Hepatic haemangioma: common and uncommon imaging features

ACG Clinical Guideline: Focal Liver Lesions

Focal liver lesions (FLLs) have become an increasingly common finding on abdominal imaging, especially asymptomatic and incidental liver lesions. Gastroenterologists and hepatologists often see these patients in consultation and make recommendations for management of multiple types of liver lesions, including hepatocellular adenoma, focal nodular hyperplasia, hemangioma, and hepatic cystic lesions including polycystic liver disease. Malignancy is important to consider in the differential diagnosis of FLLs, and healthcare providers must be familiar with the diagnosis and management of FLLs. This American College of Gastroenterology practice guideline uses the best evidence available to make diagnosis and management recommendations for the most common FLLs.

Can angiogenesis inhibitor therapy cause changes in imaging features of hepatic hemangioma- Initial study

Background

To observe whether anti-angiogenesis therapy can induce changes in size and enhancement characteristics of hepatic hemangioma.

Method

133 patients with hepatic hemangioma lesions were analyzed and classified into a Bevacizumab group (n=65) and the control group (n=68). The parameters (Volume, CT enhancement ratio, enhancement patterns) of pre-and post-treatment in the bevacizumab and control groups independently calculated and compared by two radiologists. Correlation among the systolic blood pressure, diastolic blood pressure, heart rate with the hemangioma volume was evaluated using Pearson’s correlation analysis.

Results

The hepatic hemangioma volume was significantly decreased after treatment in the Bevacizumab group (8.6 ± 18.7mL vs.7.3 ± 16.3mL, P<0.05), and there was no significant change in the control group (15.1 ± 19.8mL vs.15.4 ± 20.7mL, P = 0.504). A significant difference in enhancement patterns of hepatic hemangiomas was observed after treatment with Bevacizumab (P<0.01). There was no significant difference in arterial phase (AP)enhancement rate and arterial phase-portal venous phase (AP-PVP) enhancement ratios after treatment in the Bevacizumab and control groups (Ps>0.05).The Pearson correlation results showed that blood pressure, heart rate, and hemangioma volume were unrelated or weakly related before and after bevacizumab treatment under the control of factors including weight, contrast injection scheme and CT scanning scheme.

Conclusions

Anti-angiogenesis therapy can cause changes in enhancement pattern and volume of hepatic hemangioma. Radiologists should pay more attention to the reexamination of tumor patients treated with anti-angiogenesis therapy.

Evaluation of liver metastasis in patients with breast cancer: Comparison of single-phase abdominopelvic CT and multi-phase liver CT

PURPOSE

To compare the usefulness of multi-phase liver CT and single-phase abdominopelvic CT (APCT) in evaluating liver metastasis in newly diagnosed breast cancer patients.

METHODS

In this retrospective study, a total of 7621 newly diagnosed breast cancer patients (mean age, 49.7 years ± 10.1; 7598 women) who underwent single-phase APCT (n = 5536) or multi-phase liver CT (n = 2085) for staging workup between January 2016 and June 2019 were included. The staging CTs were categorized as having no metastasis, probable metastasis, or indeterminate lesions. MRI referral rate (proportion of patients underwent additional liver MRI), negative MRI rate (patients without true hepatic metastasis / patients underwent liver MRI), true positive CT rate (patients with true metastasis / patients categorized as probable metastasis), true metastasis rate among CT indeterminate (patients with true metastasis / patients categorized as indeterminate lesions), and overall liver metastasis rate were compared between the two groups. Further, the radiation dose was recorded for every patient.

RESULTS

The proportions of having no metastasis and indeterminate lesions on the results of CT interpretation were significantly different between the two groups (P = 0.006). However, the MRI referral rate, negative MR rate, true positive CT rate, true metastasis rate among CT indeterminate, and overall liver metastasis rate were not significantly different between the two groups. Radiation dose of multi-phase CT was three times higher than that of single-phase CT.

CONCLUSION

Multi-phase liver CT has little benefit over single-phase APCT in assessing liver metastasis in patients with breast cancer.

Microvascular flow imaging to differentiate focal hepatic lesions: the spoke-wheel pattern as a specific sign of focal nodular hyperplasia

Microvascular flow imaging (MVFI) is an advanced Doppler ultrasound technique designed to detect slow-velocity blood flow in small-caliber microvessels. This technique is capable of realtime, highly detailed visualization of tumor vessels without using a contrast agent. MVFI has been recently applied for the characterization of focal liver lesions and has revealed typical vascularity distributions in multiple types thereof. Focal nodular hyperplasia (FNH) constitutes an important differential diagnosis of malignant liver tumors. In this essay, we provide iconographic documentation of the MVFI appearance of FNH and other common solid liver lesions. Identifying the typical patterns of vascularity, including the spoke-wheel pattern with MVFI, can expedite the diagnosis, spare patients from unnecessary procedures, and save costs.

Mimics of cancer in pregnancy

Pregnancy is a remarkable time of pronounced growth and development of the fetus. Benign pathologies outside of the uterus, including those containing hormonally responsive tissue which undergo physiologic changes and other incidentally identified lesions, may mimic malignancy on clinical evaluation and imaging. A detailed history and physical exam, ultrasound and non-contrast magnetic resonance imaging features and comparison with prior imaging if available may help to narrow the list of potential differential diagnoses. Follow-up imaging in the postpartum period is often vital to confirm benignity and, in some cases, sampling to confirm the diagnosis is necessary. This review will cover the clinical, pathological and multimodality imaging features of numerous potential mimickers of cancer in the setting of pregnancy organized by organ systems. The goal is to better equip abdominal radiologists to accurately identify benign disease and help guide further imaging or follow-up recommendations to avoid unnecessarily aggressive intervention and improve patient care.

A Comprehensive Review of Hepatic Hemangioma Management

BACKGROUND

Hepatic hemangiomas (HHs) are benign liver lesions often discovered incidentally on imaging for various unrelated pathologies. We herein review the etiology, classification, diagnostic imaging, and management of HHs.

METHODS

A comprehensive systematic review was performed utilizing MEDLINE/PubMed and Web of Science databases, with the end of search date being March 1, 2022, regarding HH diagnosis, imaging, and management.

RESULTS

HHs can be broadly classified as capillary hemangiomas or cavernous hemangiomas. While the exact pathophysiology related to the development of HHs remains largely unknown, hormone exposure has been postulated to cause HH growth. HHs appear homogenously hyperechoic on US with distinct margins and posterior acoustic enhancement. While cavernous hemangiomas appear as well-defined hypodense lesions on pre-contrast CT images with the same density as the vasculature, one of the most reliable imaging features for diagnosing cavernous hemangiomas is high signal intensity on T2 weighted images. While most HHs are asymptomatic, some patients can present with pain or compressive symptoms with bleeding/rupture being very rare. Kasabach-Merritt syndrome is a rare but life-threatening condition associated with thrombocytopenia and microangiopathic hemolytic anemia. When HHs are symptomatic or in the setting of Kasabach Merritt syndrome, surgery is indicated. Enucleation is an attractive surgical option for HH as it spares normal liver tissue. Most patients experience symptom relief following surgical resection.

