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Pathologic conditions of the biliary system, although common, can be difficult to diagnose clinically. Challenges in biliary imaging include anatomic variants and the dynamic nature of the biliary tract, which can change with age and intervention, blurring the boundaries of normal and abnormal. Choledochal cysts can have numerous appearances and are important to diagnose given the risk of cholangiocarcinoma potentially requiring surgical resection. Choledocholithiasis, the most common cause of biliary dilatation, can be difficult to detect at US and CT, with MRI having the highest sensitivity. However, knowledge of the imaging pitfalls of MRI and MR cholangiopancreatography is crucial to avoid misinterpretation. Newer concepts in biliary tract malignancy include intraductal papillary biliary neoplasms that may develop into cholangiocarcinoma. New paradigms in the classification of cholangiocarcinoma correspond to the wide range of imaging appearances of the disease and have implications for prognosis. Accurately staging cholangiocarcinoma is imperative, given expanding curative options including transplant and more aggressive surgical options. Infections of the biliary tree include acute cholangitis or recurrent pyogenic cholangitis, characterized by obstruction, strictures, and central biliary dilatation. Inflammatory conditions include primary sclerosing cholangitis, which features strictures and fibrosis but can be difficult to differentiate from secondary causes of sclerosing cholangitis, including more recently described entities such as immunoglobulin G4-related sclerosing cholangitis and COVID-19 secondary sclerosing cholangitis. The authors describe a wide variety of benign and malignant biliary tract abnormalities, highlight differentiating features of the cholangitides, provide an approach to interpretation based on the pattern of imaging findings, and discuss pearls and pitfalls of imaging to facilitate accurate diagnosis. ©RSNA, 2024 Supplemental material is available for this article.
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Sistema Biliar , Humanos , Sistema Biliar/diagnóstico por imagem , Sistema Biliar/patologia , Doenças Biliares/diagnóstico por imagem , Diagnóstico DiferencialRESUMO
Pancreatic cystic neoplasms are lesions comprised of cystic components that show different biological behaviors, epidemiology, clinical manifestations, imaging features, and malignant potential and management. Benign cystic neoplasms include serous cystic neoplasms (SCAs). Other pancreatic cystic lesions have malignant potential, such as intraductal papillary mucinous neoplasms and mucinous cystic neoplasms. SCAs can be divided into microcystic (classic appearance), honeycomb, oligocystic/macrocystic, and solid patterns based on imaging appearance. They are usually solitary but may be multiple in von Hippel-Lindau disease, which may depict disseminated involvement. The variable appearances of SCAs can mimic other types of pancreatic cystic lesions, and cross-sectional imaging plays an important role in their differential diagnosis. Endoscopic ultrasonography has helped in improving diagnostic accuracy of pancreatic cystic lesions by guiding tissue sampling (biopsy) or cyst fluid analysis. Immunohistochemistry and newer techniques such as radiomics have shown improved performance for preoperatively discriminating SCAs and their mimickers.
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Pancreatic ductal adenocarcinoma (PDAC) is the most common primary pancreatic malignancy, ranking fourth in cancer-related mortality in the United States. Typically, PDAC appears on images as a hypovascular mass with upstream pancreatic duct dilatation and abrupt duct cutoff, distal pancreatic atrophy, and vascular encasement, with metastatic involvement including lymphadenopathy. However, atypical manifestations that may limit detection of the underlying PDAC may also occur. Atypical PDAC features include findings related to associated conditions such as acute or chronic pancreatitis, a mass that is isointense to the parenchyma, multiplicity, diffuse tumor infiltration, associated calcifications, and cystic components. Several neoplastic and inflammatory conditions can mimic PDAC, such as paraduodenal "groove" pancreatitis, autoimmune pancreatitis, focal acute and chronic pancreatitis, neuroendocrine tumors, solid pseudopapillary neoplasms, metastases, and lymphoma. Differentiation of these conditions from PDAC can be challenging due to overlapping CT and MRI features; however, certain findings can help in differentiation. Diffusion-weighted MRI can be helpful but also can be nonspecific. Accurate diagnosis is pivotal for guiding therapeutic planning and potential outcomes in PDAC and avoiding biopsy or surgical treatment of some of these mimics. Biopsy may still be required for diagnosis in some cases. The authors describe the typical and atypical imaging findings of PDAC and features that may help to differentiate PDAC from its mimics. ©RSNA, 2023 Online supplemental material is available for this article. Quiz questions for this article are available through the Online Learning Center. See the invited commentary by Zins in this issue.
