Characteristic Imaging Features Research Articles

Ocular manifestations of West Nile virus.

Over the past two decades, the ophthalmic manifestations of West Nile virus have been more clearly established in the literature. This review aims to summarize its diagnosis and pathogenesis, with a focus on its clinical appearance, characteristic imaging features, and management. Ocular manifestations of West Nile virus present early in the disease course and are more common in cases with severe neurological involvement. The use of optical coherence tomography (OCT), optical coherence tomography angiography (OCT-A), fundus autofluorescence (FAF), fluorescein angiogram (FA), and indocyanine green angiography (ICGA) can aid in its diagnosis and management. West Nile virus infection may present with ocular findings that include anterior uveitis, vitritis, retinitis, chorioretinitis, and optic neuropathy; visual prognosis can range from excellent to poor depending on severity of involvement and the presence of secondary complications, such as occlusive vasculitis and macular ischemia. Diagnosis may be aided by multimodal imaging assessment. The ophthalmologist should have a high clinical suspicion for ocular involvement in cases of severe systemic disease.

Consolidation in the right middle lobe in pediatric bronchial-pulmonary artery shunt: radiology's Aunt Minnie?

By retrospectively studying the chest computed tomography (CT) data of children with bronchial artery (BA)-pulmonary artery fistula, this study summarizes the characteristic imaging features of the disease and provides imaging support for the diagnosis and clinical treatment of these children. Digital subtraction angiography and CT angiography data were collected from 74 children with pulmonary hemorrhage following BA embolization. Bronchial-pulmonary shunt was present in 30 cases. Of the 74 children with pulmonary hemorrhage in this study, seven exhibited signs of consolidation in the middle lobe of the right lung, and bronchial-pulmonary shunt existed in all of them. A total of 30 children with BA-pulmonary artery shunt (PAS) had BA tortuosity and thickening. Regarding primary BA-PAS, the middle lobe and lower lobe of the right lung were involved in 94.1% (16) of the children. Those with a fistula located in the middle lobe of the right lung accounted for 58.8% (10 cases), of which 40.0% (four cases) presented consolidation. In this study, 41.2% (seven) of the children with primary BA-PAS exhibited no abnormal changes on chest CT, and 58.8% (10 cases) exhibited abnormal changes in the unilateral lung. For children with pulmonary hemorrhage who have consolidation in the right middle lobe, the formation of BA-PAS should be anticipated. The possibility of primary BA-PAS should not be disregarded in children with pulmonary hemorrhage with tortuosity and dilation of BAs, despite no apparent abnormalities on lung CT, or ground-glass density or consolidation on only one side. The chest CT of patients with pulmonary hemorrhage showed consolidation of the right middle lobe of the lung, which was highly likely to indicate BA-PAS.

Pseudoaneurysm in the Axillary Tail of the Breast After A Core Needle Biopsy.

We present the case of a forty-year-old asymptomatic female with no personal or family history of breast cancer, who underwent a core needle biopsy (CNB) following the identification of a focal asymmetry in the right breast on screening mammography. Eight months later, a prominent adjacent vascular structure with a round outpouching was detected on breast ultrasound, confirmed as a post-biopsy pseudoaneurysm. Breast pseudoaneurysms, although exceedingly rare, result from inadvertent vessel puncture during core needle biopsies, particularly when larger gauge needles are used. They present as palpable, throbbing lumps in the breast and are well-defined heterogeneous structures that exhibit turbulent flow with a feeding artery on color Doppler imaging. This swirling sign showing a to-and-fro waveform is also known as the "yin-yang" sign on Doppler ultrasound. Post-CNB pseudoaneurysms in the breast, while rare, should be considered as potential complications following core need biopsy. Understanding their characteristic imaging features, risk factors, and available management options is essential for early diagnosis and appropriate treatment. This case underscores the importance of vigilance in biopsy procedures and the need for prompt recognition and intervention in case of such complications.

Path Integration Detects Prodromal Alzheimer's Disease and Predicts Cognitive Decline.

