Real-time contrast-enhanced ultrasound in diagnosing of focal spleen lesions

Differentiating malignant from benign splenic lesions: a meta-analysis and pictorial review of imaging features

OBJECTIVES

Splenic lesions might exhibit overlapping imaging features, varying from benign entities like cysts and hemangiomas to malignancies such as lymphoma and angiosarcoma. This meta-analysis aims to delineate imaging characteristics that distinguish malignant from benign splenic lesions.

METHODS

Adhering to PRISMA guidelines, we searched PubMed, Scopus, and Web of Science for studies on imaging features differentiating malignant from benign splenic lesions. We extracted data on splenic pathology and imaging characteristics and assessed the methodological quality via QUADAS-2. Odds ratio meta-analyses were performed using STATA (Version 17.0, Stata Corp, College Station, TX).

RESULTS

Portal phase hypoenhancement, hypovascular enhancement pattern, diffusion restriction, and late phase hypoenhancement, with odds ratios above 10, highly indicate malignancy. Other features suggestive of malignancy include solid morphology, lymphadenopathy, presence of perisplenic fluid, arterial hypoenhancement, hypoechogenicity on ultrasound, splenomegaly, and presence of multiple lesions. In contrast, cystic morphology, hypervascular-washout and hypervascular-persistent pattern of enhancement, late phase hyperenhancement, anechogenicity on ultrasound, portal phase hyperenhancement, well-defined borders, and calcification are in favour of benign pathology.

CONCLUSION

The study underscores the critical role of contrast-enhanced and diffusion-weighted imaging in distinguishing malignant from benign splenic lesions, emphasizing the role of features like portal phase hypoenhancement and restricted diffusion in diagnosing malignancies. Additionally, the study emphasizes the value of contrast-enhanced ultrasound, which allows for the visualization of key contrast-enhancement patterns without the risk of ionizing radiation exposure.

Isolated splenic lymphangioma in adulthood

Isolated splenic lymphangiomas are rare benign lesions mostly seen in children are exceptionally rare in adults, often discovered incidentally due to their typically asymptomatic nature. This case report elaborates on the surgical excision of a rare splenic cystic lymphangioma in a 33-year-old woman, underscoring the diagnostic and therapeutic challenges these tumors pose. The patient's symptoms, abdominal pain and a palpable mass led to imaging through ultrasound and CT, which revealed a cystic splenic lesion. Total splenectomy was performed, revealing a large cystic mass, with pathological examination confirming a cystic lymphangioma. This case emphasizes the necessity of considering splenic lymphangiomas in adult patients presenting with splenic lesions. It also highlights the critical role of surgical interventions for definitive diagnosis and to prevent complications such as rupture and hemorrhage, thereby emphasizing on the complexity of managing rare splenic tumors.

Diagnostic performance of different imaging modalities for splenic malignancies: A comparative meta-analysis

Background and objectives

The spleen hosts both benign and malignant lesions. Despite multiple imaging modalities, the distinction between these lesions poses a diagnostic challenge, marked by varying diagnostic accuracy levels across methods. In this study, we aimed to evaluate and compare the diagnostic performance of various imaging techniques for detecting malignant splenic lesions.

Methods

Following PRISMA guidelines, we searched PubMed, Scopus, and Web of Sciences databases for studies evaluating imaging techniques in detecting malignant splenic lesions. Data extraction included diagnostic accuracy metrics, and methodological quality was assessed using QUADAS-2. Diagnostic Test Accuracy meta-analyses were conducted using R (version: 4.2.1). Subgroup analyses and meta-regression were performed to compare different modalities and clinical settings.

