ESGAR consensus statement on liver MR imaging and clinical use of liver-specific contrast agents

Objectives

To develop a consensus and provide updated recommendations on liver MR imaging and the clinical use of liver-specific contrast agents.

Methods

The European Society of Gastrointestinal and Abdominal Radiology (ESGAR) formed a multinational European panel of experts, selected on the basis of a literature review and their leadership in the field of liver MR imaging. A modified Delphi process was adopted to draft a list of statements. Descriptive and Cronbach’s statistics were used to rate levels of agreement and internal reliability of the consensus.

Results

Three Delphi rounds were conducted and 76 statements composed on MR technique (n = 17), clinical application of liver-specific contrast agents in benign, focal liver lesions (n = 7), malignant liver lesions in non-cirrhotic (n = 9) and in cirrhotic patients (n = 18), diffuse and vascular liver diseases (n = 12), and bile ducts (n = 13). The overall mean score of agreement was 4.84 (SD ±0.17). Full consensus was reached in 22 % of all statements in all working groups, with no full consensus reached on diffuse and vascular diseases.

Conclusions

The consensus provided updated recommendations on the methodology, and clinical indications, of MRI with liver specific contrast agents in the study of liver diseases.

Key points

• Liver-specific contrast agents are recommended in MRI of the liver.

• The hepatobiliary phase improves the detection and characterization of hepatocellular lesions.

• Liver-specific contrast agents can improve the detection of HCC.

Analysis of subsequent publication of scientific orally presented abstracts of the French National Congress of Radiology. Part II: Focus on the French abstracts

AIM

To evaluate the publication rate of scientific abstracts that were presented orally at the 2008, 2009, and 2010 annual meetings of the French Society of Radiology by French radiologists, and to perform a French regional analysis.

MATERIAL AND METHODS

Orally presented abstracts were identified by examining online abstract books of the 2008, 2009, and 2010 annual meetings of the French Society of Radiology, and cross-checked by reviewing the paper version of abstracts for the same period. Only abstracts from French teams were selected. The administrative region of submission was noted for each abstract and for each region the total population, the number of active radiologists, the number of active members of the French Society of Radiology and the number of academic radiologists were noted. Imaging subspecialties were also noted.

RESULTS

625 abstracts were identified resulting in 268 publications (publication rate: 43%). The median number of presentations and publications per region was 18 (range: 1-255) and 7 (range: 0-101), respectively. The ratio per million inhabitants was 7.5 and 3 respectively. The median number of presentations and publications per 100 active radiologists (respectively members of the FSR) was 7 and 3 (respectively 10 and 4). The median number of presentations and publications per academic radiologist were 2.6, and 1.2, respectively. The regional variations for each indicator were high (40-180%). Three subspecialties had a publication rate of more than 50%: thoracic imaging (58%), abdominal imaging (52%), and genitourinary imaging (51%).

CONCLUSION

The publication rate of orally presented French scientific abstracts was high, with important variations according to the regions of origin and imaging subspecialties.

Analysis of subsequent publication of scientific orally presented abstracts of the French national congress of radiology. Part I: General characteristics

PURPOSE

To evaluate the publication rate of scientific abstracts orally presented at the annual meeting of the French Society of Radiology (FSR), and to identify factors associated with publication.

MATERIAL AND METHODS

Abstracts were selected from the books of abstracts of the 2008-2010 annual meetings of the FSR. For each abstract, country of origin, diagnostic/interventional radiology, imaging techniques (plain radiography, angiography, ultrasound [US], computed tomography [CT], magnetic resonance imaging [MRI]), human/experimental study, retrospective/prospective design, number of subjects, oncologic study or not were noted. Publications were searched in Medline-indexed journals and factors associated analyzed by multivariate analysis.

RESULTS

Seven hundred and forty-four abstracts lead to 298 publications (publication rate 40%). Most abstracts reported retrospective studies (61%), in humans (94%), diagnostic imaging (85%), from European authors (90%), and oncology (27%). Median number of subject was 39 (19-87). Main imaging techniques were MRI, CT, US (46%, 29%, 21%). Publications were mostly in English (89%), in radiological journals (72%), with a mean 3.5±3.7 impact factor. Publication was associated with a prospective design (OR=1.80), a submission from Europe (OR=1.71), angiography (OR=2.44), and oncology (OR=1.81).

CONCLUSION

The annual meeting of the FSR is in French, but the rate of publication of presented abstracts is high, mostly in English in reputable journals.