The entorhinal cortex is the very earliest involvement of Alzheimer's disease (AD). Grid cells in the medial entorhinal cortex form part of the spatial navigation system. We aimed to determine whether path integration performance can be used to detect patients with mild cognitive impairment (MCI) at high risk of developing AD, and whether it can predict cognitive decline. Path integration performance was assessed in 71 patients with early MCI (EMCI) and late MCI (LMCI) using a recently developed 3D virtual reality navigation task. Patients with LMCI were further divided into those displaying characteristic brain imaging features of AD, including medial temporal lobe atrophy on magnetic resonance imaging and posterior hypoperfusion on single-photon emission tomography (LMCI+), and those not displaying such features (LMCI-). Path integration performance was significantly lower in patients with LMCI+than in those with EMCI and LMCI-. A significantly lower performance was observed in patients who showed progression of MCI during 12 months, than in those with stable MCI. Path integration performance distinguished patients with progressive MCI from those with stable MCI, with a high classification accuracy (a sensitivity of 0.88 and a specificity of 0.70). Our results suggest that the 3D virtual reality navigation task detects prodromal AD patients and predicts cognitive decline after 12 months. Our navigation task, which is simple, short (12-15 minutes), noninvasive, and inexpensive, may be a screening tool for therapeutic choice of disease-modifiers in individuals with prodromal AD.

A Case Report of Teratoma Trio: Bilateral Ovarian Teratomas Coexistent With a Mesenteric Teratoma

Teratomas arise from totipotent primordial cells and unveil a mixture of tissues of tri-dermal or bi-dermal origin. They are the most common ovarian germ cell tumors. The extragonadal teratomas may be seen in the sacrococcygeal region, mediastinum, retroperitoneum, and intracranially. These can be either mature, which are considered benign, or immature and classified as malignant. Mature cystic teratomas have characteristic imaging features and a pre-operative diagnosis that can be reliably made. The case provided was of a 48-year-old female who was diagnosed with three separate intraabdominal masses that had typical imaging features of teratomas. An extragonadal mesenteric teratoma is itself a rare entity and its coexistence with bilateral ovarian teratomas, has rarely been described in medical literature. Hence, common pathologies in an uncommon location should always be considered while providing a list of diagnostic differentials, in such a patient scenario.

Rapidly destructive hip osteoarthritis: a diagnosis not to miss.

This review illustrates the imaging features of rapidly destructive hip osteoarthritis (RDHO) across different imaging modalities. RDHO is a rare joint disease of unknown aetiology resulting in rapid deterioration of the hip joints. Patients often present with severe hip pain and can progress to complete joint destruction in 6 months to 3 years causing disability. Since its clinical and imaging features often overlap with other conditions, the diagnosis is easily missed in daily practice. The purpose of this paper is to outline the characteristic imaging features of RDHO, aiming to enhance awareness of this disease entity and promote timely treatment for patients. Sequential radiographs are particularly important in demonstrating the rapid progression of radiographic findings and with the early recognition of characteristic features, diagnosis can be made to avoid treatment delay. Although CT scan is not necessary for diagnosis, it is useful in evaluating the extent of joint destruction and guiding surgical planning. MRI can provide additional information and rule out other pathologies with similar symptoms. Overall, radiographs, CT and MRI are common modalities used in the evaluation of RDHO.

Imaging characteristics of uterine smooth muscle tumors of uncertain malignant potential: a case report and literature review.

Uterine smooth muscle tumors of uncertain malignant potential (STUMPs) are rare tumors of the uterine myometrium that are often misdiagnosed, owing to limited knowledge of their characteristics on ultrasonography (US) and magnetic resonance imaging (MRI). We report a woman in her mid-30s who was hospitalized because of a pelvic tumor. A 6-cm mass was found in her lower left abdomen. US and MRI revealed a well-demarcated mass in the left adnexal area, with both cystic and solid elements, visible blood flow within the septa, a strong signal across >50% of the volume on T2-weighted imaging (T2WI), and a strong signal on diffusion-weighted imaging (DWI). After hysterectomy and bilateral salpingectomy, immunohistochemical examination confirmed STUMP. A review of the literature revealed characteristic imaging features of STUMP. Ultrasonography reveals STUMP as a solitary, well-circumscribed lesion with isoechoic or mixed echogenicity, the absence of posterior shadowing, and variations in blood flow. STUMP is characterized by strong signal intensity on T2WI, small areas of strong signal on T1WI, and non-enhancing cystic areas on contrast-enhanced MRI scans. Early diagnosis is crucial for the management and treatment of STUMP, and here we have summarized the imaging features of the lesion, thereby providing a valuable diagnostic reference.

