SPIO-enhanced MRI findings of well-differentiated hepatocellular carcinomas: correlation with MDCT findings

APT imaging of hepatocellular carcinoma signals an effective therapeutic response in advance of tumor shrinkage

Aim: The aim of this study was to assess the utility of weighted amide proton transfer (APTw) MRI in three different rodent models of hepatocellular carcinoma (HCC).Methods: APTw MRI was evaluated in models of diethylnitrosamine (DEN) induced HCC, N1S1 syngeneic orthotopic xenograft and human HepG2 ectopic xenograft.Results: All models of HCC showed a higher APTw signal over the surrounding normal tissues. In the DEN model, the APTw signal could differentiate HCC lesions from benign nodules. Intra-arterial administration of low-density lipoprotein docosahexaenoic acid (LDL-DHA) nanoparticles to N1S1 xenografts rapidly lowered the tumor APTw signal within 72 h. Direct injections of LDL-DHA nanoparticles into HepG2 xenografts also showed similar therapeutic responses.Conclusion: We have demonstrated the utility of APTw imaging in the diagnostic/therapeutic management of HCC.

A Case Presentation of Well-Differentiated Hepatocellular Carcinoma With No Sign of Liver Disease

The type of liver cancer that occurs most frequently is hepatocellular carcinoma (HCC). The majority of cases of HCC are secondary to alcoholic cirrhosis or viral hepatitis. The presence of malignant cells with modest nuclear atypia that resemble normal hepatocytes and the lack of bare nuclei in the smears, which shows the neoplastic hepatocytes' capacity, are characteristics of a well-differentiated HCC plasma membrane to tolerate smearing. We present the case of an 83-year-old male patient with a well-differentiated HCC, who had no etiological factors and no signs of alcohol cirrhotic liver, or any symptoms of liver disease which are the main causes of the HCC.

Perfluorobutane-enhanced ultrasonography with a Kupffer phase: improved diagnostic sensitivity for hepatocellular carcinoma

OBJECTIVES

To evaluate the diagnostic accuracy of perfluorobutane contrast-enhanced ultrasonography (CEUS) for hepatocellular carcinoma (HCC) and to explore how accuracy can be improved compared to conventional diagnostic criteria in at-risk patients.

METHODS

A total of 123 hepatic nodules (≥ 1 cm) from 123 at-risk patients who underwent perfluorobutane CEUS between 2013 and 2020 at three institutions were retrospectively analyzed. Ninety-three percent of subjects had pathological results, except benign lesions stable in follow-up images. We evaluated presence of arterial phase hyperenhancement (APHE), washout time and degree, and Kupffer phase (KP) defects. KP defects are defined as hypoenhancing lesions relative to the liver in KP. HCC was diagnosed in two ways: (1) Liver Imaging Reporting and Data System (LI-RADS) criteria defined as APHE and late (≥ 60 s)/mild washout, and (2) APHE and Kupffer (AK) criteria defined as APHE and KP defect. We explored grayscale features that cause misdiagnosis of HCC and reflected in the adjustment. Diagnostic performance was compared using McNemar's test.

RESULTS

There were 77 HCCs, 15 non-HCC malignancies, and 31 benign lesions. An ill-defined margin without hypoechoic halo on grayscale applied as a finding that did not suggest HCC. Regarding diagnosis of HCC, sensitivity of AK criteria (83.1%; 95% confidence interval [CI]: 72.9-90.7%) was higher than that of LI-RADS criteria (75.3%; 95% CI: 64.2-84.4%; p = 0.041). Specificity was 91.3% (95% CI: 79.2-97.6%) in both groups.

CONCLUSION

On perfluorobutane CEUS, diagnostic criteria for HCC using KP defect with adjustment by grayscale findings had higher diagnostic performance than conventional criteria without losing specificity.

KEY POINTS

• Applying Kupffer phase defect instead of late/mild washout and adjusting with grayscale findings can improve the diagnostic performance of perfluorobutane-enhanced US for HCC. • Adjustment with ill-defined margins without a hypoechoic halo for features unlikely to be HCC decreases false positives for HCC diagnosis using the perfluorobutane-enhanced US. • After adjustment with grayscale findings, the sensitivity and accuracy of the APHE and Kupffer criteria were higher than those of the LI-RADS criteria; specificity was 91.3% for both.