Results

Our study included 28 studies (pooled sample size: 2358), primarily using retrospective designs with histopathology as the reference standard. PET scan demonstrated the highest diagnostic accuracy (AUC: 92 %), demonstrating a sensitivity of 93 % (95 % CI: 80.4 % - 97.7 %) and a specificity of 82.8 % (95 % CI: 71.1 % - 90.4 %). Contrast-enhanced ultrasound (CEUS), Contrast-enhanced CT scan, and contrast-enhanced MRI also showed impressive performance with AUCs of 91.4 %, 90.9 %, and 85.3 %, respectively. Differences among these modalities were not statistically significant, but they outperformed non-contrast-enhanced methods. PET and CEUS exhibited higher specificity for lymphoma cases compared to studies including other malignancies.

Conclusion and clinical implications

Overall, PET emerges as the best modality for splenic malignancies, and CEUS and CE-MRI show promise as potential alternatives, notably due to their reduced radiation exposure. Further research is essential for precise malignancy differentiation.

B-Mode Ultrasound and Contrast-Enhanced Ultrasound for the Detection of Splenic Involvement in Hodgkin Lymphoma: A Retrospective Analysis of 112 Patients

PURPOSE

To assess splenic involvement using B-mode ultrasound (US) and contrast-enhanced ultrasound (CEUS) compared with standard imaging with contrast-enhanced computerized tomography (CT) / 18-fluorodeoxyglucose positron-emission tomography (PET-CT) in patients with Hodgkin lymphoma.

MATERIALS AND METHODS

Imaging data from 112 patients from 12/2003 to 10/2022 with histologically confirmed Hodgkin lymphoma during staging or relapse were analyzed for splenic lymphoma involvement. In all patients, standard imaging (CT/PET-CT), along with B-mode US and CEUS examinations, was performed. Evidence of focal splenic lesions (FSLs) found by imaging procedures was suggestive of splenic involvement. Follow-up imaging was performed in each patient after treatment, and treatment response indicated definitive splenic involvement.

RESULTS

40 patients (35.7%) were identified by imaging modalities as having splenic involvement, which was confirmed by response during follow-up. Standard CT/PET-CT imaging detected splenic involvement in 36/112 patients (32.1%). FSLs were detected with B-mode US in 38 patients (33.9%) and CEUS in 36 patients (32.1%). The sensitivity of standard imaging, B-mode US, and CEUS was 90%, 95%, and 90%, respectively.

CONCLUSION

B-mode US examination is a diagnostic method used in addition to standard imaging for the detection of splenic involvement in Hodgkin lymphoma. CEUS does not provide additional benefit compared to B-mode US and the standard reference procedure.

Splenic lymphangioma in adult patient treated with laparoscopic splenectomy: A rare case report

Splenic lymphangioma is a benign cystic tumor that develops as a result of lymphatic vessels' congenital abnormalities. It is a rare condition that mostly occurs in children and young adults. Due to the lack of typical symptoms and signs, splenic lymphangioma is difficult to diagnose and often incidentally revealed during radiological examinations. We report a case of a 55-year-old Asian female, who presented with left upper quadrant abdominal pain in the past 3 days. She had mild upper abdominal tenderness, with no other specific findings. Abdominal contrast material-enhanced computed tomography revealed three hypodense lesions arising from a normal-sized spleen. The histologic findings after laparoscopic splenectomy demonstrated a 3-cm-diameter yellowish-white tumor made up of multiple cystic structures. Primary benign splenic tumors are exceedingly rare, especially in adults over 20. While small lesions are mostly asymptomatic, bigger lesions can cause organ compression or even rupture. Therefore, even in adults with pain in the left upper quadrant abdomen or enlarged spleen, splenic lymphangioma should be taken into account in the differential diagnosis. The case serves as an example of a rare congenital splenic tumor. Treatment of this benign splenic abnormality with laparoscopic splenectomy is a good, safe approach.

Applications of Contrast-Enhanced Ultrasound in Splenic Studies of Dogs and Cats

Simple Summary

Contrast-enhanced ultrasound (CEUS) is a noninvasive imaging technique that has become a reliable tool for identifying and monitoring lesions in both human and animals. In the last decade, its use in veterinary diagnostic imaging has gained increasing importance, and it can be reliable in everyday clinical practice. However, there is a lack of reviews describing existing CEUS results in the study of splenic lesions, which is of particular importance in dogs and cats. This information is important for validating its efficacy, to facilitate decision making related to sampling procedures and diagnosis, or even as a means to select CEUS as an alternative diagnostic tool in specific cases. Our goal was to review the existing studies of CEUS applications for splenic ultrasound studies in cats and dogs, present these results in a systematic manner, and combine this information into practical guidelines that can be used to help diagnosis and interpretation in both clinical cases and research.

