Expanded gallbladder fossa: simple MR imaging sign of cirrhosis

The grade of obesity affects the noninvasive diagnosis of advanced fibrosis in individuals with MASLD

OBJECTIVE

Metabolic dysfunction-associated steatotic liver disease (MASLD) is closely associated with obesity. We aimed to assess the impact of obesity on the performance of different noninvasive tests, including liver stiffness measurement (LSM) and Agile3+ (A3+), to detect advanced fibrosis (AF) in a population of patients with MASLD encompassing a wide range of BMI values.

METHODS

A total of 479 patients with MASLD were consecutively included (Lyon Hepatology Institute). Clinical data and noninvasive tests, including FibroTest, LSM, A3+, Fibrosis-4 (FIB-4), magnetic resonance elastography, and liver biopsies, were collected. AF was determined by a composite endpoint, i.e., histological stage ≥ F3, overt diagnosis of cirrhosis by magnetic resonance elastography, or concordant LSM ≥ 9.6 kPa and FibroTest ≥ F3.

RESULTS

The median BMI was 35.0 kg/m2, and the prevalence of AF was 28.6%. Patients with BMI ≥ 35 versus <35 had a lower proportion of AF, i.e., 19.3% versus 38.1% (p < 0.001), but higher indeterminate status for AF (34.2% vs. 15.4%; p < 0.001). In the case of BMI ≥ 35, LSM had lower specificity to rule in AF (77.9%) versus A3+ (90.4%), but A3+ had decreased sensitivity to rule out AF. A sequential LSM/A3+ strategy achieved high specificity to rule in AF and lowered the proportion of indeterminate cases in patients with BMI ≥ 35.

CONCLUSIONS

The grade of obesity affects the detection of MASLD-related AF. A sequential use of LSM/A3+ could improve AF detection in patients with BMI ≥ 35.

Liver cirrhosis: relationship between fibrosis-associated hepatic morphological changes and portal hemodynamics using four-dimensional flow magnetic resonance imaging

PURPOSE

The mechanisms underlying the morphological changes in liver cirrhosis remain unknown. This study aimed to clarify the relationship between fibrotic hepatic morphology and portal hemodynamic changes using four-dimensional flow magnetic resonance imaging (MRI).

MATERIALS AND METHODS

Overall, 100 patients with suspected liver disease who underwent 3-T MRI were evaluated in this retrospective study. Liver fibrosis was assessed using a combination of visual assessment of the hepatic morphology and quantitative measures, including the fibrosis-4 index and aspartate transaminase-to-platelet ratio. It was classified into three groups according to the severity of fibrosis as follows: A (normal), B (mild-to-moderate), and C (severe). Quantitative indices, including area (mm²), net flow (mL/s), and average velocity (cm/s), were measured in the right portal vein (RPV) and left portal vein (LPV), and were compared across the groups using the Kruskal-Wallis and Mann-Whitney U tests.

RESULTS

Among the 100 patients (69.1 ± 12.1 years; 59 men), 45, 35, and 20 were categorized into groups A, B, and C, respectively. The RPV area significantly differed among the groups (from p < 0.001 to p = 0.001), showing a gradual decrease with fibrosis progression. Moreover, the net flow significantly differed between groups A and B and between groups A and C (p < 0.001 and p < 0.001, respectively), showing a decrease during the early stage of fibrosis. In the LPV, the net flow significantly differed among the groups (from p = 0.001 to p = 0.030), revealing a gradual increase with fibrosis progression.

CONCLUSION

The atrophy-hypertrophy complex, which is a characteristic imaging finding in advanced cirrhosis, was closely associated with decreased RPV flow in the early stage of fibrosis and a gradual increase in LPV flow across all stages of fibrosis progression.

Noninvasive staging of liver fibrosis: review of current quantitative CT and MRI-based techniques

Liver fibrosis features excessive protein accumulation in the liver interstitial space resulting from repeated tissue injury due to chronic liver disease. Liver fibrosis eventually proceeds to cirrhosis and associated complications. So, early diagnosis and staging of liver fibrosis are of vital importance for clinical treatment. Liver biopsy remains the gold standard for the diagnosing and staging of fibrosis, but it is suboptimal due to various limitations. Recently, efforts have been made to migrate toward noninvasive techniques for assessing liver fibrosis. CT is relatively easy to perform, relatively standardized for different scanners, and does not require additional hardware in liver fibrosis staging. MRI is frequently performed to characterize indeterminate liver lesions. Because it does not use ionizing radiation and features high image contrast, its role has increased in the staging of liver fibrosis. More recently, several studies on liver fibrosis staging using deep learning algorithms in CT or MRI have been proposed and have shown meaningful results. In this review, we summarize the basic concept, diagnostic performance, and advantages and limitations of each technique to noninvasively stage liver fibrosis.

Pathological and imaging features of idiopathic non-cirrhotic portal hypertension

Idiopathic non-cirrhotic portal hypertension (INCPH), a kind of portal sinus vascular disease with unknown etiology, is characterized by the presence of clinical signs and symptoms of portal hypertension (PH) in the absence of liver cirrhosis or known risk factors accountable for PH. It has an extremely high rate of initial misdiagnosis and underdiagnosis. Liver biopsy is the only way to make a definitive diagnosis. Non-invasive modalities, such as CT imaging, are becoming a hot topic of interest in recent years. This article summarizes the pathological and CT/MRI features of INCPH and the key points of differentiation from cirrhosis, to improve clinicians' understanding of INCPH and reduce the rate of initial misdiagnosis and missed diagnoses.

EASL versus LI-RADS: Intra-individual comparison of MRI with extracellular contrast and gadoxetic acid for diagnosis of small HCC

BACKGROUND & AIMS

Liver Imaging Reporting and Data System (LI-RADS) and European Association for the Study (EASL) criteria for hepatocellular carcinoma (HCC) diagnosis have been updated in 2018. We aimed to compare the HCC diagnostic performance of LI-RADS and EASL criteria with extracellular contrast agents-MRI (ECA-MRI) and hepatobiliary agents-MRI (HBA-MRI).

METHODS

We prospectively evaluated 179 participants with cirrhosis (n = 105) or non-cirrhotic chronic hepatitis B (CHB) (n = 74) who underwent both ECA-MRI and HBA-MRI before surgery for de novo nodule(s) measuring 10-30 mm. We compared the HCC diagnostic performance of EASL and LR-5 in both MRIs.

