Magnetic resonance imaging of the cirrhotic liver: diagnosis of hepatocellular carcinoma and evaluation of response to treatment - Part 1

Retinoic acid-conjugated chitosan/manganese porphyrin ionic-complex nanoparticles for improved T1 contrast MR imaging of hepatic fibrosis

Noninvasive and precise diagnosis of hepatic fibrosis is very important for the preventive therapeutic regimen of hepatic cirrhosis and cancer. In this study, we fabricated T₁ contrast Mn-porphyrin (MnTPPS₄ )/retinoic acid-chitosan ionic-complex nanoparticles (MRC NPs). The functional properties of MRC NPs were evaluated via transmission electron microscopy (TEM) imaging, release study, cytotoxicity assay, hepatocyte-specific uptake assay, and magnetic resonance (MR) imaging study. TEM images confirmed the typical structure of an ionic-complex NPs with around 100-200 nm of diameter. MnTPPS₄ is released from MRC NPs for up to 24 hr in controlled pattern which implies that more reliable and convenient hepatic MR imaging is possible using of MRC NPs in clinical practice. Hepatocytes uptake assay proved retinoic acid-specific targeting of MRC NPs. The same results were observed in animal pharmacokinetic studies. In vitro MR phantom study, MRC NPs showed an increased T₁ relaxivity (r₁  = 6.772 mM^-1  s^-1 ) in comparison with 3.242 mM^-1  s^-1 of MnTPPS₄ . The result was confirmed again in vivo MR imaging studies. Taken together, MRC NPs displayed a potential for noninvasive diagnostic T₁ MR imaging of hepatic fibrosis with improved target specificity and prolonged MR imaging time window.

A study on the inconsistency of arterial phase hypervascularity detection between contrast-enhanced ultrasound using sonazoid and gadolinium-ethoxybenzyl-diethylenetriamine penta-acetic acid magnetic resonance imaging of hepatocellular carcinoma lesions

PURPOSE

By analyzing possible factors contributing to imaging misevaluation of arterial phase (AP) vascularity, we aimed to provide a more proper way to detect AP hypervascularity of hepatocellular carcinomas (HCCs) using the noninvasive imaging modalities magnetic resonance imaging (MRI) and contrast-enhanced ultrasound (CEUS).

METHODS

We retrospectively recruited 164 pathologically confirmed HCC lesions from 128 patients. Using CEUS with Sonazoid (SCEUS) and gadolinium-ethoxybenzyl-diethylenetriamine penta-acetic acid MRI (EOB-MRI), AP vascularity of the lesions was evaluated and inconsistencies in interpretation were examined. Indicators of margin, echogenicity, and halo and mosaic signs of lesions on grayscale US; depth of lesions on SCEUS; and tumoral homogeneity, signal contrast ratio of lesions to the surrounding area on precontrast and AP images on EOB-MRI, and histological grade were investigated.

RESULTS

When precontrast images were used to adjust the AP enhancement ratio, the proportion of inconsistent interpretations of AP vascularity declined from 26.2% (43/164; 29 non-hypervascularity instances using EOB-MRI and 14 using SCEUS) to 16.5% (27/164; 7 using EOB-MRI and 20 using SCEUS). Greater lesion depth (P = 0.017), ill-defined tumoral margin (P = 0.028), absence of halo sign (P = 0.034), and histologically early HCC (P = 0.007) on SCEUS, and small size (P = 0.012) and heterogeneity (P = 0.013) of lesions and slight enhancement (low AP enhancement ratio) (P = 0.018 and 0.009 before and after adjustment) on EOB-MRI, may relate to undetectable hypervascularity.

CONCLUSIONS

SCEUS and EOB-MRI may show discrepancies in evaluating AP vascularity in the case of deep, ill-defined, heterogeneous, slightly enhanced lesions, and histologically early HCCs. We recommend adjusting AP with precontrast images in EOB-MRI, and combining both modalities to detect hypervascularity.