Abstract

Contrast-enhanced ultrasound (CEUS) is an emerging technology in veterinary medicine involving the administration of intravenous contrast agents, and it is increasingly recognized for its high potential as a diagnostic imaging tool for small animals. This exam is easy and quick to perform, safe and reliable, and allows for the differentiation of lesions. It permits the identification of lesions that may require more invasive procedures, from those that can be safely dismissed to those that can be followed-up with ultrasound imaging. Although it has been extensively reviewed for use in human medicine, there is an overall lack of information about the application of this technique for cats and dogs, particularly in splenic studies, which can be particularly important for small animals. The present review describes and summarizes the CEUS applications used for splenic analysis in cats and dogs, providing a basic overview of CEUS technology with examples of common and uncommon features of focal splenic lesions. It also systematically gathers the results obtained for benign and malignant splenic lesions described in the literature, whilst providing guidelines for their interpretation. Furthermore, it presents the advantages of using CEUS for splenic analysis in cats and dogs and the main factors that may influence the quality of the imaging and the accuracy of the diagnosis. This type of knowledge can be used to provide a framework to help veterinarians make informed decisions regarding the use of this emerging technique for splenic lesions, guiding their interpretation of CEUS findings in the splenic ultrasounds of cats and dogs.

Contrast-enhanced ultrasound of the spleen, pancreas and gallbladder in children

Gray-scale and color/power Doppler ultrasound (US) are the first-line imaging modalities to evaluate the spleen, gallbladder and pancreas in children. The increasing use of contrast-enhanced ultrasound (CEUS) as a reliable and safe method to evaluate liver lesions in the pediatric population promises potential for imaging other internal organs. Although CEUS applications of the spleen, gallbladder and pancreas have been well described in adults, they have not been fully explored in children. In this manuscript, we present an overview of the applications of CEUS for normal variants and diseases affecting the spleen, gallbladder and pancreas. We highlight a variety of cases as examples of how CEUS can serve in the diagnosis and follow-up for such diseases in children. Our discussion includes specific examination techniques; presentation of the main imaging findings in various benign and malignant lesions of the spleen, gallbladder and pancreas in children; and acknowledgment of the limitations of CEUS for these organs.

WFUMB Position Paper-Incidental Findings, How to Manage: Spleen

The World Federation for Ultrasound in Medicine and Biology (WFUMB) is addressing the issue of incidental findings (IFs) with a series of publications entitled "Incidental Imaging Findings-The Role of Medical Ultrasound." IFs are less commonly encountered in the spleen than in many other abdominal organs but remain a frequent dilemma in clinical practice. A histological diagnosis is rarely necessary for patient management. Many IFs, such as secondary spleens and splenic cysts, are harmless and do not require any further investigation. The diagnosis of many other focal splenic lesions is, however, often problematic. The following overview is intended to illustrate a variety of incidentally detected spleen pathologies such as size variants, shape variants, secondary spleens, focal splenic lesions and splenic calcifications. It should aid the examiner in establishing the diagnosis. Moreover, it should help the ultrasound practitioner decide which pathologies need no further investigation, those requiring interval imaging and cases in which immediate further diagnostic procedures are required.

Focal splenic lesions: Imaging spectrum of diseases on CT, MRI and PET/CT

The spleen can be affected by a variety of diseases. Some of them are readily identified as variations of normal or benign diseases on imaging. However, for a substantial number of focal splenic abnormalities, the diagnosis can be difficult so that histopathologic analysis may be required for a definite diagnosis. In this review, the typical splenic abnormalities that can be diagnosed with imaging with a high degree of confidence are illustrated. The complementary role of computed tomography (CT), magnetic resonance imaging and positron emission tomography/CT that helps make a diagnostic approach is discussed. Finally, current applications and future trends of radiomics and artificial intelligence for the diagnosis of splenic diseases are addressed.

