Ferucarbotran-Enhanced Magnetic Resonance Imaging Versus Gadoxetic Acid-Enhanced Magnetic Resonance Imaging for the Preoperative Detection of Hepatocellular Carcinoma: Initial Experience

High-resolution free-breathing hepatobiliary phase MRI of the liver using XD-GRASP

PURPOSE

To evaluate the performance of high-resolution free-breathing (FB) hepatobiliary phase imaging of the liver using the eXtra-Dimension Golden-angle RAdial Sparse Parallel (XD-GRASP) MRI technique.

METHODS

Fifty-eight clinical patients (41 males, mean age = 52.9 ± 12.9) with liver lesions who underwent dynamic contrast-enhanced MRI with a liver-specific contrast agent were prospectively recruited for this study. Both breath-hold volumetric interpolated examination (BH-VIBE) imaging and FB imaging were performed during the hepatobiliary phase. FB images were acquired using a stack-of-stars golden-angle radial sequence and were reconstructed using the XD-GRASP method. Two experienced radiologists blinded to acquisition schemes independently scored the overall image quality, liver edge sharpness, hepatic vessel clarity, conspicuity of lesion, and overall artifact level of each image. The non-parametric paired two-tailed Wilcoxon signed-rank test was used for statistical analysis.

RESULTS

Compared to BH-VIBE images, XD-GRASP images received significantly higher scores (P < 0.05) for the liver edge sharpness (4.83 ± 0.45 vs 4.29 ± 0.46), the hepatic vessel clarity (4.64 ± 0.67 vs 4.15 ± 0.56) and the conspicuity of lesion (4.75 ± 0.53 vs 4.31 ± 0.50). There were no significant differences (P > 0.05) between BH-VIBE and XD-GRASP images for the overall image quality (4.61 ± 0.50 vs 4.74 ± 0.47) and the overall artifact level (4.13 ± 0.44 vs 4.05 ± 0.61).

CONCLUSION

Compared to conventional BH-VIBE MRI, FB radial acquisition combined with XD-GRASP reconstruction facilitates higher spatial resolution imaging of the liver during the hepatobiliary phase. This enhancement can significantly improve the visualization and evaluation of the liver.

[Rational imaging of hepatocellular carcinoma. The challenge of multimodal diagnostic criteria]

CLINICAL/METHODICAL ISSUE

Both computed tomography (CT) and magnetic resonance imaging (MRI) constitute the gold standard in radiological imaging of hepatocellular carcinoma (HCC). In cases of typical contrast behavior each modality as a single dynamic technique allows the diagnosis of HCC. There is still a challenge in detection of small HCCs < 2 cm, in differentiating HCC and high-grade dysplasia from other benign liver lesions as well as the evaluation of hypovascular liver lesions in the cirrhotic liver.

PERFORMANCE

Nowadays, both modalities achieve high detection rates of 90-100 % for lesions > 2 cm. Regarding lesions between 1 and 2 cm there is a higher sensitivity for MRI ranging between 80 and 90 % compared to 60-75 % with CT. Besides the multimodal diagnostic criteria, MRI provides significant benefits with the use of hepatobiliary contrast. Especially in combination with diffusion- weighted imaging (DWI) increased sensitivity and diagnostic accuracy compared to CT has been described for lesions sized < 2 cm. Regarding the differentiation from other hepatic nodules in the cirrhotic liver there is strong evidence that the coexistence of arterial enhancement and hypointensity on hepatobiliary imaging is specific for HCC. Moreover, hypointensity on hepatobiliary imaging is associated with a high positive predictive value (PPV) of up to 100 % for the presence of high-grade dysplasia and HCC.

ACHIEVEMENTS

The use of MRI including hepatobiliary imaging and DWI has to be regarded as the best non-invasive imaging modality for the detection of HCC and for the characterization of nodules in patients with liver cirrhosis. In comparison to CT there are benefits regarding detection of small lesions < 2 cm and evaluation of hypovascular liver lesions in the context of the hepatocarcinogenesis including prognostic values of premalignant lesions.

PRACTICAL RECOMMENDATIONS

Both MRI and CT provide a high diagnostic performance in evaluation of HCC in liver cirrhosis. With MRI there are considerable advantages regarding the detection rate and specificity. For daily clinical routine, CT offers a fast, reliable and easy available modality with benefits for patients in reduced general state of health and restricted compliance.

Magnetic resonance imaging with gadoxetic acid disodium for the detection of hepatocellular carcinoma: a meta-analysis of 18 studies

RATIONALE AND OBJECTIVES

To determine the accuracy of magnetic resonance imaging (MRI) with gadoxetic acid disodium for the detection of hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Various databases were searched for original articles published before May 2013. Studies were selected, which performed MRI with gadoxetic acid disodium to detect and diagnose HCC and which presented sufficient data to allow construction of contingency tables. For each study, the true-positive, false-positive, true-negative, and false-negative values were extracted or derived, and 2 × 2 contingency tables were constructed. The heterogeneity test, the threshold effect test, the publication bias analysis, and subgroup analyses were performed.

