Comparison of gadobenate dimeglumine-enhanced dynamic MRI and 16-MDCT for the detection of hepatocellular carcinoma

Diagnostic Values of the Liver Imaging Reporting and Data System in the Detection and Characterization of Hepatocellular Carcinoma: A Systematic Review and Meta-Analysis

This review was undertaken to assess the diagnostic value of the Liver Imaging Reporting and Data System (LI-RADS) in patients with a high risk of hepatocellular carcinoma (HCC). Google Scholar, PubMed, Web of Science, Embase, PROQUEST, and Cochrane Library, as the international databases, were searched with appropriate keywords. Using the binomial distribution formula, the variance of all studies was calculated, and using Stata version 16 (StataCorp LLC, College Station, TX, USA), the obtained data were analyzed. Using a random-effect meta-analysis approach, we determined the pooled sensitivity and specificity. Utilizing the funnel plot and Begg's and Egger's tests, we assessed publication bias. The results exhibited pooled sensitivity and pooled specificity of 0.80% and 0.89%, respectively, with a 95% confidence interval (CI) of 0.76-0.84 and 0.87-0.92, respectively. The 2018 version of LI-RADS showed the greatest sensitivity (0.83%; 95% CI 0.79-0.87; I ² = 80.6%; P < 0.001 for heterogeneity; T ² = 0.001). The maximum pooled specificity was detected in LI-RADS version 2014 (American College of Radiology, Reston, VA, USA; 93.0%; 95% CI 89.0-96.0; I ² = 81.7%; P < 0.001 for heterogeneity; T ² = 0.001). In this review, the results of estimated sensitivity and specificity were satisfactory. Therefore, this strategy can serve as an appropriate tool for identifying HCC.

Hepatocellular Carcinoma: Current Imaging Modalities for Diagnosis and Prognosis

As opposed to most solid cancers, hepatocellular carcinoma (HCC) does not necessarily require histological confirmation. Noninvasive diagnosis is possible and relies on imaging. In cirrhotic patients, the diagnosis can be obtained in tumors displaying typical features that include non-rim arterial phase hyperenhancement followed by washout during the portal venous and/or delayed phases on CT or MR imaging. This pattern is very specific and, as such, has been endorsed by both Western and Asian diagnostic guidelines and systems. However, its sensitivity is not very high, especially for small lesions. Numerous ancillary features favoring the diagnosis of HCC may be depicted, including appearance after injection of hepatobiliary MR imaging contrast agents. These features increase confidence in diagnosis, but cannot be used as substitutes to liver biopsy. Aside from its diagnostic purpose, imaging also helps to assess tumor biology and patient outcome, by identifying features of local invasiveness. The purpose of this review article is to offer an overview of the role of imaging for the diagnosis and prognostication of HCC.

Diagnostic accuracy of contrast-enhanced dynamic CT for small hypervascular hepatocellular carcinoma and assessment of dynamic enhancement patterns: Results of two-year follow-up using cone-beam CT hepatic arteriography

Objective

To evaluate the accuracy of CT for small, hypervascular hepatocellular carcinomas (HCCs) and assess the enhancement patterns on CT.

Materials and methods

Ninety-nine patients who underwent cone-beam CT hepatic arteriography (CBCT-HA) during initial chemoembolization for HCC suspected on CT were enrolled in this study. A total of 297 hypervascular HCCs (142 ≥ 1 cm, 155 < 1 cm) were confirmed as HCCs based on two-year follow-up CT and CBCT-HA images. During the two-year follow-up, pre-existing hypervascular foci on CBCT-HA were regarded as HCCs at the initial presentation. Two radiologists categorized HCCs according to the following enhancement patterns on CT: type I, arterial enhancement and washout; type II, arterial enhancement without washout; and type III, no arterial enhancement. Two blinded reviewers rated the possibility of HCC.

Results

For the 297 HCCs, the enhancement patterns according to size were as follows: type I ≥1 cm in 114 HCCs; type I <1 cm in 40 HCCs; type II ≥1 cm in 16 HCCs; type II <1 cm in 37 HCCs; type III ≥1 cm in 12 HCCs; and type III <1 cm in 10 HCCs. The remaining 68 HCCs (22.9%) were not detected on CT. The detection rates of HCCs ≥ 1 cm were 83.1%, 76.8%, and 83.1% in the formal report for reviewer 1 and reviewer 2. In comparison, the detection rates of HCCs < 1 cm were 20.6%, 17.4%, and 17.4% in the formal report for reviewer 1 and reviewer 2.

Conclusion

Many subcentimeter sized hypervascular HCCs were frequently missed or not evident on CT at the initial diagnostic workup. CT has limitations for diagnosing HCCs that are <1 cm in size or have atypical enhancement patterns.

Does a combined CT and MRI protocol enhance the diagnostic efficacy of LI-RADS in the categorization of hepatic observations? A prospective comparative study

OBJECTIVE

To compare diagnostic performance and agreement between CT, MRI and combined CT/MRI in reference to LI-RADS classification system to categorize hepatic observations detected in hepatic patients during screening ultrasound.

METHODS

240 patients with 296 liver observations detected during ultrasound surveillance underwent hepatic CT and MRI examinations, histopathology, and clinical and radiological follow-up. Using LI-RADS v2014, six radiologists evaluated the observations independently and assigned a LI-RADS category to each observation using CT, MRI and combined CT/MRI.

RESULTS

Combined CT and MRI in LI-RADS yielded better accuracy (91.29 %), sensitivity (90.71 %) and specificity (92.31 %) for hepatocellular carcinoma (HCC) diagnosis than using MRI or CT alone; accuracy, sensitivity and specificity decreased to 85.37 %, 86.34 %, and 83.65 %, respectively, for MRI and 67.6 %, 54.10 % and 91.35 %, respectively, for CT. The intraclass agreement of the LI-RADS scores between CT, MRI and combined CT/MRI was excellent (κ=0.9624 (95 % CI: 0.9318-0.9806)).

CONCLUSION

CT and MRI are complementary to each other. Combined CT/MRI enabled a more precise determination of LI-RADS category of hepatic observations; however, due to the expense and minor increase in accuracy, the combined methodology should only be utilized in cases of suspected HCC.

KEY POINTS

• Hepatic observation may be categorized differently depending on the imaging modality used. • We compared LI-RADS categorization between CT, MRI and combined CT/MRI. • MRI produces higher accuracy and sensitivity, while CT produces higher specificity. • Combining CT and MRI improves LIRADS categorization reports. • Considering additional cost, combined methodology could be restricted to challenging cases.

Prospective Comparison of Gd-EOB-DTPA-Enhanced MRI with Dynamic CT for Detecting Recurrence of HCC after Radiofrequency Ablation

BACKGROUND

We prospectively compared the efficacy of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) with that of dynamic multidetector computed tomography (MDCT) for detection of recurrent hypervascular hepatocellular carcinoma (HCC) after radiofrequency ablation (RFA).

METHODS

Institutional review board approval and written informed consent were obtained for this multicenter study. Ninety-seven HCC patients treated with curative RFA underwent both Gd-EOB-DTPA-enhanced MRI and dynamic MDCT every 3-4 months. HCC diagnosis was made based on the typical enhancement pattern of HCC on MRI and/or CT by on-site consensus reading. Two blinded observers independently assessed image datasets to compare diagnostic accuracy, sensitivity, specificity, and the areas under the receiver operating characteristic curve (AUROC).

