo or ribavirin (1000/1200 mg/day), or interferon alfa-2b 3 MIU three times/week plus ribavirin in a randomized, multinational, study. RESULTS: 67% of patients treated with peginterferon alfa-2a (40 KD)/ribavirin with early virological responses (HCV RNA negative or > or = 2 log10 decrease) at week 12 had SVRs at week 72 (HCV RNA < 50 IU/mL). The negative predictive value (NPV) was 97%. The probability of an SVR increased with the rapidity of HCV RNA suppression. The highest SVR rates were achieved in patients with rapid virological responses at week 4, but the corresponding NPV (74%) is too low for a decision criterion. In patients with early virological responses by week 12, the SVR rate was approximately 20% lower in those who received <80% compared with patients who received > or = 80% of the planned ribavirin dose. CONCLUSIONS: Early, sustained suppression of HCV replication portends an SVR. Cessation of treatment may be contemplated in patients without a > or = 2 log10 reduction in HCV RNA after 12 weeks.

Antiviral Agents↗

PubMed2005

Hepatitis C virus-induced hepatocellular steatosis.

Two distinct forms of hepatocellular steatosis can be seen in patients with chronic hepatitis C virus (HCV) infection. Classical metabolic risk factors for hepatocellular steatosis account for the vast majority of cases of steatosis in patients infected by non-genotype 3 HCV strains. In contrast, in patients infected by HCV genotype 3, steatosis is generally induced by the virus itself through a direct cytopathic effect, the mechanisms of which remain debated. Mixed forms of steatosis can also be seen in HCV genotype 3-infected patients with metabolic risk factors. Hepatocellular steatosis appears to be associated with more rapid progression of hepatic fibrosis. However, it is unclear whether this association is due to steatosis itself, or rather to metabolic and host factors that promote steatosis and fibrosis concomitantly. This review discusses current knowledge of HCV-induced steatosis and its relation to chronic HCV-associated liver disease.

Fatty Liver↗

PubMed2004

Low-grade steatosis and major changes in portal flow as new prognostic factors in steroid-treated alcoholic hepatitis.

The aim of this study was to assess the prevalence and prognostic value of major alterations of portal flow in patients with steroid-treated alcoholic hepatitis. Fifty patients with severe, histologically proven alcoholic hepatitis were enrolled. Clinical data, liver test results, and hepatic Doppler ultrasound findings were collected at inclusion and at month 2. Patients were followed for 1 year or until death. Major changes in portal flow were defined as reversed or alternating flow in the portal trunk and/or in intrahepatic portal branches. Changes in portal flow were observed in 24 (48.0%) of 50 and 17 (39.5%) of 43 patients at inclusion and month 2, respectively. Univariate analysis showed that age older than 50 years, steatosis less than 20% on initial liver biopsy, presence of major changes in portal flow, Child-Turcotte-Pugh score higher than 12, factor V level higher than 45%, and hepatofugal splenic blood flow were associated with a lower 1-year survival. Cox regression analysis showed that steatosis < 20% (relative hazard [RH] = 9.3, P = .0009) and major changes in portal flow (RH = 3.1, P = .04), were independently associated with poor survival. In conclusion, major changes in portal flow are frequent in patients with severe alcoholic hepatitis. Altered portal flow and steatosis < 20% are new prognostic factors in steroid-treated alcoholic hepatitis and must be taken into account in patient management.

Adult↗

PubMed2004

[Hepatocellular carcinoma without cirrhosis in a patient with nonalcoholic steatohepatitis].

All cases of hepatocellular carcinoma reported thus for in patients with nonalcoholic steatohepatitis have occurred on preexisting cirrhosis. We report the case of a 68-Year-old male patient with nonalcoholic steatohepatitis who developed hepatocellular carcinoma in the absence of cirrhosis. This observation suggests a possible relationship between nonalcoholic steatohepatitis and/or excess body weight, and hepatocellular carcinoma independent of cirrhosis. Further epidemiological studies are needed to evaluate the incidence of this association.

Aged↗

PubMed2004

Antiviral action of ribavirin in chronic hepatitis C.

BACKGROUND & AIMS: In the patients with chronic hepatitis C, the addition of ribavirin to interferon (IFN)-alpha significantly increases the virologic responses. Our aim was to assess the antiviral action of ribavirin on hepatitis C virus (HCV) as a function of ribavirin pharmacokinetics and to evaluate the influence of this antiviral effect on IFN-alpha efficacy. METHODS: Forty-five patients with chronic hepatitis C (genotype 1b) received various schedules of IFN-alpha and/or ribavirin administration. Frequent blood sampling was performed for HCV RNA kinetics and ribavirin pharmacokinetics assessment. RESULTS: Ribavirin monotherapy induced a significant, moderate, early, and transient viral load decrease in approximately half of the patients. The occurrence of this effect was associated with longer ribavirin clearance half-lives and higher serum ribavirin concentrations. Ribavirin antiviral effect partly reduced the rebound preceding the second IFN-alpha injection in patients receiving standard IFN-alpha 3 times per week plus ribavirin. The magnitude of the rebound was inversely related to ribavirin concentrations. These patients subsequently experienced a slow, but significant, second slope of viral decrease and cleared HCV RNA. The addition of ribavirin to daily IFN-alpha monotherapy did not have any impact on the second phase of viral decline. CONCLUSIONS: Ribavirin exerts a significant, moderate, and transient antiviral effect in a significant proportion of patients with chronic hepatitis C. The antiviral effect of ribavirin correlates with ribavirin pharmacokinetics and is partly responsible for the improved efficacy of the combination of standard IFN-alpha and ribavirin compared with IFN-alpha monotherapy by increasing the incidence of the initial response.