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Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Pancreatite Crônica , Humanos , Diagnóstico Diferencial , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/patologia , Carcinoma Ductal Pancreático/diagnóstico por imagem , Carcinoma Ductal Pancreático/patologia , Neoplasias PancreáticasRESUMO
The commonly taught tenet that intratesticular lesions are always malignant and extratesticular scrotal lesions are always benign is a simplistic statement that erroneously minimizes the significance of extratesticular scrotal masses and their diagnosis. Yet, disease in the extratesticular space is commonly encountered by clinicians and radiologists and is often a source of uncertainty in diagnosis and management. Given the embryologically rooted complex anatomy of this region, a wide range of pathologic conditions is possible. Radiologists may not be familiar with some of these conditions; further, many of these lesions can have a specific sonographic appearance, allowing accurate diagnosis that can minimize surgical intervention. Lastly, malignancies can occur in the extratesticular space-although this is less common than in the testicles-and proper recognition of findings that warrant additional imaging or surgery is critical in optimizing outcomes. The authors present a compartmental anatomic framework for differential diagnosis of extratesticular scrotal masses and provide a comprehensive illustrative display of many of the pathologic conditions that can be encountered to familiarize radiologists with the sonographic appearances of these lesions. They also review management of these lesions and scenarios where US may not be definitive in diagnosis and selective use of scrotal MRI can be helpful. © RSNA, 2023 Quiz questions for this article are available in the supplemental material.
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Escroto , Neoplasias Testiculares , Masculino , Humanos , Diagnóstico Diferencial , Escroto/diagnóstico por imagem , Escroto/patologia , Ultrassonografia , Neoplasias Testiculares/patologiaRESUMO
The widespread use of high-spatial-resolution cross-sectional imaging has led to an increase in detection of incidental pancreatic cystic lesions. These lesions are a diverse group, ranging from indolent and premalignant lesions to invasive cancers. The diagnosis of several of these lesions can be suggested on the basis of their imaging appearance, while many other lesions require follow-up imaging and/or aspiration. The smaller cystic lesions, often branch-duct intraductal papillary mucinous neoplasms, have overlapping imaging characteristics that make diagnostic assessment of the natural history and malignancy risk confusing. Expert panels have developed societal guidelines, based on a consensus, for surveillance of these lesions. However, these guidelines are often inconsistent and are constantly evolving as additional scientific data are accumulated. Identification of features associated with increased risk of malignancy is important for proper management. The concept of field defect, whereby pancreatic adenocarcinoma develops at a site different from the site of the pancreatic cyst, adds to the complexity of screening guidelines. As a result of the differences in guidelines, key stakeholders (eg, radiologists, gastroenterologists, and surgeons) must review and come to a consensus regarding which guideline, or combination of guidelines, to follow at their individual institutions. Standardized reporting and macros are helpful for ensuring the uniformity of interpretations. Radiologists play a critical role in the detection and characterization of pancreatic cystic lesions, in the follow-up recommendations for these lesions, and in the detection of associated cancer. An invited commentary by Zaheer is available online. Online supplemental material is available for this article. ©RSNA, 2021.
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Adenocarcinoma , Cisto Pancreático , Neoplasias Pancreáticas , Adenocarcinoma/patologia , Humanos , Pâncreas , Cisto Pancreático/diagnóstico por imagem , Cisto Pancreático/patologia , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/patologiaRESUMO
Autoimmune pancreatitis (AIP) is an inflammatory process of the pancreas that occurs most commonly in elderly males and clinically can mimic pancreatic adenocarcinoma and present with jaundice, weight loss, and abdominal pain. Mass-forming lesions in the pancreas are seen in the focal form of AIP and both clinical and imaging findings can overlap those of pancreatic cancer. The accurate distinction of AIP from pancreatic cancer is of utmost importance as it means avoiding unnecessary surgery in AIP cases or inaccurate steroid treatment in patients with pancreatic cancer. Imaging concomitantly with serological examinations (IgG4 and Ca 19-9) plays an important role in the distinction between these entities. Characteristic extra-pancreatic manifestations as well as favorable good response to treatment with steroids are characteristic of AIP. This paper will review current diagnostic parameters useful in differentiating between focal AIP and pancreatic adenocarcinoma.