RESULTS

Recurrence was observed in 48 of 97 patients. Among these, 22 were diagnosed by both Gd-EOB-DTPA-enhanced MRI and MDCT; the remainder were diagnosed by only one of these 2 modalities. Recurrence was diagnosed in more patients by Gd-EOB-DTPA-enhanced MRI than by MDCT (44 vs. 26 patients, p < 0.001). Patient-based analysis revealed that the accuracy, sensitivity, and AUROC of Gd-EOB-DTPA-enhanced MRI were significantly higher than those of MDCT for both observers (p < 0.005). The AUROC of Gd-EOB-DTPA- enhanced MRI and MDCT was 0.95 and 0.76 for observer 1 and 0.90 and 0.74 for observer 2, respectively. The κ values for MRI and MDCT were 0.83 and 0.70, respectively.

CONCLUSIONS

Compared with dynamic MDCT, Gd-EOB-DTPA-enhanced MRI had higher diagnostic accuracy and sensitivity for detection of recurrent hypervascular HCC and may be a better tool for following patients after RFA.

Small hepatocellular carcinomas displayed as a ring enhancing mass on arterial phase MRI in the chronically diseased liver

AIM

To assess the prevalence of arterial phase (AP) ring-enhancing small hepatocellular carcinomas (HCC) on magnetic resonance imaging (MRI); detail additional MRI features that enable HCC diagnosis; and examine arterial timing as one possible cause of this appearance.

MATERIALS AND METHODS

Patients undergoing HCC screening with both computed tomography (CT) and MRI within 40 days were examined at a single institution over a 7- year time period ending in 2013. From this initial group, small (1-3 cm), (AP) ring-enhancing HCC on MRI were studied.

RESULTS

From the initial group of 64 patients with 129 HCC, 20 patients with 78 HCCs had a small diameter with 32 (41%) having an AP ring at MRI. The mean age of this latter group was 63-years old, with the average tumour diameter of 1.9 cm. Histopathology and secondary imaging supported a diagnosis of HCC in 20 (100%) patients and 31 (97%) lesions. Most of the ringed lesions had early AP timing.

CONCLUSION

This study revealed a high prevalence (41%) of small, AP ring HCC with MRI. The use of other MRI sequences adds support in making the proper diagnosis with this appearance. Early AP timing may help create this pattern.

Asia-Pacific clinical practice guidelines on the management of hepatocellular carcinoma: a 2017 update

There is great geographical variation in the distribution of hepatocellular carcinoma (HCC), with the majority of all cases worldwide found in the Asia-Pacific region, where HCC is one of the leading public health problems. Since the "Toward Revision of the Asian Pacific Association for the Study of the Liver (APASL) HCC Guidelines" meeting held at the 25th annual conference of the APASL in Tokyo, the newest guidelines for the treatment of HCC published by the APASL has been discussed. This latest guidelines recommend evidence-based management of HCC and are considered suitable for universal use in the Asia-Pacific region, which has a diversity of medical environments.

Early Detection of Hepatocellular Carcinoma in Patients with Hepatocirrhosis by Soluble B7-H3

Increasing evidence has demonstrated an association between increased soluble B7-H3 (sB7-H3) levels and unfavorable progression in patients with malignant tumors. In the present study, we detected sB7-H3 levels in serum to investigate the value of sB7-H3 as a tool for differential diagnosis of cirrhotic patients with or without early-stage hepatocellular carcinoma (ESHCC). We also assessed the diagnostic value of sB7-H3regarding the prediction of overall survival (OS) of cirrhotic patients with ESHCC. sB7-H3 expression was measured in 91 healthy volunteers, 149 cirrhotic patients with ESHCC, and 87 cirrhotic patients by ELISA, and correlations between DCP1a level and clinical characteristics were analyzed. SB7-H3 concentrations were significantly higher in patients with ESHCC than in cirrhotic patients (P < 0.001). Using 48.34 ng/mL as a cutoff value, the sensitivity and specificity of sB7-H3 in differentiating between cirrhotic patients and cirrhotic patients with ESHCC were 76.5 and 93.1%, respectively. Moreover, high serum sB7-H3 in cirrhotic patients with ESHCC correlated with tumor size, tumor stage, vascular invasion, and tumor differentiation. The area under the curve (AUC) value for sB7-H3 (0.898) was significantly higher than those for AFP (0.789), CA199 (0.627), and CA125 (0.545) for differentiating between cirrhotic patients with ESHCC and sex- and age-matched cirrhotic patients without ESHCC. Our data indicate that serum sB7-H3 serves as a valuable biomarker for cirrhotic patients with ESHCC and that high levels of sB7-H3 correlate with poor clinical outcomes.

Imaging of hepatocellular carcinoma and image guided therapies - how we do it

Treatment options for hepatocellular carcinoma have evolved over recent years. Interventional radiologists and surgeons can offer curative treatments for early stage tumours, and locoregional therapies can be provided resulting in longer survival times. Early diagnosis with screening ultrasound is the key. CT and MRI are used to characterize lesions and determine the extent of tumour burden. Imaging techniques are discussed in this article as the correct imaging protocols are essential to optimise successful detection and characterisation. After treatment it is important to establish regular imaging follow up with CT or MRI as local residual disease can be easily treated, and recurrence elsewhere in the liver is common.

Functional imaging in liver tumours

Functional imaging encompasses techniques capable of assessing physiological parameters of tissues, and offers useful clinical information in addition to that obtained from morphological imaging. Such techniques may include magnetic resonance imaging with diffusion-weighted sequences or hepatobiliary contrast agents, perfusion imaging, or molecular imaging with radiolabelled tracers. The liver is of major importance in oncological practice; not only is hepatocellular carcinoma one of the malignancies with steadily rising incidence worldwide, but hepatic metastases are regularly observed with a range of solid neoplasms. Within the realm of hepatic oncology, different functional imaging modalities may occupy pivotal roles in lesion characterisation, treatment selection and follow-up, depending on tumour size and type. In this review, we characterise the major forms of functional imaging, discuss their current application to the management of patients with common primary and secondary liver tumours, and anticipate future developments within this field.

Differences in Liver Imaging and Reporting Data System Categorization Between MRI and CT

OBJECTIVE

The purpose of this study is to determine whether focal liver observations are categorized differently by CT and MRI using the Liver Imaging and Reporting Data System (LI-RADS).

MATERIALS AND METHODS

We performed a retrospective review of 58 patients at risk for hepatocellular carcinoma who underwent liver protocol CT and MRI within 1 month of each other. Two readers assigned a LI-RADS category for all focal liver observations in consensus. A significant category upgrade was defined as a change from LI-RADS categories 1 and 2 or nonvisualization to LI-RADS categories 3-5, from LI-RADS category 3 to category 4 or 5, from LI-RADS category 4 to category 5, or from any category to LI-RADS category 5V. A significant downgrade was defined as a change from LI-RADS category 5 to categories 1-4, from LI-RADS category 4 to categories 1-3, or from LI-RADS category 3 to categories 1 or 2.

RESULTS

The LI-RADS category was different between CT and MRI for 77.2% (176/228) of observations. A significant upgrade occurred on MRI for 42.5% (97/228) of observations because of nonvisualization by CT (n = 78), capsule (n = 8), arterial hyperenhancement (n = 4), intratumoral fat (n = 2), larger size (n = 2), tumor in portal vein (n = 2), and wash-out (n = 1). Of these 97 upgraded observations, two were upgraded to LI-RADS category 5V, 15 were upgraded to category 5, and 13 were upgraded to category 4. A significant downgrade occurred on MRI for 8.8% (20/228) of observations because of marked T2 hyperintensity (n = 14), smaller size (n = 2), wedge shape (n = 2), and marked T2 hypointensity (n = 2).