RESULTS

In an analysis of 215 observations (175 HCCs, 17 non-HCC malignancies and 23 benign lesions) identified from cirrhotic or non-cirrhotic CHB participants, LR-5 with ECA-MRI provided the highest sensitivity (80.7%), followed by EASL with ECA-MRI (76.2%), LR-5 with HBA-MRI (67.3%) and EASL with HBA-MRI (63.0%, all P < .05). The specificities were comparable (89.4%-91.5%). When the analysis is limited to participants with pathological cirrhosis (123 observations), the sensitivity of LR-5 with ECA-MRI was similar to that of EASL with ECA-MRI (82.7% vs 80.2%, P = .156), but higher than LR-5 with HBA-MRI (65.1%) or EASL with HBA-MRI (62.8%, both P < .001), with comparable specificities (87.5%-91.7%).

CONCLUSIONS

The LR-5 with ECA-MRI yielded the highest sensitivity with a similar specificity for HCC diagnosis in cirrhosis and non-cirrhotic CHB participants, while the sensitivities of LR-5 and EASL with ECA-MRI are similar for cirrhosis participants. This indicates non-invasive diagnosis criteria can differ by contrast agents and presence of cirrhosis.

Assessing the progression of segmental fibrosis in chronic liver disease using extracellular volume fractions

PURPOSE

To assess the segmental difference of liver fibrosis during the progression of chronic liver disease (CLD) using hepatic extracellular volume fractions (fECVs) obtained by dual-energy CT.

METHODS

A total of 218 patients (92 men and 126 women; mean age, 67.8 ± 11.7 years) with CLD and 85 patients (44 men and 41 women; mean age, 62.8 ± 13.7 years) without CLD as a control underwent dual-energy computed tomography (CT) of the liver (5-min equilibrium phase images). The iodine densities of the lateral, medial, anterior, and posterior segments and the aorta were measured, and fECVs were calculated. Comparisons of the fECV of each segment and for each albumin-bilirubin (ALBI) grade were then statistically analyzed.

RESULTS

In the control group and ALBI grades 1 and 3, no significant difference in fECV was found between each segment, whereas in ALBI grade 2, the fECVs were significantly larger in the medial and anterior than in the other segments (p < 0.001). The fECVs of the lateral and posterior segments significantly increased with higher ALBI grade (p < 0.001). The fECVs of the medial and anterior segments were significantly increased with higher ALBI grade, up to grade 2 (p < 0.001), but no significant difference was found between ALBI grades 2 and 3.

CONCLUSION

During the progression of CLD, fibrosis antecedently progressed in the medial and anterior segments, followed by the other liver segments.

Liver Fibrosis Assessment

Early diagnosis of hepatic fibrosis (HF) is pivotal for management to cease progression to cirrhosis and hepatocellular carcinoma. HF is the telltale sign of chronic liver disease, and confirmed by liver biopsy, which is an invasive technique and inclined to sampling errors. The morphologic parameters of cirrhosis are assessed on conventional imaging such as on ultrasound (US), computed tomography (CT) and magnetic resonance imaging (MRI). Newer imaging modalities such as magnetic resonance elastography and US elastography are reliable and accurate. More research studies on novel imaging modalities such as MRI with diffusion weighted imaging, enhancement by hepatobiliary contrast agents, and CT using perfusion are essential for earlier diagnosis, surveillance and accurate management. The purpose of this article is to discuss non-invasive CT, MRI, and US imaging modalities for diagnosis and stratify HF.

Performance of morphologic criteria for the diagnosis of cirrhosis in patients with non-alcoholic steatohepatitis compared to other etiologies of chronic liver disease: effect of level of training and experience

PURPOSE

To compare the diagnostic performance of morphologic criteria for detection of cirrhosis in patients with alcoholic liver disease (ALD), hepatitis C (HCV), and non-alcoholic steatohepatitis (NASH).

METHODS

One hundred patients (53 male) with different etiologies of chronic liver disease (NASH, n = 41; HCV, n = 39; and ALD, n = 20) and with different degrees of fibrosis on histopathologic examination (74 with cirrhosis) were retrospectively evaluated. Four readers (R1: fellowship-trained abdominal radiologist, R2: community attending radiologist, R3: senior radiology resident/research fellow, R4: junior radiology resident) analyzed the contrast-enhanced CTs for presence of commonly accepted morphologic changes of cirrhosis and portal hypertension. Each reader assigned an overall score (using a 5-point scale) for possibility of cirrhosis based on liver morphology and features of portal hypertension. Diagnostic performance, sensitivity, and specificity for the diagnosis of cirrhosis were calculated and compared between different etiologies of chronic liver disease.

RESULTS

Performance of readers was affected by their level of training. Less experienced readers had overall lower sensitivity for diagnosis of cirrhosis in NASH group (R3: 81.5%, R4: 63.0% compared to 96.3% for both R1 and R2). Sensitivities for detection of NASH cirrhosis significantly decreased for less experienced readers in the absence of ascites (R3: 75.0%, R4: 62.0%) or other features of portal hypertension (R3: 50.0%; R4: 0%). The specificity was consistently high among different etiologies and for all readers (85.7-100%). Inter-reader agreement for morphologic features ranged widely from fair to almost perfect (k: 0.23-0.85).

CONCLUSION

Cirrhotic changes in NASH are subtler and can be underestimated by less experienced readers.

Using qualitative descriptors of chronic liver disease on MRI: A practice prone to error

PURPOSE

Assess accuracy of qualitative descriptors for chronic liver disease (CLD) in radiology reports compared to histopathological staging.

METHODS

Database search for patients with hepatitis B/C (HBV/HCV) CLD, abdominal MRI during 2009-2016, and liver biopsy within 6 months of MRI or prior biopsy showing cirrhosis. Reports reviewed for mention of CLD and associated descriptors. Findings stratified into categories: normal/no mention of CLD; changes of CLD without qualitative descriptor; mild/early; moderate; severe/advanced and cirrhosis. Descriptive ranges categorized to the lesser degree. Percent concordance/discordance of descriptors and Scheuer stage (F0-F4), false positive (FP), false negative (FN) and sensitivity/specificity calculated.

RESULTS

309 patients, median age 54 (24-74). 91% had HCV (282/309), 7% HBV and 2% both HBV/HCV. Biopsy showed 19% without CLD/F0; 8% F1, 15% F2, 15% F3 and 43% F4. 188 MRI reports (61%) stated CLD was present; however, 16 had no fibrosis on histopathology (9% FP). 39% (121/309) did not mention or stated no CLD; however, 78 had CLD on histopathology (64% FN). 59% of FN were early fibrosis (F1 or F2), 27% F3 and 11% F4. Overall sensitivity and specificity was 69% and 73%, respectively. 77% (145/188) of MRI reports used a descriptive qualifier when describing CLD. 10% were concordant with exact histopathology staging. Of discordant reports, 90% identified CLD but under-called severity.