Tumor attenuation and quantitative analysis of perfusion parameters derived from tri-phasic CT scans in hepatocellular carcinoma: Relationship with histological grade

The aim of the current study was to explore the value of tumor attenuation and quantitative analysis of perfusion parameters obtained from traditional tri-phasic CT scans in grading hepatocellular carcinoma (HCC).Totally 39 patients (42 lesion samples) with pathologically confirmed HCC who underwent tri-phasic CT scans were enrolled. HCC lesions were divided into non-poorly differentiated HCC (NP-HCC; n = 31) and poorly differentiated HCC (pHCC; n = 11). All lesions were divided into 5 groups according to the attenuation on different CT enhancement phase. The values of tumor attenuation on different scanning phases were measured. The following parameters were calculated: arterial enhancement fraction (AEF), portal venous supply coefficient (PVC), and hepatic arterial supply coefficient (HAC). The relationship of perfusion parameters with the histological grade of HCC was analyzed. Receiver operating characteristic curves were generated.No significant correlation was observed between the perfusion parameters and tumor grading. Only HAC showed a non-significant trend in different grades of HCC (pHCC < NP-HCC; P = .07). The pHCC cases had significantly decreased values of tumor attenuation on the unenhanced phase (TAu), tumor attenuation on the portal phase portal phase (TAp), and equilibrium phase (TAe) (P < .01). The difference of tumor attenuation between the portal phase and the unenhanced phase (TAp-TAu) of the pHCC cases was decreased than that of the NP-HCC cases (P < .01), whereas the difference of attenuation between the equilibrium phase and portal phase (TAe-TAp) was significantly higher in the pHCC cases than that in the NP-HCC cases (P < .01). TAe-TAp had the highest area under the curve. The number of tumor enhancement pattern in Group 5 of HCCs with a diameter of 3 cm or more was significantly more than that of HCCs with a diameter of less than 3 cm or with other different enhancement patterns (P < .01).Histological HCC grading cannot be predicted by the perfusion parameters derived from traditional tri-phasic CT scans, whereas the tumor attenuation on different phases and the tumor attenuation differences among different phases, especially the mean value of TAe-TAp, might be useful for non-invasive prediction on the degree of HCC differentiation.

Value of perfusion parameters and histogram analysis of triphasic computed tomography in pre-operative prediction of histological grade of hepatocellular carcinoma

BACKGROUND

Pre-operative non-invasive histological evaluation of hepatocellular carcinoma (HCC) remains a challenge. Tumor perfusion is significantly associated with the development and aggressiveness of HCC. The purpose of the study was to evaluate the clinical value of quantitative liver perfusion parameters and corresponding histogram parameters derived from traditional triphasic enhanced computed tomography (CT) scans in predicting histological grade of HCC.

METHODS

Totally, 52 patients with HCC were enrolled in this retrospective study and underwent triple-phase enhanced CT imaging. The blood perfusion parameters were derived from triple-phase CT scans. The relationship of liver perfusion parameters and corresponding histogram parameters with the histological grade of HCC was analyzed. Receiver operating characteristic (ROC) curve analysis was used to determine the optimal ability of the parameters to predict the tumor histological grade.

RESULTS

The variance of arterial enhancement fraction (AEF) was significantly higher in HCCs without poorly differentiated components (NP-HCCs) than in HCCs with poorly differentiated components (P-HCCs). The difference in hepatic blood flow (HF) between total tumor and total liver flow (ΔHF = HFtumor - HFliver) and relative flow (rHF = ΔHF/HFliver) were significantly higher in NP-HCCs than in P-HCCs. The difference in portal vein blood supply perfusion (PVP) between tumor and liver tissue (ΔPVP) and the ΔPVP/liver PVP ratio (rPVP) were significantly higher in patients with NP-HCCs than in patients with P-HCCs. The area under ROC (AUC) of ΔPVP and rPVP were both 0.697 with a high sensitivity of 84.2% and specificity of only 56.2%. The ΔHF and rHF had a higher specificity of 87.5% with an AUC of 0.681 and 0.673, respectively. The combination of rHF and rPVP showed the highest AUC of 0.732 with a sensitivity of 57.9% and specificity of 93.8%. The combined parameter of ΔHF and rPVP, rHF and rPVP had the highest positive predictive value of 0.903, and that of rPVP and ΔPVP had the highest negative predictive value of 0.781.