CONCLUSION

LI-RADS categorization of focal liver observations is dependent on imaging modality. MRI results in both upgraded and downgraded categorization compared with CT in an important proportion of observations.

Rate of observation and inter-observer agreement for LI-RADS major features at CT and MRI in 184 pathology proven hepatocellular carcinomas

PURPOSE

To compare frequency and inter-reader agreement for LI-RADS v2014 major features at CT vs. MRI in pathology-proven cases of hepatocellular carcinoma.

METHODS

Pathology reports and imaging studies from patients having undergone liver transplant or hepatectomy for hepatocellular carcinoma were reviewed. Size, location, washout, and capsule appearance for each lesion were recorded by two radiologists. Cohen's kappa and intraclass correlation coefficients (ICC) were calculated.

RESULTS

One hundred and thirty-four patients with 184 tumors were reviewed. Seventy-seven percentage of lesions were imaged by CT and 23% by MRI. No lesions were evaluated with both modalities. Mean lesion diameter was 2.6 ± 1.3 cm (ICC = 0.92). Arterial phase hyperenhancement was seen in 86% of lesions (κ = 0.75). Washout was seen in 82% of studies (κ = 0.61). Arterial phase hyperenhancement and washout were seen equally at CT and MRI (p = 1.00 and 0.46, respectively). Capsule was infrequently observed (27%) but was seen more commonly at MRI (44%) than at CT (17%) with p = 0.002 and (κ = 0.56). Forty-seven percent of lesions with at least one prior study met LI-RADS criteria for threshold growth. The rates of LI-RADS categories 3, 4, and 5 were 9%, 37%, and 54%, respectively. More 1-2 cm LI-RADS 5 lesions were seen at MRI (43%) than at CT (8%), p = 0.01.

CONCLUSION

A combined LI-RADS 4/5 group was 91% sensitive for hepatocellular carcinoma. Arterial enhancement and washout were seen more frequently than capsule, the sole finding seen more frequently at MRI than at CT. Inter-reader reliability was substantial for arterial hyperenhancement and washout but moderate for capsule. Capsule remains an important finding in small arterially enhancing lesions (1-2 cm) which require a second major criterion to upgrade to a LI-RADS 5 lesion.

Effect of MRI Versus MDCT on Milan Criteria Scores and Liver Transplantation Eligibility

OBJECTIVE

The Milan criteria for the selection of patients with hepatocellular carcinoma (HCC) for liver transplantation were originally based on the findings of contrast-enhanced CT examinations. Studies have shown improvement in HCC detection of using contrast-enhanced MRI instead of CT, but they have provided little information on the potential downstream effect on patient management that might result from discrepant imaging findings. We sought to assess the effect of discrepant imaging findings on patient eligibility to undergo liver transplantation.

MATERIALS AND METHODS

From 2006 to 2013, patients with a diagnosis of HCC who underwent both MDCT and MRI examinations within a 40-day period were studied retrospectively. All examinations were independently reviewed by two abdominal radiologists who recorded the number, diameter, and location of each lesion. Secondary confirmation of the lesions was made on the basis of histopathologic findings, diffusion restriction on DWI, increased T2 signal intensity, lesion growth, presence of fat, uptake of ethiodized oil, or a combination of these findings.

RESULTS

Sixty-four patients (48 men and 16 women; mean age, 62 years) met the criteria for inclusion in the study. Of the 129 lesions identified by MRI, only 102 of these lesions (79%) were identified by MDCT. This discrepancy led to a difference in the Milan criteria scoring for nine patients (14%). There was no statistically significant difference in the mean (± SD) greatest lesion diameter measured using the two modalities, with measurements of 3.52 ± 2.8 cm and 3.46 ± 2.8 cm noted on MDCT and MRI, respectively (p = 0.8). Lesions missed on MDCT studies tended to be smaller, with a mean diameter of 2.7 cm. Of the 129 lesions identified by MRI, 112 (87%) had available histopathologic findings or other confirmatory diagnostic evidence.

CONCLUSION

MDCT missed one-fifth of the HCC lesions detected by MRI. Had MDCT been the only imaging examination performed, failure to identify these lesions would have led to a different management plan for 14% of patients.

Advances in computed tomography and magnetic resonance imaging of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver cancer. Imaging is important for establishing a diagnosis of HCC and early diagnosis is imperative as several potentially curative treatments are available when HCC is small. Hepatocarcinogenesis occurs in a stepwise manner on a background of chronic liver disease or cirrhosis wherein multiple genes are altered resulting in a range of cirrhosis-associated nodules. This progression is related to increased cellularity, neovascularity and size of the nodule. An understanding of the stepwise progression may aid in early diagnosis. Dynamic and multiphase contrast-enhanced computed tomography and magnetic resonance imaging still form the cornerstone in the diagnosis of HCC. An overview of the current diagnostic standards of HCC in accordance to the more common practicing guidelines and their differences will be reviewed. Ancillary features contribute to diagnostic confidence and has been incorporated into the more recent Liver Imaging Reporting and Data System. The use of hepatocyte-specific contrast agents is increasing and gradually changing the standard of diagnosis of HCC; the most significant benefit being the lack of uptake in the hepatocyte phase in the earlier stages of HCC progression. An outline of supplementary techniques in the imaging of HCC will also be reviewed.

Comparison of gadoxetic acid-enhanced magnetic resonance imaging and contrast-enhanced computed tomography with histopathological examinations for the identification of hepatocellular carcinoma: a multicenter phase III study

BACKGROUND

Gadoxetic acid-enhanced magnetic resonance imaging (MRI) has an important role in preoperative evaluation of hepatocellular carcinoma (HCC). However, no studies have prospectively performed intraindividual comparison of gadoxetic acid-enhanced 3T MRI and multidetector-row computed tomography (MDCT) with histopathological examination for the detection of HCCs. We prospectively compared the efficacies of gadoxetic acid-enhanced MRI and multiphasic contrast-enhanced MDCT with that of histopathological examination, used as a reference standard, for the detection of HCC in surgical candidates.

METHODS

The study was approved by the institutional review boards at each of four centers. Patients scheduled to undergo multiphasic CT, gadoxetic acid-enhanced MRI, and liver surgery were prospectively included in this study. The diagnostic abilities of MRI and CT were evaluated and compared on the basis of sensitivity and positive predictive value for detection of and differentiation between HCCs and benign lesions.

RESULTS

Fifty-four patients with 83 histopathologically confirmed HCCs were included in the study. Combined interpretation of the dynamic and hepatobiliary phases of gadoxetic acid-enhanced MRI showed statistically higher sensitivity for lesion detection (83 %) than did interpretation of multiphasic MDCT images (70 %; p < 0.001). The mean area under each alternative free-response receiver operating characteristics curve was significantly higher for MR images (0.927) than for CT images (0.864, p < 0.01).

CONCLUSIONS

The sensitivity for preoperative detection of HCCs was higher for gadoxetic acid-enhanced MRI than for multiphasic MDCT imaging.