CONCLUSION

HHs are very common benign liver lesions. High-quality imaging is imperative to distinguish HHs from other liver lesions. Surgery is generally reserved for patients who present with symptoms such as pain, obstruction, or rarely Kasabach-Merritt syndrome. Surgery can involve either formal resection or, in most instances, simple enucleation. Patients generally have good outcomes following surgery with resolution of their symptoms.

Digital Staging of Hepatic Hemangiomas Reveals Spatial Heterogeneity in Endothelial Cell Composition and Vascular Senescence

Hepatic hemangioma (HH) is the most common benign primary liver tumor; however, despite its high prevalence, a stage-specific classification of this tumor is currently missing. For a spatial stage-specific classification, a tissue microarray (TMA) consisting of 98 HHs and 80 hemangioma margins and 78 distant liver tissues was digitally analyzed for the expression of 16 functional and vascular niche-specific markers. For cross-correlation of histopathology and functional characteristics, computed tomography/MRI imaging data of 28 patients were analyzed. Functional and morphological analyses revealed a high level of intra- and interpatient heterogeneity, and morphological heterogeneity was observed with regard to cellularity, vascular diameter, and endothelial cell subtype composition. While regressed hemangiomas were characterized by low blood vessel density, low beta-catenin levels, and a microvascular phenotype, non-regressed HHs showed a pronounced cellular and architectural heterogeneity. Functionally, cellular senescence–associated p16 expression identified an HH subgroup with high vascular density and increased lymphatic endothelial cell content. Histological HH regions may be grouped into spatially defined morphological compartments that may reflect the current region-specific disease stage. The stage-specific classification of HHs with signs of regression and vascular senescence may allow a better disease course–based and cell state–based subtyping of these benign vascular lesions.

Imaging patterns in non-traumatic spleen lesions in adults-a review

The spleen is a complex organ involved in multiple physiological processes in the human body. Elective splenectomy is an uncommon operation, and the precise characterization of the lesion should be achieved to determine the risks and benefits of this operation accurately. Given the significant role of the spleen in homeostasis and the potential risks of the surgery itself and following sequelae such as infection susceptibility, accurate recognition, and classification of splenic lesions is required before surgery. This review provides an overview of malignant (e.g., lymphoma, angiosarcoma) and benign (e.g., cysts, hemangioma, hamartoma) splenic lesions that may warrant an elective splenectomy. Images from a cohort of adult patients undergoing isolated splenectomy for non-traumatic indications in a single center are provided. This review highlights the considerable overlap in imaging patterns between splenic lesions, splenic lesions masquerading as lesions in other organs, increased detection of asymptomatic splenic incidentalomas due to improvements in imaging modalities. This review also provides clinical correlations for each lesion, providing additional information to help clinicians differentiate between lesions and accurately identify diseases amenable to surgical management.

When Benign Behaves Badly: Atypical Hemangiomas on Contrast-Enhanced Ultrasonography

ABSTRACT

Hemangioma is the most common benign liver tumor and is frequently encountered as an incidental finding on imaging. The classic enhancement pattern of hemangioma is diagnostic on contrast-enhanced ultrasound (CEUS), and it follows the same pattern of enhancement on computed tomography and magnetic resonance imaging. However, there is a subset of hemangiomas that demonstrate atypical enhancement patterns on CEUS. The ability to recognize the different enhancement patterns and discern when additional imaging or biopsy may be necessary is essential to accurately interpret an atypical hemangioma on CEUS. This article reviews various enhancement patterns of hemangioma on CEUS to avoid pitfalls in characterization of focal liver lesions on CEUS.

Benign focal liver lesions: The role of magnetic resonance imaging

Liver lesions are common findings in radiologists’ daily routine. They are a complex category of pathology that range from solitary benign lesions to primary liver cancer and liver metastases. Benign focal liver lesions can arise from different liver cell types: Epithelial (hepatocytes and biliary cells) and nonepithelial (mesenchymal cells). Liver magnetic resonance imaging (MRI) is a fundamental radiological method in these patients as it allows with its multiparametric approach optimal non-invasive tissue characterization. Furthermore, advanced liver MRI techniques such as diffusion-weighted imaging and hepatobiliary contrast agents have improved the detection of focal liver lesions and can be highly effective in differentiating pseudotumor from tumors, as well as benign from malignant lesions, and can also be used for differential diagnosis. Although histological examination can be useful in making a definitive diagnosis, MRI is an important modality in the diagnosis of liver lesions with a significant impact on patient care. This aim of this review is to provide a comprehensive overview of benign liver lesions on MRI.

Diagnosis and Follow-up of Incidental Liver Lesions in Children

Incidental liver lesions are identified in children without underlying liver disease or increased risk of hepatic malignancy in childhood. Clinical and imaging evaluation of incidental liver lesions can be complex and may require a multidisciplinary approach. This review aims to summarize the diagnostic process and follow-up of incidental liver lesions based on review of the literature, use of state-of-the-art imaging, and our institutional experience. Age at presentation, gender, alpha fetoprotein levels, tumor size, and imaging characteristics should all be taken into consideration to optimize diagnosis process. Some lesions, such as simple liver cyst, infantile hemangioma, focal nodular hyperplasia (FNH), and focal fatty lesions, have specific imaging characteristics. Recently, contrast-enhanced ultrasound (CEUS) was Food and Drug Administration (FDA)-approved for the evaluation of pediatric liver lesions. CEUS is most specific in lesions smaller than 3 cm and is most useful in the diagnosis of infantile hemangioma, FNH, and focal fatty lesions. The use of hepatobiliary contrast in MRI increases specificity in the diagnosis of FNH. Recently, lesion characteristics in MRI were found to correlate with subtypes of hepatocellular adenomas and associated risk for hemorrhage and malignant transformation. Biopsy should be considered when there are no specific imaging characteristics of a benign lesion. Surveillance with imaging and alpha fetoprotein (AFP) should be performed to confirm the stability of lesions when the diagnosis cannot be determined, and whenever biopsy is not feasible.

Imaging Spectrum of Intrahepatic Mass-Forming Cholangiocarcinoma and Its Mimickers: How to Differentiate Them Using MRI

Intrahepatic cholangiocarcinoma (ICC) is the second most common primary hepatic malignancy, with mass-forming growth pattern being the most common. The typical imaging appearance of mass-forming ICC (mICC) consists of irregular ring enhancement in the arterial phase followed by the progressive central enhancement on portal venous and delayed phases. However, atypical imaging presentation in the form of hypervascular mICC might also be seen, which can be attributed to distinct pathological characteristics. Ancillary imaging features such as lobular shape, capsular retraction, segmental biliary dilatation, and vascular encasement favor the diagnosis of mICC. Nevertheless, these radiological findings may also be present in certain benign conditions such as focal confluent fibrosis, sclerosing hemangioma, organizing hepatic abscess, or the pseudosolid form of hydatid disease. In addition, a few malignant lesions including primary liver lymphoma, hemangioendothelioma, solitary hypovascular liver metastases, and atypical forms of hepatocellular carcinoma (HCC), such as scirrhous HCC, infiltrative HCC, and poorly differentiated HCC, may also pose a diagnostic dilemma by simulating mICC in imaging studies. Diffusion-weighted imaging and the use of hepatobiliary contrast agents might be helpful for differential diagnosis in certain cases. The aim of this manuscript is to provide a comprehensive overview of mICC imaging features and to describe useful tips for differential diagnosis with its potential mimickers.