CONCLUSION

Liver perfusion parameters and corresponding histogram parameters (including ΔHF, rHF, ΔPVP, rPVP, and AEFvariance) in patients with HCC derived from traditional triphasic CT scans may be helpful to non-invasively and pre-operatively predict the degree of the differentiation of HCC.

Quantitative assessment of HCC wash-out on CT is a predictor of early complete response to TACE

OBJECTIVES

To investigate the predictive value of four-phase contrast-enhanced CT (CECT) for early complete response (CR) to drug-eluting-bead transarterial chemoembolization (DEB-TACE), with a particular focus on the quantitatively assessed wash-in and wash-out.

METHODS

A retrospective analysis of preprocedural CECTs was performed for 129 HCC nodules consecutively subjected to DEB-TACE as first-line therapy. Lesion size, location, and margins were recorded. For the quantitative analysis, the following parameters were computed: contrast enhancement ratio (CER) and lesion-to-liver contrast ratio (LLC) as estimates of wash-in; absolute and relative wash-out (WO_abs and WO_rel) and delayed percentage attenuation ratio (DPAR) as estimates of wash-out. The early radiological response of each lesion was assessed by the mRECIST criteria and dichotomized in CR versus others (partial response, stable disease, and progressive disease).

RESULTS

All quantitatively assessed wash-out variables had significantly higher rates for CR lesions (WO_abs p = 0.01, WO_rel p = 0.01, and DPAR p = 0.00002). However, only DPAR demonstrated an acceptable discriminating ability, quantified by AUC = 0.80 (95% CI0.73-0.88). In particular, nodules with DPAR ≥ 120 showed an odds ratio of 3.3(1.5-7.2) for CR (p = 0.0026). When accompanied by smooth lesion margins, DPAR ≥ 120 lesions showed a 78% CR rate at first follow-up imaging. No significative association with CR was found for quantitative wash-in estimates (CER and LLC).

CONCLUSIONS

Based on preprocedural CECT, the quantitative assessment of HCC wash-out is useful in predicting early CR after DEB-TACE. Among the different formulas for wash-out quantification, DPAR has the best discriminating ability. When associated, DPAR ≥ 120 and smooth lesion margins are related to relatively high CR rates.

KEY POINTS

• A high wash-out rate, quantitatively assessed during preprocedural four-phase contrast-enhanced CT (CECT), is a favorable predictor for early radiological complete response of HCC to drug-eluting-bead chemoembolization (DEB-TACE). • The arterial phase of CECT shows great dispersion of attenuation values among different lesions, even when a standardized protocol is used, limiting its usefulness for quantitative analyses. • Among the different formulas used to quantify the wash-out rate (absolute wash-out, relative wash-out, and delayed percentage attenuation ratio), the latter (DPAR), based only on the delayed phase, is the most predictive (AUC = 0.80), showing a significant association with complete response for values above 120.

A scientometric analysis on hepatocellular carcinoma magnetic resonance imaging research from 2008 to 2017

Background

With the development of new magnetic resonance imaging (MRI) techniques, an increasing number of articles have been published regarding hepatocellular carcinoma magnetic resonance imaging (HCCMRI) in the past decade. However, few studies have statistically analyzed these published articles. In this study, we aim to systematically evaluate the scientific outcomes of HCCMRI research and explore the research hotspots from 2008 to 2017.

Methods

The included articles regarding HCCMRI research from 2008 to 2017 were downloaded from the Web of Science Core Collection and verified by two experienced radiologists. Excel 2016 was used to analyze the literature data, including the publication years and journals. CiteSpace V was used to perform co-occurrence analyses for authors, countries/regions and institutions and to generate the related collaboration network maps. Reference co-citation analysis (RCA) and burst keyword detection were also performed using CiteSpace V to explore the research hotspots in the past decade.