Liver-specific gadoxetic acid-enhanced magnetic resonance for focal lesion evaluation

Gadolinium-enhanced magnetic resonance for the evaluation of hepatic lesions is increasingly being used in clinical practice, especially in patients with suspicious focal lesions, whether benign or malignant. In regard to hepatocellular carcinoma, the diagnostic performance of magnetic resonance through the «conventional» protocols and multi-detector computerized tomography consisting of multiphase evaluation with intravenous contrast, largely depends on the size of the lesion. They are more reliable in lesions>2cm. However, in lesions measuring 1-2cm, establishing the definitive diagnosis is a real challenge, with sensitivity values of 45-65%, but generally with excellent specificity (>95%). Furthermore, if the lesion has a diameter<1cm, diagnosis is usually unreliable. In these last 2 settings, the complementary use of liver-specific contrast agents can be advantageous. The aim of our article was to review the current evidence on the usefulness of this new non-invasive diagnostic method in hepatic lesions.

Multidisciplinary perspective of hepatocellular carcinoma: A Pacific Northwest experience

Hepatocellular carcinoma (HCC) is the most rapidly increasing type of cancer in the United States. HCC is a highly malignant cancer, accounting for at least 14000 deaths in the United States annually, and it ranks third as a cause of cancer mortality in men. One major difficulty is that most patients with HCC are diagnosed when the disease is already at an advanced stage, and the cancer cannot be surgically removed. Furthermore, because almost all patients have cirrhosis, neither chemotherapy nor major resections are well tolerated. Clearly there is need of a multidisciplinary approach for the management of HCC. For example, there is a need for better understanding of the fundamental etiologic mechanisms that are involved in hepatocarcinogenesis, which could lead to the development of successful preventive and therapeutic modalities. It is also essential to define the cellular and molecular bases for malignant transformation of hepatocytes. Such knowledge would: (1) greatly facilitate the identification of patients at risk; (2) prompt efforts to decrease risk factors; and (3) improve surveillance and early diagnosis through diagnostic imaging modalities. Possible benefits extend also to the clinical management of this disease. Because there are many factors involved in pathogenesis of HCC, this paper reviews a multidisciplinary perspective of recent advances in basic and clinical understanding of HCC that include: molecular hepatocarcinogenesis, non-invasive diagnostics modalities, diagnostic pathology, surgical modality, transplantation, local therapy and oncological/target therapeutics.

Imaging Techniques for the Diagnosis of Hepatocellular Carcinoma: A Systematic Review and Meta-analysis

BACKGROUND

Several imaging modalities are available for diagnosis of hepatocellular carcinoma (HCC).

PURPOSE

To evaluate the test performance of imaging modalities for HCC.

DATA SOURCES

MEDLINE (1998 to December 2014), the Cochrane Library Database, Scopus, and reference lists.

STUDY SELECTION

Studies on test performance of ultrasonography, computed tomography (CT), or magnetic resonance imaging (MRI).

DATA EXTRACTION

One investigator abstracted data, and a second investigator confirmed them; 2 investigators independently assessed study quality and strength of evidence.

DATA SYNTHESIS

Few studies have evaluated imaging for HCC in surveillance settings. In nonsurveillance settings, sensitivity for detection of HCC lesions was lower for ultrasonography without contrast than for CT or MRI (pooled difference based on direct comparisons, 0.11 to 0.22), and MRI was associated with higher sensitivity than CT (pooled difference, 0.09 [95% CI, 0.07 to 12]). For evaluation of focal liver lesions, there were no clear differences in sensitivity among ultrasonography with contrast, CT, and MRI. Specificity was generally 0.85 or higher across imaging modalities, but this item was not reported in many studies. Factors associated with lower sensitivity included use of an explanted liver reference standard, and smaller or more well-differentiated HCC lesions. For MRI, sensitivity was slightly higher for hepatic-specific than nonspecific contrast agents.

LIMITATIONS

Only English-language articles were included, there was statistical heterogeneity in pooled analyses, and costs were not assessed. Most studies were conducted in Asia and had methodological limitations.

CONCLUSION

CT and MRI are associated with higher sensitivity than ultrasonography without contrast for detection of HCC; sensitivity was higher for MRI than CT. For evaluation of focal liver lesions, the sensitivities of ultrasonography with contrast, CT, and MRI for HCC are similar.

PRIMARY FUNDING SOURCE

Agency for Healthcare Research and Quality. (

PROSPERO

CRD42014007016).

CT and MR imaging diagnosis and staging of hepatocellular carcinoma: part II. Extracellular agents, hepatobiliary agents, and ancillary imaging features

Computed tomography (CT) and magnetic resonance (MR) imaging play critical roles in the diagnosis and staging of hepatocellular carcinoma (HCC). The second article of this two-part review discusses basic concepts of diagnosis and staging, reviews the diagnostic performance of CT and MR imaging with extracellular contrast agents and of MR imaging with hepatobiliary contrast agents, and examines in depth the major and ancillary imaging features used in the diagnosis and characterization of HCC.

2014 KLCSG-NCC Korea Practice Guidelines for the management of hepatocellular carcinoma: HCC diagnostic algorithm

Hepatocellular carcinoma (HCC) is the fifth most commonly occurring cancer in Korea and typically has a poor prognosis with a 5-year survival rate of only 28.6%. Therefore, it is of paramount importance to achieve the earliest possible diagnosis of HCC and to recommend the most up-to-date optimal treatment strategy in order to increase the survival rate of patients who develop this disease. After the establishment of the Korean Liver Cancer Study Group (KLCSG) and the National Cancer Center (NCC), Korea jointly produced for the first time the Clinical Practice Guidelines for HCC in 2003, revised them in 2009, and published the newest revision of the guidelines in 2014, including changes in the diagnostic criteria of HCC and incorporating the most recent medical advances over the past 5 years. In this review, we will address the noninvasive diagnostic criteria and diagnostic algorithm of HCC included in the newly established KLCSG-NCC guidelines in 2014, and review the differences in the criteria for a diagnosis of HCC between the KLCSG-NCC guidelines and the most recent imaging guidelines endorsed by the European Organisation for Research and Treatment of Cancer (EORTC), the Liver Imaging Reporting and Data System (LI-RADS), the Organ Procurement and Transplantation Network (OPTN) system, the Asian Pacific Association for the Study of the Liver (APASL) and the Japan Society of Hepatology (JSH).

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.

Detection of small (≤2 cm) HCC in cirrhotic patients: added value of diffusion MR-imaging

OBJECTIVES

To evaluate the usefulness of the diffusion-weighted sequence in the detection of small (≤2 cm) hepatocellular carcinoma (HCC) in patients with cirrhosis.

METHODS

Seventy cirrhotic patients with 93 HCCs underwent MR-Imaging at 1.5 T. MR acquisitions comprised unenhanced T1- and T2-weighted images and post-contrast Gd-BOPTA-enhanced T1W GRE-3D images acquired after approximately 25, 60, 180 s (dynamic phases) and 90 min (hepatobiliary phase). DWI was performed by a SSEPI sequence (b values 0, 50, 400, 800 s/mm(2)). Quantitative analysis was performed to establish significant difference of ADC values of benign lesions compared with that of HCC. Sensitivity, specificity, positive and negative predictive values and diagnostic accuracy of two different protocols with and without diffusion MRI sequence were also calculated and compared each other.