One stop shop approach for the diagnosis of liver hemangioma

Hepatic hemangioma is usually detected on a routine ultrasound examination because of silent clinical behaviour. The typical ultrasound appearance of hemangioma is easily recognizable and quickly guides the diagnosis without the need for further investigation. But there is also an entire spectrum of atypical and uncommon ultrasound features and our review comes to detail these particular aspects. An atypical aspect in standard ultrasound leads to the continuation of explorations with an imaging investigation with contrast substance [ultrasound/ computed tomography/or magnetic resonance imaging (MRI)]. For a clinician who practices ultrasound and has an ultrasound system in the room, the easiest, fastest, non-invasive and cost-effective method is contrast enhanced ultrasound (CEUS). Approximately 85% of patients are correctly diagnosed with this method and the patient has the correct diagnosis in about 30 min without fear of malignancy and without waiting for a computer tomography (CT)/MRI appointment. In less than 15% of patients CEUS does not provide a conclusive appearance; thus, CT scan or MRI becomes mandatory and liver biopsy is rarely required. The aim of this updated review is to synthesize the typical and atypical ultrasound aspects of hepatic hemangioma in the adult patient and to propose a fast, non-invasive and cost-effective clinical-ultrasound algorithm for the diagnosis of hepatic hemangioma.

Spontaneous regression of liver hemangiomas: a single-institution analysis of 46 patients

OBJECTIVE

The aim of this study was to determine the nature of spontaneous regression of liver hemangiomas.

PATIENTS AND METHODS

The records of the liver hemangioma patients who attended the out-patient clinic between 1988 and 2018 were evaluated. The data of the 716 adult patients who were followed for at least 3 years with cross-sectional imaging were analyzed.

RESULTS

Spontaneous regression was documented in 46 patients (6.4%). Twenty-eight patients had a single hemangioma (61%), eight (17%) had two hemangiomas; the other 10 patients had 3-6 hemangiomas. Of the 87 lesions in 46 patients, 69 actually regressed during the study. Twelve patients with more than one lesion exhibited discordant courses - one of the hemangiomas of a patient with multiple lesions regressed, whereas the other enlarged or remained stable. Eleven of the regressed hemangiomas exhibited enlargement first, followed by spontaneous regression. Fourteen (20%) of the regressed hemangiomas acquired atypical characteristics that would have suggested a malignancy had the original films been unavailable.

CONCLUSION

Spontaneous regression of liver hemangiomas is an underrecognized phenomenon. Enlargement should not be a straightforward indication for intervention because it may be followed by regression. A regressed hemangioma should be considered in the differential diagnosis of liver lesions suspicious for malignancy.

Cavernous hemangioma of the mesorectum involving the rectum: a rare case report

BACKGROUND

Gastrointestinal hemangiomas are very rare and are even rarer in the mesorectum. It is not clear whether mesorectal hemangiomas originate in the bowel wall or in the mesorectum. For clinicians, to correctly identify the imaging features of mesorectal hemangiomas is important.

CASE PRESENTATION

We herein describe a case of a 31-year-old male that presented with hematochezia and sensation of rectal tenesmus. Both the rectal MRI and contrast-enhanced CT scan of the whole abdomen indicated rectal wall thickening, marked dilatation, and tortuous vessels around the rectum. In addition, a contrast-enhanced portal venous phase CT scan showed the dilation of portal vein, splenic vein and inferior mesenteric vein. The dilated inferior mesenteric vein extending down to the mesorectum, and became marked dilatation and tortuous vessels around the rectum. The patient underwent laparoscopic surgical resection of the mesorectal lesion and the involved portions of the rectum. The surgical samples underwent pathological analysis, and a diagnosis of cavernous hemangioma was confirmed. Seven days after surgery, the patient was discharged without postoperative complications.

CONCLUSIONS

This case highlights the imaging features of mesorectal hemangiomas. In addition, in this current case, the mesorectal hemangioma more likely originated in the mesorectum.

Focal hepatic intrinsically hyperattenuating lesions at unenhanced CT: Not always calcifications

Due to the growing use of CT, there has been an increase in the frequency of detecting focal liver lesions. Intrinsically hyperattenuating hepatic lesions or pseudolesions are not uncommon at unenhanced CT. Hyperattenuating hepatic lesions can be divided into non-calcified and calcified. Causes of intrinsic hyperattenuation include hemorrhage, thrombosis, and calcifications. Focal liver lesions can show hyperattenuation on unenhanced CT in case of severe liver steatosis. Recognition of etiologies associated with hyperattenuation on unenhanced CT can help the radiologist in characterizing focal liver lesions and pseudolesions. In this paper, we describe the spectrum of intrinsically hyperattenuating focal liver lesions and pseudolesions at unenhanced CT.

Real-world data on the clinicopathological traits and outcomes of hospitalized liver hemangioma patients: a multicenter study

Background

There is currently a lack of consensus regarding the clinical features, diagnosis, treatment indications and options, and risk assessment of hepatic hemangioma patients.

Methods

This was a multicenter, real-world study that analyzed a large number of hepatic hemangioma cases in China and included patient data on epidemiology, diagnosis, treatment methods, and outcomes.

Results

A total of 5,143 patients hospitalized for hepatic hemangioma were included, of whom 34.42% were male and 65.58% were female. The age distribution was concentrated between 30 and 60 years old, accounting for 87.41% of the patients. Among the hepatic hemangioma patients, 60.8% had only one tumor, with the most common pathological type being cavernous hemangioma (96.07% of cases). The treatment motivations and indications included anxiety, obvious clinical symptoms, rapid tumor growth, unclear diagnoses and acute emergencies. Overall, 41.4% of the patients were treated for psychological reasons, while 30.59% were treated because they presented obvious (primarily nonspecific) clinical symptoms. Hepatic resection was the main therapeutic method and was based on various indications. There were a small number of patients with Kasabach-Merritt syndrome, according to its generally recognized definition.

Conclusions

Most patients in this study who were hospitalized for hepatic hemangioma did not meet the indications for requiring treatment. Surveillance is the recommended course of action for definitively diagnosed hepatic hemangioma, and a new classification system is needed to standardize the diagnosis of this condition.

Scoping review of clinical practice guidelines on the management of benign liver tumours

Objective

Benign liver tumours (BLT) are increasingly diagnosed as incidentalomas. Clinical implications and management vary across and within the different types of BLT. High-quality clinical practice guidelines are needed, because of the many nuances in tumour types, diagnostic modalities, and conservative and invasive management strategies. Yet, available observational evidence is subject to interpretation which may lead to practice variation. Therefore, we aimed to systematically search for available clinical practice guidelines on BLT, to critically appraise them, and to compare management recommendations.

Design

A scoping review was performed within MEDLINE, EMBASE, and Web of Science. All BLT guidelines published in peer-reviewed, and English language journals were eligible for inclusion. Clinical practice guidelines on BLT were analysed, compared, and critically appraised using the Appraisal of Guidelines, Research and Evaluation (AGREE II) checklist regarding hepatic haemangioma, focal nodular hyperplasia (FNH), and hepatocellular adenoma (HCA). Preferred Reporting Items for Systematic Reviews and Meta-Analyses recommendations (PRISMA) for scoping reviews were adhered to.