CONCLUSION

Abdominal radiologists can detect CLD on MRI but degree of CLD is often under-called compared to histopathology suggesting radiologists should refrain from qualitative descriptors in assessing CLD on MRI and reaffirms the need for quantitative imaging.

Morphologic changes in hepatitis virus-related liver cirrhosis: Relationship to hemodynamics of portal vein on dynamic contrast-enhanced CT

INTRODUCTION

The morphologic changes in the compensated stage of liver cirrhosis (cLC) are not diffuse atrophic changes. With cLC lobar or segmental changes combined with atrophy of the right lobe and medial segment together with hypertrophy of the caudate lobe and lateral segment are commonly seen. The purpose of this study was to evaluate the morphologic changes in hepatitis virus-related liver cirrhosis in relationship to haemodynamics of the portal vein on dynamic contrast-enhanced computed tomography (DCE-CT) METHODS: This study included 72 patients, 46 with hepatitis virus-related cirrhosis and 26 with a normally functioning liver, who underwent DCE-CT. In cirrhosis patients, the morphologic change index (MCI) of the liver was calculated and categorised into two groups, high-MCI (MCI ≥ 0.4) (n = 21) and low-MCI (MCI < 0.4) (n = 25). Cross-sectional areas of the main, right and left portal veins and the intra-portal distribution from splenic venous flow were evaluated for their relationships with the MCI and compared among three groups (normal-control, low MCI and high MCI).

RESULTS

There was a significant difference in the cross-sectional area of the left portal vein between the high-MCI group and the low-MCI group (p = 0.013) and the control group (p = 0.008). A significant correlation was identified between the cross-sectional area of the left portal vein and the MCI (r = 0.508, p < 0.001).

CONCLUSION

Cross-sectional area of the left portal vein may be a factor related to morphologic changes in hepatitis virus-related liver cirrhosis and could be a possible index of the left portal venous flow volume.

IMPLICATIONS FOR PRACTICE

This study may be useful for predicting the degree of hepatic morphologic changes and the condition of cirrhosis in association with regional hepatic morphologic changes.

Morphometric changes and imaging findings of diffuse liver disease in relation to intrahepatic hemodynamics

Diffuse hepatic diseases have a variety of etiologies, with each showing characteristic morphometric changes. These changes are closely related to micro- and macro-level intrahepatic hemodynamics, in addition to the specific underlying pathophysiology. Short-term disorders in intrahepatic hemodynamics caused by each pathophysiological condition are compensated for by the balance of blood perfusion systems using potential trans-sinusoidal, transversal, and transplexal routes of communication (micro-hemodynamics), while long-term alterations to the intrahepatic hemodynamics result in an increase in total hepatic vascular resistance. Blood flow disorders induced by this increased vascular resistance elicit hepatic cellular necrosis and fibrosis. These changes should be uniformly widespread throughout the whole liver. However, morphometric changes do not occur uniformly, with shrinkage or enlargement not occurring homogeneously. Against this background, several macro-intrahepatic hemodynamic effects arise, such as asymmetrical and complicating morphometric structures of the liver, intricate anatomy of portal venous flow and hepatic venous drainage, and zonal differentiation between central and peripheral zones. These hemodynamic factors and pathophysiological changes are related to characteristic morphometric changes in a complicated manner, based on the combination of selective atrophy and compensatory hypertrophy (atrophy-hypertrophy complex). These changes can be clearly depicted on CT and MR imaging.

Liver Remodeling on CT Examination in Patients with HCV Compensated Cirrhosis Who Achieved Sustained Virological Response after Direct-Acting Antivirals Treatment

Aims: The purpose of this study was to assess the changes in hepatic morphology evaluated by computed tomography (CT) examination in patients with hepatitis C virus (HCV)-related compensated cirrhosis who achieved sustained virologic response (SVR) after direct-acting antivirals (DAAs) treatment. Methods: CT examination was performed in 56 patients with HCV-related compensated cirrhosis before and within 6-18 months after the treatment with Ombitasvir/Paritaprevir/ritonavir + Dasabuvir. The liver CT changes were assessed by measuring liver volume, caudate-right lobe ratio (C/RL), hepatic vessels diameters, periportal widening space, and right posterior notch. Portal trunk, splenic and superior mesenteric vein diameters, as well as spleen volume were assessed as part of portal hypertension. Results: Right hepatic vein diameter was significantly wider after treatment (median: 8.12 mm; IQR: 4.20) than before treatment (median: 6.36 mm; IQR: 3.94) z = -3.894; p < 0.001. The liver volume was significantly higher prior to the treatment (median: 1786.77 mm³; IQR: 879.23) than after treatment (median: 1716.44 mm³; IQR: 840.50), z = -1.970; p = 0.049. Splenic volume was considerably higher before treatment (median: 564.79 mm³; IQR: 342.54) than after (median: 474.45 mm³; IQR: 330.00), z = -2.500; p = 0.012. The other parameters, such as C/RL, periportal space widening, and right hepatic notch showed no significant changes. Conclusions: SVR in patients with HCV-related compensated cirrhosis treated with DAAs is associated with some improvements of hepatic morphology detectable by CT, the most constant being the increase of right hepatic vein diameter.

'Hepato-diaphragmatic fat interposition' and 'increased right hemi-diaphragmatic thickness': new imaging signs for early diagnosis of hepatic cirrhosis on routine CT abdomen

BACKGROUND

Cirrhosis of liver is often a silent disease and need early diagnosis for effective treatment strategy.

OBJECTIVES

The present article aims to describe new imaging signs for early diagnosis of cirrhosis on routine CT. These are 'hepato-diaphragmatic fat interposition' (HDFI) and 'increased right hemi-diaphragmatic thickness' (increased r-DT sign).

MATERIALS AND METHODS

This was a retrospective study based on the presence or absence of cirrhosis of liver (n = 100). 'HDFI sign' was labeled as positive if F is more than 50% of D; where F is the medio-lateral extent of the intra-abdominal fat along the postero-medial margin of liver and D is the distance from the lateral vertebral margin to the medial margin of the outer-most rib in the same axial image. Increased 'r-DT sign' is labeled when the dimension on right side exceeds left side by at least 0.2 cm. Pearson χ² was performed to calculate the p value. A p value of < 0.05 was considered to indicate a significant difference.

