Ferucarbotran-Enhanced 3.0-T Magnetic Resonance Imaging Using Parallel Imaging Technique Compared With Triple-Phase Multidetector Row Computed Tomography for the Preoperative Detection of Hepatocellular Carcinoma:

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).

Imaging features of subcentimeter hypointense nodules on gadoxetic acid-enhanced hepatobiliary phase MR imaging that progress to hypervascular hepatocellular carcinoma in patients with chronic liver disease

BACKGROUND

With the advent of 3-T magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI), many subcentimeter hepatic nodules have been frequently detected in patients with chronic liver disease, and the prediction of subcentimeter nodules that progress to hypervascular hepatocellular carcinoma (HCC) is important.

PURPOSE

To reveal the imaging features of subcentimeter hypointense nodules on gadoxetic acid-enhanced hepatobiliary phase MR images in patients with chronic liver disease that may be related with progression to hypervascular HCC.

MATERIAL AND METHODS

This study included 109 patients with 135 subcentimeter hypointense nodules (103 hepatocellular carcinomas [HCCs] and 32 benign nodules) on gadoxetic acid-enhanced hepatobiliary phase. For each subcentimeter nodule, the following imaging features were analyzed: (i) hyperintensity on T2-weighted (T2W) image or DWI; (ii) arterial hypervascularization; and (iii) hypointensity on a portal or late phase. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of those imaging features for predicting subcentimeter nodules that progressed to hypervascular HCC were evaluated. Volume doubling time (VDT) of subcentimeter nodules that progressed to hypervascular HCC was compared to that of growing benign nodules.

RESULTS

Arterial hypervascularization with washout yielded the highest specificity (90.6%) and PPV (95.4%) for prediction of subcentimeter nodules that progressed to hypervascular HCC. Combining hyperintensity on T2W image or DWI and arterial hypervascularization with washout did not raise the specificity (90.6%) for prediction of subcentimeter nodules that progressed to hypervascular HCC. Mean VDT (112.2 ± 106.3 days) of subcentimeter nodules that progressed to hypervascular HCC during follow-up was significantly shorter than those of benign subcentimeter nodules (1258 ± 766.5 days, P < 0.001).

CONCLUSION

Arterial hypervascularization with washout in subcentimeter hypointense nodules on gadoxetic acid-enhanced hepatobiliary phase in patients with chronic liver disease is strongly related with progression to hypervascular HCC.

Upper abdominal gadoxetic acid-enhanced and diffusion-weighted MRI for the detection of gastric cancer: Comparison with two-dimensional multidetector row CT

AIM

To evaluate the diagnostic performance of abdominal magnetic resonance imaging (MRI) for the detection of gastric cancer in comparison with that of two-dimensional (2D) multidetector row computed tomography (CT).

MATERIALS AND METHODS

The study included 189 patients with 170 surgically confirmed gastric cancers and 19 patients without gastric cancer, all of whom underwent gadoxetic acid-enhanced MRI with diffusion-weighted (DW) imaging, and multidetector contrast-enhanced abdominal CT imaging. Two observers independently analysed three sets of images (CT set, conventional MRI set, and combined conventional and DW MRI set). A five-point scale for likelihood of gastric cancer was used. Diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were evaluated. Quantitative [apparent diffusion coefficient (ADC) analyses with Mann-Whitney U-test were conducted for gastric cancers and the nearby normal gastric wall.

RESULTS

The diagnostic accuracy and sensitivity for detection of gastric cancer were significantly higher on combined conventional and DW MRI set (77.8-78.3%; 75.3-75.9%) than the CT imaging set (67.7-71.4%; 64.1-68.2%) or the conventional MRI set (72-73%; 68.8-70%; p < 0.01). In particular, for gastric cancers with pT2 and pT3, the combined conventional and DW MRI set (91.6-92.6%) yielded significantly higher sensitivity for detection of gastric cancer than did the CT imaging set (76.8-81.1%) by both observers (p < 0.01). The mean ADC of gastric cancer lesions (1 ± 0.23 × 10(-3) mm(2)/s) differed significantly from that of normal gastric wall (1.77 ± 0.25 × 10(-3) mm(2)/s; p < 0.01).

CONCLUSION

Abdominal MRI with DW imaging was more sensitive for the detection of gastric cancer than 2D-multidetector row CT or conventional MRI alone.

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.

Hypervascular hepatocellular carcinoma 1 cm or smaller in patients with chronic liver disease: characterization with gadoxetic acid-enhanced MRI that includes diffusion-weighted imaging

OBJECTIVE

The purpose of this study was to determine the finding most predictive for characterizing hypervascular hepatocellular carcinoma (HCC) measuring 1 cm or less at gadoxetic acid-enhanced MRI that includes diffusion-weighted images.

MATERIALS AND METHODS

In this retrospective study, between May 2008 and June 2009, 66 patients with 108 hypervascular HCCs 1 cm or smaller underwent gadoxetic acid-enhanced 3-T MRI that included diffusion-weighted images. The diagnosis of HCC was determined by surgical resection in 32 cases, percutaneous biopsy in three cases, or interval growth to larger than 1 cm on follow-up images in accordance with the American Association for the Study of Liver Diseases guidelines in 73 cases. MRI findings of HCC and 33 benign hypervascular lesions in a control group were analyzed by two radiologists in consensus. They based their assessments on the presence or absence of the following five findings: hyperintensity on T2-weighted images, hyperintensity on diffusion-weighted images with low b values, washout pattern, capsular enhancement, and hypointensity on gadoxetic acid-enhanced hepatobiliary phase images. The findings were compared by use of univariate and multivariate analyses.