Results

A total of 835 HCCMRI articles published from 2008 to 2017 were identified. Journal of Magnetic Resonance Imaging published the most articles (79 publications, 9.46%). Extensive cooperating relationship were observed among countries/regions and among authors. South Korea had the most publications (199 publications, 21.82%), followed by the United States of America (USA) (190 publications, 20.83%), Japan (162 publications, 17.76%), and the People's Republic of China (148 publications, 16.23%). Among the top 10 co-cited authors, Bruix J (398 citations) was ranked first, followed by Llovet JM (235 citations), Kim YK (170 citations) and Forner A (152 citations). According to the RCA, ten major clusters were explored over the last decade; "LI-RADS data system" and "microvascular invasion" (MVI) were the two most recent clusters. Forty-seven burst keywords with the highest citation strength were detected over time. Of these keywords, "microvascular invasion" had the highest strength in the last 3 years. The LI-RADS has been constantly updated with the latest edition released in July 2018. However, the LI-RADS still has limitations in identifying certain categories of lesions by conceptual and non-quantitative probabilistic methods. Plenty of questions still need to be further answered such as the difference of diagnostic efficiency of each major/ancillary imaging features. Preoperative prediction of MVI of HCC is very important to therapeutic decision-making. Some parameters of Gd-EOB-DTPA-enhanced MRI were found to be useful in prediction of MVI, however, with a high specificity but a very low sensitivity. Comprehensive predictive model incorporating both imaging and clinical variables may be the more preferable in prediction of MVI of HCC.

Conclusions

HCCMRI-related publications displayed a gradually increasing trend from 2008 to 2017. The USA has a central position in collaboration with other countries/regions, while South Korea contributed the most in the number of publications. Of the ten major clusters identified in the RCA, the two most recent clusters were "LI-RADS data system" and "microvascular invasion", indicative of the current HCCMRI research hotspots.

Non-alcoholic fatty liver disease-associated hepatocellular carcinoma: effect of hepatic steatosis on major hepatocellular carcinoma features at MRI

OBJECTIVE:

To evaluate the effect of hepatic steatosis on LI-RADS® major features at MRI in patients with non-alcoholic fatty liver disease (NAFLD)-associated hepatocellular carcinoma (HCC).

METHODS:

HCC and liver parenchyma features at MRI from 48 consecutive patients with NAFLD and histology proven HCC (mean ± SD; 4.5 ± 3.4 cm) were independently reviewed by three radiologists. Inter-rater agreement was determined by prevalence/bias-adjusted kappa. Hepatic fat signal fraction (FS%) was independently calculated. HCC features were compared by FS% at MRI using logistic regression analysis and histologic steatosis grade using Cochran-Armitage test for trend, stratified by cirrhotic liver morphology or histologic fibrosis stage. Receiver operating characteristic curves were generated to determine the sensitivity and specificity for major HCC features by FS%.

RESULTS:

Major HCC features included arterial phase hyperenhancement (APHE) in 45 (93%), portal venous phase washout (PVWO) in 30 (63%), delayed phase washout (DPWO) in 38 (79%) and enhancing "capsule" in 34 (71%). Cirrhotic morphology was present in 22 (46%). Inter-rater agreement was 0.75 for APHE, 0.42-0.58 for PVWO, 0.58-0.71 for DPWO and 0.38-0.67 for enhancing "capsule". There was an 18%, 14% and 22% increase in the odds of absent PVWO, DPWO and capsule appearance for every 1% increase in hepatic FS% in patients with non-cirrhotic liver morphology (p = 0.011, 0.040 and 0.029, respectively). Hepatic FS% ≥ 14.8% had a sensitivity and specificity of 64 and 100% for absent PVWO and 71 and 90% for absent DPWO in patients with non-cirrhotic liver morphology.

CONCLUSION:

Absent washout and capsule appearance are associated with increasing hepatic steatosis in patients with non-cirrhotic, NAFLD-associated HCC.

ADVANCES IN KNOWLEDGE:

In patients with non-cirrhotic, non-alcoholic fatty liver disease (NAFLD)-associated hepatocellular carcinoma (HCC), absent HCC washout and capsule appearance are associated with increasing hepatic steatosis, thereby potentially impacting the noninvasive imaging diagnosis of HCC in these patients. Lack of washout or capsule appearance in steatotic livers at MRI may require alternative criteria for the diagnosis of HCC in patients with non-cirrhotic NAFLD.