Value of Contrast-Enhanced Ultrasound in the Differential Diagnosis of Focal Splenic Lesions

Purpose

To identify and validate contrast-enhanced ultrasound (CEUS) features for differentiating malignant from benign splenic lesions.

Patients and Methods

Splenic lesions in 123 patients who underwent conventional ultrasound (B-mode US) and CEUS were included in this study. Two radiologists evaluated the sonograms of B-mode and CEUS. Statistical analysis was performed to identify significant imaging predictors for splenic malignant lesions. Two other radiologists independently reviewed B-mode and CEUS sonograms and diagnosed the lesions based on proposed criteria as 1) benign, 2) probably benign, 3) probably malignant or 4) malignant. The diagnostic efficiency between B-mode US and CEUS was compared.

Results

Common imaging findings of malignant lesions included hypoechoic, ill-defined margin, absence of cystic/necrotic portion, presence of splenomegaly on B-mode US, and hypoenhancement, rapid washout and presence of intralesional vessels on CEUS (P < 0.05). Among them, three independent features were identified using multivariate logistic regression analysis: hypoechoic pattern, hypoenhancement pattern and intralesional vessels. When three of these findings were combined as a predictor for splenic malignant lesions, 22 (55.0%) of 40 malignant splenic lesions were identified with a specificity of 100%. The diagnostic performance of two readers using receiver operating characteristic curve analysis was 0.622 and 0.533, respectively, for B-mode US, which was significantly improved to 0.908 and 0.906 for CEUS (P < 0.001). The degree of other diagnostic efficiency and inter-reader agreement also increased with CEUS compared to B-mode US.

Conclusion

CEUS may provide more useful information than B-mode US and improve the diagnosis efficiency for distinguishing malignant from benign splenic lesions.

Conventional Ultrasound and Contrast-Enhanced Ultrasound in the Diagnosis of Splenic Diseases: A Systematic Review and Meta-analysis

Accurate diagnosis of splenic diseases is important for timely and accurate treatment. The objective of this study was to compare the accuracy of contrast-enhanced ultrasound (CEUS) and conventional ultrasound (US) in detecting splenic lesions. A systematic literature search was undertaken, and 8 studies met the inclusion criteria. The sensitivity and specificity of the consolidated results of CEUS were 0.95 (95% confidence interval [CI], 0.92-0.97) and 0.97 (95% CI, 0.90-0.99), respectively (I² = 27.4%; area under the curve [AUC] from a summary receiver operating characteristic curve = 0.97). The sensitivity and specificity of the consolidated results of conventional US were 0.70 (95% CI, 0.56-0.80) and 0.96 (95% CI, 0.76-0.99; I² = 83.4%; AUC = 0.84). In this systematic review and meta-analysis, the sensitivity and specificity of CEUS were higher than those of conventional US in diagnosing splenic lesions. Contrast-enhanced US is a promising method for accurately diagnosing splenic lesions.

Clinical use of contrast-enhanced ultrasound beyond the liver: a focus on renal, splenic, and pancreatic applications

Contrast-enhanced ultrasound (CEUS) is a relatively novel, but increasingly used, diagnostic imaging modality. In recent years, due to its safety, quickness, and repeatability, several studies have demonstrated the accuracy, specificity, and sensitivity of CEUS. The European Federation of Societies for Ultrasound in Medicine and Biology has recently updated the previous guidelines from 2012 for the use of CEUS in non-hepatic applications. This review deals with the clinical use and applications of CEUS for the evaluation of non-hepatic abdominal organs, focusing on renal, splenic, and pancreatic applications.