Hepatic capsular retraction: spectrum of diagnosis at MRI

Hepatic capsular retraction is an imaging feature that deserves the attention of the radiologist. Hepatic capsular retraction is associated with a number of hepatic lesions, benign or malignant, treated or untreated. The purpose of this pictorial review is to discuss the most common benign and malignant hepatic lesions associated with this feature with an emphasis on magnetic resonance imaging (MRI).

Radioembolisation with yttrium‒90 microspheres versus sorafenib for treatment of advanced hepatocellular carcinoma (SARAH): study protocol for a randomised controlled trial

Background

Untreated advanced hepatocellular carcinoma (HCC) is linked to poor prognosis. While sorafenib is the current recommended treatment for advanced HCC, radioembolisation (RE; also called selective internal radiation therapy or SIRT) with yttrium-90 microspheres has shown efficacy in cohort studies. However, there are no head-to-head trials comparing radiation therapy with yttrium-90 microspheres and sorafenib in advanced HCC. The SARAH trial has been designed to compare the efficacy and safety of sorafenib therapy and RE using yttrium-90 resin microspheres (SIR-Spheres™; Sirtex Medical Limited, North Sydney, Australia) in patients with advanced HCC. Quality of life (QoL) and cost-effectiveness will also be compared between therapies.

Methods/Design

SARAH is a prospective, randomised, controlled, open-label, multicentre trial comparing the efficacy of RE with sorafenib in the treatment of patients with advanced HCC. The trial aims to recruit adults with a life expectancy of >3 months, Eastern Cooperative Oncology Group (ECOG) performance status ≤1, and: advanced HCC according to the Barcelona criteria (stage C) or recurrent HCC after surgical or thermoablative treatment who are not eligible for surgical resection, liver transplantation or thermal ablation; or two rounds of failed chemoembolisation. Patients will be randomised 1:1 to receive either RE or sorafenib 400 mg twice daily. All patients will be monitored for between 12 and 48 months following start of treatment. The primary endpoint of the SARAH trial is overall survival (OS). Secondary endpoints include: adverse events, progression-free survival at 6 months; tumour response rate; general or liver disease-specific QoL scores; and cost of each treatment strategy. Assuming an increase in median OS of 4 months with RE versus sorafenib therapy, randomising at least 400 patients (200 in each treatment arm) will be sufficient for 80% power and a bilateral alpha risk of 5%; therefore, 440 patients will be enrolled to allow for 10% loss of patients due to ineligibility.

Discussion

The SARAH trial is the first randomised head-to-head study to compare RE with sorafenib in advanced HCC, and will establish the potential role of RE in HCC treatment guidelines.

Trial registration

ClinicalTrials.gov identifierNCT01482442, first received 28 November 2011

Electronic supplementary material

The online version of this article (doi:10.1186/1745-6215-15-474) contains supplementary material, which is available to authorized users.

Diagnosis and management of solid benign liver lesions

More and more asymptomatic benign liver tumours are discovered incidentally and can be divided into regenerative lesions and true neoplastic lesions. The most common regenerative lesions include hemangioma, focal nodular hyperplasia and inflammatory pseudotumours of the liver. Neoplastic lesions include hepatocellular adenomas and angiomyolipomas. Regenerative lesions rarely increase in volume, do not yield a higher risk of complications and usually do not require treatment. By contrast, hepatocellular adenomas and angiomyolipomas can increase in volume and are associated with a risk of complications. Large hepatocellular adenomas (>5 cm in diameter) are undoubtedly associated with a risk of bleeding and malignant transformation, particularly the inflammatory (also known as telangiectatic) and β-catenin mutated subtypes. Accurate diagnosis needs to be obtained to select patients eligible for surgical resection. MRI has markedly improved diagnosis and can identify the major hepatocellular adenomas subtypes. The use of biopsy results to inform the indication for resection remains questionable. However, when diagnosis remains uncertain after imaging, percutaneous biopsy could help improve diagnostic accuracy.