Human Clinical-Grade Parthenogenetic ESC-Derived Dopaminergic Neurons Recover Locomotive Defects of Nonhuman Primate Models of Parkinson's Disease

Clinical application of stem cell derivatives requires clinical-grade cells and sufficient preclinical proof of safety and efficacy, preferably in primates. We previously successfully established a clinical-grade human parthenogenetic embryonic stem cell (hPESC) line, but the suitability of its subtype-specific progenies for therapy is not clear. Here, we compared the function of clinical-grade hPESC-derived midbrain dopaminergic (DA) neurons in two canonical protocols in a primate Parkinson's disease (PD) model. We found that the grafts did not form tumors and produced variable but apparent behavioral improvement for at least 24 months in most monkeys in both groups. In addition, a slight DA increase in the striatum correlates with significant functional improvement. These results demonstrated that clinical-grade hPESCs can serve as a reliable source of cells for PD treatment. Our proof-of-concept findings provide preclinical data for China's first ESC-based phase I/IIa clinical study of PD (ClinicalTrials.gov number NCT03119636).

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.

How to Differentiate Borderline Hepatic Nodules in Hepatocarcinogenesis: Emphasis on Imaging Diagnosis

BACKGROUND

Rapid advances in liver imaging have improved the evaluation of hepatocarcinogenesis and early diagnosis and treatment of hepatocellular carcinoma (HCC). In this situation, detection of early-stage HCC in its development is important for the improvement of patient survival and optimal treatment strategies. Because early HCCs are considered precursors of progressed HCC, precise differentiation between a dysplastic nodule (DN), especially a high-grade DN, and early HCC is important. In clinical practice, these nodules are frequently called "borderline hepatic nodules."

SUMMARY

This article discusses radiological and pathological characteristics of these borderline hepatic nodules and offers an understanding of multistep hepatocarcinogenesis by focusing on the descriptions of the imaging changes in the progression of DN and early HCC. Detection and accurate diagnosis of borderline hepatic nodules are still a challenge with contrast enhanced ultrasonography, CT, and MRI with extracellular contrast agents. However, gadoxetic acid-enhanced MRI may be useful for improving the diagnosis of these borderline nodules.

KEY MESSAGES

Since there is a net effect of incomplete neoangiogenesis and decreased portal venous flow in the early stage of hepatocarcinogenesis, borderline hepatic nodules commonly show iso- or hypovascularity. Therefore, precise differentiation of these nodules remains a challenging issue. In MRI using hepatobiliary contrast agents, signal intensity of HCCs on hepatobiliary phase (HBP) is regarded as a potential imaging biomarker. Borderline hepatic nodules are seen as nonhypervascular and hypointense nodules on the HBP, which is important for predicting tumor behavior and determining appropriate therapeutic strategies.

Diffusion-weighted imaging of hepatocellular carcinomas: a retrospective analysis of correlation between apparent diffusion coefficients and histological grade

PURPOSE

To define correlations between the pathological grades of hepatocellular carcinomas (HCCs) and apparent diffusion coefficients (ADCs) derived using breath-holding diffusion-weighted imaging (BH-DWI).

METHODS

We retrospectively evaluated 94 patients (105 lesions) with pathologically proved HCC who underwent hepatic DWI on a 3.0-T MR platform. HCCs were divided into five groups: well-differentiated (n = 10), well-to-moderately differentiated (n = 11), moderately differentiated (n = 51), moderately to poorly differentiated (n = 20), and poorly differentiated (n = 13) groups. The ADCs of carcinomas across different histological grades were compared by one-way analysis of variance. Spearman's rank correlation test was used to analyze correlations between the degree of histopathological differentiation and ADC. Results were corrected for multiple comparisons using the Bonferroni correction.

RESULTS

The BH technique yielded ADC values that differed significantly by the extent of differentiation (F = 8.392, p < 0.001). A significant negative correlation was found between the extent of differentiation and ADCs (r = -0.462, p < 0.001). The mean ADC values of poorly differentiated HCCs were significantly lower than the well-, well-to-moderately, moderately, and moderately to poorly differentiated HCCs (p values were <0.001, <0.001, 0.003, and 0.031, respectively).