High glypican-1 expression is a prognostic factor for predicting a poor clinical prognosis in patients with hepatocellular carcinoma

Hepatocellular carcinoma (HCC) has a high mortality rate, which imposes a huge burden on patients and society. Glypican-1 (GPC1) is considered to be an ideal diagnostic marker. The present study aimed to investigate GPC1 expression in HCC, its association with clinicopathological factors and its prognostic significance in HCC progression. Reverse transcription-quantitative PCR, western blotting and immunohistochemical staining were used to investigate GPC1 expression in 175 HCC and paired normal tissues, and in HCC and normal cells. Serolo2gical levels of GPC1 were examined via enzyme-linked immunosorbent assay in patients with HCC. Kaplan-Meier survival analysis and Cox regression analysis were used to assess the prognostic significance of GPC1. The present results suggested that GPC1 expression was upregulated in HCC tissues, especially in metastatic HCC. Similar results were observed in HCC cell lines. Serum GPC1 was higher in patients with HCC than in healthy controls (HCs). Patients with high GPC1 expression had shorter recurrence-free survival (RFS) and disease-specific survival (DSS) times compared with those with low GPC1 expression. In addition, high GPC1 expression was significantly associated with tumor size and Tumor-Node-Metastasis (TNM) stage (P<0.05). Furthermore, tumor size, TNM stage and GPC1 expression were independent predictive factors for RFS and DSS in patients with HCC. In conclusion, the present results revealed that high GPC1 expression was closely associated with a poor prognosis in patients with HCC and that it may therefore be used as a potential target for accurate diagnosis and treatment of HCC.

Predicting the Outcome of Transcatheter Arterial Embolization Therapy for Unresectable Hepatocellular Carcinoma Based on Radiomics of Preoperative Multiparameter MRI

BACKGROUND

In unresectable hepatocellular carcinoma (HCC), methods to predict patients at increased risk of progression are required.

PURPOSE

To investigate the feasibility of radiomics model in predicting early progression of unresectable HCC after transcatheter arterial chemoembolization (TACE) therapy using preoperative multiparametric magnetic resonance imaging (MP-MRI).

STUDY TYPE

Retrospective.

POPULATION

A total of 84 patients with BCLC B stage HCC from one medical center. According to the modified response evaluation criteria in solid tumors, patients who progressed at 6 months after TACE therapy were assigned as the progressive disease (PD) group (n = 32). Patients whose MRI was performed on four devices were divided into a training cohort (n = 67). Patients whose MRI was performed on other than the previous four devices were used as the testing set (n = 17).

FIELD STRENGTH/SEQUENCE

3.0T, 1.5T axial T₂ -weighted imaging (T₂ WI), diffusion-weighted imaging (DWI, b = 0, 500 s/mm² ), and apparent diffusion coefficient (ADC) ASSESSMENT: PD was confirmed via imaging studies with MRI. Risk factors, including age, alpha fetoprotein (AFP), size, and radiomic-related features of PD were assessed. In addition, the discrimination ability of each radiomics signature was tested on an independent testing set.

STATISTICAL TESTS

The area under the receiver-operator characteristic (ROC) curve (AUC) was used to evaluate the predictive accuracy of the radiomic signature in both the training and testing sets. The results indicated that the MP-MRI model achieved the greatest benefit.

RESULTS

In the testing set, the model based on DWI features presented an AUC of (b = 0, 0.786; b = 500, 0.729), followed by T₂ WI features (0.729) and ADC (0.714). The AUC of the MP-MRI signature was increased to 0.800 compared to any single MRI signature. The multivariate logistic analysis identified the radiomics signature as independent parameters of PD, while clinical information such as age, AFP, size, etc., had no significance in the PD group.

DATA CONCLUSION

Preoperative MP-MRI has the potential to predict the outcome of TACE therapy for unresectable HCC. In addition, these image features may be complementary to the current staging systems of HCC patients.

LEVEL OF EVIDENCE

2.

TECHNICAL EFFICACY STAGE

3. J. Magn. Reson. Imaging 2020;52:1083-1090.

Diffusion-weighted imaging and apparent diffusion coefficient values for evaluating terminal ileitis in patients with Crohn's disease

Objective:

To determine the accuracy of diffusion-weighted imaging (DWI) in identifying terminal ileitis in patients with Crohn’s disease.