RESULTS

A good inverse correlation was found between reference standard and ADC values (ρ = -0.688). The mean ADC value of HCC was significantly lower than the mean value of benign focal liver lesions (p < 0.0001). No significant difference was reported in term of sensitivity, specificity, PPV, NPV and diagnostic accuracy between the two datasets. A trend to a better sensitivity was found when DWI images were considered.

CONCLUSIONS

The adjunction of DWI does not significantly improve the diagnostic accuracy in the detection of small HCC.

Evaluation of a method for improving the detection of hepatocellular carcinoma

OBJECTIVE

To improve the detection of liver lesions in patients with hepatocellular carcinoma (HCC) via an iodine contrast enhancement tool.

METHODS

Thirty-two patients with clinically proven HCCs underwent imaging with a three-phase protocol on a 256-slice MDCT. The contrast enhancement in the reconstructed slices was improved via a post-processing tool. Mean image noise was measured in four different regions: liver lesion, healthy liver, subcutaneous fat and bone. For each image set the image noise and contrast-to-noise ratio (CNR) were assessed. For subjective image assessment, four experienced radiologists evaluated the diagnostic quality.

RESULTS

While employing the post-processing algorithm, CNR between the liver lesion and healthy liver tissue improves significantly by a factor of 1.78 (CNRwithout vC = 2.30 ± 1.92/CNRwith vC = 4.11 ± 3.05) (P* = 0.01). All results could be achieved without a strengthening of artefacts; mean HU values of subcutaneous fat and bone did not significantly change. Subjective image analysis illustrated a significant improvement when employing post-processing for clinically relevant criteria such as diagnostic confidence.

CONCLUSION

With post-processing we see a significantly improved detection of arterial uptake in hepatic lesions compared with non-processed data. The improvement in CNR was confirmed by subjective image assessment for small lesions and for lesions with limited uptake.

KEY POINTS

• Enhancement with iodine-based contrast agents is an essential part of CT. • A new post-processing tool significantly improves the diagnostics of hepatocellular carcinoma. • It also improves detection of small lesions with limited iodine uptake.

Gd-EOB-DTPA-enhanced MRI is better than MDCT in decision making of curative treatment for hepatocellular carcinoma

BACKGROUND

We assessed the change in the therapeutic decision among curative treatments after adding Gd-EOB-DTPA-enhanced MRI to triple-phase MDCT for patients with early-stage HCC.

METHODS

This study retrospectively investigated two groups: 33 pathologically confirmed HCC patients after liver transplantation in group 1; 34 HCC patients without pathology in group 2. In group 1, we simulated the therapeutic decision-making process by pretransplant MDCT and Gd-EOB-DTPA-enhanced MRI. In group 2, including the 34 early-stage HCC patients consecutively enrolled, we investigated the change of therapeutic decision after adding Gd-EOB-DTPA-enhanced MRI to MDCT.

RESULTS

In the simulation from group 1, after adding Gd-EOB-DTPA-enhanced MRI, 33.3% (11/33 patients) of treatment decisions were changed from the decision based on MDCT alone. Among 22 patients considered eligible for resection and 33 patients for radiofrequency ablation, the therapeutic decision was changed for 10 patients in the surgical group and 4 patients for the RFA group (45.5 and 12.1%). In group 2, the rate of change in the therapeutic decision after adding Gd-EOB-DTPA-enhanced MRI to MDCT was 41.2% (14/34 patients). In group 1 with explants pathology, the median diameter of HCCs not detected by MDCT but detected by Gd-EOB-DTPA-enhanced MRI was 1.15 cm (0.3-3.0 cm). The median diameter of HCCs seen only in the explanted liver was 1.0 cm (0.3-1.7 cm), and 60.7% of them were well-differentiated HCCs.

CONCLUSIONS

This study suggests that performing Gd-EOB-DTPA-enhanced MRI before deciding on curative treatment for early-stage HCC may improve the accuracy of treatment decision for early-stage HCC.

Imaging of hepatocellular carcinoma: diagnosis, staging and treatment monitoring

Hepatocellular carcinoma (HCC) is the most common primary liver cancer. Imaging is important for establishing a diagnosis of HCC. Several imaging modalities including ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI), positron emission tomography (PET) and angiography are used in evaluating patients with chronic liver disease and suspected HCC. CT, MRI and contrast-enhanced US have replaced biopsy for diagnosis of HCC. Dynamic multiphase contrast-enhanced CT or MRI is the current standard for imaging diagnosis of HCC. Functional imaging techniques such as perfusion CT and diffusion-weighted MRI provide additional information about tumor angiogenesis that may be useful for treatment. Techniques evaluating tissue mechanical properties such as magnetic resonance elastography, and acoustic radiation force impulse imaging are being explored for characterizing liver lesions. The role of PET in the evaluation of HCC is evolving with promise seen especially with the use of a hepatocyte-specific PET tracer. Imaging is also critical for assessment of treatment response and detection of recurrence following locoregional treatment. Knowledge of the post-treatment appearance of HCC is essential for correct interpretation. This review article provides an overview of the role of imaging in the diagnosis, staging and post-treatment follow-up of HCC.

Hepatocellular carcinoma in cirrhotic patients: prospective comparison of US, CT and MR imaging

OBJECTIVES

To prospectively compare the diagnostic performance of ultrasound (US), multidetector computed tomography (MDCT) and contrast-enhanced magnetic resonance imaging (MRI) in cirrhotic patients who were candidates for liver transplantation.

METHODS

One hundred and forty consecutive patients with 163 hepatocellular carcinoma (HCC) nodules underwent US, MRI and MDCT. Diagnosis of HCC was based on pathological findings or substantial growth at 12-month follow-up. Four different image datasets were evaluated: US, MDCT, MRI unenhanced and dynamic phases, MRI unenhanced dynamic and hepatobiliary phase. Diagnostic accuracy, sensitivity, specificity, PPV and NPV, with corresponding 95 % confidence intervals, were determined. Statistical analysis was performed for all lesions and for three lesion subgroups (<1 cm, 1-2 cm, >2 cm).

RESULTS

Significantly higher diagnostic accuracy, sensitivity and NPV was achieved on dynamic + hepatobiliary phase MRI compared with US, MDCT and dynamic phase MRI alone. The specificity and PPV of US was significantly lower than that of MDCT, dynamic phase MRI and dynamic + hepatobiliary phase MRI. Similar results were obtained for all sub-group analyses, with particular benefit for the diagnosis of smaller lesions between 1 and 2 cm.

CONCLUSIONS

Dynamic + hepatobiliary phase MRI improved detection and characterisation of HCC in cirrhotic patients. The greatest benefit is for diagnosing lesions between 1 and 2 cm.

New paradigm for management of hepatocellular carcinoma by imaging

Based on recent clinical practice guidelines, imaging is largely replacing pathology as the preferred diagnostic method for determination of hepatocellular carcinoma (HCC). A variety of imaging modalities, including ultrasound (US), computed tomography (CT), magnetic resonance imaging (MRI), nuclear medicine, and angiography, are currently used to examine patients with chronic liver disease and suspected HCC. Advancements in imaging techniques such as perfusion imaging, diffusion imaging, and elastography along with the development of new contrast media will further improve the ability to detect and characterize HCC. Early diagnosis of HCC is essential for prompt treatment, which may in turn improve prognosis. Considering the process of hepatocarcinogenesis, it is important to evaluate sequential changes via imaging which would help to differentiate HCC from premalignant or benign lesions. Recent innovations including multiphasic examinations, high-resolution imaging, and the increased functional capabilities available with contrast-enhanced US, multidetector row CT, and MRI have raised the standards for HCC diagnosis. Although hemodynamic features of nodules in the cirrhotic liver remain the main diagnostic criterion, newly developed cellspecific contrast agents have shown great possibilities for improved HCC diagnosis and may overcome the diagnostic dilemma associated with small or borderline hepatocellular lesions. In the 20th century paradigm of medical imaging, radiological diagnosis was based on morphological characteristics, but in the 21st century, a paradigm shift to include biomedical, physiological, functional, and genetic imaging is needed. A multidisciplinary team approach is necessary to foster an integrated approach to HCC imaging. By developing and combining new imaging modalities, all phases of HCC patient care, including screening, diagnosis, treatment, and therapy, can be dramatically improved.