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Pancreatite Autoimune/diagnóstico por imagem , Carcinoma Ductal Pancreático/diagnóstico por imagem , Neoplasias Pancreáticas/diagnóstico por imagem , Corticosteroides/uso terapêutico , Pancreatite Autoimune/tratamento farmacológico , Biomarcadores/sangue , Antígeno CA-19-9/sangue , Diagnóstico Diferencial , Humanos , Imunoglobulina G/sangue , Neoplasias PancreáticasRESUMO
Intraluminal pathologic conditions of the bile ducts and gallbladder are common, most frequently consisting of calculi and adenocarcinoma. In recent years, intraductal papillary neoplasm of the bile ducts (IPN-B), which is analogous to intraductal papillary mucinous neoplasm of the pancreas, has been recognized as a distinct pathologic entity and a precursor lesion to adenocarcinoma of the bile ducts. Intraductal tubulopapillary neoplasm (ITPN) of the bile duct was subsequently described as a distinct pathologic entity. With increased awareness and advances in imaging techniques, these lesions are diagnosed with increased frequency at preoperative imaging. A similar neoplasm in the gallbladder is referred to as intracholecystic papillary neoplasm. These lesions are often diagnosed at a preinvasive stage and have a better prognosis than invasive cholangiocarcinoma when treated with curative resection, underscoring the importance of an accurate imaging diagnosis. The most common causes of polypoid lesions of the gallbladder are cholesterol polyps and adenomyomatosis. These lesions need to be differentiated from the less common but clinically important adenocarcinoma of the gallbladder. Imaging is crucial to identify polyps that are at high risk for malignancy so that the appropriate management choice between imaging follow-up and cholecystectomy can be made by the treating physicians. Other less common gallbladder tumors, such as gallbladder adenomas, lymphoma, and metastases to the gallbladder, can manifest as intraluminal tumors; and awareness of these lesions is also important. In this article, the recent literature is reviewed; and the imaging appearances, histopathologic findings, and management of uncommon intraluminal tumors of the bile ducts and gallbladder and their mimics are discussed. ©RSNA, 2019.
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Neoplasias dos Ductos Biliares/diagnóstico por imagem , Carcinoma Papilar/diagnóstico por imagem , Neoplasias da Vesícula Biliar/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Tomografia Computadorizada por Raios X/métodos , Adenoma/diagnóstico por imagem , Neoplasias dos Ductos Biliares/patologia , Carcinoma Papilar/patologia , Diagnóstico Diferencial , Feminino , Doenças da Vesícula Biliar/diagnóstico por imagem , Neoplasias da Vesícula Biliar/patologia , Humanos , Masculino , Fatores de RiscoRESUMO
PURPOSE: This article reviews the current evidence surrounding pancreatic cancer screening. The current targets of screening include identification of early pancreatic cancer, as well as the two most important precursor lesions; intraductal papillary mucinous neoplasm and high grade pancreatic intraepithelial neoplasia. Given the relatively low incidence of pancreatic adenocarcinoma in the general population, patients with elevated risk based on family history or an underlying genetic syndrome are felt to be the most appropriate patients to undergo screening. METHODS: An extensive review of the literature was performed and the major findings of the available literature regarding pancreatic screening are reviewed in detail. RESULTS: Several prospective trials have evaluated pancreatic cancer screening in high-risk groups. The results of those trials are summarized in this article. Current consensus guidelines and recommendations from the International Cancer of the Pancreas Screening Consortium Summit are also discussed. CONCLUSIONS: The exact benefit of pancreatic cancer screening remains unclear at this time, but emerging evidence suggests that there is a window of opportunity to detect precursor lesions and early pancreatic adenocarcinomas in high-risk patient populations. Better understanding of the pathway of carcinogenesis will hopefully improve our ability to detect early, resectable pancreatic carcinomas, and provide a mortality benefit to patients at significantly elevated risk of pancreatic adenocarcinoma.