Ultrasound imaging of abdominal sarcoidosis: State of the art

Since it has been recognized that sarcoidosis (SA) is not an exclusive disorder of the lungs but can also affect other organs such as the liver and spleen, efforts have been made to define specific imaging criteria for the diagnosis of the single organ involvement, and the concept has been reinforced that the exclusion of alternative causes is important to achieve the correct diagnosis. Ultrasound (US) is a useful tool to evaluate patients with suspected abdominal SA, such as of the liver, spleen, kidney, pancreas and other organs, showing findings such as organomegaly, focal lesions and lymphadenopathy. While the diagnosis of abdominal SA is more predictable in the case of involvement of other organs (e.g., lungs), the problem is more complex in the case of isolated abdominal SA. The recent use of contrast-enhanced ultrasound and endoscopic ultrasound elastography has provided additional information about the enhancement patterns and tissue rigidity in abdominal SA. Here we critically review the role of US in abdominal SA, reporting typical findings and limitations of current evidence and by discussing future perspectives of study.

Isolated cystic lymphangiomatosis of spleen in an adult: a diagnostic conundrum

Lymphangiomatosis is a rare developmental disorder characterised by diffuse proliferation of anastomosing lymphatic channels (lymphangiomas). It is believed to result from anomalous lymphatic development and usually presents in childhood. It typically occurs as a part of systemic lymphangiomatosis and isolated organ involvement is rare. Only nine cases of isolated cystic lymphangiomatosis of spleen have been reported between 1990 and 2010. Tuberculosis is a significant health problem in India and varied forms of this disease are seen in clinical practice. Isolated splenic tuberculosis, though a rare entity, has been described in the Indian population. We present a case of isolated splenic lymphangiomatosis in a 42-year-old woman that was initially misdiagnosed as splenic tuberculosis and was treated accordingly. Unresponsive to medical treatment, the patient underwent splenectomy and on histopathological examination, cystic lymphangiomatosis was diagnosed. The patient's symptoms resolved after surgery and she is doing well at a follow-up of 3 months.

[A case of splenic hamartoma diagnosed by contrast-enhanced ultrasonography and magnetic resonance imaging]

Splenic hamartoma is a very rare benign tumor, which is usually found incidentally after splenectomy or autopsy. Although percutaneous needle biopsy can be performed, it carries a high risk of bleeding after the procedure. Therefore, diagnosis is usually made by surgical resection. Herein, we report a case of splenic hamartoma diagnosed by magnetic resonance imaging and contrast-enhanced ultrasonography, which enables visualization of the unique signals of microbubbles in the vessels in real time. Relevant literature is also reviewed.

Contrast-enhanced ultrasound of the spleen

Abnormalities in the spleen are less common than in most other abdominal organs. However, they will be regularly encountered by ultrasound practitioners, who carefully evaluate the spleen in their abdominal ultrasound studies. Conventional grey scale and Doppler ultrasound are frequently unable to characterise focal splenic abnormalities; even when clinical and laboratory information is added to the ultrasound findings, it is often not possible to make a definite diagnosis. Contrast-enhanced ultrasound (CEUS) is easy to perform, inexpensive, safe and will usually provide valuable additional information about splenic abnormalities, allowing a definitive or short differential diagnosis to be made. It also identifies those lesions that may require further imaging or biopsy, from those that can be safely dismissed or followed with interval ultrasound imaging. CEUS is also indicated in confirming the nature of suspected accessory splenic tissue and in selected patients with abdominal trauma. This article describes the CEUS examination technique, summarises the indications for CEUS and provides guidance on interpretation of the CEUS findings in splenic ultrasound.

International guidelines for contrast-enhanced ultrasonography: ultrasound imaging in the new millennium

The intent of this review is to discuss and comment on common clinical scenarios in which contrast-enhanced ultrasonography (CEUS) may play a decisive role and to illustrate important points with typical cases. With the advent of CEUS, the scope of indications for ultrasonography has been dramatically extended, and now includes functional imaging and tissue characterization, which in many cases enable tumor diagnosis without a biopsy. It is virtually impossible to imagine the practice of modern medicine as we know it in high-income countries without the use of imaging, and yet, an estimated two thirds of the global population may receive no such care. Ultrasound imaging with CEUS has the potential to correct this inequity.

