Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 128
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
AJR Am J Roentgenol ; : 1-10, 2019 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-31593515

RESUMO

OBJECTIVE. Imaging plays an important role in the diagnosis and staging of malignancies. Many common lymphoproliferative and other solid tumor malignancies can be viral-related. CONCLUSION. This review discusses the imaging findings that can be associated with common viral-induced malignancies. Knowledge of these imaging presentations can help narrow the differential diagnosis to reach a specific diagnosis through a precise workup and proper management.

2.
Abdom Radiol (NY) ; 2019 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-31529204

RESUMO

Adrenal adenoma is the most common adrenal lesion. Due to its wide prevalence, adrenal adenomas may demonstrate various imaging features. Thus, it is important to identify typical and atypical imaging features of adrenal adenomas and to be able to differentiate atypical adrenal adenomas from potentially malignant lesions. In this article, we will discuss the diagnostic approach, typical and atypical imaging features of adrenal adenomas, as well as other lesions that mimic adrenal adenomas.

3.
Abdom Radiol (NY) ; 2019 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-31538225

RESUMO

The spectrum of adrenal masses in the pediatric population markedly differs from that in the adult population. Imaging plays a crucial role in detecting adrenal masses, differentiating malignant from benign lesions, recognizing extra-adrenal lesions in the suprarenal fossa, and directing further management. Ultrasound is the primary imaging modality of choice for the evaluation of adrenal masses in the neonatal period, whereas MRI or CT is used as a problem-solving tool. In older children, computed tomography or magnetic resonance imaging is often required after initial sonographic evaluation for further characterization of a lesion. Herein, we discuss the salient imaging features along with pathophysiology and clinical features of pediatric adrenal masses.

4.
Abdom Radiol (NY) ; 2019 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-31165195

RESUMO

Due to the widespread use of imaging, incidental adrenal masses are commonly encountered. A number of pitfalls can result in misdiagnosis of these lesions, including inappropriate choice of imaging technique, presence of pseudolesions, and overlap of imaging features of different adrenal lesions. This article explores the potential pitfalls in imaging of the adrenal glands, on computed tomography and magnetic resonance imaging, that can lead to misinterpretation. Clues to correct diagnoses are provided to evade potential misinterpretation.

5.
J Magn Reson Imaging ; 2019 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-31215119

RESUMO

The Liver Imaging Reporting and Data System (LI-RADS) is a comprehensive system for standardizing the terminology, technique, interpretation, reporting, and data collection of liver imaging, created specifically for patients at risk for hepatocellular carcinoma. Over the past years, LI-RADS has been progressively implemented into clinical practice, but pitfalls remain related to user error and inherent limitations of the system. User pitfalls include the inappropriate application of LI-RADS to a low-risk patient population, incorrect measurement techniques, inaccurate assumptions about LI-RADS requirements, and improper usage of LI-RADS terminology and categories. System pitfalls include areas of discordance with the Organ Procurement and Transplantation Network (OPTN) as well as pitfalls related to rare ancillary features. This article reviews common user pitfalls in applying LI-RADS v2018 and how to avoid preventable errors and also highlights deficiencies of the current version of LI-RADS and how it might be improved in the future. Level of Evidence:3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019.

6.
J Comput Assist Tomogr ; 43(3): 499-506, 2019 May/Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31082956

RESUMO

PURPOSE: This pilot study evaluates the feasibility of automated volumetric quantification of hepatocellular carcinoma (HCC) as an imaging biomarker to assess treatment response for sorafenib. METHODS: In this institutional review board-approved, Health Insurance Portability and Accountability Act-compliant retrospective study, a training database of manually labeled background liver, enhancing and nonenhancing tumor tissue was established using pretherapy and first posttherapy multiphasic computed tomography images from a registry of 13 HCC patients. For each patient, Hounsfield density and geometry-based feature images were generated from registered multiphasic computed tomography data sets and used as the input for a random forest-based classifier of enhancing and nonenhancing tumor tissue. Leave-one-out cross-validation of the dice similarity measure was applied to quantify the classifier accuracy. A Cox regression model was used to confirm volume changes as predictors of time to progression (TTP) of target lesions for both manual and automatic methods. RESULTS: When compared with manual labels, an overall classification accuracy of dice similarity coefficient of 0.71 for pretherapy and 0.66 posttherapy enhancing tumor labels and 0.45 for pretherapy and 0.59 for posttherapy nonenhancing tumor labels was observed. Automated methods for quantifying volumetric changes in the enhancing lesion agreed with manual methods and were observed as a significant predictor of TTP. CONCLUSIONS: Automated volumetric analysis was determined to be feasible for monitoring HCC response to treatment. The information extracted using automated volumetrics is likely to reproduce labor-intensive manual data and provide a good predictor for TTP. Further work will extend these studies to additional treatment modalities and larger patient populations.