Adult↗

PubMed2004

Efficacy and safety of two-dose regimens of peginterferon alpha-2a compared with interferon alpha-2a in chronic hepatitis C: a multicenter, randomized controlled trial.

OBJECTIVES: This study compared the efficacy and safety of peginterferon alpha-2a 135 microg/wk, peginterferon alpha-2a 180 microg/wk and interferon alpha-2a in patients with chronic hepatitis C. METHODS: A total of 639 patients received peginterferon alpha-2a 135 microg or 180 microg once weekly, or interferon alpha-2a 3 MIU thrice weekly for 48 wk. RESULTS: Sustained virological responses were significantly higher with peginterferon alpha-2a than with interferon alpha-2a 3 MIU (28% in the 135 microg and 180 microg peginterferon alpha-2a groups vs 11% with interferon alpha-2a, p = 0.001). The proportion of patients with clinically significant histological improvement was lower in the peginterferon alpha-2a 135 microg (48%) than the 180 microg group (58%, p = 0.035 vs peginterferon alpha-2a 135 microg), but similar to that in the interferon alpha-2a group (45%, p = 0.820 vs peginterferon alpha-2a 135 microg and p = 0.017 vs peginterferon alpha-2a 180 microg, respectively). The overall safety profiles were similar for the three treatments. In patients with chronic hepatitis C, peginterferon alpha-2a 135 microg/wk and 180 microg/wk produced similar sustained virological response rates, both of which were significantly higher than that achieved with interferon alpha-2a thrice weekly. A significantly higher proportion of patients treated with the 180 microg dose of peginterferon alpha-2a had clinically significant histological improvement.

Adult↗

PubMed2004

Hepatitis C virus quasispecies variability modulates nonstructural protein 5A transcriptional activation, pointing to cellular compartmentalization of virus-host interactions.

Hepatitis C virus (HCV) behaves in infected patients as a complex mixture of genetically distinct but closely related variants referred to as a "quasispecies." By using quasispecies analysis strategies, we showed that HCV nonstructural protein 5A (NS5A) has a quasispecies distribution in infected humans and that NS5A quasispecies undergo significant genetic evolution over time, as a result of random accumulation of nucleotide mutations during replication. Genetic evolution of the NS5A quasispecies results in sporadic amino acid changes in the protein sequence. By using the functional in vitro model of HCV NS5A transcriptional activation in Saccharomyces cerevisiae, we showed that natural NS5A quasispecies variants induce different levels of transcriptional activation, according to the charge of the residues (and possibly minor conformational changes) in the quasispecies variant sequence. These findings show that the accumulation of mutations on HCV genomes during replication randomly generates variant proteins with quantitatively different functional properties. The fact that each new variant protein is initially produced in a single infected hepatocyte and may or may not subsequently spread throughout the liver (depending on the replication capacities of the variant virus) points to cellular compartmentalization of virus-host interactions during chronic infection. This feature of quasispecies-distributed viruses could play an important role in various aspects of the viral life cycle and related disease.

Amino Acid Sequence↗

PubMed2004

MRI of atypical focal nodular hyperplasia of the liver: radiology-pathology correlation.

OBJECTIVE: The purpose of our study was to determine the MRI features of atypical focal nodular hyperplasia of the liver and to compare them to pathology findings. MATERIALS AND METHODS: We retrospectively reviewed MRI and pathology findings in 27 focal nodular hyperplasia lesions with atypical MRI features. Six criteria for typical focal nodular hyperplasia were required: iso- or hypointensity on T1-weighted sequences and iso- or slight hyperintensity on T2-weighted sequences; homogeneous signal intensity; central hyperintense area on T2-weighted sequences; marked lesion contrast enhancement; accumulation of gadolinium chelates within the central area on delayed contrast-enhanced T1-weighted sequences; and absence of capsule. RESULTS: The most common atypical radiology features included absence of, or an atypical, stellate area; heterogeneity on both T1- and T2-weighted images; and high-intensity signal on T1-weighted sequences. MRI-pathology correlation showed that T1 hyperintensity with no other atypical MRI feature (n = 3) could be explained by steatosis, sinusoidal dilatation, or hemorrhage. In addition, in two patients with lesions smaller than 3 cm in diameter, the only atypical MRI feature was absence of a stellate area. CONCLUSION: These findings suggest a lesion that is hyperintense on T1-weighted sequences or that lacks a stellate area but is smaller than 3 cm in diameter can be diagnosed as focal nodular hyperplasia provided all other MRI criteria for this diagnosis are present. In such cases, close monitoring on MRI without invasive diagnostic procedures may be warranted. However, in large lesions (> 3 cm) without a stellate area and in lesions with heterogeneity, histopathology examination is mandatory to rule out other diagnoses.

Adolescent↗