CONCLUSION

ADC values obtained with BH-DWI may be of importance to non-invasively predict HCC tumor differentiation, and the extent of histological HCC differentiation was inversely correlated with ADC values.

Gadolinium Ethoxybenzyl Diethylenetriamine Pentaacetic Acid (Gd-EOB-DTPA)-Enhanced Magnetic Resonance Imaging and Multidetector-Row Computed Tomography for the Diagnosis of Hepatocellular Carcinoma: A Systematic Review and Meta-analysis

The purpose of this meta-analysis was to compare the diagnostic accuracy of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) and multidetector-row computed tomography (MDCT) for hepatocellular carcinoma (HCC).Medline, Cochrane, EMBASE, and Google Scholar databases were searched until July 4, 2014, using combinations of the following terms: gadoxetic acid disodium, Gd-EOB-DTPA, multidetector CT, contrast-enhanced computed tomography, and magnetic resonance imaging. Inclusion criteria were as follows: confirmed diagnosis of primary HCC by histopathological examination of a biopsy specimen; comparative study of MRI using Gd-EOB-DTPA and MDCT for diagnosis of HCC; and studies that provided quantitative outcome data. The pooled sensitivity and specificity of the 2 methods were compared, and diagnostic accuracy was assessed with alternative-free response receiver-operating characteristic analysis.Nine studies were included in the meta-analysis, and a total of 1439 lesions were examined. The pooled sensitivity and specificity for 1.5T MRI were 0.95 and 0.96, respectively, for 3.0T MRI were 0.91 and 0.96, respectively, and for MDCT were 0.74 and 0.93, respectively. The pooled diagnostic odds ratio for 1.5T and 3.0T MRI was 242.96, respectively, and that of MDCT was 33.47. To summarize, Gd-EOB-DTPA-enhanced MRI (1.5T and 3.0T) has better diagnostic accuracy for HCC than MDCT.

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.

Autologous transplantation of GDNF-expressing mesenchymal stem cells protects against MPTP-induced damage in cynomolgus monkeys

Glial cell-derived neurotrophic factor (GDNF) has shown beneficial effects in models of Parkinson's disease. The mild results observed in the double-blind clinical trial by intraputamenal infusion of recombinant GDNF proteins warrant a search for alternative delivery methods. In this study, we investigated the function of autologous mesenchymal stem cells (MSCs) expressing GDNF (GDNF-MSCs) for protection against MPTP-induced injury in cynomolgus monkeys. MSCs were obtained from the bone marrow of individual monkeys and gene-modified to express GDNF. Following unilateral engraftment of GDNF-MSCs into the striatum and substantia nigra, the animals were challenged with MPTP to induce a stable systemic Parkinsonian state. The motor functions were spared in the contralateral limbs of monkeys receiving GDNF-MSCs, but not in those receiving MSCs alone. In the striatum of the grafted hemisphere, dopamine levels were higher and dopamine uptake was enhanced. The results suggest that autologous MSCs may be a safe vehicle to deliver GDNF for enhancing nigro-striatum functions.

Methods to improve resectability of hepatocellular carcinoma

Liver resection is associated with prolonged survival in selected patients with hepatocellular carcinoma (HCC). Surgical resection of HCC may be decided on an individual basis according to the extent of the tumor and the severity of chronic liver disease. In patients with compensated cirrhosis, the volume of the future liver remnant (FLR) is the most reliable factor for predicting postoperative liver function. Methods of increasing the FLR volume, including portal vein embolization and sequential transarterial chemoembolization in patients who are primarily not eligible for liver resection, have been shown to be safe and have contributed to the increase in the number of surgical candidates.

Histologic characteristics of hepatocellular carcinomas showing atypical enhancement patterns on 4-phase MDCT examination

Objective

To retrospectively define which histologic characteristics of small-sized hepatocellular carcinomas (HCCs) are related to atypical dynamic enhancement on multi-detector computed tomography (MDCT) imaging.