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Adenocarcinoma/diagnóstico por imagem , Programas de Rastreamento , Neoplasias Pancreáticas/diagnóstico por imagem , Lesões Pré-Cancerosas/diagnóstico por imagem , Adenocarcinoma/patologia , Detecção Precoce de Câncer , Humanos , Neoplasias Pancreáticas/patologiaRESUMO
OBJECTIVE: Meckel diverticulum may become symptomatic if it is complicated by hemorrhage, intestinal obstruction, diverticulitis, or tumor. Although classically described in children, it is often missed in adults because of lack of suspicion and difficulty in detection. The purpose of this article is to review the imaging findings and management of Meckel diverticulum and its complications. CONCLUSION: Although it is infrequently encountered incidentally, Meckel diverticulum should be considered especially when interpreting examinations for abdominal pain, small-bowel obstruction, and gastrointestinal bleeding.
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Divertículo Ileal/complicações , Divertículo Ileal/diagnóstico por imagem , Adulto , Humanos , Divertículo Ileal/terapiaRESUMO
Adrenal lesions are a common imaging finding. The vast majority of adrenal lesions are adenomas, which contain intracytoplasmic (microscopic) fat. It is important to distinguish between adenomas and malignant tumors, and chemical shift magnetic resonance (MR) imaging can be used to accomplish this distinction by depicting the fat in adenomas. Chemical shift imaging is based on the difference in precession frequencies of water and fat molecules, which causes them to be in different relative phases during the acquisition sequence and allows in-phase and opposed-phase images to be obtained. It is important to acquire these images by using the earliest possible echo times, with the opposed-phase echo before the in-phase echo, and by using a single breath hold to preserve diagnostic accuracy. Intracytoplasmic fat is depicted as signal drop on opposed-phase images when compared with in-phase images. Both qualitative and quantitative methods for assessing signal drop are detailed. The appearances of adrenal adenomas and other adrenal tumors on chemical shift MR images are described, and discriminatory ability at chemical shift MR imaging compared with that at adrenal computed tomography (CT) is explained. Other adrenal-related conditions in which chemical shift MR imaging is helpful are also discussed. Chemical shift MR imaging is a robust tool for evaluating adrenal lesions that are indeterminate at nonenhanced CT. However, it is important to know the advantages and disadvantages, including several potential imaging pitfalls. The characterization of adrenal lesions by using chemical shift MR imaging and adrenal CT should always occur in the appropriate clinical setting.
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Adenoma/diagnóstico por imagem , Neoplasias das Glândulas Suprarrenais/diagnóstico por imagem , Glândulas Suprarrenais/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Tecido Adiposo/diagnóstico por imagem , Neoplasias das Glândulas Suprarrenais/secundário , Tumor de Resto Suprarrenal/diagnóstico por imagem , Artefatos , Água Corporal , Carcinoma/diagnóstico por imagem , Hemossiderose/diagnóstico por imagem , Humanos , Processamento de Imagem Assistida por Computador/métodos , Achados Incidentais , Lipoma/diagnóstico por imagem , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Primárias Múltiplas/diagnóstico por imagem , Feocromocitoma/diagnóstico por imagem , Prótons , Tomografia Computadorizada por Raios XRESUMO
Hemorrhage of the kidneys and adrenal glands has many etiologies. In the adrenal glands, trauma, anticoagulation, stress, sepsis, surgery, and neoplasms are common causes of hemorrhage. In the kidneys, reasons for hemorrhage include trauma, bleeding diathesis, vascular diseases, infection, infarction, hemorrhagic cyst rupture, the Antopol-Goldman lesion, and neoplasms. Angiomyolipoma and renal cell carcinoma are the neoplasms most commonly associated with hemorrhage in the kidneys and adrenal cortical carcinoma, metastases, and pheochromocytoma are associated with hemorrhage in the adrenal glands. Understanding the computed tomography and magnetic resonance imaging features, and causes of hemorrhage in the kidneys and adrenal glands is critical. It is also important to keep in mind that mimickers of hemorrhage exist, including lymphoma in both the kidneys and adrenal glands, and melanoma metastases in the adrenal glands. Appropriate imaging follow-up of renal and adrenal hemorrhage should occur to exclude an underlying malignancy as the cause. If there is suspicion for malignancy that cannot be definitively diagnosed on imaging, surgery or biopsy may be warranted. Angiography may be indicated when there is a suspected underlying vascular disease. Unnecessary intervention, such as nephrectomy, may be avoided in patients with benign causes or no underlying disease. Appropriate management is dependent on accurate diagnosis of the cause of renal or adrenal hemorrhage and it is incumbent upon the radiologist to determine the etiology.
