Fading hepatic hemangiomas on multiphasic CT

Evaluation of qualitative and quantitative imaging features of hepatic hemangiomas with and without pseudo-washout sign on gadoxetic acid-enhanced MRI: a descriptive and comparative study

BACKGROUND

Hepatic hemangiomas are the most common benign liver tumors. It is important to know the imaging features of hemangiomas on gadoxetic acid (GA)-enhanced magnetic resonance imaging (MRI).

PURPOSE

To evaluate the qualitative and quantitative imaging features of hemangiomas on GA-enhanced MRI, and to compare imaging features of hemangiomas with and without pseudo-washout sign (PWS).

MATERIAL AND METHODS

We retrospectively included 93 cases of hemangioma that underwent GA-enhanced MRI. The presence of an enhancement pattern in the arterial phase (AP) and PWSs in the transitional phase (TP) were evaluated. Signal-to-norm ratios (SINorm) of hemangiomas, liver parenchyma, and portal vein (PV) as well as contrast-to-norm ratio (CNorm) were assessed. Additionally, hemangiomas with and without PWSs were defined as two separate subgroups, and imaging features were compared.

RESULTS

Of the 93 cases of hemangiomas, 49 (52.6%) had PWSs in the TP. The mean SINorms of hemangiomas showed the highest value in the AP (P < 0.05). The mean CNorms showed positive values in the AP, and gradually decreased (P < 0.05). Hemangiomas with PWSs were significantly rapidly enhanced and smaller in size (P < 0.05), and the mean SINorms was lower in the TP (P = 0.023). While the mean CNorms showed a significant difference in the AP between subgroups (P < 0.001), the enhancement pattern was equal to that of the PV.

CONCLUSION

When evaluating GA-enhanced MRI, radiologists should utilize quantitative measures in addition to qualitative assessment and should be aware that SI matching with PV in all phases can be a distinguishing finding in the diagnosis of hemangioma.

Prevalence of nodal metastases in the individual lymph node stations for different T-stages in gastric cancer: a systematic review

BACKGROUND

Gastrectomy with lymph node dissection is the cornerstone of curative treatment of gastric cancer. Extent of lymphadenectomy may differ depending on T-stage, as the rate of lymph node metastases may differ. The objective of this systematic review is to investigate and compare the prevalence of nodal metastases in the individual lymph node stations between different T-stages.

METHODS

Data reporting and structure of this systematic review follows the PRISMA checklist. The Medline and PubMed databases were systematically searched. The search included the following Mesh terms: "Stomach Neoplasms", "Lymphatic Metastasis" and "Lymph Node Excision". The primary outcome was the highest prevalence of nodal metastases per T-stage.

RESULTS

The initial search resulted in 175 eligible articles. Five articles met the inclusion criteria and were accordingly analyzed. Concerning the lymph node stations 1 to 7, the lymph nodes along the lesser gastric curvature (station 3) show the highest metastases rate (T1: 5.5%, T2: 21.9%, T3: 41.9%, T4: 71.0%). Concerning the lymph node stations 8 to 20, the lymph nodes around the common hepatic artery (station 8) show the highest metastases rate (T1: 0.8%, T2: 7.9%, T3: 14.0%, T4: 28.2%).

CONCLUSION

An overall low prevalence of nodal metastases in the individual lymph node stations in early, T1 gastric carcinomas and an overall high prevalence in more advanced, T3 and T4 gastric carcinomas endorse a more tailored approach based on the different gastric T-stages. In addition, a less extensive lymphadenectomy seems justified in early T1 carcinoma.

SYNOPSIS

This systematic review provides an overview of the prevalence of nodal metastases for the individual lymph node stations between different T-stages, showing an overall low prevalence in early, T1 gastric carcinomas and an overall high prevalence in the more advanced, T3 and T4 gastric carcinomas.

Hepatic sclerosed hemangioma and sclerosing cavernous hemangioma: a radiological study

Purpose

To investigate and compare the CT and MRI features of hepatic sclerosed hemangioma (HSH) and sclerosing cavernous hemangioma (SCH).

Materials and methods

Twelve HSH cases and 36 SCH cases were included, the imaging findings on CT (9 HSH and 34 SCH) and MRI (8 HSH and 10 SCH) were analyzed. Qualitative image analysis included the location, size, shape, capsular retraction, density, calcification, signal intensity on T₁-weighted image (T₁WI) and T₂-weighted image (T₂WI), presence of diffusion restriction, apparent diffusion coefficient (ADC) map, transient hepatic attenuation difference around the lesion, and the dynamic enhancement patterns.