Results

The literature search yielded unique 367 papers, 348 were excluded after screening of title/abstract, and 16 after full-text screening. Three guidelines were included: the American College of Gastroenterology (ACG; 2014), Brazilian Society of Hepatology (SBH; 2015), and European Association for the Study of the Liver (EASL; 2016). There was no uniformity in the assessment methods for grading and gravity of recommendations between guidelines. Among observed differences were: (1) indications for biopsy in all three tumours; (2) advices on contraceptive pills and follow-up in FNH and HCA; (3) use of an individualised approach to HCA; (4) absence of recommendations for treatment of HCA in men; and (5) approaches to HCA subtype identification on magnetic resonance imaging.

Conclusion

Recognising differences in recommendations can assist in harmonisation of practice standards and identify unmet needs in research. This may ultimately contribute to improved global patient care.

Dynamic magnetic resonance imaging features of cavernous hemangioma in the manubrium: A case report

BACKGROUND

Osseous hemangiomas, especially those located in the manubrium, are rare benign tumors. In a review of the literature, only three case reports of sternal hemangioma were found. A precise diagnosis is difficult because of their nonspecific findings on computed tomography (CT)/magnetic resonance imaging (MRI).

CASE SUMMARY

An 88-year-old woman was suffering from a progressively enlarging mass in the manubrium. Chest CT images showed an osteolytic and expansile lesion with cortical destruction. Vascular malformation was suspected after CT-guided biopsy. On the dynamic MRI scans, the mass showed a bright signal on the T2-weighted image, peripheral nodular enhancement on the early-phase images and progressive centripetal fill-in on the delayed-phase images. Cavernous hemangioma was suspected preoperatively based on the MRI features and finally confirmed by histopathologic analysis.

CONCLUSION

This uncommon case demonstrates the possible characteristic features of manubrium cavernous hemangioma on dynamic MRI scans; knowledge about these features may prevent patients from developing catastrophic complications, such as rupture or internal hemorrhage, caused by biopsy or surgery.

Imaging Characteristics and Management of Infected Hepatic Hemangioma: Case-in Discussion

Hepatic hemangiomas are the most common type of benign liver tumors. We present a case of an infected hepatic hemangioma, which posed a diagnostic challenge. A 43-year-old female presented with right upper quadrant pain after blunt force trauma and intentional weight loss. CT and MRI were done, showing a posterior right lobe liver mass. Imaging characteristics were thought to be suggestive of metastatic disease, with a differential diagnosis of abscess. Drainage and biopsy of the mass revealed Streptococcus sp. infection, and pathology showed a cavernous hemangioma with inflammation. Patients presenting with systemic symptoms and an indeterminate liver mass on imaging should be evaluated for infected hepatic hemangiomas. Biopsy may be needed to rule out cancer. Management may include surgical resection; however, antibiotics and percutaneous drainage can suffice, as in this case.

[Imaging of hepatic tumors in children and adolescents]

BACKGROUND

Pediatric liver tumors are relatively rare, but thorough knowledge of their imaging features is still important.

OBJECTIVES

Frequency and imaging features of benign and malignant liver masses during childhood and adolescence.

MATERIALS AND METHODS

Discussion of relevant original articles, review manuscripts and expert recommendations concerning imaging of childhood liver tumors.

RESULTS

The most common malignant tumors of the liver are hepatoblastoma, which usually occur in younger children, as well as in some regions hepatocellular carcinoma. In contrast to most benign masses, such as focal nodular hyperplasia, simple cysts or fatty liver infiltrations, their imaging morphology is not very characteristic. Radiologically, sonography and magnetic resonance imaging (MRI) are used for assessment. Both methods benefit from intravenous contrast agent administration.

CONCLUSIONS

Childhood liver tumors show a broad spectrum of morphological manifestations. Some entities can be characterized using standard imaging, some require multimodal imaging or histological assessment. In addition to morphological imaging criteria, age and the medical history as well as laboratory data play an important role in establishing the correct diagnosis.

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.

Radiomics analysis of contrast-enhanced CT for classification of hepatic focal lesions in colorectal cancer patients: its limitations compared to radiologists

OBJECTIVE

To evaluate diagnostic performance of a radiomics model for classifying hepatic cyst, hemangioma, and metastasis in patients with colorectal cancer (CRC) from portal-phase abdominopelvic CT images.

METHODS

This retrospective study included 502 CRC patients who underwent contrast-enhanced CT and contrast-enhanced liver MRI between January 2005 and December 2010. Portal-phase CT images of training (n = 386) and validation (n = 116) cohorts were used to develop a radiomics model for differentiating three classes of liver lesions. Among multiple handcrafted features, the feature selection was performed using ReliefF method, and random forest classifiers were used to train the selected features. Diagnostic performance of the developed model was compared with that of four radiologists. A subgroup analysis was conducted based on lesion size.

RESULTS

The radiomics model demonstrated significantly lower overall and hemangioma- and metastasis-specific polytomous discrimination index (PDI) (overall, 0.8037; hemangioma-specific, 0.6653; metastasis-specific, 0.8027) than the radiologists (overall, 0.9622-0.9680; hemangioma-specific, 0.9452-0.9630; metastasis-specific, 0.9511-0.9869). For subgroup analysis, the PDI of the radiomics model was different according to the lesion size (< 10 mm, 0.6486; ≥ 10 mm, 0.8264) while that of the radiologists was relatively maintained. For classifying metastasis from benign lesions, the radiomics model showed excellent diagnostic performance, with an accuracy of 84.36% and an AUC of 0.9426.

CONCLUSION

Albeit inferior to the radiologists, the radiomics model achieved substantial diagnostic performance when differentiating hepatic lesions from portal-phase CT images of CRC patients. This model was limited particularly to classifying hemangiomas and subcentimeter lesions.

KEY POINTS

• Albeit inferior to the radiologists, the radiomics model could differentiate cyst, hemangioma, and metastasis with substantial diagnostic performance using portal-phase CT images of colorectal cancer patients. • The radiomics model demonstrated limitations especially in classifying hemangiomas and subcentimeter liver lesions.

Multilocular cystic hemangioma of the liver mimicking mucinous cystic neoplasm

Hepatic hemangiomas infrequently exhibit atypical imaging features, which may cause diagnostic confusion with hepatic malignancies and lead to unnecessary surgery. We report a rare case of multilocular cystic hemangioma of the liver mimicking a mucinous cystic neoplasm of the liver in a 48-year-old female, focusing on computed tomography and magnetic resonance imaging features and their differential diagnosis.

Two hepatic cavernous hemangiomas mimicking colorectal liver metastasis: A rare case report

•

Hepatic cavernous hemangioma is a common benign lesion of the liver.

•

Commonly seen in women and most of the patients are asymptomatic.

•

The radiological features can resemble those of hepatic malignancies, which make the preoperative definitive diagnosis difficult.

•

Surgical resection is necessary to confirm the diagnosis.

Introduction

1 Hepatic cavernous hemangioma (HCH) is a common benign lesion of the liver. The radiological features of HCH can resemble those of hepatic malignancies such as metastatic liver cancer, which make the preoperative definitive diagnosis difficult.