Imaging the Impact: Computed Tomography Thorax in COVID-19 - A Comprehensive Review and Clinical Analysis

This comprehensive review and clinical analysis explore the pivotal role of thorax computed tomography (CT) in the context of COVID-19. As the world grapples with the ongoing pandemic, the need for effective diagnostic tools and management strategies remains paramount. This review meticulously examines the impact of thorax CT imaging on the understanding, diagnosis, and clinical management of COVID-19. The review encompasses an extensive analysis of the existing literature, shedding light on the nuances of thorax CT findings in COVID-19 patients. It explores the characteristic imaging features, such as ground-glass opacities, consolidations, and other pulmonary abnormalities, providing insights into the pathophysiology of the disease. Furthermore, the clinical analysis component synthesizes data from diverse studies to elucidate the diagnostic accuracy and sensitivity of thorax CT, particularly in cases where molecular testing may present challenges. The review also delves into the role of thorax CT in early detection, risk stratification, and longitudinal monitoring of patients with COVID-19, offering valuable perspectives for healthcare professionals. Importantly, considerations of radiation exposure and ethical use of thorax CT are addressed, emphasizing the judicious integration of imaging into clinical practice. The article concludes with practical recommendations for optimizing the utility of thorax CT in the broader context of COVID-19 diagnosis and patient care.

Atypical Parkinsonian Syndromes: Structural, Functional, and Molecular Imaging Features.

Atypical parkinsonian syndromes, also known as Parkinson-plus syndromes, are a heterogeneous group of movement disorders, including dementia with Lewy bodies (DLB), progressive supranuclear palsy (PSP), multisystem atrophy (MSA), and corticobasal degeneration (CBD). This review highlights the characteristic structural, functional, and molecular imaging features of these complex disorders. DLB typically demonstrates parieto-occipital hypometabolism with involvement of the cuneus on FDG-PET, whereas dopaminergic imaging, such as [123I]-FP-CIT SPECT (DaTscan) or fluorodopa (FDOPA)-PET, can be utilized as an adjunct for diagnosis. PSP typically shows midbrain atrophy on structural imaging, whereas FDG-PET may be useful to depict frontal lobe hypometabolism and tau-PET confirms underlying tauopathy. MSA typically demonstrates putaminal or cerebellar atrophy, whereas FDG-PET highlights characteristic nigrostriatal or olivopontocerebellar hypometabolism, respectively. Finally, CBD typically shows asymmetric atrophy in the superior parietal lobules and corpus callosum, whereas FDG and tau-PET demonstrate asymmetric hemispheric and subcortical involvement contralateral to the side of clinical deficits. Additional advanced neuroimaging modalities and techniques described may assist in the diagnostic work-up or are promising areas of emerging research.

Imaging approach for jaw and maxillofacial bone tumors with updates from the 2022 World Health Organization classification.

Jaw and maxillofacial bone lesions encompass a wide variety of both neoplastic and non-neoplastic pathologies. These lesions can arise from various tissues, including bone, cartilage, and soft tissue, each presenting distinct challenges in diagnosis and treatment. While some pathologies exhibit characteristic imaging features that aid in diagnosis, many others are nonspecific. This overlap often necessitates a multimodal imaging approach, combining techniques such as radiographs, computed tomography, and magnetic resonance imaging to achieve a diagnosis or narrow the diagnostic considerations. This article provides a comprehensive review of the imaging approach to jaw and maxillofacial bone tumors, including updates on the 2022 World Health Organization classification of these tumors. The relevant anatomy of the jaw and dental structures that is important for accurate imaging interpretation is discussed.