Materials and Methods:

This was a retrospective study of 38 consecutive patients with Crohn’s disease who underwent magnetic resonance enterography with DWI in a 3.0 T scanner. The patients were divided into two groups, on the basis of colonoscopy and biopsy findings: active inflammation; and inactive disease. Apparent diffusion coefficient (ADC) values were determined, as were the magnetic resonance index of activity (MaRIA) and the Clermont score.

Results:

Of the 38 patients evaluated, 18 (47%) had active inflammation. The patients with active inflammation showed greater restricted diffusion, more pronounced mucosal edema, greater wall thickening, a higher MaRIA, and a higher Clermont score than did those with inactive disease. The level of interobserver agreement (intraclass correlation coefficient) was excellent for the MaRIA and the Clermont score, whereas it was substantial for the ADC values. For identifying colonoscopy-proven inflammation, the best ADC cut-off point was 2.1 × 10⁻³ mm²/s, which had a sensitivity of 88.8% and a specificity of 95.0%, whereas DWI presented an overall accuracy of 89.4%, with a sensitivity of 88.9% and a specificity of 90.0%.

Conclusion:

Visual analysis of the DWI sequence has good accuracy in detecting terminal ileitis in patients with Crohn’s disease. In addition, low ADC values have good sensitivity for detecting colonoscopy-proven inflammation.

Microvascular invasion in hepatocellular carcinoma: is it predictable with quantitative computed tomography parameters?

Objective

To investigate whether quantitative computed tomography (CT) measurements can predict microvascular invasion (MVI) in hepatocellular carcinoma (HCC).

Materials and Methods

This was a retrospective analysis of 200 cases of surgically proven HCCs in 125 consecutive patients evaluated between March 2010 and November 2017. We quantitatively measured regions of interest in lesions and adjacent areas of the liver on unenhanced CT scans, as well as in the arterial, portal venous, and equilibrium phases on contrast-enhanced CT scans. Enhancement profiles were analyzed and compared with histopathological references of MVI. Univariate and multivariate logistic regression analyses were used in order to evaluate CT parameters as potential predictors of MVI.

Results

Of the 200 HCCs, 77 (38.5%) showed evidence of MVI on histopathological analysis. There was no statistical difference between HCCs with MVI and those without, in terms of the percentage attenuation ratio in the portal venous phase (114.7 vs. 115.8) and equilibrium phase (126.7 vs. 128.2), as well as in terms of the relative washout ratio, also in the portal venous and equilibrium phases (15.0 vs. 8.2 and 31.4 vs. 26.3, respectively).

Conclusion

Quantitative dynamic CT parameters measured in the preoperative period do not appear to correlate with MVI in HCC.

Relationship between MRI delayed enhancement of primary hepatocellular carcinoma and distribution of different fibrous components in pathological tissues

BACKGROUND

Primary hepatocellular carcinoma (HCC) is one of common malignant tumors in China, and magnetic resonance imaging (MRI) has a big advantage in the diagnosis of tumor diseases due to its high resolution. However, tumors with different fibrous components may have different enhancement characteristics. This research aimed to explore the relationship between MRI delayed enhancement characteristics of primary HCC and the distribution of different fibrous components in tumor tissue.

AIM

To observe the relationship between MRI delayed enhancement and the distribution of different fibrous components in primary HCC.

METHODS

From April 2016 to May 2019, 56 patients diagnosed with primary HCC and treated at our hospital were included. All patients underwent routine and enhanced MRI examinations, and 2-min delay images were analyzed to assess the degree of enhancement of the edge and internal portion of lesions and measure the thickness of edge annular enhancement in the MRI delay phase. Surgical samples were collected for routine HE staining. Resorcin-fuchsin staining, Masson trichromic staining, and argento-ammonia hydroxide staining were used to observe the thickness and distribution characteristics of the three types of fibers in the capsule.