RESULTS

From 623 citations, 18 were included in the meta-analysis with a total of 2572 lesions. We detected heterogeneity between studies and evidence of publication bias. The methodological quality was moderate. The pooled weighted sensitivity was 0.91 (95% confidence interval [CI], 0.90-0.93), the specificity was 0.94 (95% CI, 0.93-0.96), the positive likelihood ratio was 12.31 (95% CI, 7.66-19.78), the negative likelihood ratio was 0.10 (95% CI, 0.07-0.13), and the diagnostic odds ratio was 159.72 (95% CI, 91.72-276.08). The area under the receiver operating characteristic curve was 0.98 (95% CI, 0.96-0.99).

CONCLUSIONS

MRI with gadoxetic acid disodium is a noninvasive and no radiation exposure imaging modality with high sensitivity and specificity for the detection of HCC. Nonetheless, it should be applied cautiously in liver nodule <1 cm, and large-scale well-designed trials are necessary to assess its clinical value.

Is liver-specific gadoxetic acid-enhanced magnetic resonance imaging a reliable tool for detection of hepatocellular carcinoma in patients with chronic liver disease?

BACKGROUND

Gadoxetic acid is a recently developed hepatobiliary-specific contrast material used for magnetic resonance imaging (MRI) which enables highly sensitive detection of hepatocellular carcinoma (HCC).

AIM

We performed a meta-analysis of all available studies of the diagnostic performance of gadoxetic acid-enhanced MRI (Gd-EOB-MRI) for detection of HCC in patients with chronic liver disease.

METHODS

Databases including MEDLINE and EMBASE were searched for relevant original articles published from January 2000 to April 2012. Pooled estimation and subgroup analysis data were obtained by statistical analysis.

RESULTS

Across 10 studies of 570 patients, Gd-EOB-MRI sensitivity was 0.91 (95 % CI 0.77, 0.97) and specificity was 0.93 (95 % CI 0.85, 0.97). Overall, LR+ was 13.6 (95 % CI 5.6, 33.2), LR- was 0.10 (95 % CI 0.04, 0.27), and DOR was 140.36 (95 % CI 28, 696). Among patients with high pre-test probabilities, MRI enabled confirmation of HCC; among patients with low pre-test probabilities, MRI enabled exclusion of HCC. Worst-case-scenario (pre-test probability, 50 %) post-test probabilities were 93 and 9 % for positive and negative MRI results, respectively. In studies in which both Gd-EOB-MRI and contrast enhanced computed tomography (CE-CT) were performed, Gd-EOB-MRI was more sensitive than CE-CT (0.93 vs. 0.78; p < 0.05). Subgroup analysis suggested average lesion size (<2 vs. >2 cm) did not affect the diagnostic accuracy of the test (p > 0.05).

CONCLUSIONS

A limited number of small studies suggest Gd-EOB-MRI has good diagnostic performance in the detection of HCC among patients with chronic liver disease. It is also confirmed to be a reliable tool for evaluation of small early-stage HCC.

Detection of hepatocellular carcinoma in gadoxetic acid-enhanced MRI and diffusion-weighted MRI with respect to the severity of liver cirrhosis

BACKGROUND

As gadoxetic acid-enhanced magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) have been widely used for the evaluation of hepatocellular carcinoma (HCC), it is clinically relevant to determine the diagnostic efficacy of gadoxetic acid-enhanced MRI and DWI for detection of HCCs with respect to the severity of liver cirrhosis.

PURPOSE

To compare the diagnostic accuracy and sensitivity of gadoxetic acid-enhanced MRI and DWI for detection of HCCs with respect to the severity of liver cirrhosis.

MATERIAL AND METHODS

A total of 189 patients with 240 HCCs (≤3.0 cm) (Child-Pugh A, 81 patients with 90 HCCs; Child-Pugh B, 65 patients with 85 HCCs; Child-Pugh C, 43 patients with 65 HCCs) underwent DWI and gadoxetic acid-enhanced MRI at 3.0 T. A gadoxetic acid set (dynamic and hepatobiliary phase plus T2-weighted image) and DWI set (DWI plus unenhanced MRIs) for each Child-Pugh class were analyzed independently by two observers for detecting HCCs using receiver-operating characteristic analysis. The diagnostic accuracy and sensitivity were calculated.

RESULTS

There was a trend toward decreased diagnostic accuracy for gadoxetic acid and DWI set with respect to the severity of cirrhosis (Child-Pugh A [mean 0.974, 0.961], B [mean 0.904, 0.863], C [mean 0.779, 0.760]). For both observers, the sensitivities of both image sets were highest in Child-Pugh class A (mean 95.6%, 93.9%), followed by class B (mean 83.0%, 77.1%), and class C (mean 60.6%, 60.0%) (P < 0.05).