Assuntos
Carcinoma Hepatocelular/diagnóstico por imagem , Tomografia Computadorizada de Feixe Cônico/métodos , Neoplasias Hepáticas/diagnóstico por imagem , Sorafenibe/administração & dosagem , Idoso , Carcinoma Hepatocelular/tratamento farmacológico , Feminino , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Análise de Regressão , Estudos Retrospectivos , Sorafenibe/uso terapêutico , Resultado do Tratamento
7.
Abdom Radiol (NY) ; 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-31093730

RESUMO

Adrenal hyperplasia is non-malignant enlargement of the adrenal glands, which is often bilateral. It can be incidental or related to indolent disease process and may be related to benign or malignant etiologies causing biochemical alterations in the hypothalamic-pituitary-adrenal axis which controls steroidogenesis and in particular cortisol production. Clinical significance of the adrenal hyperplasia is variable ranging from asymptomatic finding to serious manifestations of Cushing syndrome. This is often associated with anatomical changes in the adrenal glands, which typically manifests as diffuse and sometimes nodular enlargement of the adrenal glands radiologically. Approaching adrenal hyperplasia requires careful clinical and biochemical evaluation in correlation with imaging review to differentiate ACTH-dependent and ACTH-independent etiologies. CT is the primary modality of choice for adult adrenal imaging owing to reproducibility, temporal and spatial resolution and broader access, while MRI often serves a complimentary role. Ultrasound and MRI are most commonly used in pediatric cases to evaluate congenital adrenal hyperplasia. This article will discuss the clinical presentation and imaging features of different types and mimics of adrenal cortical hyperplasia.

8.
Artigo em Inglês | MEDLINE | ID: mdl-31082984

RESUMO

PURPOSE: This pilot study evaluates the feasibility of automated volumetric quantification of hepatocellular carcinoma (HCC) as an imaging biomarker to assess treatment response for sorafenib. METHODS: In this institutional review board-approved, Health Insurance Portability and Accountability Act-compliant retrospective study, a training database of manually labeled background liver, enhancing and nonenhancing tumor tissue was established using pretherapy and first posttherapy multiphasic computed tomography images from a registry of 13 HCC patients. For each patient, Hounsfield density and geometry-based feature images were generated from registered multiphasic computed tomography data sets and used as the input for a random forest-based classifier of enhancing and nonenhancing tumor tissue. Leave-one-out cross-validation of the dice similarity measure was applied to quantify the classifier accuracy. A Cox regression model was used to confirm volume changes as predictors of time to progression (TTP) of target lesions for both manual and automatic methods. RESULTS: When compared with manual labels, an overall classification accuracy of dice similarity coefficient of 0.71 for pretherapy and 0.66 posttherapy enhancing tumor labels and 0.45 for pretherapy and 0.59 for posttherapy nonenhancing tumor labels was observed. Automated methods for quantifying volumetric changes in the enhancing lesion agreed with manual methods and were observed as a significant predictor of TTP. CONCLUSIONS: Automated volumetric analysis was determined to be feasible for monitoring HCC response to treatment. The information extracted using automated volumetrics is likely to reproduce labor-intensive manual data and provide a good predictor for TTP. Further work will extend these studies to additional treatment modalities and larger patient populations.

9.
AJR Am J Roentgenol ; : 1-9, 2019 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-30973778

RESUMO

OBJECTIVE: The purposes of this article are to discuss a variety of liver masses that can present with hemorrhage, including their characteristic imaging features, and to propose a diagnostic approach. CONCLUSION: A broad spectrum of pathologic conditions can present as spontaneous hemorrhage within or surrounding the liver and may present acutely or as a chronic or incidental finding. Imaging characteristics and clinical history can often narrow the differential diagnosis and guide management.

10.
AJR Am J Roentgenol ; : 1-9, 2019 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-30973780

RESUMO

OBJECTIVE: The purpose of this article is to provide a multimodality imaging review of ileal carcinoid tumor. CONCLUSION: Ileal carcinoid tumors display a variety of radiologic findings. Delay in diagnosis is common because of initial nonspecific symptoms and subtle imaging findings. Reviewing the multimodality imaging appearance of the primary tumor, metastatic disease, and associated ancillary findings can help improve patient care.

13.
14.
Artigo em Inglês | MEDLINE | ID: mdl-30371618

RESUMO

A multitude of pathologic entities involve abnormal iron deposition in the abdomen. These lesions demonstrate decreased signal on longer magnetic resonance sequences with longer echo time due to T2* effect. Dual-echo gradient-echo sequences demonstrate increased susceptibility artifact with longer echo sequences. In this article, the spectrum of iron-containing abdominal pathologies is illustrated, with their characteristic distributions. Included is a brief discussion of the physics of magnetic resonance imaging of iron-containing lesions.