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.

Hepatocellular carcinoma: current trends in worldwide epidemiology, risk factors, diagnosis, and therapeutics

Hepatocellular carcinoma (HCC) is a common malignancy in developing countries and its incidence is on the rise in the developing world. The epidemiology of this cancer is unique since its risk factors, including hepatitis C and B, have been clearly established. The current trends in the shifting incidence of HCC in different regions of the world can be explained partly by the changing prevalence of hepatitis. Early detection offers the only hope for curative treatment for patients with HCC, hence effective screening strategies for high-risk patients is of utmost importance. Liver transplantation and surgical resection remains the cornerstone of curative treatment. But major advances in locoregional therapies and molecular-targeted therapies for the treatment of advanced HCC have occurred recently. In this review, current trends in the worldwide epidemiology, surveillance, diagnosis, standard treatments, and the emerging therapies for HCC are discussed.

Morphological and functional MDCT: problem-solving tool and surrogate biomarker for hepatic disease clinical care and drug discovery in the era of personalized medicine

This article explains the significant role of morphological and functional multidetector computer tomography (MDCT) in combination with imaging postprocessing algorithms served as a problem-solving tool and noninvasive surrogate biomarker to effectively improve hepatic diseases characterization, detection, tumor staging and prognosis, therapy response assessment, and novel drug discovery programs, partial liver resection and transplantation, and MDCT-guided interventions in the era of personalized medicine. State-of-the-art MDCT depicts and quantifies hepatic disease over conventional CT for not only depicting lesion location, size, and extent but also detecting changes in tumor biologic behavior caused by therapy or tumor progression before morphologic changes. Color-encoded parameter display provides important functional information on blood flow, permeability, leakage space, and blood volume. Together with other relevant biomarkers and genomics, the imaging modality is being developed and validated as a biomarker to early response to novel, targeted anti-VEGF(R)/PDGFR or antivascular/angiogenesis agents as its parameters correlate with immunohistochemical surrogates of tumor angiogenesis and molecular features of malignancies. MDCT holds incremental value to World Health Organization response criteria and Response Evaluation Criteria in Solid Tumors in liver disease management. MDCT volumetric measurement of future remnant liver is the most important factor influencing the outcome of patients who underwent partial liver resection and transplantation. MDCT-guided interventional methods deliver personalized therapies locally in the human body. MDCT will hold more scientific impact when it is fused with other imaging probes to yield comprehensive information regarding changes in liver disease at different levels (anatomic, metabolic, molecular, histologic, and other levels).

Gadoxetic acid (Gd-EOB-DTPA)-enhanced MRI versus gadobenate dimeglumine (Gd-BOPTA)-enhanced MRI for preoperatively detecting hepatocellular carcinoma: an initial experience

OBJECTIVE

This study was designed to compare the diagnostic performance of gadoxetic acid-enhanced magnetic resonance imaging (MRI) with gadobenate dimeglumine-enhanced MRI for preoperatively detecting hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Eighteen consecutive patients (17 men and one woman, age range: 31-73 years) with 22 HCCs underwent examinations with gadoxetic acid enhanced MRI and gadobenate dimeglumine-enhanced MRI on a 3.0-Tesla unit. The diagnosis of HCC was established after surgical resection and pathological conformation. Three observers independently reviewed each MR image in a random order on a tumor-by-tumor basis. The diagnostic accuracy of these techniques for the detection of HCC was assessed by performing an alternative free-response receiver operating characteristic (ROC) analysis. The sensitivity and positive predictive values were evaluated.

RESULTS

The average value of the area under the ROC curve (Az) for gadoxetic acid enhanced MRI (0.887) was not significantly different from the Az (0.899) for gadobenate dimeglumine-enhanced MRI (p > 0.05). The overall sensitivities of gadoxetic acid enhanced MRI and gadobenate dimeglumine-enhanced MRI were 80% and 83%, respectively, with no significant difference (p > 0.05). The differences of the positive predictive values for the two contrast agents for each observer were not statistically significant (p > 0.05).

CONCLUSION

The diagnostic performance of gadoxetic acid-enhanced MRI and gadobenate dimeglumine-enhanced MRI for preoperatively detecting HCC is quite similar.

Pretreatment assessment of hepatocellular carcinoma: expert consensus statement

Staging of hepatocellular carcinoma (HCC) is complex and relies on multiple factors including tumor extent and hepatic function. No single staging system is applicable to all patients with HCC. The staging of the American Joint Committee on Cancer / International Union for Cancer Control should be used to predict outcome following resection or liver transplantation. The Barcelona Clinic Liver Cancer scheme is appropriate in patients with advanced HCC not candidate for surgery. Dual phase computed tomography or magnetic resonance imaging can be used for pretreatment assessment of tumor extent but the accuracy of these methods remains poor to characterize < 1 cm lesions. Assessment of tumor response should not rely only on tumor size and new imaging methods are available to evaluate response to therapy in HCC patients. Liver volumetry is part of the preoperative assessment of patients with HCC candidate for resection as it reflects liver function. Preoperative portal vein embolization is indicated in patients with small future liver remnant (≤ 20% in normal liver; ≤ 40% in fibrotic or cirrhotic liver). Tumor size is not a contraindication to liver resection. Liver resection can be proposed in selected patients with multifocal HCC. Besides tumor extent, surgical resection of HCC may be performed in selected patients with chronic liver disease.

Detection and characterization of focal liver lesions: a Japanese phase III, multicenter comparison between gadoxetic acid disodium-enhanced magnetic resonance imaging and contrast-enhanced computed tomography predominantly in patients with hepatocellular carcinoma and chronic liver disease

OBJECTIVES

To prospectively evaluate the safety and efficacy of combined unenhanced and gadoxetic acid disodium (Gd-EOB-DTPA)-enhanced magnetic resonance (MR) imaging compared with unenhanced MR imaging and triphasic contrast-enhanced spiral computed tomography (CT) for the detection and characterization of focal liver lesions.

MATERIALS AND METHODS

The study was reviewed and approved by the institutional review board at each of the 15 centers involved in the study, and informed written consent was given by all patients. In total, 178 patients with suspected focal hepatic lesions (based, in most patients, on CT, tumor marker and ultrasound examinations) underwent combined MR imaging with a single, rapid injection of Gd-EOB-DTPA 0.025 mmol/kg, including T1-weighted dynamic and delayed MR images 20 to 40 minutes postinjection. Triphasic contrast-enhanced CT, the comparator examination, was performed within 4 weeks of MR imaging. Standard of references (SOR) were resection histopathology and intraoperative ultrasonography, or combined CT during arterial portography and CT hepatic arteriography; in cases where, although the major lesions were treated, some lesion(s) were not treated, follow-up superparamagnetic iron oxide-enhanced MR imaging was additionally performed. All images were assessed for differences in lesion detection and characterization (specific lesion type) by on-site readers and 3, blinded (off-site) reviewers. All adverse events (AEs) occurring within 72 hours after Gd-EOB-DTPA administration were reported.

