Detection of small hypervascular hepatocellular carcinomas by EASL criteria: Comparison with double-phase CT during hepatic arteriography

Iodine maps derived from sparse-view kV-switching dual-energy CT equipped with a deep learning reconstruction for diagnosis of hepatocellular carcinoma

Deep learning-based spectral CT imaging (DL-SCTI) is a novel type of fast kilovolt-switching dual-energy CT equipped with a cascaded deep-learning reconstruction which completes the views missing in the sinogram space and improves the image quality in the image space because it uses deep convolutional neural networks trained on fully sampled dual-energy data acquired via dual kV rotations. We investigated the clinical utility of iodine maps generated from DL-SCTI scans for assessing hepatocellular carcinoma (HCC). In the clinical study, dynamic DL-SCTI scans (tube voltage 135 and 80 kV) were acquired in 52 patients with hypervascular HCCs whose vascularity was confirmed by CT during hepatic arteriography. Virtual monochromatic 70 keV images served as the reference images. Iodine maps were reconstructed using three-material decomposition (fat, healthy liver tissue, iodine). A radiologist calculated the contrast-to-noise ratio (CNR) during the hepatic arterial phase (CNRa) and the equilibrium phase (CNRe). In the phantom study, DL-SCTI scans (tube voltage 135 and 80 kV) were acquired to assess the accuracy of iodine maps; the iodine concentration was known. The CNRa was significantly higher on the iodine maps than on 70 keV images (p < 0.01). The CNRe was significantly higher on 70 keV images than on iodine maps (p < 0.01). The estimated iodine concentration derived from DL-SCTI scans in the phantom study was highly correlated with the known iodine concentration. It was underestimated in small-diameter modules and in large-diameter modules with an iodine concentration of less than 2.0 mgI/ml. Iodine maps generated from DL-SCTI scans can improve the CNR for HCCs during hepatic arterial phase but not during equilibrium phase in comparison with virtual monochromatic 70 keV images. Also, when the lesion is small or the iodine concentration is low, iodine quantification may result in underestimation.

Utility of Radial Scanning for the Identification of Arterial Hypervascularity of Hepatocellular Carcinoma on Gadoxetic Acid-Enhanced Magnetic Resonance Images

OBJECTIVES

This study aimed to compare the accuracy of assessing the arterial hypervascularity of hepatocellular carcinoma (HCC) on dynamic computed tomography (CT) scans and gadoxetic acid (EOB)-enhanced magnetic resonance imaging (MRI) scans performed with radial sampling.

METHODS

We studied the images of 40 patients with hypervascular HCC. A radiologist recorded the standard deviation of the attenuation (or the signal intensity [SI]) in subcutaneous fat tissue as the image noise (N) and calculated the contrast-to-noise ratio (CNR) as follows: (CNR) = (n-ROIT - n-ROIL)/N, where n-ROIT is the mean attenuation (or SI) of the tumor divided by the mean attenuation (or SI) of the aorta and n-ROIL is the mean attenuation (or SI) of the liver parenchyma divided by the mean attenuation (or SI) of the aorta.

RESULTS

The CNR was significantly higher on EOB-enhanced MRI than on dynamic CT scans.

CONCLUSIONS

For the assessment of HCC vascularity, EOB-enhanced MRI scans acquired with radial sampling were more accurate than dynamic CT images.

Clinical Indication for Computed Tomography During Hepatic Arteriography (CTHA) in Addition to Dynamic CT Studies to Identify Hypervascularity of Hepatocellular Carcinoma

PURPOSE

To identify factors benefiting from computed tomography during hepatic arteriography (CTHA) in addition to dynamic CT studies at the preoperative evaluation of the hypervascularity of hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

We retrospectively divided 45 patients with HCC, who underwent both dynamic CT (dCT) and CTHA, into two groups based on the number of hypervascular HCCs identified on dCT and CTHA studies. In group A, the number of HCCs identified by dCT and CTHA was the same and additive CTHA had not been indicated. In group B, fewer HCCs were counted on dCT than on CTHA images, indicating that additive CTHA studies had been appropriate. We compared the patient characteristics, the serum alpha-fetoprotein level, and the tumor-liver contrast (TLC) of the main tumor on dCT scans of both groups. To identify factors alerting to the benefit of additional CTHA studies, we performed univariate logistic regression analysis. Statistically significant parameters were subjected to receiver operating characteristic analysis for obtaining the optimal cutoff value indicative of the benefit of CTHA.