Materials and Methods

Seventy-three patients with 83 HCCs (3 cm or less in diameter) were included in this study. All patients underwent 4-phase MDCT imaging and subsequent surgery within eight weeks. Two independent radiologists blinded to the histologic findings retrospectively classified the HCCs as either typical (showing increased enhancement on arterial phase images followed by washout in late phase images) or atypical lesions demonstrating any other enhancement pattern. From the original pathologic reports, various histologic characteristics including gross morphology, nuclear histologic grades, presence of capsule formation, and capsule infiltration when a capsule was present, were compared among the two groups.

Results

An atypical enhancement pattern was seen in 30 (36.2%) of the 83 HCCs. The mean size of atypical HCCs (1.71 ± 0.764) was significantly smaller than that of typical HCCs (2.31 ± 0.598, p < 0.001). Atypical HCCs were frequently found to be vaguely nodular in gross morphology (n = 13, 43.3%) and to have grade I nuclear grades (n = 17, 56.7%). Capsule formation was significantly more common in typical HCCs (p < 0.001). Capsular infiltration was also more common in typical HCCs (p = 0.001).

Conclusion

HCCs showing atypical dynamic enhancement on MDCT imaging are usually smaller than typical HCCs, vaguely nodular type in gross morphology in most cases, and well-differentiated in nuclear grades, and they lack of capsule formation or capsular infiltration.

Comparison of usefulness of clinical diagnostic criteria for hepatocellular carcinoma in a hepatitis B endemic area

Background/Aims

We compared the accuracy and usefulness of clinical diagnostic criteria for hepatocellular carcinoma in a hepatitis B virus (HBV)-endemic area.

Methods

We reviewed the medical records of 355 patients who had undergone liver resection or biopsy at our institution between January 2008 and December 2009. These patients were reevaluated using four noninvasive diagnostic criteria for hepatocellular carcinoma proposed by the European Association for the Study of the Liver (EASL), the American Association for the Study of Liver Diseases (AASLD), the Korean Liver Cancer Study Group and the National Cancer Center (KLCSG/NCC), and National Comprehensive Cancer Network (NCCN) guidelines.

Results

The overall sensitivity was highest using the KLCSG/NCC criteria (79.8%), followed by the AASLD (51.5%), EASL (38.4%), and NCCN (10.1%; P<0.001) criteria, whereas the specificity (84.5-98.3%) and positive predictive value (96.2-98.3%) were similar for all of the criteria. The KLCSG/NCC criteria had an acceptable false-positive rate and the highest sensitivity among all of the patients, including those positive for HBsAg, those without liver cancer, and those with a tumor of at least 2 cm.

Conclusions

The KLCSG/NCC and AASLD criteria exhibited the highest sensitivity, and all four guidelines had a high specificity among all of the patients. Based on the sensitivity and false-positive rate, the KLCSG/NCC criteria was the most useful in the majority of patients. Inclusion of HBV infection in the clinical diagnostic criteria for hepatocellular carcinoma would be reasonable and may lead to an improvement in the sensitivity, with acceptable false-positive rates, in HBV-endemic areas.

Labeling of cynomolgus monkey bone marrow-derived mesenchymal stem cells for cell tracking by multimodality imaging

Recently, transplantation of allogeneic and autologous cells has been used for regenerative medicine. A critical issue is monitoring migration and homing of transplanted cells, as well as engraftment efficiency and functional capability in vivo. Monitoring of superparamagnetic iron oxide (SPIO) particles by magnetic resonance imaging (MRI) has been used in animal models and clinical settings to track labeled cells. A major limitation of MRI is that the signals do not show biological characteristics of transplanted cells in vivo. Bone marrow mesenchymal stem cells (MSCs) have been extensively investigated for their various therapeutic properties, and exhibit the potential to differentiate into cells of diverse lineages. In this study, cynomolgus monkey MSCs (cMSCs) were labeled with Molday ION Rhodamine-B™ (MIRB), a new SPIO agent, to investigate and characterize the biophysical and MRI properties of labeled cMSCs in vitro and in vivo. The results indicate that MIRB is biocompatible and useful for cMSCs labeling and cell tracking by multimodality imaging. Our method is helpful for detection of transplanted stem cells in vivo, which is required for understanding mechanisms of cell therapy.