CONCLUSION

In HCC detection, the diagnostic accuracy and sensitivity for gadoxetic acid-enhanced MRI and DWI were highest in Child-Pugh class A, followed by Child-Pugh class B, and Child-Pugh class C, indicating a tendency toward decreased diagnostic capability with the severity of cirrhosis.

Imaging of HCC

Imaging techniques play a crucial role in the management of patients with liver cirrhosis in whom a nodular hepatic lesion is detected. The most severe complication of patients with liver cirrhosis is the development of a hepatocellular carcinoma (HCC), and the prognosis of the disease depends on the tumoral stage. Surveillance programs based on ultrasonography (US) are recommended in cirrhotic patients with possibility to be treated if an HCC is detected, in order to improve the patient's survival. Nevertheless, early detection and diagnostic confirmation of HCC remains a challenge despite technological advances. The non-invasive criteria to characterize small HCCs in patients with cirrhosis are based on the evaluation of the vascular profile of the lesion. Dynamic multidetector computed tomography (MDCT) and dynamic magnetic resonance imaging (MRI) are the suitable techniques for this purpose. When diagnosis is not achieved, fine US-guided fine needle biopsy (FNB) is indicated. Cellular-MRI contrast agents may have a role in lesions with atypical vascular pattern in which FNB is not feasible. The assessment of the disease extent is another important goal for imaging techniques. Again, dynamic MDCT and dynamic MRI may be used for staging purposes. Although MRI is more accurate in the detection of additional nodules ranging 1-2 cm, both remain relatively insensitive for the detection of tiny satellite nodules below 1 cm. The therapeutic decision can be made in any particular patient on the basis of the tumoral extension, the liver function, and the general status. After curative and palliative therapeutic procedures, the monitoring of the response is mandatory to decide the next approach: to follow-up, to repeat the treatment, to modify the treatment indication, or to suspend the treatment. In this review, we discuss the most recent information on the imaging of HCC.

Diagnostic accuracy and sensitivity of diffusion-weighted and of gadoxetic acid-enhanced 3-T MR imaging alone or in combination in the detection of small liver metastasis (≤ 1.5 cm in diameter)

PURPOSE

To compare the diagnostic accuracy and sensitivity of combined gadoxetic acid-enhanced magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) with each imaging approach alone for detecting small hepatic metastases (≤ 1.5 cm).

MATERIALS AND METHODS

Institutional review board approved this retrospective study and waived informed patient consent. Eighty-six patients with 179 liver metastases underwent liver MRI including unenhanced and gadoxetic acid-enhanced imaging and DWI at 3.0 T. Three image sets including unenhanced images-gadoxetic acid set (early dynamic and hepatocyte phase), DWI set, and the combined set-were analyzed independently and in consensus by 2 observers for detecting liver metastases using receiver operating characteristic analysis.

RESULTS

There was a tendency toward an increased diagnostic accuracy for the combined set (mean, 0.965) compared with that for each image set alone (mean, 0.911 for gadoxetic acid set; 0.926 for DWI set). The combined set showed better sensitivity (mean, 97.47%/95.0%: values on per-lesion/per-patient basis) than each imaging set alone (mean, 90.7%/83.7% for gadoxetic acid set; 91.6%/83.0% for DWI set) (P < 0.05) on both per-lesion basis and per-patient basis. All image sets showed similar positive predictive values.

CONCLUSIONS

The combination of gadoxetic acid-enhanced MRI and DWI yielded better diagnostic accuracy and sensitivity in the detection of small liver metastasis than each magnetic resonance scan sequence alone.

Recent advances in cytogenetics and molecular biology of adult hepatocellular tumors: implications for imaging and management