Results

The presence of liver cirrhosis in patients with HSH (3/12) was higher than SCH (1/36) (P = 0.043). The morphology appearance before enhancement showed no significant difference between HSH and SCH. Moreover, SCH had a stronger trend of centripetal enhancement patterns of cavernous hemangiomas (83.3%) compared to HSH (25%) (P < 0.001). Due to more frequent atypical enhancement features, containing rim-like enhancement, no enhancement, and peripheral heterogeneous enhancement, the misdiagnosis rate of HSH (75%) was significantly higher than that of SCH (16.7%) (P < 0.001). Furthermore, the ADC values of HSH and SCH were both higher than that of the surrounding liver parenchyma (P = 0.009, P = 0.002); however, there was no significant difference in ADC values between themselves (P = 0.613).

Conclusion

SCH showed the same trend of centripetal enhancement characteristics as typical hemangioma, while HSH exhibited atypical enhancement features due to complete sclerosis. Higher ADC values might contribute to the identification of atypical HSH and SCH from malignancies.

The humbling hemangioma: uncommon CT and MRI imaging features and mimickers of hepatic hemangiomas

Cavernous hemangiomas are among the most common liver lesions encountered in abdominal imaging. While classical imaging characteristics usually aid the radiologist in confidently arriving at its diagnosis, atypical hemangiomas can prove to be difficult to distinguish from other more worrisome hepatic lesions such as metastases and hepatocellular carcinoma. Furthermore, some malignant lesions can display features that simulate hemangiomas. The radiologist must be aware of these pitfalls to make an accurate diagnosis, when possible.

Atypical Appearance of Hepatocellular Carcinoma and Its Mimickers: How to Solve Challenging Cases Using Gadoxetic Acid-Enhanced Liver Magnetic Resonance Imaging

Hepatocellular carcinoma (HCC) can be diagnosed noninvasively with contrast-enhanced dynamic computed tomography, magnetic resonance imaging, or ultrasonography on the basis of its hallmark imaging features of arterial phase hyperenhancement and washout on portal or delayed phase images. However, approximately 40% of HCCs show atypical imaging features, posing a significant diagnostic challenge for radiologists. Another challenge for radiologists in clinical practice is the presentation of many HCC mimickers such as intrahepatic cholangiocarcinoma, combined HCC-cholangiocarcinoma, arterioportal shunt, and hemangioma in the cirrhotic liver. The differentiation of HCCs from these mimickers on preoperative imaging studies is of critical importance. Hence, we will review the typical and atypical imaging features of HCCs and the imaging features of its common mimickers. In addition, we will discuss how to solve these challenges in practice.

Imaging findings of mimickers of hepatocellular carcinoma

Radiological imaging plays a crucial role in the diagnosis of hepatocellular carcinoma (HCC) as the noninvasive diagnosis of HCC in high-risk patients by typical imaging findings alone is widely adopted in major practice guidelines for HCC. While imaging techniques have markedly improved in detecting small liver lesions, they often detect incidental benign liver lesions and non-hepatocellular malignancy that can be misdiagnosed as HCC. The most common mimicker of HCC in cirrhotic liver is nontumorous arterioportal shunts that are seen as focal hypervascular liver lesions on dynamic contrast-enhanced cross-sectional imaging. Rapidly enhancing hemangiomas can be easily misdiagnosed as HCC especially on MR imaging with liver-specific contrast agent. Focal inflammatory liver lesions mimic HCC by demonstrating arterial-phase hypervascularity and subsequent washout on dynamic contrast-enhanced imaging. It is important to recognize the suggestive imaging findings for intrahepatic cholangiocarcinoma (CC) as the management of CC is largely different from that of HCC. There are other benign mimickers of HCC such as angiomyolipomas and focal nodular hyperplasia-like nodules. Recognition of their typical imaging findings can reduce false-positive HCC diagnosis.

Evaluation of liver lesions

The differential diagnosis of a liver mass is large and requires understanding of the clinical and imaging features of liver lesions. A detailed history, physical examination, hepatic biochemical tests, and imaging studies are all essential in making the diagnosis. Decisions regarding specific imaging modalities for diagnoses, the use of liver biopsy, therapeutic options, and appropriate follow-up are all determined by the presentation of the lesion and associated patient characteristics.