RESULTS

Univariate analysis identified only the TLC of the main tumor on dCT images as a significant factor for the benefit of CTHA images (P < 0.01). At the optimal cutoff value for the TLC of the main tumor on dCT images (15.9 Hounsfield units), the sensitivity and specificity for the benefit of CTHA were 85.0 and 92.0%, respectively.

CONCLUSION

Evaluation of the TLC of the main tumor on dCT scans identifies patients in whom additive CTHA studies are beneficial.

Superparamagnetic iron oxide-enhanced magnetic resonance imaging is useful in predicting malignant potential of vascular transformation of hypointense hypovascular nodules on gadoxetic acid-enhanced magnetic resonance imaging

AIM

To examine whether superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance imaging (MRI) can be used to assess the malignant potential of hepatic hypovascular nodules showing hypointensity during the hepatobiliary phase (HBP) on gadoxetic acid (Gd-EOB-DTPA)-enhanced MRI.

METHODS

The study included 42 patients with chronic liver disease who had small hypovascular nodules (5-15 mm) showing hypointensity during the HBP on Gd-EOB-DTPA-enhanced MRI. The SPIO-enhanced T2-weighted MRI analyzed whether the signal intensity of each nodule was high. Nodules were prospectively followed up until hypervascularization by periodic Gd-EOB-DTPA-enhanced MRI. Initial MRI findings and clinical variables were used to analyze predictive factors for hypervascularization.

RESULTS

We analyzed 77 nodules, of which 19 (25%) showed hypervascularization during the observation period. The cumulative rates for hypervascularization were 11% and 22% at 1 and 2 years, respectively. Hyperintensity was observed in 12 nodules (16%) on SPIO-enhanced T2-weighted MRI; among these, 7 (58%) showed hypervascularization, whereas 12 (18%) of the remaining 65 nodules without hyperintensity showed hypervascularization (P = 0.007). A Cox model revealed that independent predictors of hypervascularization included hyperintense nodules on SPIO-enhanced MRI (P < 0.001). The cumulative rates for hypervascularization in hyperintense nodules on SPIO-enhanced MRI were 52% at 1 year, whereas these rates were 3% for non-hyperintense nodules.

CONCLUSION

Superparamagnetic iron oxide-enhanced MRI is useful for predicting the malignant potential of vascular transformation of hypovascular nodules with hypointensity observed in the HBP on Gd-EOB-DTPA-enhanced MRI.

Diagnostic performance of gadoxetic acid (Primovist)-enhanced MR imaging versus CT during hepatic arteriography and portography for small hypervascular hepatocellular carcinoma

To compare the diagnostic performance of gadoxetic acid-enhanced magnetic resonance imaging (MRI) with that of computed tomography (CT) during hepatic arteriography and arterial portography (CT HA/AP) for detecting hepatocellular carcinoma (HCC) from small hypervascular nodules.This retrospective study included 38 patients with 131 hypervascular nodules (≤2 cm) who had underwent MRI and CT HA/AP within a 2-week interval. Two observers analyzed MRI while other 2 observers analyzed CT HA/AP. Thereafter, MRI observers reviewed the CT HA/AP and magnetic resonance (MR) images again using both modalities. HCC was diagnosed by pathologic or imaging studies according to American Association for the Study of Liver Diseases (AASLD) criteria. Alternative free-response receiver operating characteristic (ROC) analysis was performed on a lesion-by-lesion basis. Diagnostic accuracy (area under the ROC curve [Az]), sensitivity, specificity, and positive and negative predictive values were calculated.The pooled Az was significantly higher for the combined modalities (0.946) than for MRI alone (0.9, P = 0.004), and for MRI than for CT HA/AP alone (0.827, P = 0.0154). Subgroup analysis for HCC ≤1 cm showed the sensitivity of the combined modalities (79.4%) was significantly higher than for MRI (52.9%) and CT HA/AP alone (50%) (both, P < 0.005). The specificity of the combined modalities was not different from MRI alone (98.8% vs. 97.3%, P = 0.5), but was significantly higher than for CT HA/AP alone (98.8% vs. 92.5%, P = 0.022).Hypervascular HCCs >1 to 2 cm can be diagnosed sufficiently by MRI. The combined modalities increased the diagnostic accuracy of HCCs ≤1 cm, compared with MRI or CT HA/AP alone.