15.
Radiographics ; 38(7): 2051-2068, 2018 Nov-Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30339518

RESUMO

The risk of developing malignancy is higher in patients with human immunodeficiency virus (HIV) infection than in non-HIV-infected patients. Several factors including immunosuppression, viral coinfection, and high-risk lifestyle choices lead to higher rates of cancer in the HIV-infected population. A subset of HIV-related malignancies are considered to be acquired immunodeficiency syndrome (AIDS)-defining malignancies, as their presence confirms the diagnosis of AIDS in an HIV-infected patient. The introduction of highly active antiretroviral therapy (HAART) has led to a significant drop in the rate of AIDS-defining malignancies, including Kaposi sarcoma, non-Hodgkin lymphoma, and invasive cervical carcinoma. However, non-AIDS-defining malignancies (eg, Hodgkin lymphoma, lung cancer, hepatocellular carcinoma, and head and neck cancers) now account for an increasing number of cancer cases diagnosed in HIV-infected patients. Although the number has decreased, AIDS-defining malignancies account for 15%-19% of all deaths in HIV-infected patients in the post-HAART era. Most HIV-related malignancies in HIV-infected patients manifest at an earlier age with a more aggressive course than that of non-HIV-related malignancies. Understanding common HIV-related malignancies and their specific imaging features is crucial for making an accurate and early diagnosis, which impacts management. Owing to the weakened immune system of HIV-infected patients, other entities such as various infections, particularly opportunistic infections, are prevalent in these patients. These processes can have confounding clinical and imaging manifestations that mimic malignancy. This article reviews the most common AIDS-defining and non-AIDS-defining malignancies, the role of imaging in their diagnosis, and the imaging mimics of malignancies in HIV-infected patients. ©RSNA, 2018.

16.
J Magn Reson Imaging ; 2018 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-30295343

RESUMO

The following is an illustrative review of common pitfalls in liver MRI that may challenge interpretation. This article reviews common technical and diagnostic challenges encountered when interpreting dynamic multiphasic T1 -weighted imaging, hepatobiliary phase imaging, and diffusion-weighted imaging of the liver. Additionally, each section includes suggestions for avoiding diagnostic and technical errors. LEVEL OF EVIDENCE: 5 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018.

17.
Radiographics ; 38(7): 1973-2001, 2018 Nov-Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30289735

RESUMO

The Liver Imaging Reporting and Data System (LI-RADS) standardizes performance of liver imaging in patients at risk for hepatocellular carcinoma (HCC) as well as interpretation and reporting of the results. Developed by experts in liver imaging and supported by the American College of Radiology, LI-RADS assigns to observations categories that reflect the relative probability of benignity, HCC, or other malignancy. While category assignment is based mainly on major imaging features, ancillary features may be applied to improve detection and characterization, increase confidence, or adjust LI-RADS categories. Ancillary features are classified as favoring malignancy in general, HCC in particular, or benignity. Those favoring malignancy in general or HCC in particular may be used to upgrade by a maximum of one category up to LR-4; those favoring benignity may be used to downgrade by a maximum of one category. If there are conflicting ancillary features (ie, one or more favoring malignancy and one or more favoring benignity), the category should not be adjusted. Ancillary features may be seen at diagnostic CT, MRI performed with extracellular agents, or MRI performed with hepatobiliary agents, with the exception of one ancillary feature assessed at US. This article focuses on LI-RADS version 2018 ancillary features seen at MRI. Specific topics include rules for ancillary feature application; definitions, rationale, and illustrations with clinical MRI examples; summary of evidence and diagnostic performance; pitfalls; and future directions. ©RSNA, 2018.

18.
Radiology ; 289(3): 816-830, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30251931

RESUMO

The Liver Imaging Reporting and Data System (LI-RADS) is composed of four individual algorithms intended to standardize the lexicon, as well as reporting and care, in patients with or at risk for hepatocellular carcinoma in the context of surveillance with US; diagnosis with CT, MRI, or contrast material-enhanced US; and assessment of treatment response with CT or MRI. This report provides a broad overview of LI-RADS, including its historic development, relationship to other imaging guidelines, composition, aims, and future directions. In addition, readers will understand the motivation for and key components of the 2018 update.

20.
AJR Am J Roentgenol ; 211(4): 760-766, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30063381

RESUMO

OBJECTIVE: Topical tissue sealants and hemostatic agents, seen on postoperative imaging in a variety of intraabdominal and pelvic locations, have the potential to be mistaken for abdominal abnormalities, especially if the radiologist is not aware of the patient's surgical history. The normal appearance of these agents may mimic abscesses, tumors, enlarged lymph nodes, or retained foreign bodies. Therefore, it is important to be familiar with their typical imaging appearances and to review the surgical records when needed to avoid misdiagnoses. The purpose of this article is to increase the radiologist's familiarity with various types of topical tissue sealants and hemostatic agents used during surgical and percutaneous procedures in the abdomen and pelvis along with their radiologic appearances. CONCLUSION: Various types of hemostatic agents are now commonly used during surgery and percutaneous procedures in the abdomen and pelvis, and it is important to recognize the various appearances of these agents. Although there are suggestive features outlined in this article, the most important factor for the radiologist is to be aware of the patient's history and the possibility that a hemostatic agent may be present. On postoperative imaging, hemostatic agents may mimic abscesses, tumors, enlarged lymph nodes, or retained foreign bodies, and accurate diagnosis can save a patient unnecessary treatment. It is therefore crucial to incorporate knowledge of the patient's surgical history with recognition of the typical imaging appearances of hemostatic agents and other pseudolesions to avoid misdiagnoses.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA