Nodule-in-nodule appearance of hepatocellular carcinomas: comparison of gadolinium-enhanced and ferumoxides-enhanced magnetic resonance imaging

Lesions hyper- to isointense to surrounding liver in the hepatobiliary phase of gadoxetic acid-enhanced MRI

OBJECTIVES

Hyper- or isointensity in the hepatobiliary phase (HBP) of gadoxetic acid-enhanced MRI has high specificity for focal nodular hyperplasia (FNH) but may be present in hepatocellular adenoma and carcinoma (HCA/HCC). This study aimed to identify imaging characteristics differentiating FNH and HCA/HCC.

MATERIALS AND METHODS

This multicenter retrospective cohort study included patients with pathology-proven FNH or HCA/HCC, hyper-/isointense in the HBP of gadoxetic acid-enhanced MRI between 2010 and 2020. Diagnostic performance of imaging characteristics for the differentiation between FNH and HCA/HCC were reported. Univariable analyses, multivariable logistic regression analyses, and classification and regression tree (CART) analyses were conducted. Sensitivity analyses evaluated imaging characteristics of B-catenin-activated HCA.

RESULTS

In total, 124 patients (mean age 40 years, standard deviation 10 years, 108 female) with 128 hyper-/isointense lesions were included. Pathology diagnoses were FNH and HCA/HCC in 64 lesions (50%) and HCA/HCC in 64 lesions (50%). Imaging characteristics observed exclusively in HCA/HCC were raster and atoll fingerprint patterns in the HBP, sinusoidal dilatation on T2-w, hemosiderin, T1-w in-phase hyperintensity, venous washout, and nodule-in-nodule partification in the HBP and T2-w. Multivariable logistic regression and CART additionally found a T2-w scar indicating FNH, less than 50% fat, and a spherical contour indicating HCA/HCC. In our selected cohort, 14/48 (29%) of HCA were B-catenin activated, most (13/14) showed extensive hyper-/isointensity, and some had a T2-w scar (4/14, 29%).

CONCLUSION

If the aforementioned characteristics typical for HCA/HCC are encountered in lesions extensively hyper- to isointense, further investigation may be warranted to exclude B-catenin-activated HCA.

CLINICAL RELEVANCE

Hyper- or isointensity in the HBP of gadoxetic acid-enhanced MRI is specific for FNH, but HCA/HCC can also exhibit this feature. Therefore, we described imaging patterns to differentiate these entities.

KEY POINTS

FNH and HCA/HCC have similar HBP intensities but have different malignant potentials. Six imaging patterns exclusive to HCA/HCC were identified in this lesion population. These features in liver lesions hyper- to isointense in the HBP warrant further evaluation.

Pathognomonic imaging signs in abdominal radiology

The imaging evaluation of the abdomen is of crucial importance for every radiologist. In addition to ultrasound, conventional radiographs and contrast-enhanced computed tomography (CT) are the most common imaging procedures in the abdominal region. Numerous pathognomonic signs should be known in this context by every radiologist. Radiographs of the abdomen are an often used first step in radiologic imaging, while CT examinations are carried out for further differentiation, in oncological settings and in time-critical emergency situations. A fast and clear assignment of these signs to a specific disease is the basis for a correct diagnosis. This pictorial review describes the most common pathognomonic signs in abdominal imaging. The knowledge of these pictograms is therefore essential for radiologists interested in abdominal medicine and should also be addressed in training and further education.

Magnetic resonance imaging of the cirrhotic liver: An update

Noninvasive imaging has become the standard for hepatocellular carcinoma (HCC) diagnosis in cirrhotic livers. In this review paper, we go over the basics of MR imaging in cirrhotic livers and describe the imaging appearance of a spectrum of hepatic nodules marking the progression from regenerative nodules to low- and high-grade dysplastic nodules, and ultimately to HCCs. We detail and illustrate the typical imaging appearances of different types of HCC including focal, multi-focal, massive, diffuse/infiltrative, and intra-hepatic metastases; with emphasis on the diagnostic value of MR in imaging these lesions. We also shed some light on liver imaging reporting and data system, and the role of different magnetic resonance imaging (MRI) contrast agents and future MRI techniques including the use of advanced MR pulse sequences and utilization of hepatocyte-specific MRI contrast agents, and how they might contribute to improving the diagnostic performance of MRI in early stage HCC diagnosis.

Magnetic resonance imaging in cirrhosis: what's new?

Cirrhosis is the main risk factor for the development of hepatocellular carcinoma (HCC). The major causative factors of cirrhosis in the United States and Europe are chronic hepatitis C infection and excessive alcohol consumption with nonalcoholic steatohepatitis emerging as another important risk factor. Magnetic resonance imaging is the most sensitive imaging technique for the diagnosis of HCC, and the sensitivity can be further improved with the use of diffusion-weighted imaging and hepatocyte-specific contrast agents. The combination of arterial phase hyperenhancement, venous or delayed phase hypointensity "washout feature," and capsular enhancement are features highly specific for HCC with reported specificities of 96% and higher. When these features are present in a mass in the cirrhotic liver, confirmatory biopsy to establish the diagnosis of HCC is not necessary. Other tumors, such as cholangiocarcinoma, sometimes occur in the cirrhotic at a much lower rate than HCC and can mimic HCC, as do other benign lesions such as perfusion abnormalities. In this article, we discuss the imaging features of cirrhosis and HCC, the role of magnetic resonance imaging in the diagnosis of HCC and other benign and malignant lesions that occur in the cirrhotic liver, and the issue of nonspecific arterially hyperenhancing nodules often seen in cirrhosis.

Chronic hepatitis and cirrhosis on MR imaging

This article focuses on the current role of magnetic resonance imaging in the detection and characterization of chronic hepatitis and cirrhosis. In particular, the characteristic MR imaging features of morphologic changes and focal manifestations of chronic liver disease are highlighted.

Hepatocellular carcinoma with marginal superparamagnetic iron oxide uptake on T2*-weighted magnetic resonance imaging: histopathologic correlation

PURPOSE

To evaluate the characteristics of hepatocellular carcinomas (HCCs) with marginal superparamagnetic iron oxide (SPIO) uptake on T2*-weighted MRI.

MATERIALS AND METHODS

The study group consisted of 73 patients with 83 surgically resected HCCs. Preoperative SPIO-enhanced MRI studies were retrospectively reviewed. Marginal SPIO uptake was considered positive if a rim-like or band-like low intensity area was present on SPIO-enhanced T2*-weighted images. The prevalence of marginal SPIO uptake was evaluated. Pathological specimens with hematoxylin and eosin staining and immunohistochemical staining of CD68 were reviewed in HCCs with marginal SPIO uptake and 33 HCCs without marginal SPIO uptake (control group).

RESULTS

Ten of 83 (12%) HCCs showed marginal SPIO uptake. All HCCs were hypervascular, and only one nodule showed a nodule-in-nodule appearance on imaging findings. The pathology specimens suggested possible causes of marginal SPIO uptake, including marginal macrophage infiltration in moderately or poorly differentiated HCC (n=4), residual normal hepatic tissue at the marginal area of confluent multinodular or single nodular with extranodular growth type HCC (n=3), and a well-differentiated HCC component in nodule-in-nodule type HCC (n=3). Marginal macrophage infiltration was not seen in the control group.

CONCLUSION

SPIO-enhanced MRI may be able to demonstrate marginal macrophage infiltration in HCC.

MR Imaging of hepatocellular carcinoma in the cirrhotic liver: challenges and controversies

The incidence of hepatocellular carcinoma (HCC) is expected to increase in the next 2 decades, largely due to hepatitis C infection and secondary cirrhosis. HCC is being detected at an earlier stage owing to the implementation of screening programs. Biopsy is no longer required prior to treatment, and diagnosis of HCC is heavily dependent on imaging characteristics. The most recent recommendations by the American Association for the Study of Liver Diseases (AASLD) state that a diagnosis of HCC can be made if a mass larger than 2 cm shows typical features of HCC (hypervascularity in the arterial phase and washout in the venous phase) at contrast material-enhanced computed tomography or magnetic resonance (MR) imaging or if a mass measuring 1-2 cm shows these features at both modalities. There is an ever-increasing demand on radiologists to detect smaller tumors, when curative therapies are most effective. However, the major difficulty in imaging cirrhosis is the characterization of hypervascular nodules smaller than 2 cm, which often have nonspecific imaging characteristics. The authors present a review of the MR imaging and pathologic features of regenerative nodules and dysplastic nodules and focus on HCC in the cirrhotic liver, with particular reference to small tumors and lesions that may mimic HCC. The authors also review the sensitivity of MR imaging for the detection of these tumors and discuss the staging of HCC and the treatment options in the context of the guidelines of the AASLD and the imaging criteria required by the United Network for Organ Sharing for transplantation. MR findings following ablation and chemoembolization are also reviewed.