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.

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).

Perfusion computed tomography for detection of hepatocellular carcinoma in patients with liver cirrhosis

PURPOSE

To evaluate the diagnostic performance of dynamic perfusion CT (P-CT) for detection of hepatocellular carcinoma (HCC) in the cirrhotic liver.

MATERIALS AND METHODS

Twenty-six cirrhotic patients (19 men, aged 69 ± 10 years) with suspicion of HCC prospectively underwent P-CT of the liver using the 4D spiral-mode (100/80 kV; 150/175mAs/rot) of a dual-source system. Two readers assessed: (1) arterial liver-perfusion (ALP), portal-venous liver-perfusion (PLP) and hepatic perfusion-index (HPI) maps alone; and (2) side-by-side with maximum-intensity-projections of arterial time-points (art-MIP) for detection of HCC using histopathology and imaging follow-up as standard of reference. Another reader quantitatively assessed perfusion maps of detected lesions.

RESULTS

A total of 48 HCCs in 21/26 (81%) patients with a mean size of 20 ± 10 mm were detected by histopathology (9/48, 19%) or imaging follow-up (39/48, 81%). Detection rates (Reader1/Reader2) of HPI maps and side-by-side analysis of HPI combined with arterial MIP were 92/88% and 98/96%, respectively. Positive-predictive values were 63/63% and 68/71%, respectively. A cut-off value of ≥85% HPI and ≥99% HPI yielded a sensitivity and specificity of 100%, respectively, for detection of HCC.

CONCLUSION

P-CT shows a high sensitivity for detection of HCC in the cirrhotic liver. Quantitative assessment has the potential to reduce false-positive findings improving the specificity of HCC diagnosis.

KEY POINTS

• Visual analysis of perfusion maps shows good sensitivity for detection of HCC. • Additional assessment of anatomical arterial MIPs further improves detection rates of HCC. • Quantitative perfusion analysis has the potential to reduce false-positive findings. • In cirrhotic livers, a hepatic-perfusion-index ≥ 9 9% might be specific for HCC.

Warming effect on miriplatin-lipiodol suspension as a chemotherapeutic agent for transarterial chemoembolization for hepatocellular carcinoma: preliminary clinical experience

PURPOSE

To retrospectively elucidate the preliminary clinical impact of warmed miriplatin-lipiodol suspension (MPT-LPD) when used as a chemotherapeutic agent for transarterial chemoembolization (TACE) for hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Between June and December 2010, TACE was performed with MPT-LPD at room temperature (RT group), and after January 2011, TACE with MPT-LPD warmed to 40 °C was performed (W group). The intraarterial appearance of MPT-LPD immediately after injection through microcatheters at the second-order branches was compared between the two groups with a 5-point grading system. Local therapeutic effects of HCCs as assessed by follow-up computed tomography (CT) obtained 1-3 months after TACE were compared between the groups with a 4-point grading system (TE1-TE4). After April 2011, angiography-assisted CT was routinely performed at TACE, and HCCs that revealed apparent corona enhancement (CE) were retrospectively selected. The degree of concordance between CE and MPT-LPD accumulation as assessed by CT immediately after TACE was assessed with a 3-point grading scale.

RESULTS

MPT-LPD therapy resulted in a smooth and continuous appearance in the W group (grades 1, 2, 3, 4, and 5 were, respectively, 1, 2, 11, 18, and 4) compared to the RT group (4, 0, 1, 2, and 0). The W group (TE1, TE2, TE3, and TE4 were 1, 9, 11, and 12) revealed better local therapeutic effects than the RT group (6, 3, 9, and 0) (p < 0.05). CE was found in 26 HCC nodules, and concordance between CE and MPT-LPD accumulation was observed in 66% (grades 1, 2, and 3 were, respectively, 2, 8, and 19).