RESULTS

There was a significant difference between cirrhotic and normal group, The sensitivity, specificity, positive predictive value and the negative predictive value of HDFI sign was found to be 94%, 62%, 71.21% and 91.17%, while that of increased r-DT sign was found to be 96%,52%, 66.66% and 92.85%. The area under the ROC curve for the HDFI sign was found to be 0.78 as compared to 0.74 for the increased r-DT sign.

CONCLUSION

Both these new signs should be used as additional imaging signs for early diagnosis of cirrhosis.

Can we differentiate HIV-associated obliterative portopathy from liver cirrhosis using MRI?

AIM

To describe the magnetic resonance imaging (MRI) features of HIV-associated obliterative portopathy (HIV-OP) and determine the most indicative appearance of this condition on MRI by using a retrospective case-control study.

METHODS

MRI examinations of 24 patients with HIV-OP (16 men, 8 women; mean age = 48 ± 6.6 [SD] years; age range, 35-71 years) were analyzed by two blinded observers and compared with those obtained in 18 HIV-infected patients with hepatic cirrhosis (14 men, 4 women; mean age = 51 ± 3.4 [SD] years; age range, 35-60 years). Images were qualitatively and quantitatively analyzed with respect to imaging presentation. Comparisons were performed using uni- and multivariate analyses.

RESULTS

Regular liver contours had the highest accuracy for the diagnosis of HIV-OP (83%, 35 of 42; 95% confidence interval [CI], 69-93%) and was the most discriminating independent variable for the diagnosis of HIV-OP (odds ratio, 51; 95%CI, 4.96-1272%) (p < 0.0001). At multivariate analysis, the width of segment 4 in millimeters (OR = 1.23 [95%CI, 1.05-1.44%]; p = 0.011) and the presence of regular liver contours (OR = 7.69 [95%CI, 1.48-39.92%]; p = 0.015) were the variables independently associated with the diagnosis of HIV-OP.

CONCLUSIONS

Regular liver contours are the most discriminating independent variable for the diagnosis of HIV-OP but have limited accuracy. Familiarity with this finding may help differentiate HIV-OP from cirrhosis in HIV-infected patients.

KEY POINTS

• Regular liver contour is the most discriminating independent variable for the diagnosis of HIV-OP (odds ratio = 51) with 83% accuracy. • At multivariate analysis, the width of segment 4 in millimeters and the presence of regular liver contours are the variables independently associated with the diagnosis of HIV-OP. • MRI helps diagnose HIV-OP in the presence of several categorical findings, which are more frequently observed in HIV-OP patients than in HIV patients with cirrhosis.

Ultrasound Evaluation in Patients at Risk for Hepatocellular Carcinoma

In the context of chronic liver disease (CLD), sonographic features of hepatic steatosis, cirrhosis, and portal hypertension are discussed and examples are provided. The impact of CLD and hepatocellular carcinoma (HCC) is introduced, providing the rationale for a robust HCC screening and surveillance program for at-risk patients. The American College of Radiology Liver Imaging Reporting and Data System algorithms for screening and surveillance by ultrasound and for the definitive diagnosis of HCC by contrast-enhanced ultrasound are explained, with imaging examples provided. Contrast-enhanced ultrasound technique, limitations, and pitfalls also are introduced.

Multidetector Computed Tomography for Retrospective, Noninvasive Staging of Liver Fibrosis

Although not traditionally used to assess hepatic fibrosis, computed tomography (CT) is fast, accessible, robust, and commonly used for abdominal indications. CT metrics are often easily retrospectively obtained without special equipment. Metrics such as liver segmental volume ratio, which quantifies regional hepatic volume changes; splenic volume; and liver surface nodularity scoring show diagnostic performance comparable to elastography techniques for detecting significant and advanced fibrosis. Other emerging CT tools, such as CT texture analysis and fractional extracellular volume, have also shown promise in identifying fibrosis and warrant further study.

Long-term Nucleos(t)ides Analogues for Chronic Hepatitis B Improve Liver and Spleen Size: A Noninvasive Sonographic Study

Background:

Histological improvement and regression of liver fibrosis after long-term use of nucleos(t)ides analogues (NUCs) have been documented. The aim of the present investigation was to evaluate the usefulness of traditional sonography to detect hepatic and splenic changes during NUC therapy in chronic hepatitis B (CHB) patients.

Methods:

A total of 181 CHB patients receiving NUC treatment were enrolled in this study. The study population was divided into three groups 72 cirrhotic, 58 noncirrhotic CHB, and 51 nonreplicative hepatitis B virus carriers. All patients had blood chemistries taken and sonography at baseline and during the NUC treatment period. The changes in liver size, liver edge, spleen size, platelet count, and platelet count/spleen diameter (PC/SD) ratio were compared among the three groups of patients.

Results:

CHB Patients with and without cirrhosis have improved clinical features during NUC therapy with lower aspartate aminotransferase, alanine aminotransferase, international normalized ratio, hepatitis B virus DNA, and spleen size and higher platelet, liver edge, liver size, and PC/SD ratio compared with the baseline data (p < 0.05). The differences in liver edge, liver size, spleen size, and PC/SD ratio are higher in the cirrhosis group than in the non-cirrhotic group (p < 0.001). A decrease in spleen size exhibited a linear relationship with treatment duration (R² = 0.905).

Conclusions:

Traditional sonography is helpful to monitor changes in liver fibrosis of CHB patients under NUC therapy.

Abbreviations: AFP, α-fetoprotein; ALT, alanine transaminase; AST, aspartate transaminase; CHB, chronic hepatitis B; Hb, hemoglobin; HBV, hepatitis B virus; INR, international normalized ratio; NUCs, nucleos(t)ides analogues; PC/SD, platelet count/spleen diameter; WBC, white blood cells.

Putting it all together: established and emerging MRI techniques for detecting and measuring liver fibrosis

Chronic injury to the liver leads to inflammation and hepatocyte necrosis, which when untreated can lead to myofibroblast activation and fibrogenesis with deposition of fibrous tissue. Over time, liver fibrosis can accumulate and lead to cirrhosis and end-stage liver disease with associated portal hypertension and liver failure. Detection and accurate measurement of the severity of liver fibrosis are important for assessing disease severity and progression, directing patient management, and establishing prognosis. Liver biopsy, generally considered the clinical standard of reference for detecting and measuring liver fibrosis, is invasive and has limitations, including sampling error, relatively high cost, and possible complications. For these reasons, liver biopsy is suboptimal for fibrosis screening, longitudinal monitoring, and assessing therapeutic efficacy. A variety of established and emerging qualitative and quantitative noninvasive MRI methods for detecting and staging liver fibrosis might ultimately serve these purposes. In this article, we review multiple MRI methods for detecting and measuring liver fibrosis and discuss the diagnostic performance and specific strengths and limitations of the various techniques.