Imaging of benign hepatocellular lesions: current concepts and recent updates

Focal nodular hyperplasia (FNH) and hepatocellular adenoma (HCA) are a variety of solid lesions mostly found in the absence of underlying chronic liver disease in young patients. HCA is no longer to be considered as a unique lesion but as a recollection of different entities sharing common points but most of all separated by different typical morphological aspects. Accurate diagnosis is of clinical importance as the management is most of the time conservative for FNH, whereas HCAs expose patients to hemorrhage and malignant transformation, and may lead to a more invasive treatment, mainly surgical resection. Moreover, the different HCA subtypes expose to different risks of complication. The best imaging techniques for the differentiation between FNH and HCAs and for the subtyping of HCAs are contrast-enhanced ultrasound (CEUS) and magnetic resonance imaging (MRI), as specific combinations of imaging features have been associated with the different lesions. They should be considered as complementary examinations. Atypical or multiple lesions, lesions containing fat or presence of an associated steatosis represent diagnostic challenges. Recently, MR hepatospecific contrast agents have been shown to be useful. Emergent elastography techniques might also be helpful in the near future. Biopsy should always be performed in case of uncertain diagnosis to reach a final diagnosis and avoid unnecessary invasive treatment.

Validation of dynamic contrast-enhanced ultrasound in predicting outcomes of antiangiogenic therapy for solid tumors: the French multicenter support for innovative and expensive techniques study

OBJECTIVES

Dynamic contrast-enhanced ultrasound (DCE-US) has been used in single-center studies to evaluate tumor response to antiangiogenic treatments: the change of area under the perfusion curve (AUC), a criterion linked to blood volume, was consistently correlated with the Response Evaluation Criteria in Solid Tumors response. The main objective here was to do a multicentric validation of the use of DCE-US to evaluate tumor response in different solid tumor types treated by several antiangiogenic agents. A secondary objective was to evaluate the costs of the procedure.

MATERIALS AND METHODS

This prospective study included patients from 2007 to 2010 in 19 centers (8 teaching hospitals and 11 comprehensive cancer centers). All patients treated with antiangiogenic therapy were eligible. Dynamic contrast-enhanced ultrasound examinations were performed at baseline as well as on days 7, 15, 30, and 60. For each examination, a perfusion curve was recorded during 3 minutes after injection of a contrast agent. Change from baseline at each time point was estimated for each of 7 fitted criteria. The main end point was freedom from progression (FFP). Criterion/time-point combinations with the strongest correlation with FFP were analyzed further to estimate an optimal cutoff point.

RESULTS

A total of 1968 DCE-US examinations in 539 patients were analyzed. The median follow-up was 1.65 years. Variations from baseline were significant at day 30 for several criteria, with AUC having the most significant association with FFP (P = 0.00002). Patients with a greater than 40% decrease in AUC at day 30 had better FFP (P = 0.005) and overall survival (P = 0.05). The mean cost of each DCE-US was 180&OV0556;, which corresponds to $250 using the current exchange rate.

CONCLUSIONS

Dynamic contrast-enhanced ultrasound is a new functional imaging technique that provides a validated criterion, namely, the change of AUC from baseline to day 30, which is predictive of tumor progression in a large multicenter cohort. Because of its low cost, it should be considered in the routine evaluation of solid tumors treated with antiangiogenic therapy.

Prospective comparison of spleen and liver stiffness by using shear-wave and transient elastography for detection of portal hypertension in cirrhosis

PURPOSE

To prospectively compare the technical success rate and accuracy of shear-wave elastography (SWE) and transient elastography (TE) for the detection of clinically significant portal hypertension (PH) in patients with advanced cirrhosis who are undergoing hepatic vein pressure gradient (HVPG) measurements.

MATERIALS AND METHODS

The institutional ethics committee approved the study, and written informed consent was obtained. Seventy-nine consecutive patients with cirrhosis who were undergoing SWE and TE at the time of HVPG measurement were studied. The technical success rate of SWE and TE was compared with the diagnostic value of liver stiffness (LS) and spleen stiffness (SS) measurements and composite scores (LS spleen-diameter-to-platelet-ratio score [LSPS] and PH risk score) by using SWE and TE to detect clinically significant PH (HVPG ≥ 10 mm Hg) and esophageal varices at high risk of bleeding. Areas under the receiver operating characteristic curve and the DeLong test were used.

RESULTS

The technical success rate of SWE was significantly better than that of TE for both LS and SS (97% and 97% vs 44% and 42%, respectively; P < .001). LS of more than 24.6 kPa with SWE had a sensitivity, specificity, and accuracy for clinically significant PH of 81%, 88%, and 82%, respectively. Diagnostic performance of LS by using SWE was significantly better than that for SS for the diagnosis of clinically significant PH (area under the receiver operating characteristic curve of 0.87 vs 0.64, P = .003). LS, SS, LSPS, and PH risk score (according to SWE or TE) did not differ between patients with and those without high-risk esophageal varices (P = .09-.42).