Splenic cystic lymphangioma with atypical ultrasound findings

Splenic lymphangiomas are rare benign tumors occurring more frequently in children. Because of their asymptomatic growth, splenic lymphangiomas are usually suspected based on incidental findings, the diagnosis relying on different imaging techniques and requiring histological confirmation. The rarity of the disease and its atypical imaging findings make the diagnosis of splenic lymphangiomas challenging. We describe the case of an isolated splenic cystic lymphangioma affecting an elderly female patient. The patient was asymptomatic and the blood tests were normal. The tumor appeared on gray-scale ultrasound as an inhomogeneous, mostly hyperechoic septated mass, which is atypical for a cystic lymphangioma. Contrast-enhanced ultrasound and contrast-enhanced computed tomography suggested the benign nature of the tumor and narrowed the diagnosis. The tumor received histopathological confirmation after splenectomy. Various CT and MRI findings in splenic lymphangiomas have been described, but very few reports regarding CEUS exist to this point.

Splenic Lymphangioma

Splenic lymphangioma is a rare malformation of the splenic lymphatic channels, mostly seen in children. It is characterized by the presence of cysts, resulting from increases in the size and number of thin-walled lymphatic vessels that are abnormally interconnected and dilated. The condition may be restricted to the spleen, but in most cases it involves multiple organs (systemic lymphangiomatosis). The clinical picture is variable; small lesions are often incidentally detected through imaging studies, while larger lesions can result in compression of organs, causing pain or rupture even after minor trauma. Therefore, splenic lymphangiomas should be considered in the differential diagnosis of splenomegaly or left upper quadrant pain even among adults and should be immediately treated with splenectomy; delay in the therapeutic intervention can lead to life-threatening complications.

Differentiation of malignant from benign focal splenic lesions: added value of diffusion-weighted MRI

OBJECTIVE

The objective of our study was to evaluate the added value of diffusion-weighted imaging (DWI) for distinguishing between malignant and benign focal splenic lesions.

MATERIALS AND METHODS

This study included 53 patients with 11 malignant and 42 benign splenic lesions who underwent gadoxetic acid-enhanced MRI and DWI. Qualitative and quantitative analyses were conducted for splenic lesions. Two blinded observers evaluated the two image sets--that is, the conventional MR images alone versus the combined conventional MR and DW images--and scored their confidence for malignancy of splenic lesions. The Fisher exact test and Mann-Whitney U test were performed, and diagnostic performance values (ROC curve analysis) were evaluated.

RESULTS

All malignant lesions showed a progressive hypovascular enhancement pattern, whereas the hypervascular enhancement patterns were shown in only benign lesions (n = 20, 47.6%) (p < 0.05). The mean apparent diffusion coefficient (ADC) of the malignant lesions (0.73 × 10(-3) mm(2)/s) was significantly lower than that of the benign lesions (1.21 × 10(-3) mm(2)/s) (p < 0.001). The addition of DW images to conventional MR images showed a significant improvement for predicting malignant splenic lesions (area under ROC curve [Az] without DW images vs with DW images: 0.774 vs 0.983 for observer 1 and 0.742 vs 0.986 for observer 2) (p < 0.001). In addition, the diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of combined conventional MR and DW images were higher than those of conventional MR images alone.

CONCLUSION

The addition of DWI to conventional MRI improves differentiation of malignant from benign splenic lesions.