Hepatic morphology abnormalities: beyond cirrhosis

The diagnosis of cirrhosis can be reached on the basis of established hepatic morphological changes. However, some other conditions can mimic cirrhosis. The aim of this pictorial essay is to review the CT and MRI appearances of hepatic morphology abnormalities in the cirrhotic liver and other diseases, describing pathologic conditions that can mimic cirrhosis, with useful tips for the differential diagnosis. Mimickers of cirrhosis include congenital hepatic fibrosis, Caroli disease, Budd-Chiari Syndrome, hepatoportal sclerosis, cavernous transformation of the portal vein, pseudocirrhosis from metastatic disease, acute liver failure, post-therapeutic morphologic changes in the liver, and infective conditions including schistosomiasis and oriental cholangiohepatitis. Recognizing the hepatic morphological changes in images can help radiologists to diagnose cirrhosis and other diseases in early stages.

Evaluation of hepatic fibrosis: a review from the society of abdominal radiology disease focus panel

Hepatic fibrosis is potentially reversible; however early diagnosis is necessary for treatment in order to halt progression to cirrhosis and development of complications including portal hypertension and hepatocellular carcinoma. Morphologic signs of cirrhosis on ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI) alone are unreliable and are seen with more advanced disease. Newer imaging techniques to diagnose liver fibrosis are reliable and accurate, and include magnetic resonance elastography and US elastography (one-dimensional transient elastography and point shear wave elastography or acoustic radiation force impulse imaging). Research is ongoing with multiple other techniques for the noninvasive diagnosis of hepatic fibrosis, including MRI with diffusion-weighted imaging, hepatobiliary contrast enhancement, and perfusion; CT using perfusion, fractional extracellular space techniques, and dual-energy, contrast-enhanced US, texture analysis in multiple modalities, quantitative mapping, and direct molecular imaging probes. Efforts to advance the noninvasive imaging assessment of hepatic fibrosis will facilitate earlier diagnosis and improve patient monitoring with the goal of preventing the progression to cirrhosis and its complications.

Morphometric changes in liver cirrhosis: aetiological differences correlated with progression

OBJECTIVE

To evaluate the morphometric changes in liver cirrhosis using multidetector CT volumetry and to analyse the differences in morphometric changes among different aetiologies and stages of cirrhosis.

METHODS

Each portal segment with the respective proportion relative to total liver volume was measured in 54 patients without cirrhosis as a control (male/female, 29/25; 62.4 ± 7.6 years) and 250 patients with cirrhosis (male/female, 172/78; 64.6 ± 9.2 years) related to hepatitis virus infection (n = 96), alcoholism (n = 88) and non-alcoholic steatohepatitis (NASH) (n = 66). 149 patients were classified as patients with Child-Pugh Class A, 57 patients as patients with Class B and 44 patients as patients with Class C. The Kruskal-Wallis test was used for statistical analysis (p < 0.05).

RESULTS

Cirrhosis associated with all aetiologies commonly showed atrophy of the medial and anterior segments and right lobe and hypertrophy of the lateral segment and caudate lobe compared with the control (p < 0.05). In Child-Pugh Class A, hypertrophy of the caudate lobe progressed more in alcoholism and NASH than in virus-related aetiologies (p < 0.001). Hypertrophy of the lateral segment and atrophy of the medial and anterior segments and right lobe progressed less in NASH than in cases with virus related and alcoholic cirrhosis (p < 0.001). In patients with Class B, these differences were less prominent than in those with Class A (p < 0.001). In Class C, no significant differences were noted in any segment, regardless of aetiology (p > 0.05).

CONCLUSION

Morphometric changes of cirrhosis display different patterns according to aetiology. Differences between aetiologies would decrease with progression of cirrhosis.

ADVANCES IN KNOWLEDGE

Morphometric changes of cirrhosis display different patterns according to aetiology. Differences between aetiologies would decrease with progression of cirrhosis.

Non-invasive prediction of portal pressures using CT and MRI in chronic liver disease

PURPOSE

To assess the diagnostic value of a fast scoring system based on non-invasive cross-sectional imaging to predict portal hypertension (PH) in patients with liver disease.

METHODS

In this retrospective study, we included patients who underwent contrast-enhanced CT or MRI within 3 months of hepatic venous pressure gradient (HVPG) measurements. Two independent observers provided an imaging-based scoring system (max of 9): number of variceal sites, volume of ascites, and spleen size. ROC analysis was performed to predict the presence of PH (HVPG ≥ 5 mmHg) and clinically significant PH (HVPG ≥ 10 mmHg).

RESULTS

Our cohort consists of 143 patients with mean HVPG of 13.1 ± 2.0 mmHg. Mean PH scores from the two observers were 3.9 ± 2.7 and 3.2 ± 2.5. There was a significant correlation between PH score and HVPG (r = 0.58, p < 0.001 for both observers) with high inter-observer agreement (kappa 0.71). AUCs of 0.78-0.76 and 0.83-0.81 were observed for diagnosing HVPG ≥ 5 mmHg and HVPG ≥ 10 mmHg, respectively, for observers 1 and 2.

CONCLUSIONS

We have developed a fast PH imaging-based composite score, which could be used for non-invasive detection of clinically significant PH.

Non-invasive detection of liver fibrosis: MR imaging features vs. MR elastography

PURPOSE

To compare accuracy of morphological features of liver on MRI and liver stiffness with MR elastography (MRE) for detection of significant liver fibrosis and cirrhosis.

MATERIALS AND METHODS

In this retrospective study, we evaluated 62 patients who underwent liver MRI with MRE and histological confirmation of liver fibrosis within 6 months. Two radiologists, blinded to histology results, independently evaluated liver parenchyma texture, surface nodularity, signs of volumetric changes, and portal hypertension for presence of significant fibrosis and cirrhosis. Two more readers independently calculated mean liver stiffness values with MRE. Interobserver agreement was evaluated with kappa and intra-class correlation coefficient (ICC) analysis. Diagnostic accuracy was assessed with area under receiver operating characteristic (AUROC) analysis. Comparison of AUROCs of MRI and MRE was performed.