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Doenças das Glândulas Suprarrenais/diagnóstico , Glândulas Suprarrenais , Hemorragia/diagnóstico , Nefropatias/diagnóstico , Rim , Doenças das Glândulas Suprarrenais/etiologia , Glândulas Suprarrenais/diagnóstico por imagem , Glândulas Suprarrenais/lesões , Angiografia , Hemorragia/etiologia , Humanos , Rim/diagnóstico por imagem , Rim/lesões , Nefropatias/etiologia , Imageamento por Ressonância Magnética , Tomografia Computadorizada por Raios X , UltrassonografiaRESUMO
Cystic renal lesions are commonly encountered in abdominal imaging. Although most cystic renal lesions are benign simple cysts, complex renal cysts, infectious cystic renal disease, and multifocal cystic renal disease are also common phenomena. The Bosniak classification system provides a useful means of categorizing cystic renal lesions but places less emphasis on their underlying pathophysiology. Cystic renal diseases can be categorized as focal, multifocal, or infectious lesions. Diseases that manifest with focal lesions, such as cystic renal cell carcinoma, mixed epithelial and stromal tumor, and cystic nephroma, are often difficult to differentiate but have differing implications for follow-up after resection. Multifocal cystic renal lesions can be categorized as acquired or heritable. Acquired entities, such as glomerulocystic kidney disease, lithium-induced nephrotoxicity, acquired cystic kidney disease, multicystic dysplastic kidney, and localized cystic renal disease, often have distinct imaging and clinical features that allow definitive diagnosis. Heritable diseases, such as autosomal dominant polycystic kidney disease, von Hippel-Lindau disease, and tuberous sclerosis, are usually easily identified and have various implications for patient management. Infectious diseases have varied imaging appearances, and the possibility of infection must not be overlooked when assessing a cystic renal lesion. A thorough understanding of the spectrum of cystic renal disease will allow the radiologist to make a more specific diagnosis and provide the clinician with optimal recommendations for further diagnostic testing and follow-up imaging.
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Doenças Renais Císticas/diagnóstico , Neoplasias Renais/diagnóstico , Imageamento por Ressonância Magnética/métodos , Meios de Contraste , Diagnóstico Diferencial , Humanos , Doenças Renais Císticas/classificação , Doenças Renais Císticas/diagnóstico por imagem , Neoplasias Renais/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodosRESUMO
Natural orifice transluminal endoscopic surgery (NOTES) is a surgical technique that has been evolving rapidly. Endoscopic submucosal dissection was initiated in 1999, in Japan, for en-bloc resection of large lesions of the stomach (Zhou et al., World J Gastroenterol 19:6962-6968, 2013, ; Kobara et al., Clin Exp Gastroenterol 7:67-74, 2014). Since then, many additional therapies utilizing natural transluminal endoscopic approach have evolved. Peroral endoscopic myotomy (POEM) is a minimally invasive type of transluminal endoscopic surgery that was recently developed for the treatment of achalasia and esophageal motility disorders. The peroral endoscopic myotomy is a less invasive surgical treatment that is suitable for all types of achalasia and used as an alternate to the Heller myotomy. The radiographic findings of achalasia and surgical changes after Heller myotomy have been described, however, very little is available on the post-POEM esophagram appearance. The purpose of this article is to illustrate the anatomy, surgical procedure, and normal and abnormal findings seen on esophagrams in patients who have undergone a POEM.