RESULTS

Overall, 9.6% of patients who received Gd-EOB-DTPA reported 21 drug-related AEs. A total of 151 patients were included in the efficacy analysis. Combined MR imaging showed statistically higher sensitivity in lesion detection (67.5%-79.5%) than unenhanced MR imaging (46.5%-59.1%; P < 0.05 for all). Combined MR imaging also showed higher sensitivity in lesion detection than CT (61.1%-73.0%), with the results being statistically significant (P < 0.05) for on-site readers and 2 of 3 blinded readers. Higher sensitivity in lesion detection with combined MR imaging compared with CT was also clearly demonstrated in the following subgroups: lesions with a diameter <or=20 mm (lesions <or=10 mm: 38.0%-55.4% vs. 26.1%-47.3%, respectively; lesions 10-20 mm: 71.1%-87.3% vs. 65.7%-78.4%, respectively); in cirrhotic patients (64.5%-75.4% vs. 54.5%-70.3%, respectively); and in patients with hepatocellular carcinoma (66.6%-78.6% vs. 59.1%-71.6%, respectively). Combined MR imaging demonstrated a higher proportion of correctly characterized lesions (50.5%-72.1%) than unenhanced MR imaging (30.2%-50.0%; P < 0.05 for all), whereas there were no significant differences compared with CT (49.0%-68.1%), except for one blinded reader (P < 0.05).

CONCLUSION

In this study, hepatocyte-specific Gd-EOB-DTPA was shown to be safe and to improve the detection and characterization of focal hepatic lesions compared with unenhanced MR imaging. When compared with spiral CT, Gd-EOB-DTPA enhanced MRI seems to be beneficial especially for the detection for smaller lesions or hepatocellular carcinoma underlying cirrhotic liver.

Gadoxetic acid-enhanced magnetic resonance imaging for differentiating small hepatocellular carcinomas (< or =2 cm in diameter) from arterial enhancing pseudolesions: special emphasis on hepatobiliary phase imaging

OBJECTIVES

To determine the characteristic enhancing features of hepatocellular carcinoma (HCC) and arterial-enhancing pseudolesion (AEP) on gadoxetic acid (Primovist)-enhanced magnetic resonance imaging (MRI) and to assess its performance compared with that of multirow detector computed tomography (MDCT) for differentiating small HCC (< or =2 cm in diameter) from AEP in cirrhotic liver.

MATERIALS AND METHODS

A total of 69 patients with 97 small, arterial enhancing hepatic lesions (0.5-2 cm in diameter), ie, 44 HCCs and 53 AEPs, detected on gadoxetic acid-enhanced MRI, were included in this study. HCCs were diagnosed either through histopathology confirmation (n = 16) or by a combination of liver computed tomography (CT), angiographic findings, lipiodol CT, and AFP levels (n = 28). AEPs were diagnosed either through histopathology confirmation (n = 2) or were based on the angiographic findings, liver CT, and follow-up imaging (n = 51). Two radiologists jointly analyzed the morphologic features and the enhancement characteristics on the gadoxetic acid-enhanced MRI. Of the 69 study patients, 42 patients with 60 arterial enhancing lesions underwent quadruple-phase CT in addition to their MRI examination within 4 weeks before or after the MRI, and 2 other radiologists who were blinded to the final diagnosis independently reviewed the MRI and CT images in random order, at an interval of 2 weeks. Diagnostic performance was evaluated using receiver operating characteristics. The Kappa test was used to evaluate interobserver agreement.

RESULTS

Among 44 HCCs, 42 (95.4%) demonstrated low signal intensity (SI) and only 2 showed iso- or high SI on the hepatobiliary phase of gadoxetic acid-enhanced MRI. Alternatively, most AEPs showed iso SI on the hepatobiliary (n = 50, 94.3%) phase, and only 2 AEPs showed low SI. Compared with the diagnostic performance of the 2 imaging modalities, the mean areas under the receiver-operator characteristic curves on MR imaging were 0.975 for reviewer 1 and 0.966 for reviewer 2, whereas those of CT imaging were 0.892 for reviewer 1 and 0.888 for reviewer 2 (P = 0.069 and P = 0.106, respectively). The sensitivity for each reviewer with MR imaging (93.9% and 90.9%, respectively) was significantly higher than that with multiphasic CT (54.5%, in both) (P = 0.001 and 0.0018, respectively).

CONCLUSION

HCCs and AEPs show different enhancing features on the delayed dynamic and hepatobiliary phases of gadoxetic acid-enhanced MRI. Gadoxetic acid-enhanced MRI may, therefore, help to differentiate between HCC and AEP.

MRI versus 64-row MDCT for diagnosis of hepatocellular carcinoma

AIM: To compare the diagnostic capability of multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) for the detection of hepatocellular carcinoma (HCC) tumour nodules and their effect on patient management.

METHODS: A total of 28 patients (25 male, 3 female, mean age 67 ± 10.8 years) with biopsy-proven HCC were investigated with 64-row MDCT (slice 3 mm native, arterial and portal-venous phase, 120 mL Iomeprol, 4 mL/s, delay by bolus trigger) and MRI (T1fs fl2d TE/TR 2.72/129 ms, T2tse TE/TR 102/4000 ms, 5-phase dynamic contrast-enhanced T1fs fl3d TE/TR 1.56/4.6, Gadolinium-DTPA, slice 4 mm). Consensus reading of both modalities was used as reference. Tumour nodules were analyzed with respect to number, size, and location.

RESULTS: In total, 162 tumour nodules were detected by consensus reading. MRI detected significantly more tumour nodules (159 vs 123, P < 0.001) compared to MDCT, with the best sensitivity for early arterial phase MRI. False-negative CT findings included nodules ≤ 5 mm ( n = 5), ≤ 10 mm ( n = 17), ≤ 15 mm ( n = 12 ), ≤ 20 mm ( n = 4 ), and 1 nodule > 20 mm. MRI missed 2 nodules ≤ 10 mm and 1 nodule ≤ 15 mm. On MRI, nodule diameters were greater than on CT (29.2 ± 25.1 mm, range 5-140 mm vs 24.1 ± 22.7 mm, range 4-129 mm, P < 0.005). In 2 patients, MDCT showed only unilobar tumour spread, whereas MRI revealed additional nodules in the contralateral lobe. Detection of these nodules could have changed the therapeutic strategy.

CONCLUSION: Contrast-enhanced MRI is superior to 64-row MDCT for the detection of HCC nodules. Patients should be allocated to interventional or operative treatment according to a dedicated MRI-protocol.

Diagnostic performance of multidetector row computed tomography, superparamagnetic iron oxide-enhanced magnetic resonance imaging, and dual-contrast magnetic resonance imaging in predicting the appropriateness of a transplant recipient based on milan criteria: correlation with histopathological findings

PURPOSE

To retrospectively evaluate the diagnostic performance of multidetector row CT (MDCT), superparamagnetic iron oxide (SPIO)-enhanced MRI (S-MRI), and dual-contrast MRI (DC-MRI) in predicting the appropriateness of recipients with hepatocellular carcinoma (HCC) for liver transplantation (LT), based on Milan criteria.