RESULTS

Liver fibrosis was present in 37 patients. The interobserver agreement was poor to good (κ = 0.12-0.74) for MRI features and excellent for MRE (ICC 0.97, 95% CI 0.95-0.98). MRI features had 48.5%-87.9% sensitivity, 55.2%-100% specificity, and 71.5%-81.6% accuracy/for detection of significant fibrosis. MRE performed better with 100% sensitivity, 96.5% specificity, and 98.9% accuracy. For the detection of cirrhosis, MRE performed better than MRI features with 88.2% sensitivity (vs. 41.2%-82.3%), 91.1% specificity (vs. 64.4%-95.6%), and 93.5% accuracy (vs. 60.6%-80.5%). Among the MRI features, surface nodularity and overall impression had the best accuracies of 80.3% and 81.6% for detection of significant fibrosis, respectively. For cirrhosis, parenchyma texture and overall impression had the best accuracies of 80.5% and 79.7%, respectively. Overall, MRE had significantly greater AUROC than MRI features for detection of both significant fibrosis (0.98.9 vs 0.71-0.82, P < 0.001) and cirrhosis (0.93.5 vs. 0.61-0.80.5, P < 0.01).

CONCLUSION

MRE is superior to MRI for the non-invasive diagnosis of significant liver fibrosis and cirrhosis.

State-of-the-art imaging of liver fibrosis and cirrhosis: A comprehensive review of current applications and future perspectives

•

MR elastography (MRE) appears to be the most reliable method for grading liver fibrosis.

•

CT fibrosis score correlates with the stage of fibrosis.

•

Caudate-to-right-lobe ratio and diameters of the liver veins contribute to the CT fibrosis score.

Objective

The purpose of this article is to provide a comprehensive overview of imaging findings in patients with hepatic fibrosis and cirrhosis; and to describe which radiological/clinical modality is best for staging hepatic fibrosis.

Conclusion

MR elastography (MRE) appears to be the most reliable method for grading liver fibrosis, although the CT fibrosis score derived from the combination of caudate-to-right-lobe ratio and the diameters of the liver veins significantly correlates with the stage of fibrosis.

Persistent hepatitis C virus infections and hepatopathological manifestations in immune-competent humanized mice

The majority of hepatitis C virus (HCV) infection develops chronic infection, which causes steatosis, cirrhosis and hepatocellular carcinoma. However, understanding HCV chronicity and pathogenesis is hampered by its narrow host range, mostly restricted to human and chimpanzee. Recent endeavour to infect a variety of humanized mice has not been able to achieve persistent HCV infection unless the essential innate immune responsive genes are knocked out. Nevertheless, such immune-compromised humanized mice still lacked HCV infection-induced hepatopathogenesis. Here we report that transgenic mice in ICR background harboring both human CD81 and occludin genes (C/O^Tg) are permissive to HCV infection at a chronicity rate comparable to humans. In this mouse model, HCV accomplishes its replication cycle, leading to sustained viremia and infectivity for more than 12 months post infection with expected fibrotic and cirrhotic progression. Host factors favorable for HCV replication, and inadequate innate immune-response may contribute to the persistence. Lastly, NS3/4 protease inhibitor telaprevir can effectively inhibit de novo RNA synthesis and acute HCV infection of C/O^Tg mice. Thus, chronic HCV infection with complete replication cycle and hepatopathologic manifestations is recapitulated, for the first time, in immune-competent mice. This model will open a new venue to study the mechanisms of chronic hepatitis C and develop better treatments.

Magnetic resonance imaging in cirrhosis: what's new?

Cirrhosis is the main risk factor for the development of hepatocellular carcinoma (HCC). The major causative factors of cirrhosis in the United States and Europe are chronic hepatitis C infection and excessive alcohol consumption with nonalcoholic steatohepatitis emerging as another important risk factor. Magnetic resonance imaging is the most sensitive imaging technique for the diagnosis of HCC, and the sensitivity can be further improved with the use of diffusion-weighted imaging and hepatocyte-specific contrast agents. The combination of arterial phase hyperenhancement, venous or delayed phase hypointensity "washout feature," and capsular enhancement are features highly specific for HCC with reported specificities of 96% and higher. When these features are present in a mass in the cirrhotic liver, confirmatory biopsy to establish the diagnosis of HCC is not necessary. Other tumors, such as cholangiocarcinoma, sometimes occur in the cirrhotic at a much lower rate than HCC and can mimic HCC, as do other benign lesions such as perfusion abnormalities. In this article, we discuss the imaging features of cirrhosis and HCC, the role of magnetic resonance imaging in the diagnosis of HCC and other benign and malignant lesions that occur in the cirrhotic liver, and the issue of nonspecific arterially hyperenhancing nodules often seen in cirrhosis.

Noninvasive classification of hepatic fibrosis based on texture parameters from double contrast-enhanced magnetic resonance images

PURPOSE

To demonstrate a proof of concept that quantitative texture feature analysis of double contrast-enhanced magnetic resonance imaging (MRI) can classify fibrosis noninvasively, using histology as a reference standard.

MATERIALS AND METHODS

A Health Insurance Portability and Accountability Act (HIPAA)-compliant Institutional Review Board (IRB)-approved retrospective study of 68 patients with diffuse liver disease was performed at a tertiary liver center. All patients underwent double contrast-enhanced MRI, with histopathology-based staging of fibrosis obtained within 12 months of imaging. The MaZda software program was used to compute 279 texture parameters for each image. A statistical regularization technique, generalized linear model (GLM)-path, was used to develop a model based on texture features for dichotomous classification of fibrosis category (F ≤2 vs. F ≥3) of the 68 patients, with histology as the reference standard. The model's performance was assessed and cross-validated. There was no additional validation performed on an independent cohort.

RESULTS

Cross-validated sensitivity, specificity, and total accuracy of the texture feature model in classifying fibrosis were 91.9%, 83.9%, and 88.2%, respectively.

CONCLUSION

This study shows proof of concept that accurate, noninvasive classification of liver fibrosis is possible by applying quantitative texture analysis to double contrast-enhanced MRI. Further studies are needed in independent cohorts of subjects.

Ultrasound and magnetic resonance imaging findings in Schistosomiasis mansoni: expanded gallbladder fossa and fatty hilum signs

INTRODUCTION: There is no study relating magnetic resonance imaging (MRI) to ultrasound (US) findings in patients with Schistosomiasis mansoni. Our aim was to describe MRI findings inpatients with schistosomal liver disease identified by US. METHODS: Fifty-four patients (mean age 41.6±13.5years) from an area endemic for Schistosomiasis mansoni were selected for this study.All had US indicating liver schistosomal fibrosis and were evaluated with MRI performed witha 1.5-T superconducting magnet unit (Sigma). RESULTS: Forty-seven (87%) of the 54 patientsshowing signs of periportal fibrosis identified through US investigation had confirmed diagnosesby MRI. In the seven discordant cases (13%), MRI revealed fat tissue filling in the hilar periportalspace where US indicated isolated thickening around the main portal vein at its point of entryto the liver. We named this the fatty hilum sign. One of the 47 patients with MRI evidence ofperiportal fibrosis had had his gallbladder removed previously. Thirty-five (76.1%) of the other46 patients had an expanded gallbladder fossa filled with fat tissue, whereas MRI of the remainingeleven showed pericholecystic signs of fibrosis. CONCLUSIONS: Echogenic thickening of thegallbladder wall and of the main portal vein wall heretofore attributed to fibrosis were frequentlyidentified as fat tissue in MRI. However, the gallbladder wall thickening shown in US (expandedgallbladder fossa in MRI) is probably secondary to combined hepatic morphologic changes inschistosomiasis, representing severe liver involvement.