Presentation of case

We report the case of a 77-year-old woman who presented with a 2-month history of abdominal pain and per rectum fresh bleeding. The initial diagnosis at the referral hospital, based on computed tomography (CT) scan of the chest, abdomen, and pelvis, was sigmoid colon cancer with liver metastasis. Further evaluation at our hospital, the patient underwent colonoscopy and biopsy. Histopathological examination of the biopsy revealed an invasive moderately differentiated adenocarcinoma. The patient underwent laparoscopic sigmoidectomy and left hepatectomy. The histopathological examination of the sigmoid colon mass revealed an invasive moderately to poorly differentiated adenocarcinoma. One out of twenty lymph nodes is positive for metastatic carcinoma. The pathological stage is pT3, pN1a, pM0. The histopathological examination of the left hepatic lobe revealed two hyalinized cavernous hemangiomas with no malignancy is seen. The postoperative recovery was uneventful, and the patient was discharged home with regular follow-up in our outpatient clinic.

Discussion

HCH is congenital vascular malformation and is the most common benign hepatic tumors. Fine-needle biopsy during diagnostic laparoscopy for undiagnosed multiple liver tumor can differentiate atypical HCH from colorectal metastasis but can potentially lead to rupture or seeding of cancer cells.

Conclusion

Surgical resection is necessary to determine if the mass is malignant in some atypical HCH mimicking liver metastasis to confirm the diagnosis with histopathologic examination.

Evaluation of the Effect of Patient Preparation Using Castor Oil on ADC Value of Focal Liver Lesion

Purpose

To estimate the role of patient preparation using castor oil on the ADC value of focal liver lesion.

Patients and Methods

Retrospective case-control study over more than two years. Magnetic resonance imaging (MRI) scan, including diffusion-weighted imaging (DWI) of the upper abdomen performed for 87 cases and 71 controls in patients with focal hepatic hemangiomas. Cases were prepared using castor oil prior to the scan without identifiable unwanted effect, while controls did not receive any special preparation. Since liver hemangioma is a common lesion, it was selected and used as a sample. Apparent Diffusion Coefficient (ADC) values of focal liver lesion were calculated in cases and controls.

Results

The mean ADC value of liver hemangioma was lower in cases compared to controls; the mean ADC value was (2.21±0.39x10ˉ³mm²/s) in cases and (2.51±0.49x10ˉ³mm²/s) in controls. Left lobes were more affected by lesions; the mean ADC value of the left lobe lesions was (2.26±0.37 x10ˉ³mm²/s) and (2.86±0.43 x10ˉ³mm²/s) in cases and controls, respectively. The ADC value of lesions in the right lobe was (2.19±0.39x10ˉ³mm²/s) in cases and (2.39± 0.45x10ˉ³mm²/s) in controls. There was a significant segmental ADC variation; lesions at segments II, III, IVb, and V demonstrated illusive ADC elevation in controls.

Conclusion

There is erroneous elevation of lobar and segmental ADC value of liver hemangiomas in non prepared patients. This Potential source of error (peristalsis, partial volume, and paramagnetic gas effect of gastrointestinal tract) on hepatic lesions’ ADC value can be avoided by proper preparation using castor oil prior to MRI scanning.

Superb microvascular imaging technology of ultrasound examinations for the evaluation of tumor vascularity in hepatic hemangiomas

Purpose

This study aimed to investigate and categorize the diverse features of hepatic hemangiomas on superb microvascular imaging (SMI) in a relatively large prospective study.

Methods

In this prospective study, 70 patients with 92 hepatic hemangiomas were consecutively enrolled. All nodules were radiologically confirmed with the typical imaging features of hepatic hemangiomas on dynamic computed tomography (CT) or magnetic resonance imaging (MRI). Using SMI, all lesions were evaluated and categorized into subgroups according to the flow pattern on SMI. Differences in the frequencies of SMI patterns according to lesion size and enhancement patterns on dynamic CT or MRI were also compared.

Results

In 67.4% (62/92) of hemangiomas, tumor vascularity was detected using SMI, while 32.6% (30/92) did not show any signal on the SMI examination, and the absence of an SMI signal was not shown in rapidly enhancing hemangiomas (0% [0/30] vs. 100% [30/30], P=0.002) and was more frequent in lesions <2 cm than in lesions ≥2 cm (44.0% [22/50] vs. 2.7% [8/42], P=0.011). In hepatic hemangiomas in which vascularity was detected (n=62), the strip rim pattern was the most common SMI pattern of hepatic hemangiomas (48.4%, 30/62), followed by the nodular rim pattern involving spotty dot-like engorged vessels (37.1%, 23/62).

Conclusion

The evaluation of the inner vascularity of hepatic hemangiomas with SMI was feasible for most hemangiomas, especially in larger (≥2 cm) or rapidly enhancing hemangiomas. The most frequent SMI patterns of hepatic hemangiomas were the strip rim pattern and nodular rim pattern.

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.

Comparison of multiplexed sensitivity encoding and single-shot echo-planar imaging for diffusion-weighted imaging of the liver

PURPOSE

To compare multiplexed sensitivity encoding (MUSE) and conventional diffusion-weighted magnetic resonance imaging (cDWI) techniques in liver MRI.

METHODS

Fifty-nine patients who underwent both two-shot echo-planar DWI using MUSE and single-shot echo-planar cDWI at a 3.0-T MRI system were included. Qualitative parameters were independently evaluated by three radiologists, and quantitative parameters were calculated on the basis of region of interest measurements. Receiver operating characteristic curve analysis and McNemar's test were used to compare solid lesion characterization results and lesion detectability, respectively.

RESULTS

All reviewers found less image noise, sharper liver contours, milder susceptibility artifacts, and better lesion conspicuity in MUSE-DWI than in cDWI (reader average mean, 4.1-4.5 vs. 3.5-4.0; p < 0.05). The signal-to-noise ratio (SNR) of the liver was significantly higher in MUSE-DWI than in cDWI (right lobe: mean, 9.39 vs. 8.10, p < 0.001; left lobe: mean, 8.34 vs. 7.19, p < 0.001), while the SNR of the lesion (mean, 23.72 vs. 23.88, p = 0.911) and lesion-to-liver contrast-to-noise ratio (mean, 14.65 vs. 15.41, p = 0.527) were comparable between MUSE-DWI and cDWI. Solid lesion characterization results were comparably accurate between MUSE-DWI and cDWI (reader average area under the receiver operating characteristic curve, 0.985 vs. 0.986, p = 0.480). The detectability of lesions was better in MUSE-DWI than in cDWI (reader consensus, 83.7 % [41/49] vs. 67.3 % [33/49], p = 0.021).

CONCLUSION

MUSE-DWI can provide multi-shot liver DWI with less noise, fewer distortions, improved SNR of the liver, and better lesion detectability.

A New Diagnostic Criterion with Gadoxetic Acid-Enhanced MRI May Improve the Diagnostic Performance for Hepatocellular Carcinoma

BACKGROUND

To prospectively establish and validate new diagnostic criterion (DC) for liver-specific contrast agents and further compared the diagnostic sensitivity and specificity with conventional DC.