MAPK pathway alterations in polymorphous low-grade neuroepithelial tumor of the young: diagnostic considerations.

Polymorphous low-grade neuroepithelial tumor of the young (PLNTY) is a recently recognised tumor type with indolent behaviourwith characteristic imaging and histomolecular features. We describe the clinical, imaging, histo-molecular features of 15 cases diagnosed as low-grade glioma suggestive of PLNTY,over a period of 3years.Immunohistochemistry (IHC) and fluorescence in situ hybridisation were used to assess molecular alterations. The tumors were seen predominantly in children (range 5-65years). Most of the patients presented with history of seizures. Imaging revealed cortical-subcortical well demarcated solid-cystic tumor with intratumoral calcification. Histopathologyrevealed a low-grade tumor with oligodendroglia-Iike cells admixed with astrocytic cells immunopositive for CD34. BRAF p.V600E mutations and FGFR2 breakapart were observed in six cases each, while three showed FGFR3 breakapart. FGFR2 breakapart positive PLNTY were seen in children exclusively. The majority of cases were seizure free post-surgery, except two patients who succumbed to the illness. PLNTY, needs to be considered as a prime differential diagnosis in a solid-cystic tumor in a young patient with history of seizures. Characteristic clinical features, radiology, histomorphology with an IHC panel of OLIG2, GFAP and CD34 correlates with one of the MAPK alterations in PLNTY (BRAF p.V600E, FGFR2/3 gene rearrangement). In a resource limited setting, this limited panel may be sufficient for a correlative diagnosis.

Uterine Angioleiomyoma: Clinical and Histopathologic Differentiation of an Underrecognized Mimicker of Uterine Leiomyoma.

Angioleiomyoma is an uncommon benign neoplasm of mesenchymal origin that arises from perivascular smooth muscle cells. This soft tissue neoplasm usually occurs in the dermal or subcutaneous tissues of the extremities, head and neck, or trunk with fewer than 40 reported angioleiomyomas arising in the uterine corpus. Herein we report a uterine angioleiomyoma in a 44-year-old G5P4 Hispanic woman with a longstanding history of recurrent abdominal pain, pelvic organ prolapse, abnormal uterine bleeding, anemia, and hypertension. The patient underwent surgical treatment with total laparoscopic hysterectomy with bilateral salpingectomy and a uterosacral ligament suspension. Uterine angioleiomyoma was diagnosed post-operatively based on gross and microscopic features. The location of the uterine angioleiomyoma within the myometrium corresponded with contrast enhancement apparent on preoperative imaging. This and other uterine angioleiomyomas have characteristic imaging, macroscopic, and microscopic features which distinguish it from leiomyoma. Enhancing awareness of this underrecognized entity will facilitate precise diagnosis and thereby enable improved understanding of the clinicopathological characteristics of uterine angioleiomyoma.

Novel variants in CSF1R associated with adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP)

The CSF1R gene, located on chromosome 5, encodes a 108 kDa protein and plays a critical role in regulating myeloid cell function. Mutations in CSF1R have been identified as a cause of a rare white matter disease called adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP, also known as CSF1R-related leukoencephalopathy), characterized by progressive neurological dysfunction. This study aimed to broaden the genetic basis of ALSP by identifying novel CSF1R variants in patients with characteristic clinical and imaging features of ALSP. Genetic analysis was performed through whole-exome sequencing or panel analysis for leukodystrophy genes. Variant annotation and classification were conducted using computational tools, and the identified variants were categorized following the recommendations of the American College of Medical Genetics and Genomics (ACMG). To assess the evolutionary conservation of the novel variants within the CSF1R protein, amino acid sequences were compared across different species. The study identified six previously unreported CSF1R variants (c.2384G>T, c.2133_2919del, c.1837G>A, c.2304C>A, c.2517G>T, c.2642C>T) in seven patients with ALSP, contributing to the expanding knowledge of the genetic diversity underlying this rare disease. The analysis revealed considerable genetic and clinical heterogeneity among these patients. The findings emphasize the need for a comprehensive understanding of the genetic basis of rare diseases like ALSP and underscored the importance of genetic testing, even in cases with no family history of the disease. The study’s contribution to the growing spectrum of ALSP genetics and phenotypes enhances our knowledge of this condition, which can be crucial for both diagnosis and potential future treatments.