Accuracy of MR elastography and anatomic MR imaging features in the diagnosis of severe hepatic fibrosis and cirrhosis

PURPOSE

To compare the diagnostic accuracy of magnetic resonance imaging elastography (MRE) and anatomic MRI features in the diagnosis of severe hepatic fibrosis and cirrhosis.

MATERIALS AND METHODS

Three readers independently assessed presence of morphological changes associated with hepatic fibrosis in 72 patients with liver biopsy including: caudate to right lobe ratios, nodularity, portal venous hypertension (PVH) stigmata, posterior hepatic notch, expanded gallbladder fossa, and right hepatic vein caliber. Three readers measured shear stiffness values using quantitative shear stiffness maps (elastograms). Sensitivity, specificity, and diagnostic accuracy of stiffness values and each morphological feature were calculated. Interreader agreement was summarized using weighted kappa statistics. Intraclass correlation coefficient was used to assess interreader reproducibility of stiffness measurements. Binary logistic regression was used to assess interreader variability for dichotomized stiffness values and each morphological feature.

RESULTS

Using 5.9 kPa as a cutoff for differentiating F3-F4 from F0-2 stages, overall sensitivity, specificity, and diagnostic accuracy for MRE were 85.4%, 88.4%, and 87%, respectively. Overall interreader agreement for stiffness values was substantial, with an insignificant difference (P = 0.74) in the frequency of differentiating F3-4 from F0-2 fibrosis. Only hepatic nodularity and PVH stigmata showed moderately high overall accuracy of 69.4% and 72.2%. Interreader agreement was substantial only for PVH stigmata, moderate for C/R m, deep notch, and expanded gallbladder fossa. Only posterior hepatic notch (P = 0.82) showed no significant difference in reader rating.

CONCLUSION

MRE is a noninvasive, accurate, and reproducible technique compared with conventional features of detecting severe hepatic fibrosis.

Segmental difference of the hepatic fibrosis from chronic viral hepatitis due to hepatitis B versus C virus infection: comparison using dual contrast material-enhanced MRI

OBJECTIVE

We wanted to identify the geographic differences in hepatic fibrosis and their associations with the atrophy-hypertrophy complex in patients with chronic viral hepatitis using the dual-contrast material-enhanced MRI (DC-MRI) with gadopentetate dimeglumine and ferucarbotran.

MATERIALS AND METHODS

Patients with chronic C (n = 22) and B-viral hepatitis (n = 35) were enrolled for determining the subjective grade of fibrosis (the extent and thickness of fibrotic reticulations) in the right lobe (RL), the caudate lobe (CL), the medial segment (MS) and the lateral segment (LS) of the liver, with using a 5-grade scale, on the gradient echo T2(*)-weighted images of DC-MRI. The fibrosis grades of different segments were compared using the Kruskal-Wallis test followed by post-hoc analysis to establish the segment-by-segment differences. The incidences of two pre-established morphologic signs of cirrhosis were also compared with each other between the two groups of patients.

RESULTS

There were significant intersegmental differences in fibrosis grades of the C-viral group (p = 0.005), and the CL showed lower fibrosis grades as compared with the grades of the RL and MS, whereas all lobes were similarly affected in the B-viral group (p = 0.221). The presence of a right posterior hepatic notch was significantly higher in the patients with intersegmental differences of fibrosis between the RL and the CL (19 out of 25, 76%) than those without such differences (6 out of 32, 19%) (p < 0.001). An expanded gallbladder fossa showed no significant relationship (p = 0.327) with the segmental difference of the fibrosis grades between the LS and the MS.

CONCLUSION

The relative lack of fibrosis in the CL with more advanced fibrosis in the RL can be a distinguishing feature to differentiate chronic C-viral hepatitis from chronic B-viral hepatitis and this is closely related to the presence of a right posterior hepatic notch.

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.

Clinical application of liver MR imaging in Wilson's disease

OBJECTIVE

To determine whether there is a correlation between liver MR findings and the clinical manifestations and severity of liver dysfunction in patients with Wilson's disease.

MATERIALS AND METHODS

Two radiologists retrospectively evaluated MR images of the liver in 50 patients with Wilson's disease. The Institutional Review Board approved this retrospective study and informed consent was waived. MR images were evaluated with a focus on hepatic contour abnormalities and the presence of intrahepatic nodules. By using Fisher's exact test, MR findings were compared with clinical presentations (neurological and non-neurological) and hepatic dysfunction, which was categorized by the Child-Pugh classification system (A, B and C). Follow-up MR images were available for 17 patients.

RESULTS

Contour abnormalities of the liver and intrahepatic nodules were observed in 31 patients (62%) and 25 patients (50%), respectively. Each MR finding showed a statistically significant difference (p < 0.05) among the three groups of Child-Pugh classifications (A, n = 36; B, n = 5; C, n = 9), except for splenomegaly (p = 0.243). The mean age of the patients with positive MR findings was higher than that of patients with negative MR findings. For patients with Child-Pugh class A (n = 36) with neurological presentation, intrahepatic nodules, surface nodularity, and gallbladder fossa widening were more common. Intrahepatic nodules were improved (n = 8, 47%), stationary (n = 5, 29%), or aggravated (n = 4, 24%) on follow-up MR images.

CONCLUSION

MR imaging demonstrates the contour abnormalities and parenchymal nodules of the liver in more than half of the patients with Wilson's disease, which correlates with the severity of hepatic dysfunction and clinical manifestations.

Gd-EOB-DTPA enhanced MR imaging: evaluation of biliary and renal excretion in normal and cirrhotic livers

OBJECTIVE

The purpose of this study was to assess the difference in the activity of biliary and renal excretion between normal and cirrhotic livers on contrast-enhanced MR imaging obtained with gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid (Gd-EOB-DTPA).