METHODS

Institutional Review Board approved and written informed consent were obtained for this prospective study. Two board-certified reviewers established the reference standard as hepatocellular carcinoma (HCC), non-HCC lesions by using marks on all cross-sectional MR images. Another 2 abdominal radiologists independently performed the marked lesion observations using 5 different DCs, including DC-1: arterial phase hyperenhancement (APHE) and portal venous phase washout; DC-2: APHE and hepatobiliary phase (HBP) hypointensity; DC-3: APHE and diffusion-weighted imaging (DWI) hyperintensity; DC-4: HBP hypointensity and DWI hyperintensity; DC-5: HBP hypointensity, DWI hyperintensity and excluded these markedly T2 hyperintensity. Diagnostic performance of sensitivity, specificity, and accuracy for each imaging DC was calculated, per-lesion diagnostic sensitivity and specificity of imaging criteria were compared by using McNemars test.

RESULTS

A total of 215 patients were included (mean age 53.82 ± 11.24 years; range 24-82 years) with 265 hepatic nodules (175 HCCs and 90 non-HCCs). The DC-4 (93.71%; 164/175) and DC-5 (92.57%; 162/175) yielded the highest diagnostic sensitivity and was better than DC-1 (72.57%; 127/175), DC-2 (82.86%; 145/175), and DC-3 (82.29%; 144/175) (all p < 0.001). The specificity of DC-1 (94.44%; 85/90) was significantly higher than that with DC-2 (83.33%; 75/90), DC-3 (84.44%; 76/90), DC-4 (74.44%; 67/90), and DC-5 (82.22%; 74/90) (all p < 0.05). Additionally, the DC-4 and DC-5 achieved the highest area under curve value of 0.841 (95% CI 0.783-0.899) and 0.874 (95% CI 0.822-0.925).

CONCLUSIONS

The combined use of HBP hypointensity and DWI hyperintensity as a new DC for HCC enables a high diagnostic sensitivity and comparable specificity.

Sclerotic changes of cavernous hemangioma in the cirrhotic liver: long-term follow-up using dynamic contrast-enhanced computed tomography

PURPOSE

To determine the intra- and extralesional factors that predict sclerotic degeneration of hepatic hemangiomas in the cirrhotic liver on long-term follow-up computed tomography (CT) examinations.

MATERIALS AND METHODS

Fifty-seven hepatic hemangiomas (> 5 mm in diameter) in 41 cirrhotic patients, recruited over a 5-year period (January 2005-December 2009), were subjected to CT to determine which factors predict sclerotic contraction or degeneration in hemangiomas. Prior and follow-up CT examinations (from 2000 to 2018) were included to observe time-related changes. The patients' gender, age, cause of cirrhosis, progression of background liver cirrhosis, lesion size/location/contrast enhancement pattern, and serum aspartate transaminase to platelet ratio index were correlated with sclerotic changes of each lesion.

RESULTS

According to the dynamic CT features, 36 of 57 (63%) hemangiomas were determined to have sclerotic changes during the follow-up period (1.1-14.4 years, median: 7.8 years), including 28 lesions (49%) reduced by ≥ 20% in diameter. In univariate analysis, age (p = 0.047) and morphological progression of background cirrhosis (p = 0.013) were significantly related to sclerotic change of hemangiomas. In the logistic regression analysis, only morphological progression of background liver cirrhosis independently predicted sclerotic change (odds ratio: 4.88, p = 0.007). With the exception of exophytic location free from size reduction (p = 0.023 in multivariate analysis), no other analyzed factors were significantly correlated with sclerotic changes.

CONCLUSION

Overall, sclerotic changes of hepatic cavernous hemangioma followed the morphological progression of background liver cirrhosis, while exophytic lesions tended to be free of size reduction.

Imaging of hepatic hemangioma: from A to Z

The hemangioma is the most common solid lesion of the liver. Therefore, radiologists must know the typical and atypical imaging findings of this lesion in order to reach a correct diagnosis and avoid diagnostic errors. However, only few papers have comprehensively described the entire spectrum of atypical and uncommon imaging features. In this updated review, we provide the imaging features of hepatic hemangioma, in both typical and atypical forms, as well as its association with abnormalities in the adjacent hepatic parenchyma and other hepatic lesions, and its complications.

Preoperative detection of colorectal liver metastases: DWI alone or combined with MDCT is no substitute for Gd-EOB-DTPA-enhanced MRI

Background

Magnetic resonance imaging (MRI) with hepatocyte specific contrast has the highest sensitivity for colorectal liver metastases but comes at high costs and long examination times.

Purpose

To evaluate if preoperative detection of colorectal liver metastases with less resource-consuming diffusion-weighted imaging (DWI) alone or in combination with multidetector computed tomography (MDCT) can compete with gadolinium-etoxybenzyl-diethylenetriaminepentaacetic acid (Gd-EOB-DTPA)-enhanced MRI.

Material and Methods

Forty-four patients with 123 colorectal liver metastases received MDCT and Gd-EOB-DTPA-enhanced MRI including DWI before liver resection for colorectal liver metastases. Five image sets were evaluated by two radiologists. The DWI set consisted of DWI, ADC map, coronal, axial T2-weighted single-shot sequences. The DWI-T2F set contained additionally respiratory-triggered T2-weighted TSE-SPIR sequences. The MDCT set consisted of four-phase MDCT, the MDCT-DWI set also contained DWI. The CE-MRI set contained all MRI sequences including Gd-EOB-DTPA. Reference standards was histopathology and follow-up.

Results

CE-MRI set had highest sensitivity ( P ≤ 0.013) with 95% compared to 72%, 73%, 73%, and 87% the for DWI set, DWI-T2W-FS set, MDCT set, and MDCT-DWI set, respectively. The CE-MRI set had the highest sensitivity ( P≤0.012) for colorectal liver metastases <10 mm with 87% compared to 55%, 52%, 23%, and 58% for the DWI set, DWI-T2W-FS set, MDCT set, and MDCT-DWI set, respectively. The MDCT-DWI set improved sensitivity overall and in size-dependent subgroup analyses compared to the MDCT set ( P ≤ 0.031). The MDCT-DWI set showed the highest specificity of 98% followed by 98%, 98%, 95%, and 88% for the DWI set, DWI-T2W-FS set, MDCT set, and CE-MRI set, respectively.

Conclusion

The less resource and time-consuming DWI sets are inferior to Gd-EOB-DTPA-enhanced MRI for the detection of colorectal liver metastases. Gd-EOB-DTPA-enhanced MRI with its excellent sensitivity should be the preferred preoperative modality when meticulous lesion identification is essential. Combination of DWI with MDCT improved significantly sensitivity compared to each modality alone.

Intrahepatic and intra-abdominal splenosis: A case report and review of literature

BACKGROUND

Splenosis is defined as the process by which tissue from the spleen disseminates through the body and grows in an ectopic location following trauma or a splenectomy. Visceral sites of splenosis are rare.

CASE SUMMARY

We report a case of intrahepatic splenosis in a 57-year-old man with a history of trauma over 40 years ago who initially presented with chest pain. Findings initially mimicked malignancy but a diagnosis of intrahepatic splenosis was confirmed using computed tomography and scintigraphy with technetium-99m heat-denatured red blood cells (Tc-99 DRBC).