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

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.

Mesenchymal stem cell labeling and in vitro MR characterization at 1.5 T of new SPIO contrast agent: Molday ION Rhodamine-B™

In vivo detection of transplanted stem cells is requisite for improving stem cell-based treatments by developing a thorough understanding of their therapeutic mechanisms. MRI tracking of magnetically labeled cells is non-invasive and is suitable for longitudinal studies. Molday ION Rhodamine-B™ (MIRB) is a new superparamagnetic iron oxide (SPIO) contrast agent specifically formulated for cell labeling and is readily internalized by non-phagocytic cells. This investigation characterizes mesenchymal stem cell (MSC) labeling and MR imaging properties of this new SPIO agent. Effects of MIRB on MSC viability and differentiation as well as cellular loading properties were assessed for MSC labeled with MIRB at concentrations from 5 to 100 µg Fe/ml. Labeled MSC were evaluated, in vitro, on a clinical 1.5 T MRI. Optimal scanning sequences and imaging parameters were determined based on contrast-to-noise ratio and contrast modulation. Relaxation rates (1/T(2)*) for gradient-echo sequences were approximated and an idealized limit of detection was established. MIRB labeling did not affect MSC viability or the ability to differentiate into either bone or fat. Labeling efficiency was found to be approximately 95% for labeling concentrations at or above 20 µg Fe/ml. Average MIRB per MSC ranged from 0.7 pg Fe for labeling MIRB concentration of 5 µg Fe/ml and asymptotically approached a value of 20-25 pg Fe/MSC as labeling concentration increased to 100 µg Fe/ml. MRI analysis of MIRB MSC revealed long echo time, gradient echo sequences to provide the most sensitivity. Limit of detection for gradient echo sequences was determined to be less than 1000 MSC, with approximately 15 pg Fe/MSC (labeled at 20 µg Fe/ml). These investigations have laid the groundwork and established feasibility for the use of this contrast agent for in vivo MRI detection of MSC. Properties evaluated in this study will be used as a reference for tracking labeled MSC for in vivo studies.

Apparent diffusion coefficient value of diffusion-weighted imaging for hepatocellular carcinoma: correlation with the histologic differentiation and the expression of vascular endothelial growth factor

Objective

To evaluate whether the histopathological differentiation and the expression of vascular endothelial growth factor (VEGF) of hepatocellular carcinoma (HCC) do show correlation with the apparent diffusion coefficient (ADC) value on diffusion-weighted imaging (DWI).

Materials and Methods

Twenty-seven HCCs from 27 patients who had undergone preoperative liver MRI (1.5T) and surgical resection were retrospectively reviewed. DWI was obtained with a single-shot, echo-planar imaging sequence in the axial plane (b values: 0 and 1,000 sec/mm²). On DWIs, the ADC value of the HCCs was measured by one radiologist, who was kept 'blinded' to the histological findings. Histopathologically, the differentiation was classified into well (n = 9), moderate (n = 9) and poor (n = 9). The expression of VEGF was semiquantitatively graded as grade 0 (n = 8), grade 1 (n = 9) and grade 2 (n = 10). We analyzed whether the histopathological differentiation and the expression of VEGF of the HCC showed correlation with the ADC value on DWI.

Results

The mean ADC value of the poorly-differentiated HCCs (0.9 ± 0.13×10^-3 mm²/s) was lower than those of the well-differentiated HCCs (1.2 ± 0.22×10^-3 mm²/s) (p = 0.031) and moderately-differentiated HCCs (1.1 ± 0.01×10^-3 mm²/s) (p = 0.013). There was a significant correlation between the differentiation and the ADC value of the HCCs (r = -0.51, p = 0.012). The mean ADC of the HCCs with a VEGF expression grade of 0, 1 and 2 was 1.1 ± 0.17, 1.1 ± 0.21 and 1.1 ± 0.18×10^-3 mm²/s, respectively. The VEGF expression did not show correlation with the ADC value of the HCCs (r = 0.07, p = 0.74).

Conclusion

The histopathological differentiation of HCC shows inverse correlation with the ADC value. Therefore, DWI with ADC measurement may be a valuable tool for noninvasively predicting the differentiation of HCC.