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Acalasia Esofágica/diagnóstico por imagem , Acalasia Esofágica/cirurgia , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Cirurgia Endoscópica por Orifício Natural/métodos , Esôfago/diagnóstico por imagem , Esôfago/cirurgia , Fluoroscopia , HumanosRESUMO
The ampulla of Vater is an important anatomic landmark where the common bile duct and main pancreatic duct converge in the major duodenal papilla. Imaging evaluation of the ampulla and periampullary region poses a unique diagnostic challenge to radiologists because of the region's complex and variable anatomy and the variety of lesions that can occur. Lesions intrinsic to the ampulla and involved segment of the biliary tree can be neoplastic, inflammatory, or congenital. Neoplastic lesions include ampullary adenocarcinomas and adenomas, which often are difficult to differentiate, as well as pancreatic or duodenal adenocarcinomas, pancreatic neuroendocrine tumors, and cholangiocarcinomas. Ultrasonography (US), computed tomography, magnetic resonance (MR) imaging, and MR cholangiopancreatography are commonly used to evaluate this region. Endoscopic retrograde cholangiopancreatography or endoscopic US examination may be necessary for more definitive evaluation. Periampullary conditions in the duodenum that may secondarily involve the ampulla include neoplasms, duodenitis, duodenal diverticula, and Brunner's gland hyperplasia or hamartomas. Because these lesions can exhibit a wide overlap of imaging features and subtle or nonspecific imaging findings, diagnosis is made on the basis of patient age, clinical history, and imaging and laboratory findings. Given the complexity of imaging evaluation of the ampulla and periampullary region, it is essential for radiologists to understand the variety of lesions that can occur and recognize their imaging characteristics.
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Ampola Hepatopancreática/patologia , Neoplasias dos Ductos Biliares/diagnóstico , Doenças do Ducto Colédoco/diagnóstico , Diagnóstico por Imagem/métodos , Ampola Hepatopancreática/diagnóstico por imagem , Colangiopancreatografia Retrógrada Endoscópica , Colangiopancreatografia por Ressonância Magnética , Ducto Colédoco/diagnóstico por imagem , Ducto Colédoco/patologia , Humanos , Perfuração Intestinal/diagnóstico por imagem , UltrassonografiaRESUMO
PURPOSE: To determine whether asymmetric spermatic cord vessel enhancement (ASE) on contrast-enhanced computed tomography (CECT) indicates scrotal pathology. METHODS: Sixty-one male patients with scrotal symptoms who underwent both scrotal ultrasound (US) and CECT within 24 h were identified through a radiology information system. Twenty-eight emergency department patients who underwent CECT only for unrelated symptoms were included for comparison. Two blinded radiologists independently reviewed each CECT scan for qualitative ASE. These data were compared with US diagnoses, when present. A third blinded radiologist reviewed each CECT scan for quantitative ASE by measuring Hounsfield unit (HU) density ratios. McNemar, Kappa, Student's t test, and ANOVA were used for analysis. RESULTS: Eighty-nine total patients included 28 with CECT only and 61 with CECT and US, of which 41 had abnormal US: 15 acute epididymitis and/or orchitis, 7 testicular neoplasms, 11 varicoceles, and 8 with other pathologies. Twenty patients with normal US and 28 patients with CECT only served as control groups. Identification of ASE agreed with US diagnosis of epididymitis (and/or orchitis) or testicular neoplasm (reader 1: κ = 0.79, reader 2: κ = 0.75) with average 95.5% sensitivity and 88.8% specificity, and no significant difference between readers (p = 0.58). For epididymitis (and/or orchitis) or testicular neoplasm patients, the average ratio of spermatic cord HU density (ipsilateral:contralateral) was significantly different from other patients (4.01 vs. 1.26, p = 0.0025). CONCLUSION: ASE on CECT shows stronger correlation with epididymitis (and/or orchitis) and testicular neoplasm compared with other scrotal pathologies. If discovered on CECT, this should prompt further clinical and/or imaging workup.
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Meios de Contraste , Epididimite/diagnóstico por imagem , Intensificação de Imagem Radiográfica/métodos , Cordão Espermático/diagnóstico por imagem , Neoplasias Testiculares/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Reprodutibilidade dos Testes , Estudos Retrospectivos , Ultrassonografia , Adulto JovemRESUMO
Contrast-enhanced multiphase CT and dynamic gadolinium-enhanced MR have been validated in the literature as outstanding modalities for the evaluation of pancreatic pathology. In addition to the more frequently seen pancreatic adenocarcinoma, neuroendocrine tumors of the pancreas and cystic lesions such as serous and mucinous cystadenomas and IPMNs, a variety of benign and malignant lesions may occur in the pancreas. The purpose of this pictorial essay is to review the imaging findings of a variety of uncommon, benign and malignant, pancreatic neoplasms.