RESULTS

There was no significant difference between patients with different degrees of edge annular enhancement in MRI delay phase in terms of capsule thickness and the infiltration degree of inflammatory cells outside the capsule (P > 0.05), while there was a significant difference between the vessels inside the capsule (P < 0.05). Lesions with a complete capsule had full annular enhancement, while those with an incomplete capsule had discontinuous enhancement. The thickness of annular enhancement in the 44 lesions was significantly correlated with capsule thickness, degree of inflammatory cell infiltration outside the capsule, and the number of capsular vessels (P < 0.05). Inside the lesions, the tumor tissue was rich in blood vessels, had less fiber content, and showed various fibrous tissue distribution in different lesions. There were statistically significant differences in the infiltration degree of inflammatory cells and the contents of collagen fibers, elastic fibers, and reticular fibers in patients with different degrees of internal enhancement in the MRI delay phase (P < 0.05).

CONCLUSION

The peripheral and internal enhancement characteristics of primary HCC in the delay phase of MRI are related to the infiltration of inflammatory cells and fibrous tissue distribution.

68Ga-PSMA is a novel PET-CT tracer for imaging of hepatocellular carcinoma: A prospective pilot study

Background:⁶⁸Ga-Prostate Specific Membrane Antigen (⁶⁸Ga-PSMA), a positron emission tomography (PET) tracer that was recently introduce for imaging of prostate cancer, may accumulate in other solid tumors including Hepatocellular Carcinoma (HCC). The aim of the study was to assess the potential role of ⁶⁸Ga-PSMA PET-Computed Tomography (CT) for imaging of HCC. Material and Methods: A prospective pilot study in seven patients with HCC with 41 liver lesions: 37 suspected malignant lesions (tumor lesions) and 4 regenerative nodules. For each liver lesion, uptake of ⁶⁸Ga-PSMA and ¹⁸F-FDG uptake were measured [standard uptake value (SUV) and lesion-to-liver background ratios (TBR-SUV)], and correlated with dynamic characteristics (HU and TBR-HU) obtained on contrast enhanced CT data. Immunohistochemistry staining of PSMA in the tumor tissue was analyzed in samples obtained from 5 patients with HCC and compared to control samples from 3 patients with prostate cancer. Results: Thirty-six of the 37 tumor lesions and none of the regenerative nodules showed increased ⁶⁸Ga-PSMA uptake while only 10 lesions were ¹⁸F-FDG avid. Based on contrast enhancement, tumor lesions were categorized into 27 homogeneously enhancing lesions, nine lesions with "mosaic" enhancement composed of enhancing and non-enhancing regions in the same lesion and a single non-enhancing lesion, the latter being the only non-⁶⁸Ga-PSMA avid lesion. Using the Mann-Whitney test, ⁶⁸Ga-PSMA uptake was found significantly higher in enhancing tumor areas compared to non-enhancing areas and in contrast, ¹⁸F-FDG uptake was higher in non-enhancing areas, P<0.001 for both. ⁶⁸Ga-PSMA uptake (TBR SUV_max) was found to correlate with vascularity (TBR-HU) (Spearman r=0.866, p<0.001). Immunohistochemistry showed intense intra-tumoral microvessel staining for PSMA in HCC, in contrast with cytoplasmic and membranous staining, mainly in the luminal border, in prostate cancer samples. In two of the study patients ⁶⁸Ga-PSMA PET-CT identified unexpected extrahepatic metastases. Four regenerative liver nodules showed no increased uptake of either of the PET tracers. Conclusion:⁶⁸Ga-PSMA PET-CT is superior to ¹⁸F-FDG PET-CT in imaging patients with HCC. HCC lesions are more commonly hypervascular taking up ⁶⁸Ga-PSMA in tumoral micro-vessels. ⁶⁸Ga-PSMA PET-CT is a potential novel modality for imaging patients with HCC.

Integrating bilingual musculoskeletal imaging education into radiology and diagnostic imaging residency programs

Objective

To analyze the perception of the relevance of introducing bilingual (Portuguese-English) musculoskeletal imaging education into radiology and diagnostic imaging residency programs, describing the method used.

Materials and Methods

To evaluate the relevance of incorporating the bilingual study of musculoskeletal imaging into medical residency programs, we administered a questionnaire, consisting of several multiple-choice questions and one subjective question, to 21 radiology residents at a private tertiary hospital. The residents completed the questionnaire voluntarily and anonymously.

Results

Integrating English teaching into radiology training was considered important by 95.2% of the residents. Approximately 90% of residents believe that the method applied at their institution is suitable for learning.