Imaging Spectrum in Pulmonary Tuberculosis

AbstractPulmonary tuberculosis is one of the most common pulmonary infections prevalent in our country. Although definitive diagnosis is microbiological, characteristic imaging features help in establishing a certain diagnosis in most of the cases. While chest radiography remains the primary screening tool, computed tomography helps in clinching the diagnosis with a spectrum of findings described on cross-sectional imaging. The radiologist must be familiar with the features denoting potential complications and differential diagnosis to aid better treatment planning and case prognostication. This article describes in detail the imaging features of pulmonary tuberculosis, active disease, disease sequelae, and complications.

The Use of Apparent Diffusion Coefficient Values for Differentiating Bevacizumab-Related Cytotoxicity from Tumor Recurrence and Radiation Necrosis in Glioblastoma.

Glioblastomas (GBM) are the most common primary invasive neoplasms of the brain. Distinguishing between lesion recurrence and different types of treatment related changes in patients with GBM remains challenging using conventional MRI imaging techniques. Therefore, accurate and precise differentiation between true progression or pseudoresponse is crucial in deciding on the appropriate course of treatment. This retrospective study investigated the potential of apparent diffusion coefficient (ADC) map values derived from diffusion-weighted imaging (DWI) as a noninvasive method to increase diagnostic accuracy in treatment response. A cohort of 21 glioblastoma patients (mean age: 59.2 ± 11.8, 12 Male, 9 Female) that underwent treatment with bevacizumab were selected. The ADC values were calculated from the DWI images obtained from a standardized brain protocol across 1.5-T and 3-T MRI scanners. Ratios were calculated for rADC values. Lesions were classified as bevacizumab-induced cytotoxicity based on characteristic imaging features (well-defined regions of restricted diffusion with persistent diffusion restriction over the course of weeks without tissue volume loss and absence of contrast enhancement). The rADC value was compared to these values in radiation necrosis and recurrent lesions, which were concluded in our prior study. The nonparametric Wilcoxon signed rank test with p < 0.05 was used for significance. The mean ± SD age of the selected patients was 59.2 ± 11.8. ADC values and corresponding mean rADC values for bevacizumab-induced cytotoxicity were 248.1 ± 67.2 and 0.39 ± 0.10, respectively. These results were compared to the ADC values and corresponding mean rADC values of tumor progression and radiation necrosis. Significant differences between rADC values were observed in all three groups (p < 0.001). Bevacizumab-induced cytotoxicity had statistically significant lower ADC values compared to both tumor recurrence and radiation necrosis. The study demonstrates the potential of ADC values as noninvasive imaging biomarkers for differentiating recurrent glioblastoma from radiation necrosis and bevacizumab-induced cytotoxicity.

Magnetic Resonance Imaging Features of Sporadic Optic Chiasmatic-Hypothalamic Gliomas and Correlation with Histopathology and BRAF Gene Alterations.