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Imageamento por Ressonância Magnética , Neoplasias Pancreáticas/diagnóstico , Adenocarcinoma Mucinoso/diagnóstico , Carcinoma de Células Acinares/diagnóstico , Colangiopancreatografia por Ressonância Magnética , Tumores de Células Gigantes/diagnóstico , Humanos , Lipoma/diagnóstico , Plasmocitoma/diagnóstico , Tomografia Computadorizada por Raios XRESUMO
Although the most common renal infection, acute pyelonephritis, can typically be diagnosed on clinical and laboratory examinations, radiologic studies play a role in evaluating for complications and in examining the high-risk patient for more serious complications and atypical infections. It is imperative that the radiologist be familiar with renal infections beyond the common acute pyelonephritis.
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Aspergilose/diagnóstico por imagem , Equinococose/diagnóstico por imagem , Enfisema/diagnóstico por imagem , Pielonefrite/diagnóstico por imagem , Pionefrose/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Tuberculose Renal/diagnóstico por imagem , Meios de Contraste , Diagnóstico Diferencial , Humanos , Pielonefrite Xantogranulomatosa/diagnóstico por imagemRESUMO
Diffusion-weighted magnetic resonance (MR) imaging is increasingly used in the detection and characterization of pancreatic lesions. Diffusion-weighted imaging may provide additional information to radiologists evaluating patients who have cystic or solid neoplasms of the pancreas. Because of greater freedom of motion of water molecules in fluid-rich environments, simple cysts in the pancreas have higher signal intensity on diffusion-weighted images with a b value of 0 sec/mm2 and lower signal intensity on high-b-value images. High apparent diffusion coefficient (ADC) values can be obtained on ADC maps because of the T2 "shine-through" effect. In contrast, solid neoplasms of the pancreas show increased signal intensity relative to the pancreas on diffusion-weighted images with a b value of 0 sec/mm2 and relatively high signal intensity on high-b-value images. Diffusion-weighted imaging can help detect solid pancreatic neoplasms with extremely dense cellularity or extracellular fibrosis by demonstrating significantly low ADC values, and these neoplasms may be better detected on diffusion-weighted MR images because of better contrast, although the resolution is generally worse. However, diffusion-weighted imaging may not be capable of helping definitively characterize solid lesions as inflammatory or neoplastic because of an overlap in ADC values between the two types. For example, it is difficult to distinguish poorly differentiated pancreatic adenocarcinoma from mass-forming pancreatitis at diffusion-weighted imaging because of similarly low ADC values attributed to dense fibrosis.
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Imagem de Difusão por Ressonância Magnética/métodos , Cisto Pancreático/diagnóstico , Pancreatopatias/diagnóstico , Meios de Contraste , Humanos , Cisto Pancreático/patologia , Pancreatopatias/patologia , Sensibilidade e EspecificidadeRESUMO
Primary sclerosing cholangitis is a chronic, progressive disease of inflammation and fibrosis of the bile ducts. The ability to predict survival is important for appropriate management and treatment decisions. The purpose of this study was to examine the relationship between specific findings on the enhanced magnetic resonance imaging (MRI) examination of the liver and the corresponding magnetic resonance cholangiopancreatogram (MRCP) and a survival model for primary sclerosing cholangitis (PSC), the Mayo Risk Score. During a five-year period, 47 patients with primary sclerosing cholangitis were identified who had a complete MRI/MRCP examination. The extent of anatomical changes of the biliary tree and the degree of peribiliary enhancement in the hepatic parenchyma were compared with the Mayo Risk Score for each patient. Peribiliary enhancement was present to a varying extent in 38 of 47 cases of PSC. Peribiliary enhancement 3 min after gadolinium administration had a weak correlation with the Mayo Risk Score (analysis of variance P<0.01, Pearson correlation r=0.37). No statistically significant relationship between the severity of extrahepatic or intrahepatic duct changes and the Mayo Risk Score was found (analysis of variance P=0.24, P=0.38, respectively). Although biliary tree changes on MRCP aid in the diagnosis of PSC, they do not correlate with survival, as predicted by the Mayo Risk Score. Peribiliary enhancement on MRI of the liver is a finding occurring to a variable extent in primary sclerosing cholangitis but does not correlate significantly with survival.