CONCLUSION

In patients with advanced cirrhosis who are undergoing HVPG measurements, LS measurements obtained by using SWE have a higher technical success rate and a better diagnostic value than TE for clinically significant PH.

Hepatocellular carcinoma: diagnostic criteria by imaging techniques

Imaging plays a very important role in the diagnosis of HCC. Indeed, in high-risk patients a noninvasive diagnosis can only be obtained by imaging in presence of typical features. These features include arterial enhancement followed by washout during the portal venous and/or delayed phases on CT scan or MRI. This pattern is quite specific and has been endorsed by both Western and Asian diagnostic guidelines. However, its sensitivity is not very high, especially for small lesions. Therefore ancillary signs may be needed to increase the reliability of the diagnosis. Recent hepatobiliary MRI contrast agents seem to be interesting to improve characterization of small nodules in the cirrhotic liver.

CT and MR imaging of multilocular acinar cell cystadenoma: comparison with branch duct intraductal papillary mucinous neoplasia (IPMNs)

OBJECTIVES

To describe CT and MR imaging findings of acinar cell cystadenoma (ACC) of the pancreas and to compare them with those of branch duct intraductal papillary mucinous neoplasia (BD-IPMN) to identify distinctive elements.

METHODS

Five patients with ACC and the 20 consecutive patients with histologically proven BD-IPMN were retrospectively included. Clinical and biological information was collected and histological data reviewed. CT and MR findings were analysed blinded to pathological diagnosis in order to identify imaging diagnostic criteria of ACC.

RESULTS

Patients with ACC were symptomatic in all but one case and were younger than those with BD-IPMN (p = 0.006). Four radiological criteria allowed for differentiating ACC from IPMN: five or more cysts, clustered peripheral small cysts, presence of cyst calcifications and absence of communication with the main pancreatic duct (p < 0.05). Presence of at least two or three of these imaging criteria had a strong diagnostic value for ACC with a sensitivity of 100% and 80% and a specificity of 85% and 100%, respectively.

CONCLUSIONS

Preoperative differential diagnosis between ACC and BD-IPMN can be achieved using a combination of four CT and/or MR imaging criteria. Recognition of ACC patients could change patient management and lead to more conservative treatment.

KEY POINTS

Four imaging findings are associated with acinar cell cystadenoma (ACC). Imaging could achieve differential diagnosis between ACC and BD-IPMN. Diagnosis on imaging would change patient management and avoid surgical resection.

Detection of liver micrometastases from colorectal origin by perfusion CT in a rat model

BACKGROUND

Some patients with colorectal carcinoma have liver metastases (LMs) which cannot be detected by conventional imaging. This study aimed to assess whether hepatic perfusion changes induced by micrometastases can be detected by perfusion computed tomography (CT).

METHODS

LMs were produced in rats by injecting carcinoma cells into the portal vein. Perfusion CT was performed at microscopic (day 10), interval (day 17), and macroscopic stage (day 34). Perfusion parameters were computed using a dual-input one-compartmental model.

RESULTS

Micro and macro LMs presented a mean diameter of 0.5 and 2.6 mm, respectively. Compared to controls, LMs at interval (1.1 mm) and macroscopic stage induced significant perfusion changes: a decrease of 42% (P=0.004) and 41% (P=0.029) in hepatic transit time and an increase of 292% (P=0.073) and 240% (P=0.001) in portal delay, respectively.

CONCLUSIONS

LMs with a mean diameter between 1.1 and 2.6 mm induced significant hepatic perfusion changes, detected by CT. Such detection may help to select patients and propose chemotherapy at the time of primary tumor resection.

Colorectal liver metastases growth in the embolized and non-embolized liver after portal vein embolization: influence of initial response to induction chemotherapy

PURPOSE

To compare tumor progression in both embolized and non-embolized liver lobes after portal vein embolization (PVE) in patients with bilobar colorectal liver metastases (CLM), according to the initial response to induction chemotherapy.

METHODS

From 2002 to 2012, a total of 42 consecutive patients with bilobar CLM initially treated using induction chemotherapy underwent right PVE to achieve adequate future liver remnant volume. Tumoral and liver parenchyma volumes, as well as their volume variations, were measured on computed tomography before and after PVE in both embolized and non-embolized. Patients were classified as fast (≤6 cycles of induction chemotherapy) and slow (>6 cycles) responders.