Detection of hypervascular malignant foci in borderline lesions of hepatocellular carcinoma: comparison of dynamic multi-detector row CT, dynamic MR imaging and superparamagnetic iron oxide-enhanced MR imaging

The study object was to retrospectively compare the detection rate of hypervascular foci visualized by CT during hepatic arteriography (CTHA) in borderline nodules, which was observed upon cirrhotic livers, on dynamic MDCT, dynamic gadolinium-enhanced MR (dynamic MR), and SPIO-enhanced MR imaging. Eighty-five nodules in 49 patients with cirrhosis were evaluated. When a part of the nodule showed hyperdensity relative to the surrounding areas of the nodule on CTHA, it was defined as "hypervascular focus." The relationships between the dynamic MDCT and dynamic MR and SPIO-enhanced MR imaging findings of these foci were analyzed using X(2) test. Hypervascular foci were detected in 17 (53%) of 32 on the arterial dominant phase of dynamic MDCT, in 19 (37%) of 51 on the arterial dominant phase of dynamic MR and in 6 (26%) of 23 on SPIO-enhanced MR imaging. Arterial dominant phase of dynamic MDCT demonstrated a significantly higher detection rate of hypervascular foci less than 5 mm in diameter than did dynamic and SPIO MR imaging (p<0.05). Hypervascular foci in borderline nodules could be better visualized by dynamic MDCT than by gadolinium- and SPIO-enhanced MR imaging. Dynamic MDCT is recommended for the follow-up examination of hypovascular borderline lesions.

Magnetic resonance imaging of liver malignancies

The histological structure of the liver is complex, consisting of hepatocytes, biliary epithelium, and mesenchymal cells. From this large variety of cells, a broad spectrum of benign and malignant liver lesions in originate. An accurate diagnosis of these lesions is mandatory for choosing an appropriate therapeutic approach. With the recent developments in hardware and software, magnetic resonance imaging (MRI) has emerged as the method of choice in the diagnostic workup of focal liver lesions, in particular in the pretherapeutic stage. The introduction of high-field MRI at 3.0 T in the routine workup and the selective use of liver-specific contrast agents, including hepatobiliary and reticuloendothelial agents, have also strengthened the role of MRI in liver imaging. In this overview article, we will review the recent developments in 3.0-T MRI and MRI contrast agents in the diagnostic workup of the most common malignant liver tumors.

Evaluation of HCPTd1, d14-double passaged intervening chemotherapy protocol for hepatocellular carcinoma

AIM: To establish a kind of standardization of the clinical chemotherapeutic prototypes for unresectable hepatocellular carcinomas (HCC).

METHODS: 10-Hydroxycamptothecin (HCPT) was applied through transcatheter arterial embolization (TAE) to HCC patients who were categorized into three groups: (1) test group: treatment with HCPT twice (HCPT d1 and 14) through TAE and portal venous embolization. (2) Control I: treatment with anticancer drugs without HCPT. (3) Control II: treatment with HCPT as a major component in anticancer drugs once (HCPT d1). A set of comparisons between test groups and control I and II groups were performed before and after the treatment to study the effectiveness of each treatment, in terms of tumor volumes, dynamic variations in serum alpha-fetoprotein (AFP), gamma-glutamyl transferase hepatoma-specific band (GGT-II), patient survival and adverse events.

RESULTS: The general effectiveness rate of the test group reached 62.1% (72/116), remarkably higher than that of control I (32.1%, 40/124) and control II (54.7%, 47/56), (P<0.01 and P<0.05, respectively). Especially, the reduction rate or disappearance of the portal vein tumor emboli was as high as 88.4% (61/69) in the test group, in contrast with 13.9% (10/72) in control I and 35.9% (18/51) in control II (P<0.01 and P<0.01, respectively). After treatment, AFP decreased or turned to negative levels at 52.3% (34/65) in control I, 67.3% (35/52) in control II, and 96.8% (60/62) in the test group. Also GGT-II declined or became negative at 37.8% (28/74) in control I, 69.5% (57/82) in control II, and 94.7% (89/94) in test group (P<0.01 and P<0.05, respectively).

CONCLUSION: We have designed a good protocol (test group) to treat HCC with excellent advantages of high efficiency, low cost, low toxicity and low adverse events and easy application. It could be recommended as one of the standardizations for HCC treatment in clinical practice.