Sporadic optic chiasmatic-hypothalamic gliomas (OCHGs), though histologically low-grade tumors, manifest as aggressive neoplasms radiologically, leading to difficulty in diagnosis. Molecular alterations of the BRAF gene are detectable in a majority of sporadic OCHGs. The purpose of our study was to elucidate the characteristic imaging features of sporadic OCHGs and to investigate whether imaging phenotypes could potentially correlate with specific BRAF gene alterations associated with these tumors. We retrospectively reviewed baseline magnetic resonance (MR) images and medical records of 26 patients with histopathologically proven sporadic OCHGs. MR imaging (MRI) features were systematically evaluated. Statistical analysis was performed to determine whether there was a significant association between imaging findings and BRAF molecular alterations. Twenty-two cases (84.6%) presented with solid-cystic masses, while four (15.4%) presented with purely solid lesions. In all 26 cases, the solid component revealed central necrosis; there was minimal necrosis in 11 cases (42.3%), moderate in 8 (30.7%), and marked in 7 (26.9%). The presence of multiple cysts (>4) and minimal necrosis showed a significant association with BRAFV600E mutation (P < 0.005). Marked necrosis in the solid component significantly correlated with BRAF wild genotype (P < 0.001). The presence of a single peripheral cyst significantly correlated with BRAF fusion (P = 0.04). Sporadic OCHGs have a distinctive appearance on imaging. The solid-cystic composition coupled with varying degrees of central necrosis are clues to the radiological diagnosis of this entity and can facilitate early recognition in clinical practice. Imaging could potentially serve as a non-invasive predictor of the BRAF alteration status, thereby serving as a prognostic marker and guiding personalized management.

Qualitative and quantitative assessment of non-clear cell renal cell carcinoma using contrast-enhanced ultrasound

BackgroundNon-clear cell renal cell carcinoma (nccRCC) represents a rare form of renal cell carcinoma (RCC) in the clinic. It is now understood that contrast-enhanced ultrasound (CEUS) exhibits diverse manifestations and can be prone to misdiagnosis. Therefore, summarizing the distinctive features of contrast-enhanced ultrasonography is essential for differentiation from ccRCC.ObjectiveThis study aims to evaluate the diagnostic efficacy of qualitative and quantitative CEUS in diagnosing nccRCC to enhance our understanding of this condition.MethodsWe conducted a retrospective analysis of 21 patients with confirmed nccRCC following surgery and assessed the characteristic conventional ultrasound and CEUS imaging features. The paired Wilcoxon signed-rank sum test was employed to compare differences in CEUS time-intensity curve (TIC) parameters between the lesions and the normal renal cortex.ResultsRoutine ultrasound revealed the following primary characteristics in the 21 nccRCC cases: hypoechoic appearance (10/21, 47.6%), absence of liquefaction (18/21, 66.7%), regular shape (19/21, 90.5%), clear boundaries (21/21, 100%), and absence of calcification (17/21, 81%). Color Doppler flow imaging (CDFI) indicated a low blood flow signal (only 1 case of grade III). Qualitative CEUS analysis demonstrated that nccRCC predominantly exhibited slow progression (76.1%), fast washout (57%), uniformity (61.9%), low enhancement (71.5%), and ring enhancement (61.9%). Quantitative CEUS analysis revealed that parameters such as PE, WiAUC, mTTI, WiR, WiPI, WoAUC, WiWoAUC, and WOR in the lesions were significantly lower than those in the normal renal cortex (Z=-3.980, -3.563, -2.427, -3.389, -3.980, -3.493, -3.528, -2.763, P < 0.001, < 0.001, = 0.015, = 0.001, < 0.001, < 0.001, < 0.001, = 0.006). However, there were no significant differences in RT, TTP, FT, or QOF (all P > 0.05).ConclusionnccRCC exhibits distinctive CEUS characteristics, including slow progression, fast washout, low homogeneity enhancement, and ring enhancement, which can aid in distinguishing nccRCC from ccRCC.

Ultra-high-field 7-Tesla magnetic resonance imaging in fragile X tremor/ataxia syndrome (FXTAS).