METHODS

A total of 78 patients with cirrhotic liver (n=44) and with normal liver (n=34) underwent multi-phase Gd-EOB-DTPA enhanced MR imaging (arterial, portal, equilibrium, and three hepatobiliary phases (10, 15 and 20 min HP), respectively), and these contrast-enhanced images were qualitatively and quantitatively evaluated for the differences of the biliary and renal excretion between normal and cirrhotic livers.

RESULTS

The timing of biliary excretion of contrast agents in the cirrhotic liver was significantly slower than that in the normal liver (P<0.001). The degree of contrast enhancement in the common bile duct in the normal liver was significantly better than that in the cirrhotic liver (P=0.003). Contrast agents were demonstrated in the duodenum at 20 min HP in 8/44 (18%) cirrhotic liver while they were seen in 15/34 (44%) normal liver (P=0.013). The enhancement effects of renal medulla and portal vein at 20 min HP in the cirrhotic liver were significantly higher than those of normal liver (P=0.043 and P<0.001, respectively).

CONCLUSION

Biliary excretion of Gd-EOB-DPTA was impaired in cirrhotic livers in comparison with normal livers while renal excretion of Gd-EOB-DPTA was increased.

MR imaging in liver cirrhosis: classical and new approaches

Objective

The typical histological features of chronic hepatitis and cirrhosis are variable degrees of hepatocellular necrosis and inflammation (activity or grade of disease), fibrosis (stage of disease), and associated fat and iron deposition. These features influence the liver’s appearance and must be assessed separately by imaging biomarkers in order to be clinically useful. Hepatic morphologic alterations and features of portal hypertension identify most cases of established cirrhosis. Nowadays, research is focused on developing ways to improve detection of early and intermediate stages of fibrosis as well as hepatocyte dysfunction. Even more, most imaging-related measurements are subject to complex interactions and are influenced by different pathologic processes, such as fatty infiltration, edema, necrosis and iron accumulation.

Methods and results

MR experience throughout the last 15 years at the Dr Peset University Hospital is reviewed.

Conclusion

Nowadays, several biomarkers have been developed to grade the liver status in cirrhosis. This review will focus on these topics.

Advanced MRI methods for assessment of chronic liver disease

OBJECTIVE

With recent advances in technology, advanced MRI methods such as diffusion-weighted and perfusion-weighted MRI, MR elastography, chemical shift-based fat-water separation, and MR spectroscopy can now be applied to liver imaging. We will review the respective roles of these techniques for assessment of chronic liver disease.

CONCLUSION

MRI plays an increasingly important role in assessment of patients with chronic liver disease because of the lack of ionizing radiation and the possibility of performing multiparametric imaging.

Double contrast-enhanced MRI of viral hepatitis-induced cirrhosis: correlation of gross morphological signs with hepatic fibrosis

The purpose of this study was to evaluate the diagnostic ability of the expanded gallbladder fossa and right posterior hepatic notch signs for hepatic fibrosis determined by double contrast-enhanced MRI. For patients with chronic viral hepatitis B (n = 96) or hepatitis C (n = 13) who underwent gadopentate dimeglumine-enhanced dynamic MRI followed by ferucarbotran-enhanced gradient-echo imaging, the degree of parenchymal fibrosis was categorised into three groups based on the extent of reticulation and nodularity: (1) pre-cirrhotic or minimal fibrosis; (2) mild to moderate fibrosis; (3) advanced cirrhosis. Each group was evaluated for the presence of a sharp notch in the posterior-medial surface of the right lobe of the liver and expanded gallbladder fossa. The expanded gallbladder fossa sign gradually increased with an increasing degree of fibrosis (Group 1, 50%; Group 2, 61%; Group 3, 78%), and there was no significant difference (p>0.5) between hepatitis B (67%) and C (73%). In the case of the right posterior hepatic notch sign, only 6% of Group 1 and Group 2 patients were positive; 27% of hepatitis B patients and 90% of hepatitis C patients in Group 3 exhibited the sign (p<0.05). Owing to its low prevalence, even in advanced cirrhosis, the right posterior hepatic notch sign is of little value in the diagnosis of cirrhosis due to chronic hepatitis B virus infection, whereas an expanded gallbladder fossa could be used as a non-specific indicator of early fibrosis before the gross appearance of advanced hepatic fibrosis.

Changes in hepatic venous morphology with cirrhosis on MRI

PURPOSE

To identify changes in vascular morphology on magnetic resonance imaging (MRI) in patients with cirrhosis and to compare these findings to liver donors.

MATERIALS AND METHODS

Patients undergoing liver transplantation with biopsy-proven cirrhosis (n = 74) and liver donor candidates (n = 85) underwent dynamic gadolinium-enhanced 3D MR at 1.5T. Vessel diameters were measured independently by three radiologists and features of cirrhosis were identified and correlated with cirrhosis.

RESULTS

Hepatic veins were smaller in patients with cirrhosis (4.9, 4.5, and 5.0 mm for right, middle, and left vs. 9.9, 7.6, and 8.9 mm in donors, P << 0.001) and were negatively correlated with cirrhosis (P < 0.001). Right hepatic vein (RHV) <5 mm diagnosed cirrhosis with 59% sensitivity and 99% specificity; the sensitivity and specificity were 88% and 85% for RHV <7 mm. Main portal vein was minimally larger in cirrhosis, 14 versus 12 mm (P < 0.001) in donors. Right portal veins were smaller in cirrhotic patients, 6.5 and 6.2 mm compared to 8.4 and 7.6 mm (P << 0.001), respectively, in donors.

CONCLUSION

Vascular features of cirrhosis include small hepatic veins, minimally enlarged main portal vein, and small intrahepatic portal veins; these features may facilitate identification of cirrhosis.

Primary hepatocellular lesions: imaging findings on state-of-the-art magnetic resonance imaging, with pathologic correlation

Magnetic resonance imaging is routinely used for the workup of patients with focal or diffuse liver disease, including primary hepatocellular lesions, storage diseases, metastatic liver disease, and diseases of the hepatobiliary tree. The most important magnetic resonance imaging sequences used for diagnostic imaging of the liver consist of T1-weighted sequences, T2-weighted sequences, and at least the arterial and delayed phases of dynamic gadolinium-enhanced imaging. This article provides an overview of magnetic resonance imaging of primary hepatocellular lesions and will describe the following: (1) the classification and etiology of primary hepatocellular lesions, including focal nodular hyperplasia, hepatocellular adenoma, and hepatocellular carcinoma; (2) the stepwise carcinogenesis of hepatocellular carcinoma in cirrhosis on magnetic resonance imaging; and (3) the typical imaging findings of primary hepatocellular lesions on magnetic resonance imaging, with differential diagnoses.