CONCLUSION

Scintigraphy with Tc-99 DRBC is a reliable technique to diagnose splenosis and should be performed before using more invasive procedures are carried out. Splenosis should be considered as a possible differential diagnosis for a hepatic nodule in any patient with a history of abdominal trauma, previous splenectomy or atypical radiological features on imaging.

[Mesenchymal abdominal tumors in children]

Mesenchymal tumors in childhood comprise benign and malign entities and differ regarding typical sites of manifestation, age peak and clinical symptoms. In some cases biopsy is mandatory. If nephroblastoma is a possible diagnosis, biopsy must be avoided by all means in order to avoid biopsy tract metastasis. Imaging is used to narrow the differential diagnosis, describe the exact extent of the lesion and deliver complete staging. In pediatric patients sonography and MRI are the most important imaging modalities. Low-dose CT of the thorax serves for assessment of possible pulmonary metastases.

Late Gadolinium Hyperintensity of Suspected Colorectal Liver Metastases on Gadofosveset-Enhanced Magnetic Resonance Imaging: A Predictor of Benignity and a Potential Problem-Solving Tool

PURPOSE

Late gadolinium hyperintensity (LGH) is sometimes seen in colorectal liver metastasis (CRLM) and represents a significant diagnostic pitfall due to overlap with LGH in benign hemangiomas; therefore, the objective of this study was to determine the prevalence of LGH and the ability of LGH to differentiate between CRLM and benign lesions with intravascular (gadofosveset) vs extracellular contrast agents (gadobutrol).

METHODS

Patients with known colorectal cancer and suspected liver lesions were prospectively recruited into this institutional review board-approved, single institution study and received magnetic resonance imaging of the liver with gadofosveset and gadobutrol. The prevalence of LGH for CRLMs and solid benign lesions was determined. Receiver operating characteristics curves were determined for the presence of LGH as a predictor of benignity. The utility of LGH to differentiate between CRLM and solid benign lesions using gadofosveset vs gadobutrol was compared using the generalized estimating equation.

RESULTS

Twenty-five patients with 131 solid focal liver lesions were recruited. The prevalence of LGH of CRLMs was 11.2% (95% confidence interval [CI]: 0.5%-21.8%) with gadofosveset vs 63.7% (95% CI: 45.7%-81.7%) with gadobutrol. The area under the receiver operating characteristic curve for the presence of LGH as a predictor of benignity was 0.86 using gadofosveset vs 0.75 using gadobutrol. Both LGH (P = .003) and the interaction of contrast agent and LGH (P = .003) statistically significantly differentiated CRLM from benign lesions.

CONCLUSION

LGH is more common with extracellular than with intravascular contrast agents and is statistically significantly associated with benign lesions rather than metastases.

Anastomosing hemangioma of liver

Anastomosing hemangiomas are a rare subtype of benign vascular hemangioma which most commonly arise in the genitourinary tract and retroperitoneum. In only a small number of reports has this entity been shown originating within the liver parenchyma. Despite their benign behavior, on contrast-enhanced computer tomography and magnetic resonance imaging studies anastomosing hemangiomas can demonstrate enhancement characteristics similar to primary and metastatic liver lesions. This case report highlights the imaging features of this entity and provides a brief review of the limited literature that exists on this rare hepatic lesion.

Budd-Chiari Syndrome and hepatic regenerative nodules: Magnetic resonance findings with emphasis of hepatobiliary phase

Budd-Chiari syndrome (BCS) is a disorder with numerous causes that is a result of hepatic outflow obstruction, in the absence of right heart failure or constrictive pericarditis. Acute Budd-Chiari syndrome is uncommon and clinically characterized by ascites, hepatomegaly, and hepatic insufficiency. In the majority of cases, patients present with chronic BCS, showing a dysmorphic liver disease with variable fibrosis deposition. In chronic Budd-Chiari syndrome, hepatocellular carcinoma (HCC) and benign regenerative nodules (called large regenerative nodules or FNH-like lesions) have been described in the literature. Very few studies have reported magnetic resonance imaging (MRI) findings about these nodules, using hepatobiliary contrast medium. The aim of our review is to describe the magnetic resonance imaging findings of hepatic regenerative nodules in BCS, with emphasis on the hepatobiliary phase, and to compare the imaging features of benign nodules with those of HCC.

Unusual MRI appearance of a well differentiated hepatocellular carcinoma, mimicking a cavernous hemangioma: A case report

The typical imaging findings in hepatocellular carcinoma (HCC) are arterial hyperenhancement with washout on portal venous and/or equilibrium phases. Larger HCCs can have atypical imaging findings including fibrous capsule or mosaic appearance. We describe an unusual biopsy proven HCC in a cirrhotic liver with imaging features mimicking cavernous hemangioma which also demonstrated some atypical features such as thick capsule. In addition to knowing the typical imaging findings of HCC, it is important to be familiar with its atypical imaging findings especially in larger lesions.

A hepatic sclerosing hemangioma emerged in the postoperative course of multiple gastric carcinoid tumors masquerading as metachronous liver metastasis

•

The authors present an unusual case of newly appearing hepatic sclerosing hemangioma newly emerged in the postoperative course after the resection of multiple gastric carcinoid tumors.

•

Hepatic sclerosing hemangioma is often misdiagnosed as malignant lesion for its resemblance on the imaging studies.

•

Although preoperative diagnosis is still difficult, hepatic sclerosing hemangioma must be included into the differential diagnosis of hepatic tumors.

Introduction

Hepatic sclerosing hemangiomas are rare tumors whose appearance on imaging is similar to that of malignant tumors. The resulting difficulties in preoperative diagnosis frequently lead to surgical resection in order to accurately identify the tumor.

Case presentation

A 68-year-old man was diagnosed with multiple gastric carcinoid tumors (T1N1M0, pStage IIIB) after total gastrectomy with D2 lymph node dissection. Enhanced computed tomography of the abdomen 2 years after the initial surgery revealed a novel solid lesion with ring enhancement measuring 22 × 15 mm at S5 of the liver. Metachronous liver metastasis from multiple gastric carcinoid tumors was suspected, and partial hepatectomy of S5 was successfully performed. Histopathological diagnosis was sclerosing hemangioma with no malignant findings.

Discussion

Ours is the first reported case of a newly appearing sclerosing hemangioma excised and diagnosed histopathologically. Hepatic sclerosing hemangiomas are rarely observed, but they are often resected under a preoperative diagnosis of malignant lesion due to the similarity on imaging studies.

Conclusion

Surgeons must consider that a hepatic tumor may be a sclerosing hemangioma, particularly when the lesion appears to be ring enhanced.

CT- and ultrasound-characteristics of hepatic lesions in patients with multiple endocrine neoplasia syndrome. A retrospective image review of 25 cases

Introduction

Liver metastases from neuroendocrine tumors in multiple endocrine neoplasia syndrome are common (75%) and significantly impairs the prognosis. Characterisation of liver lesions in these patients is challenging, as liver metastases are difficult to differentiate from benign liver lesions such as haemangioma.

Methods

In this study we aimed to characterize the radiological findings of hepatic metastases in MEN patients. The findings of contrast-enhanced CT were considered for the main diagnosis. We retrospectively evaluated 25 patients with MEN-syndrome (10 MEN1/ 15 MEN2) including 11 men and 14 women between 28–62 years of age.