CONCLUSION

Warmed MPT-LPD flowed more smoothly within vascular lumen, passed through tumor sinusoid of HCC, and had better local therapeutic effects at short-term observation than MPT-LPD at room temperature.

Intranodular signal intensity analysis of hypovascular high-risk borderline lesions of HCC that illustrate multi-step hepatocarcinogenesis within the nodule on Gd-EOB-DTPA-enhanced MRI

OBJECTIVES

To analyze intranodular signal intensity pattern of hypovascular high-risk borderline lesions of HCC that illustrate multi-step hepatocarcinogenesis within the nodule on Gd-EOB-DTPA-enhanced MRI.

METHODS

A total of 73 nodules showing hypervascular foci in hypovascular high-risk borderline lesions identified by angiography-assisted CT were included in this study. The intranodular signal intensities of both the hypervascular foci and the hypovascular high-risk borderline lesions were evaluated on hepatobiliary-phase EOB-enhanced MRI obtained 20 min after intravenous injection of contrast media.

RESULTS

Among 59 hypervascular foci within hypointense hypovascular high-risk borderline lesions, 6 showed more hypointensity, 32 isointensity, and 21 hyperintensity compared to the surrounding hypointense, hypovascular portion of the nodules. Among 14 hypervascular foci within isointense hypovascular high-risk borderline lesions, 5 showed isointensity, and 9 hypointensity compared to the surrounding isointense hypovascular high-risk borderline lesions. No hypervascular foci showed hyperintensity compared to the surrounding isointense hypovascular high-risk borderline lesions.

CONCLUSIONS

In most of the hypovascular high-risk borderline lesions containing hypervascular foci within the nodule, the signal intensity was decreased in hypervascular foci as compared with hypovascular high-risk borderline lesions and the surrounding background liver parenchyma. This supports the concept of signal intensity decrease during the dedifferentiation process in multistep hepatocarcinogenesis. However, around 30% of the nodules did not follow this rule, and hypervascular foci showed hyperintensity relative to the hypovascular high-risk borderline lesions.

Intrahepatic cholangiocarcinomas in cirrhosis are hypervascular in comparison with those in normal livers

BACKGROUND AND AIMS

Intrahepatic cholangiocarcinomas (ICCs) are usually adenocarcinomas with fibrotic and hypovascular stroma. Intrahepatic cholangiocarcinomas in cirrhosis and precirrhotic liver (ICC-cirrhosis) are increasingly being diagnosed, and can display hypervascular enhancement resembling a hepatocellular carcinoma on dynamic imaging.

METHODS

In this study using ICC-cirrhosis (71 cases), ICC with non-specific reactive changes (ICC-reactive) (72 cases) and the cholangiocarcinoma component of combined hepatocellular cholangiocarcinoma (HCC-ICC) (30 cases), we tried to compare the tumour vasculature.

RESULTS

It was found that ICC-cirrhosis and the cholangiocarcinoma component of HCC-ICC showed a higher density of arteries and microvessels (1.59 ± 0.58/mm(2) (mean ± SD) and 140 ± 43/mm(2) in ICC-cirrhosis and 1.74 ± 0.67/mm(2) and 131 ± 46/mm(2) in the cholangiocarcinoma component of HCC-ICC) than in ICC-reactive (1.26 ± 0.61/mm(2) and 103 ± 45/mm(2) ). Dynamic computed tomography (CT) and magnetic resonance imaging (MRI) showed that a majority of ICC-cirrhosis displayed strong hypervascular enhancement, whereas one-third of ICC-reactive each showed strong, weak and no or minimal enhancement respectively. The increased vascular density was positively correlated with enhanced arterial phase of dynamic CT and MRI.

CONCLUSION

The density of arteries and microvessels of ICC-cirrhosis was higher than that in ICC-reactive and comparable to that in the cholangiocarcinoma component of HCC-ICC, and the higher density of arteries and microvessels in ICC may be responsible for the hypervascular enhancement of ICC-cirrhosis.

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.