Fragile X tremor/ataxia syndrome (FXTAS) is an adult-onset neurodegenerative disorder characterized by premutation expansion of fragile X mental retardation 1 (FMR1) gene. It is a common single-gene cause of tremor, ataxia, and cognitive decline in adults. FXTAS affects the central, peripheral and autonomic nervous systems, leading to a range of neurological symptoms from dementia to dysautonomia. A characteristic imaging feature of FXTAS is symmetric T2 hyperintensity in the deep white matter of the cerebellar hemispheres and middle cerebral peduncle. However, recent studies have reported additional findings on diffusion weighted images (DWI), such as a symmetric high-intensity band-like signal at the cerebral corticomedullary junction. These findings, along with the characteristic cerebellar signal alterations, overlap with imaging findings seen in adult-onset neuronal intranuclear inclusion disease (NIID). Importantly, recent pathology studies have shown that both FXTAS and NIID can manifest intranuclear inclusion bodies, posing a diagnostic challenge and potential for misdiagnosis. We describe a 58-year-old man with FXTAS who received an erroneous diagnosis based on imaging and histopathology results. We emphasize the potential pitfalls in distinguishing NIID from FXTAS and stress the importance of genetic analysis in all cases with suspected NIID and FXTAS for confirmation. Additionally, we present the 7T MRI brain findings of FXTAS.

Imaging of pediatric gastrointestinal tumors: A tertiary center experience over 19 years

PurposeGastrointestinal tract (GIT) tumors in children are rare and there is a scarcity of data on their imaging features. The purpose of this study was to determine thefrequency of various GIT tumor types in children and to identify key imaging characteristics. MethodsThis retrospective, single-center study was approved by the local ethics committee. Children with histologically proven GIT tumours (malignantand benign) who had imaging available on the institutional PACS between May 1, 2000 and Dec 31, 2019 were included. Demographic data and available imaging was reviewed by two blinded radiologists. ResultsIn total, 90 children (45 male, mean age 9.3 ± 4.3 years) with GIT tumours were included. The final diagnoses included polyps (n = 28), lymphomas/PTLD (n = 27), neuroendocrine tumours (n = 16), adenocarcinoma (n = 6), adenoma (n = 5), gastrointestinal stromal tumor (GIST) (n = 3), inflammatory myofibroblastic tumours (n = 2) and lastly leiomyoblastoma, leiomyoma and lipoma (1 each). All GIT segments were affected, but overall the small and large bowel had most lesions. Eighty-one percent children had a single lesion while remaining 19 % had multiple lesions. The neoplastic process manifested as intra-luminal lesion (58 %) or wall thickening (42 %) on imaging. Multiple cystic areas and vascular pedicle for polyps; and hypoechogenecity of the mass or wall thickening and aneurysmal dilatation for lymphomas, were the characteristic imaging features. None of the neuroendocrine tumours affecting appendix were seen on pre-resection imaging. ConclusionsVariety of benign and malignant tumors are seen throughout the childhood. Polyps, lymphomas and appendiceal neuroendocrine tumors are common lesions. Characteristic imaging features of juvenile polyps and lymphomas on ultrasound may help narrowing the differentials, and guide further work up.

Epicardial Space: Comprehensive Anatomy and Spectrum of Disease.

The epicardial space (ES) is the anatomic region located between the myocardium and the pericardium. This space includes the visceral pericardium and the epicardial fat that contains the epicardial coronary arteries, cardiac veins, lymphatic channels, and nerves. The epicardial fat represents the main component of the ES. This fat deposit has been a focus of research in recent years owing to its properties and relationship with coronary gossypiboma plaque and atrial fibrillation. Although this region is sometimes forgotten, a broad spectrum of lesions can be found in the ES and can be divided into neoplastic and nonneoplastic categories. Epicardial neoplastic lesions include lipoma, paraganglioma, metastases, angiosarcoma, and lymphoma. Epicardial nonneoplastic lesions encompass inflammatory infiltrative disorders, such as immunoglobulin G4-related disease and Erdheim-Chester disease, along with hydatidosis, abscesses, coronary abnormalities, pseudoaneurysms, hematoma, lipomatosis, and gossypiboma. Initial imaging of epicardial lesions may be performed with echocardiography, but CT and cardiac MRI are the best imaging modalities to help characterize epicardial lesions. Due to the nonspecific onset of signs and symptoms, the clinical history of a patient can play a crucial role in the diagnosis. A history of malignancy, multisystem diseases, prior trauma, myocardial infarction, or cardiac surgery can help narrow the differential diagnosis. The diagnostic approach to epicardial lesions should be made on the basis of the specific location, characteristic imaging features, and clinical background. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.