Results

Liver metastases (48%, 12/25) and hemangioma (40%, 10/25) were the most common liver lesions among our patients. The most common primary tumors in our MEN1 and MEN2 patients with liver metastases were of pancreatic neuroendocrine tumor (70%, 7/10) und medullary thyroid carcinoma (100%, 15/15) origin, respectively. CT-characteristics were grouped into three main categories, depending on contrast dynamics. The majority of hepatic metastases (75%, 14/25) are presented as multiple lesions with a slow growth in an average 5 years of follow-up-period. We were able to find a common CT pattern and categorise these for each MEN-syndrome. Hepatic metastases in MEN1 presented commonly a blurred arterial enhancement with a low portal venous enhancement and less frequently a prominent enhancement in the arterial phase, which mimics the classical haemangioma. In MEN2 the liver metastases exhibited disseminated mixed hyper- and hypo-enhanced lesions in CT-scans. Moreover, lesion calcifications are pathognomonic in MEN2. The main limitation of this study is the missing histopathological confirmation in the majority of cases.

Conclusions

In this retrospective imaging study, we were able to categorise and find a common CT pattern for hepatic lesions in patients with MEN-syndrome. In order to differentiate these lesions sufficiently, a combination of a 3-phasic CT-scan with US is required. Other liver specific imaging modalities (MRI, CEUS, SMS-PET/CT) should complement the diagnosis in individual cases.

A study of the MR imaging manifestations with injection of sedative at the buttocks in pediatric patients

BACKGROUND

During the MRI examination, pediatric patients sleep under the sedation so that the image artifacts caused by the patient motion could be minimized. However, the sedative injection at the buttocks might cause a difficulty in the diagnosis of the buttock diseases using the MRI manifestations.

OBJECTIVE

This study aims to explore the imaging characteristics of MR for the pediatric patients with the sedative injected at the buttocks in order to correctly diagnose the diseases.

METHODS

MR imaging data of 64 pediatric patients injected with the sedative at the buttocks were retrospectively collected, including 8 cases of buttock disease. The imaging manifestations were analyzed and compared.

RESULTS

Out of 64 patients, 8 were diagnosed as the buttock diseases. MR imaging manifestations of the sedatives injected at the buttocks were the locally patchy and streaky long T1 and long T2 signals and were different from what were shown for the normal tissues and diseases.

CONCLUSION

The sedative injected at the buttocks has the MRI manifestations different from the normal tissues and diseases. Correctly understanding the MRI manifestations for the pediatric patients with the injection of sedative at the buttocks would reduce the chances of the misdiagnosis on the diseases.

Assessment of arterially hyper-enhancing liver lesions using virtual monoenergetic images from spectral detector CT: phantom and patient experience

PURPOSE

To investigate a benefit from virtual monoenergetic reconstructions (VMIs) for assessment of arterially hyper-enhancing liver lesions in phantom and patients and to compare hybrid-iterative and spectral image reconstructions of conventional images (CI-IR and CI-SR).

METHODS

All imaging was performed on a SDCT (Philips Healthcare, Best, The Netherlands). Images of a non-anthropomorphic phantom with a lesion-mimicking insert (containing iodine in water solution) and arterial-phase images from contrast-enhanced patient examinations were evaluated. VMIs (40-200 keV, 10 keV increment), CI-IR, and CI-SR were reconstructed using different strengths of image denoising. ROIs were placed in lesions, liver/matrix, muscle; signal-to-noise, contrast-to-noise, and lesion-to-liver ratios (SNR, CNR, and LLR) were calculated. Qualitatively, 40, 70, and 110 keV and CI images were assessed by two radiologists on five-point Likert scales regarding overall image quality, lesion assessment, and noise.

RESULTS

In phantoms, SNR was increased threefold by VMI_40keV compared with CI-IR/SR (5.8 ± 1.1 vs. 18.8 ± 2.2, p ≤ 0.001), while no difference was found between CI-IR and CI-SR (p = 1). Denoising was capable of noise reduction by 40%. In total, 20 patients exhibiting 51 liver lesions were assessed. Attenuation was the highest in VMI_40keV, while image noise was comparable to CI-IR resulting in a threefold increase of CNR/LLR (CI-IR 1.3 ± 0.8/4.4 ± 2.0, VMI_40keV: 3.8 ± 2.7/14.2 ± 7.5, p ≤ 0.001). Subjective lesion delineation was the best in VMI_40keV image (p ≤ 0.01), which also provided the lowest perceptible noise and the best overall image quality.

CONCLUSIONS

VMIs improve assessment of arterially hyper-enhancing liver lesions since they increase lesion contrast while maintaining low image noise throughout the entire keV spectrum. These data suggest that to consider VMI screening after arterially hyper-enhancing liver lesions.

Magnetic resonance imaging findings for differential diagnosis of perianal plexiform schwannoma: Case report and review of the literature

Plexiform schwannoma is an extremely rare variant of schwannoma, accounting for approximately 5% of cases. Due to the rarity and lack of typical symptoms, signs and radiological images, a definite diagnosis of plexiform schwannoma may not be made by clinicians prior to biopsy. In the present study, we report the first case (to our knowledge) of perianal plexiform schwannoma arising from the overlapped skin of the ischioanal fossa, and we propose an intratumorally nonenhanced circumferential capsule dividing the tumour into multiple homogeneously enhanced nodules as a magnetic resonance imaging feature to aid in the differential diagnosis of plexiform schwannoma from ancient schwannoma, cavernous haemangioma, liposarcoma and plexiform neurofibroma.

[Benign mesenchymal tumors of the abdomen]

BACKGROUND

Benign mesenchymal tumors of the abdomen are-except for hemangiomas-rare neoplasms that are associated with potentially life-threatening complications. Thus, awareness of the most important entities and knowledge of their imaging characteristics is fundamental for the radiologist.

OBJECTIVES

An overview of the most frequent benign abdominal soft tissue tumors and their common imaging features is given. Furthermore, other facts concerning the individual entities that are relevant to radiologic practice are outlined.

MATERIALS AND METHODS

A literature search and evaluation of the institutional image database were performed.

RESULTS

Hemangiomas, desmoid tumors, lipomas and lipoma variants are presented. Typical characteristics and radiological signs (e. g., iris diaphragm sign, band sign, India ink artifact) are elucidated and illustrated by image examples.

CONCLUSION

Despite the lack of distinctive imaging features, there are a few radiological characteristics suggestive for each of the entities that in many cases allow for correct diagnosis. In cases of doubt, biopsy or surgery is necessary to distinguish them from malignancies.

Atypical hepatic haemangiomas

Hepatic haemangioma is the most common benign liver lesion in the general population. It often exhibits a uniform pattern of characteristics, thus being called “typical.” However, a certain number of hepatic haemangiomas have special or uncommon characteristics and are termed “atypical.” The majority of patients are asymptomatic. Its differential diagnosis is critical, and its differentiation from other aetiological possibilities can be challenging, especially in cases of atypical haemangiomas, which may lead to confusion or even misleading diagnoses. We report on a 55-year-old patient with atypical multiple hepatic haemangiomas mimicking metastasis or echinococcus infection.