Hepatosplenic sarcoidosis: contrast-enhanced ultrasound findings and implications for clinical practice

Sarcoidosis is a complex granulomatous disease that affects virtually every organ and tissue, with a prevalence that varies significantly among the sites involved. The role of conventional imaging, such as computed tomography and magnetic resonance imaging, in the assessment of hepatosplenic sarcoidosis is well established by revealing organ enlargement, multiple discrete nodules, and lymphadenopathy. In this review, we aim to describe contrast-enhanced ultrasound (CEUS) findings in liver and spleen involvement by sarcoidosis, reporting evidence from the literature and cases from our experience, after a brief update on safety profile, cost-effectiveness, and clinical indications of this novel technique. Furthermore, we highlight potential advantages of CEUS in assessing hepatosplenic sarcoidosis that may be useful in the clinical practice.

Real-time contrast enhanced ultrasound imaging of focal splenic lesions

OBJECTIVE

To investigate the imaging features of focal splenic lesions (FSLs) on contrast-enhanced ultrasound (CEUS).

METHODS

Thirty two patients with FSLs proved by pathology were retrospectively analyzed. CEUS was performed using intravenous bolus injection of 2.4 ml sulfur hexafluoride-filled microbubble contrast agent and real time scanning. There were hemangioma (n=7), lymphoma (n=8), true cyst (n=3), infarction (n=4), hematolymphangioma (n=2), metastasis tumor (n=2), and one for each of the following entities extramedullary hemopoiesis, hamartoma, tuberculosis, Langerhans' cell histiocytosis, inflammatory pseudotumor and myxofibrosarcoma.

RESULTS

Among 21 benign lesions, 4 infarctions and 3 cysts presented non-enhancement throughout CEUS scanning, and the other 14 lesions displayed various enhancement levels with 6 (42.9%) hyper-enhancement, 2 (14.3%) iso-enhancement and 6 (42.9%) hypo-enhancement in arterial phase and 11 (78.6%) hypo-enhancement, 1 (7.1%) iso-enhancement and 2 (14.3%) hyper-enhancement in late phase, respectively. The enhancement pattern included 9 (64.3%) homogeneous, 4 (28.6%) heterogeneous and 1 (7.1%) rim-like enhancement. As for the malignant FSLs, all the lesions became completely or extensively hypo-enhancement during the late phase no matter their vascularity during arterial phase.

CONCLUSIONS

The CEUS features reported in this series may enrich the knowledge for CEUS characterization of FSLs.

Errors made in the ultrasound diagnostics of the spleen

Ultrasonography, like any imaging method, entails the risk of errors. From among all means of imaging, it is the most subjective and dependent on the examiner's knowledge and experience. This paper presents the causes of examiner-dependent errors as well as those which result from technical settings and preparation of the patient for the examination. Moreover, the authors discuss the most frequent errors in the diagnosis of splenic conditions, which result from insufficient knowledge concerning anatomical variants of this organ, wrong measurements and incorrect examination technique. The mistakes made in the differentiation of focal lesions of the spleen and its hilum are also discussed. Additionally, the differentiation of collateral circulation, lymph nodes and accessory spleens is mentioned. The authors also draw attention to erroneous interpretation of the left liver lobe as a fragment of the spleen as well as the prominent tail of the pancreas filled with gastric contents and intestinal loops as abnormal masses or fluid cisterns in the area of the splenic hilum. Furthermore, the pathologies of the hilum are discussed such as tumors of the splenic flexure of the colon, lesions arising from the left kidney or the left adrenal gland. The authors list characteristic imaging features of the most common focal lesions visualized in a standard ultrasound scan as well as enhancement patterns appearing in contrast-enhanced examinations. The article discusses the features and differentiation of, among others, infarction, splenic cysts including hydatid ones, abscesses and angiomas. The ultrasound appearance of lymphoma and secondary involvement of the spleen by other malignant neoplasms is also mentioned. Moreover, the authors provide useful tips connected with imaging techniques and interpretation of the findings. The ultrasound examination carried out in compliance with current standards allows for an optimal assessment of the organ and reduction of the error-making risk. This article is based on the publication of the experts from the Polish Ultrasound Society of 2005 and updated with the latest findings in pertinent literature. The photographic documentation, which provides images of the discussed lesions, is attached to this article.