RESULTS

No HCC with capsular enhancement was found. Fifty-seven HCCs (52.8%) had four findings, 36 (33.3%) had three, nine (8.3%) had two findings, and six (5.6%) had one finding. Univariate analysis showed significant differences between the HCC and control groups with respect to four findings (p < 0.0001). Multivariate analysis showed that hyperintensity on T2-weighted (p < 0.0001) and diffusion-weighted (p = 0.0081) images were statistically significant MRI findings for predicting HCC.

CONCLUSION

Hyperintensity on both T2- and diffusion-weighted images is helpful in the diagnosis of hypervascular HCC smaller than 1 cm in diameter.

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.

Comparison of multi-echo and single-echo gradient-recalled echo sequences for SPIO-enhanced liver MRI at 3 T

AIM

To assess the utility of a T2*-weighted, multi-echo data imaging combination sequenced on superparamagnetic iron oxide (SPIO)-enhanced liver magnetic resonance imaging (MRI) using a 3 T system.

MATERIALS AND METHODS

Fifty patients underwent SPIO-enhanced MRI at 3 T using T2*-weighted, single-echo, gradient-recalled echo (GRE) sequences [fast imaging with steady precession; repetition time (TR)/echo time (TE), 126 ms/9 ms; flip angle, 30°] and multi-echo GRE (multi-echo data image combination) sequences (TR/TE, 186 ms/9 ms; flip angle, 30°). Three radiologists independently reviewed the images in a random order. The sensitivity and accuracy for the detection of focal hepatic lesions (a total of 76 lesions in 33 patients; 48 solid lesions, 28 non-solid lesions) were compared by analysing the area under the receiver operating characteristic curves. Image artefacts (flow artefacts, susceptibility artefacts, dielectric artefacts, and motion artefacts), lesion conspicuity, and overall image quality were evaluated according to a four-point scale: 1, poor; 2, fair; 3, good; 4, excellent. The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of the lesions were compared.

RESULTS

Image artefacts were more frequent with single-echo GRE (p<0.05). The mean scale of image quality assessment for flow, susceptibility, dielectric, and motion artefacts were 2.76, 3.13, 3.42, and 2.89 with single-echo, respectively, compared with 3.47, 3.43, 3.47, and 3.39, respectively, with multi-echo GRE. There was no significant difference in lesion conspicuity between single-echo (3.15) and multi-echo (3.30) GRE sequences. The overall image quality was significantly (p<0.05) better with multi-echo (3.37) than with single-echo GRE (2.89). The mean SNR and CNR of the lesions were significantly (p<0.05) higher on multi-echo (79±23 and 128±59, respectively) images than on single-echo (38±11 and 102±44, respectively) images. Lesion detection accuracy and sensitivity were not significantly different between the two sequences. Mean accuracies and sensitivities were 0.864 and 0.785 for single-echo and 0.847 and 0.785 for multi-echo GRE, respectively.

CONCLUSION

At 3 T, the T2*-weighted, multi-echo data image combination sequence performs comparably to the T2*-weighted, single-echo GRE sequence for SPIO-enhanced MRI with good overall image quality and a decrease in undesired artefacts.

Comparison of ferucarbotran-enhanced fluid-attenuated inversion-recovery echo-planar, T2-weighted turbo spin-echo, T2*-weighted gradient-echo, and diffusion-weighted echo-planar imaging for detection of malignant liver lesions

PURPOSE

To compare the diagnostic accuracy of superparamagnetic iron oxide (SPIO)-enhanced fluid-attenuated inversion-recovery echo-planar imaging (FLAIR EPI) for malignant liver tumors with that of T2-weighted turbo spin-echo (TSE), T2*-weighted gradient-echo (GRE), and diffusion-weighted echo-planar imaging (DW EPI).

MATERIALS AND METHODS

SPIO-enhanced magnetic resonance imaging (MRI) that included FLAIR EPI, T2-weighted TSE, T2*-weighted GRE, and DW EPI sequences was performed using a 3 T system in 54 consecutive patients who underwent surgical exploration with intraoperative ultrasonography. A total of 88 malignant liver tumors were evaluated. Images were reviewed independently by two blinded observers who used a 5-point confidence scale to identify lesions. Results were correlated with results of histopathologic findings and surgical exploration with intraoperative ultrasonography. The accuracy of each MRI sequence was measured with jackknife alternative free-response receiver operating characteristic analysis. The sensitivity of each observer with each MRI sequence was compared with McNemar's test.

RESULTS

Accuracy values were significantly higher with FLAIR EPI sequence (0.93) than with T2*-weighted GRE (0.80) or DW EPI sequences (0.80) (P < 0.05). Sensitivity was significantly higher with the FLAIR EPI sequence than with any of the other sequences.

CONCLUSION

SPIO-enhanced FLAIR EPI sequence was more accurate in the diagnosis of malignant liver tumors than T2*-weighted GRE and DW EPI sequences. SPIO-enhanced FLAIR EPI sequence is helpful for the detection of malignant liver tumors.

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.