MATERIALS AND METHODS

This retrospective study received Institutional Review Board approval. Requirement for patient informed consent was waived. During a 3-year period, 80 patients who underwent LT were enrolled in this study. However, 2 patients in whom >10 HCCs were present were excluded from the analysis of detection performance of imaging modalities for HCC. MDCT and DC-MRI examinations with the sequential use of SPIO and gadolinium were performed in all patients. Interval readings for MDCT, S-MRI, and DC-MRI were performed. Two radiologists independently recorded confidence levels using a 4- and 5-point scale for the presence of HCC and for the appropriateness regarding LT, respectively. Image interpretation was compared with histopathological results on a lesion-by-lesion basis. Diagnostic performance of the 3 imaging techniques was compared using jackknife alternative free-response receiver operating characteristic and ROC analyses.

RESULTS

Eighty-two HCCs were detected in 38 of 78 patients. Twenty-seven HCCs were larger than 2 cm in diameter and 55 HCCs were smaller than 2 cm in diameter. Among 80 patients included for the assessment of eligibility for LT, 69 recipients were categorized as appropriate and the remaining 11 patients were found to be inappropriate for LT based on Milan criteria. In terms of detecting HCCs, the reader-averaged figure of merit was highest for DC-MRI (0.764), followed by S-MRI (0.702) and MDCT (0.672). The use of DC-MRI was significantly better than the use of the other 2 modalities specifically for HCCs smaller than 2 cm in diameter (P < 0.001) although not for those larger than or equal to 2 cm (P = 0.125-1). The AZ value for predicting the appropriateness for LT was highest with the use of S-MRI (0.841), followed by the use of DC-MRI (0.830) and the use of MDCT (0.790). However, significant differences were not seen for the predictions determined by both radiologists (P = 0.384-1). This result might be because of the small number of patients who had a critical number of HCCs (ie, 2 approximately 4 HCCs).

CONCLUSION

DC-MRI showed significantly better diagnostic performance in transplantation candidates for the detection of HCCs, particularly small HCCs, than both MDCT and S-MRI. However, for assessing the appropriateness of a transplantation recipient based on Milan criteria, MDCT, S-MRI, and DC-MRI showed comparable diagnostic accuracy without a statistical difference.

Gadoxetic acid-enhanced MRI versus triple-phase MDCT for the preoperative detection of hepatocellular carcinoma

OBJECTIVE

We compared the diagnostic performance of gadoxetic acid-enhanced MRI with that of triple-phase 16-, 40-, and 64-MDCT in the preoperative detection of hepatocellular carcinoma (HCC).

SUBJECTS AND METHODS

Sixty-two consecutively registered patients (54 men, eight women; age range, 31-67 years) with 83 HCCs underwent triple-phase (arterial, portal venous, equilibrium) CT at 16-, 40-, or 64-MDCT and gadoxetic acid-enhanced 3-T MRI. The diagnosis of HCC was established after surgical resection. Three observers independently and randomly reviewed the MR and CT images on a tumor-by-tumor basis. The diagnostic accuracy of these techniques in the detection of HCC was assessed with alternative free response receiver operating characteristic (ROC) analysis. Sensitivity, positive and negative predictive values, and sensitivity according to tumor size were evaluated.

RESULTS

For each observer, the areas under the ROC curve were 0.971, 0.959, and 0.967 for MRI and 0.947, 0.950, and 0.943 for CT. The differences were not statistically significant between the two techniques for each observer (p > 0.05). The differences in sensitivity and positive and negative predictive values between the two techniques for each observer were not statistically significant (p > 0.05). Among 10 HCCs 1 cm in diameter or smaller, each of the observers detected seven tumors with MRI. With CT, one observer detected five, one observer detected four, and one observer detected three HCCs with no statistically significant difference (p > 0.05).

CONCLUSION

Gadoxetic acid-enhanced MRI and triple-phase MDCT have similar diagnostic performance in the preoperative detection of HCC, but MRI may be better than MDCT in the detection of HCC 1 cm in diameter or smaller.

Comparison of dynamic MRI at 3.0 T and MDCT of pancreatobiliary disease: evaluation with source, MPR, CPR, and MIP images for image quality and hepatic arterial and portal venous vessel conspicuity

PURPOSE

To compare contrast material-enhanced three-dimensional (3D) magnetic resonance imaging (MRI) at 3.0T and multidetector row computed tomography (MDCT) in the same patient with regard to image quality of pancreatobiliary disease and hepatic vascular conspicuity.

MATERIALS AND METHODS

This study enrolled 32 patients with pancreatobiliary disease who underwent both gadolinium-enhanced 3D dynamic MRI and multiphasic CT using 16-MDCT. Data analysis of image quality was performed by two radiologists based on source images, multiplanar reconstruction (MPR), curved planar reconstruction (CPR), and maximum intensity projection (MIP) reconstruction. Determination of image quality was based on a 4-point image quality rating scale.

RESULTS

The overall image quality of the MRI axial images was superior to that of the axial MDCT images. The MRI protocol yielded an average score of 3.8 points versus 3.5 for the CT imaging. No significant difference was found between 3.0T MRI and MDCT images in MPR or CPR image quality. Image quality for visualization of the distal intrahepatic segmental arteries was significantly improved using MDCT imaging. No significant difference was found between the MDCT and 3.0T MR in portal vein branch image quality.

CONCLUSION

High-resolution dynamic contrast-enhanced MR imaging at 3.0T is a comprehensive technique which provides high image quality in pancreatobiliary disease.

Hepatocellular carcinoma in patients with cirrhosis: qualitative comparison of gadobenate dimeglumine-enhanced MR imaging and multiphasic 64-section CT

PURPOSE

To prospectively investigate whether combined interpretation of dynamic and hepatobiliary phase magnetic resonance (MR) images can improve the accuracy of gadobenate dimeglumine-enhanced MR imaging in the detection of hepatocellular carcinoma (HCC) compared with either dynamic MR or multiphasic multidetector computed tomographic (CT) images alone.

MATERIALS AND METHODS

Institutional review board approval and informed patient consent were obtained. Fifty-two patients (39 men, 13 women; mean age, 68 years; range, 38-81 years) suspected of having HCC underwent gadobenate dimeglumine-enhanced MR imaging and multiphasic 64-section multidetector CT. Images were qualitatively analyzed independently by three observers in three separate reading sessions. The alternating free-response receiver operating characteristic (AFROC) method was used to analyze the results. Differences in sensitivity and positive predictive values were calculated at a statistical significance of P < .05.

RESULTS

A total of 67 HCCs were detected in 36 patients. The mean area under the AFROC curve (A(z)) was significantly higher for either the combined interpretation of dynamic and hepatobiliary phase MR images (A(z) = 0.95) or dynamic MR images alone (0.91) than for CT images (0.77) (P = .01 for both comparisons). The mean sensitivity of combined interpretation of MR images (0.72) was significantly higher than those of dynamic MR images alone (0.63) and multidetector CT images (0.61) (P = .008 and .001, respectively). The mean positive predictive value was not significantly different among the three imaging sets.

CONCLUSION

The combined interpretation of dynamic and hepatobiliary phase MR images improves diagnostic accuracy of gadobenate dimeglumine-enhanced MR imaging for the detection of HCC compared with either dynamic MR or multiphasic multidetector CT images alone.