Pitfalls of contrast-enhanced ultrasound (CEUS) in the diagnosis of splenic sarcoidosis

By observing the real-time behavior of focal liver lesions at three vascular phases (arterial, portal-venous, and late), contrast-enhanced ultrasound (CEUS) has been successfully applied to differentiate benign from malignant hepatic nodules. In recent years, numerous studies highlighted the usefulness of CEUS also for other applications such as abdominal trauma, renal, pancreatic, thyroid, and inflammatory bowel diseases, supporting its role even in differentiating benign from malignant splenic nodules. Therefore, the European Federation of Societies for Ultrasound in Medicine and Biology (EFSUMB) recently updated the guidelines for the use of ultrasound contrast agents in clinical practice, pointing out the indication to characterize splenic parenchymal inhomogeneity or suspected lesions found on conventional ultrasound (BUS). We describe the case of a patient with a history of colon cancer and finding, at BUS and CEUS, of hypoechoic lesions with a highly suggestive pattern for metastases, subsequently histologically proved to be splenic localizations of a benign and multisystemic granulomatous disease such as sarcoidosis. We therefore reviewed the current literature focusing on the role of CEUS in differentiating benign from malignant splenic lesions, emphasizing on the lack of data and numerical shortage of sarcoidosis derived-lesions in the available studies. We conclude that sarcoidosis remains a diagnosis of exclusion and new studies are needed before defining precise indications of CEUS in these patients.

Standards of the Polish Ultrasound Society - update. Spleen examination

Ultrasound scan of the spleen is an integral part of the overall abdominal examination. Due to its anatomical position, physical examination of the spleen is frequently supplemented with an ultrasound which plays a special role in the differential diagnostics of splenic diseases and facilitates the determination of further diagnostic and therapeutic procedures. Similarly to other types of ultrasound scans, the examiner should be familiar with all significant clinical information as well as results of examinations and tests conducted so far. This enables to narrow the scope of search for etiological factors and indicate specific disease entities in the findings as well as allows for accurate assessment of coexistent pathologies. The article presents the standards of the Polish Ultrasound Society concerning the apparatus, preparation for the examination, technique and description of the findings. The authors discuss the normal anatomy of the spleen and the most common pathologies ranging from splenomegaly to splenic traumas. The indications for the contrast-enhanced ultrasound and characteristic patterns of enhancement of individual focal lesions are presented. This article is supplemented with photographic documentation, which provides images of the discussed lesions. The ultrasound examination, if carried out in compliance with current standards, allows for accurate interpretation of detected changes. This article has been prepared on the basis of the Ultrasound Examination Standards of the Polish Ultrasound Society (2011) and updated with the current knowledge.

Unusual imaging profile of a solitary splenic lymphangioma

Splenic lymphangioma is a rare, benign lesion of the spleen that is characterized microscopically by a proliferation of thin-walled vascular channels filled by proteinacious material. Based on microscopic features, three types of lymphangiomas are described as simple capillary, cavernous, and cystic; however, the distinction between these types is not uniformly accepted. The cystic type is the most common type and has well described imaging characteristics. However, little is known about the less common cavernous and capillary forms of lymphangioma. Herein, we present a case of a patient with two synchronous colon cancers that presented with a concomitant splenic mass that was initially suspected to be metastatic disease. Despite the use of multiple imaging modalities including computed tomography (CT), magnetic resonance imaging (MRI), nuclear imaging, and contrast-enhanced ultrasound, the final diagnosis of cavernous lymphangioma was made following core needle biopsy of the lesion. A thorough review of literature and this case now demonstrate the difficulty in differentiating atypical forms of splenic lymphangiomas from other benign lesions such as hemangioma.

Contrast-enhanced ultrasound of the spleen: an introduction and pictorial essay

A wide variety of pathologies can produce focal lesions within the spleen. These are being more frequently encountered as imaging technology improves. It is vital that radiologists are aware of these pathologies to enable accurate diagnosis. The role of ultrasound contrast in splenic disease will be discussed and illustrated with cases likely to be encountered by general and abdominal radiologists.