Focal nodular hyperplasia (FNH), hepatocellular adenoma (HCA), and hepatocellular carcinoma (HCC) compose hepatocellular neoplasms that occur in adults. These tumors demonstrate characteristic epidemiologic and histopathologic features and clinical and imaging manifestations. HCAs are monoclonal neoplasms characterized by increased predilection to hemorrhage or rupture and occasional transformation to HCC. On the other hand, FNH is a polyclonal tumorlike lesion that occurs in response to increased perfusion and has an indolent clinical course. Up to 90% of HCCs occur in the setting of cirrhosis. Chronic viral hepatitis (hepatitis B and hepatitis C) infection and metabolic syndrome are major risk factors that can induce HCCs in nonfibrotic liver. Recent advances in pathology and genetics have led to better understanding of the histogenesis, natural history, and molecular events that determine specific oncologic pathways used by these neoplasms. HCAs are now believed to result from specific genetic mutations involving TCF1 (transcription factor 1 gene), IL6ST (interleukin 6 signal transducer gene), and CTNNB1 (β catenin-1 gene); FNHs are characterized by an "imbalance" of angiopoietin. While the β catenin signaling pathway is associated with well- and moderately differentiated HCCs, mutations involving p53 (tumor protein 53 gene), MMP14 (matrix metalloproteinase 14 gene), and RhoC (Ras homolog gene family, member C) are associated with larger tumor size, higher tumor grade with resultant shortened tumor-free survival, and poor prognosis. Fibrolamellar carcinoma (FLC), a unique HCC subtype, exhibits genomic homogeneity that partly explains its better overall prognosis. On the basis of recent study results involving cytogenetics and oncologic pathways of HCCs, novel drugs that act against molecular targets are being developed. Indeed, sorafenib (a multikinase inhibitor) is currently being used in the successful treatment of patients with advanced HCC. Characterization of genetic abnormalities and genotype-phenotype correlations in adult hepatocellular tumors provides better understanding of tumor pathology and biology, imaging findings, prognosis, and response to molecular therapeutics.

Comparison of enhancement patterns of histologically confirmed hepatocellular carcinoma between gadoxetate- and ferucarbotran-enhanced magnetic resonance imaging

PURPOSE

To compare enhancenent patterns of hepatocellular carcinoma (HCC) and dysplastic nodule (DN) between gadoxetate- and ferucarbotran-enhanced MRI.

MATERIALS AND METHODS

Patients recruited from ultrasound surveillance for HCC in chronic liver diseases were enrolled in this prospective study approved by institutional review board. Thirty-six patients with 37 histologically proven HCC, including 22 well-differentiated HCCs (wHCC), 15 moderately to poorly differentiated HCCs (mpHCCs), and 4 DNs, underwent gadoxetate-enhanced and ferucarbotran-enhanced MRI. We compared hepatobiliary phase image of gadoxetate-enhanced MRI with ferucarbotran-enhanced MR image regarding signal intensity of HCC and DN relative to surrounding liver parenchyma. We calculated contrast ratios between tumor and liver on pre-enhancement, hepatobiliary phase of gadoxetate-enhanced MRI and ferucarbotran-enhanced MRI.

RESULTS

On ferucarbotran-enhanced MRI, all mpHCCs showed hyper-intensity, while 14 wHCCs (14/22;63%) showed iso-intensity. On hepatobiliary phase of gadoxetate-enhanced MRI, 13 mpHCCs (13/15;86%) and 20 wHCCs (20/22;91%) showed hypo-intensity. Two DNs and the other two showed iso- and hypo-intensity, respectively, on gadoxetate-enhanced MRI, whereas all DNs revealed iso-intensity on ferucarbotran-enhanced MRI. Gadoxetate-postcontrast ratio was significantly lower than ferucarbotran-postcontrast ratio in wHCC (P = 0.015).

CONCLUSION

The uptake function of hepatocytes that are targeted by gadoxetate is more sensitive than that of Kupffer cells targeted by ferucarbotran in stepwise hepatocarcinogenesis.

APASL and AASLD Consensus Guidelines on Imaging Diagnosis of Hepatocellular Carcinoma: A Review

Consensus guidelines for radiological diagnosis of hepatocellular carcinoma (HCC) have been drafted by several large international working groups. This article reviews the similarities and differences between the most recent guidelines proposed by the American Association for Study of Liver Diseases and the Asian Pacific Association for the Study of the Liver. Current evidence for the various imaging modalities for diagnosis of HCC and their relevance to the consensus guidelines are reviewed.

Gadoxetate Acid-Enhanced MR Imaging for HCC: A Review for Clinicians

Hepatocellular carcinoma (HCC) is increasingly being detected at an earlier stage, owing to the screening programs and regular imaging follow-up in high-risk populations. Small HCCs still pose diagnostic challenges on imaging due to decreased sensitivity and increased frequency of atypical features. Differentiating early HCC from premalignant or benign nodules is important as management differs and has implications on both the quality of life and the overall survival for the patients. Gadoxetate acid (Gd-EOB-DTPA, Primovist(®), Bayer Schering Pharma) is a relatively new, safe and well-tolerated liver-specific contrast agent for magnetic resonance (MR) imaging of the liver that has combined perfusion- and hepatocyte-specific properties, allowing for the acquisition of both dynamic and hepatobiliary phase images. Its high biliary uptake and excretion improves lesion detection and characterization by increasing liver-to-lesion conspicuity in the added hepatobiliary phase imaging. To date, gadoxetate acid-enhanced MRI has been mostly shown to be superior to unenhanced MRI, computed tomography, and other types of contrast agents in the detection and characterization of liver lesions. This review article focuses on the evolving role of gadoxetate acid in the characterization of HCC, differentiating it from other mimickers of HCC.