Conclusion

The introduction of the English language into the teaching of musculoskeletal imaging in the radiology residency program was perceived positively by the residents, and the preceptors effectively supported those activities.

Fat-containing liver lesions: a pictorial review

The aim of this pictorial essay is to review the spectrum of fat-containing liver lesions and their characterisation on magnetic resonance imaging with focus on the radiological features that aid in the differential diagnoses. Fat-containing liver lesions comprise a heterogeneous group of tumours with variable imaging findings. Magnetic resonance imaging clearly displays the micro- and macroscopic fat components of the lesions and other characteristic features that are helpful tools to make the differential diagnosis.

Differential diagnosis between hepatocellular carcinoma and cirrhosis by serum amino acids and acylcarnitines

The routine biochemical parameters for hepatocellular carcinoma (HCC) diagnosis are all protein markers. Serum concentrations of these markers can be affected by some benign diseases. Most of the occurrence of HCC has a background of cirrhosis, posing a great challenge to differential diagnosis of HCC from cirrhosis using traditional biochemical parameters. Values of serum small molecular metabolites for HCC diagnosis are not fully evaluated. In this study, a traditionalmass spectrometry-based screening strategy was employed to profile amino acids and acylcarnitines in blood samples collected from HCC and cirrhosis patients. Each whole blood specimen was sampled on filter paper and dried at room temperature. Metabolites in the dried blood spots were extracted using organic solvent and then concentrated for mass spectrometry analysis. It was found that 11 parameters, including amino acids, acylcarnitines and some of their relevant ratios, could be used to construct a satisfied differential diagnosis model. In this model, most of the relevant amino acids were essential amino acids. It was noticed that short-chain acylcarnitines tended to be risk factors for HCC. Long-chain acylcarnitines seemed to be risk factors for cirrhosis. This study demonstrates the value of mass spectrometry-based analysis for differential diagnosis of HCC and cirrhosis. Improved differential diagnosis ability may be achieved by combined use of traditional protein markers along with metabolite markers.

Magnetic resonance imaging ancillary features used in Liver Imaging Reporting and Data System: An illustrative review

Hepatocellular carcinoma (HCC) usually develops in the setting of chronic liver disease. In the adequate clinical context, both multiphasic contrast-enhanced CT and magnetic resonance imaging are non-invasive modalities that allow accurate diagnosis and staging of HCC, although the latter demonstrates greater sensitivity and specificity. Imaging criteria for HCC diagnosis rely on hemodynamic features such as hyperenhancement in the arterial phase and washout in the portal or equilibrium phase. However, imaging performance drops considerably for small (< 20 mm) nodules because their tendency to exhibit atypical enhancement patterns. In order to improve accuracy in the diagnosis and staging of HCC, particularly in cases of atypical nodules, ancillary features, i.e., imaging characteristics that modify the likelihood of HCC, have been described and incorporated into clinical reports, especially in Liver Imaging Reporting and Data System. In this paper, ancillary imaging features will be reviewed and illustrated.

Computed tomography angiography study of variations of the celiac trunk and hepatic artery in 100 patients

Objective

To describe the main anatomical variations of the celiac trunk and the hepatic artery at their origins.

Materials and Methods

This was a prospective analysis of 100 consecutive computed tomography angiography studies of the abdomen performed during a one-year period. The findings were stratified according to classification systems devised by Sureka et al. and Michels.

Results

The celiac trunk was "normal" (i.e., the hepatogastrosplenic trunk and superior mesenteric artery originating separately from the abdominal aorta) in 43 patients. In our sample, we identified four types of variations of the celiac trunk. Regarding the hepatic artery, a normal anatomical pattern (i.e., the proper hepatic artery being a continuation of the common hepatic artery and bifurcating into the right and left hepatic arteries) was seen in 82 patients. We observed six types of variations of the hepatic artery.

Conclusion

We found rates of variations of the hepatic artery that are different from those reported in the literature. Our findings underscore the need for proper knowledge and awareness of these anatomical variations, which can facilitate their recognition and inform decisions regarding the planning of surgical procedures, in order to avoid iatrogenic intraoperative injuries, which could lead to complications.