RESULTS

Overall, 432 metastases were analyzed in 42 patients. Patients were slow responders in 29 (69 %) cases. Tumoral volume increased in 29 (69 %) cases in the embolized liver (+48 %; p < 0.0001), and in 28 (66 %) cases in the non-embolized liver (+31 %; p < 0.0001). Fast responders had a tumoral volume decrease in both embolized (-4 %) and non-embolized (-9 %) lobes. On the opposite side, slow responders had tumoral volume increase in both embolized (+79 %) and non-embolized (+32 %) lobes. On multivariate analysis, a 'slow' response to induction chemotherapy was the only factor associated with tumoral progression in both embolized (p = 0.0012) and non-embolized (p = 0.001) lobes.

CONCLUSION

Tumor growth after PVE is observed in both embolized and non-embolized liver lobes in most patients but is significantly associated with slow response to induction chemotherapy.

Viscoelastic parameters for quantifying liver fibrosis: three-dimensional multifrequency MR elastography study on thin liver rat slices

Objective

To assess in a high-resolution model of thin liver rat slices which viscoelastic parameter at three-dimensional multifrequency MR elastography has the best diagnostic performance for quantifying liver fibrosis.

Materials and Methods

The study was approved by the ethics committee for animal care of our institution. Eight normal rats and 42 rats with carbon tetrachloride induced liver fibrosis were used in the study. The rats were sacrificed, their livers were resected and three-dimensional MR elastography of 5±2 mm liver slices was performed at 7T with mechanical frequencies of 500, 600 and 700 Hz. The complex shear, storage and loss moduli, and the coefficient of the frequency power law were calculated. At histopathology, fibrosis and inflammation were assessed with METAVIR score, fibrosis was further quantified with morphometry. The diagnostic value of the viscoelastic parameters for assessing fibrosis severity was evaluated with simple and multiple linear regressions, receiver operating characteristic analysis and Obuchowski measures.

Results

At simple regression, the shear, storage and loss moduli were associated with the severity of fibrosis. At multiple regression, the storage modulus at 600 Hz was the only parameter associated with fibrosis severity (r = 0.86, p<0.0001). This parameter had an Obuchowski measure of 0.89+/−0.03. This measure was significantly larger than that of the loss modulus (0.78+/−0.04, p = 0.028), but not than that of the complex shear modulus (0.88+/−0.03, p = 0.84).

Conclusion

Our high resolution, three-dimensional multifrequency MR elastography study of thin liver slices shows that the storage modulus is the viscoelastic parameter that has the best association with the severity of liver fibrosis. However, its diagnostic performance does not differ significantly from that of the complex shear modulus.

Alternative Response Criteria (Choi, European association for the study of the liver, and modified Response Evaluation Criteria in Solid Tumors [RECIST]) Versus RECIST 1.1 in patients with advanced hepatocellular carcinoma treated with sorafenib

INTRODUCTION

Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST 1.1), may underestimate activity and does not predict survival in patients with hepatocellular carcinoma (HCC) treated with sorafenib. This study assessed the value of alternative radiological criteria to evaluate response in HCC patients treated with sorafenib.

PATIENTS AND METHODS

A retrospective blinded central analysis was performed of computed tomography (CT) scans from baseline and the first tumor evaluation in consecutive patients treated with sorafenib over a 2-year period in a single institution. Four different evaluation criteria were used: Choi, European Association for the Study of the Liver (EASL), modified RECIST (mRECIST), and RECIST 1.1.

RESULTS

Among 82 HCC patients, 64 with Barcelona Clinic Liver Cancer stage B-C were evaluable with a median follow-up of 22 months. Median duration of sorafenib treatment was 5.7 months, and median overall survival was 12.8 months. At the time of the first CT scan, performed after a median of 2.1 months, Choi, EASL, mRECIST, and RECIST 1.1 identified 51%, 28%, 28%, and 3% objective responses, respectively. Responders by all criteria showed consistent overall survival >20 months. Among patients with stable disease according to RECIST 1.1, those identified as responders by Choi had significantly better overall survival than Choi nonresponders (22.4 vs. 10.6 months; hazard ratio: 0.43, 95% confidence interval: 0.15-0.86, p = .0097).

CONCLUSION

Choi, EASL, and mRECIST criteria appear more appropriate than RECIST 1.1 to identify responders with long survival among advanced HCC patients benefiting from sorafenib.