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1.
Proc Natl Acad Sci U S A ; 120(10): e2214888120, 2023 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-36853945

RESUMO

Necrosis in the tumor interior is a common feature of aggressive cancers that is associated with poor clinical prognosis and the development of metastasis. How the necrotic core promotes metastasis remains unclear. Here, we report that emergence of necrosis inside the tumor is correlated temporally with increased tumor dissemination in a rat breast cancer model and in human breast cancer patients. By performing spatially focused transcriptional profiling, we identified angiopoietin-like 7 (Angptl7) as a tumor-specific factor localized to the perinecrotic zone. Functional studies showed that Angptl7 loss normalizes central necrosis, perinecrotic dilated vessels, metastasis, and reduces circulating tumor cell counts to nearly zero. Mechanistically, Angptl7 promotes vascular permeability and supports vascular remodeling in the perinecrotic zone. Taken together, these findings show that breast tumors actively produce factors controlling central necrosis formation and metastatic dissemination from the tumor core.


Assuntos
Neoplasias da Mama , Neoplasias Mamárias Animais , Células Neoplásicas Circulantes , Animais , Feminino , Humanos , Ratos , Proteína 7 Semelhante a Angiopoietina , Proteínas Semelhantes a Angiopoietina , Angiopoietinas/genética , Neoplasias da Mama/genética , Necrose
2.
J Theor Biol ; 588: 111835, 2024 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-38643962

RESUMO

Obesity is a contributing factor to asthma severity; while it has long been understood that obesity is related to greater asthma burden, the mechanisms though which this occurs have not been fully elucidated. One common explanation is that obesity mechanically reduces lung volume through accumulation of adipose tissue external to the thoracic cavity. However, it has been recently demonstrated that there is substantial adipose tissue within the airway wall itself, and that the presence of adipose tissue within the airway wall is related to body mass index. This suggests the possibility of an additional mechanism by which obesity may worsen asthma, namely by altering the behaviour of the airways themselves. To this end, we modify Anafi & Wilson's classic model of the bistable terminal airway to incorporate adipose tissue within the airway wall in order to answer the question of how much adipose tissue would be required in order to drive substantive functional changes. This analysis suggests that adipose tissue within the airway wall on the order of 1%-2% of total airway cross-sectional area could be sufficient to drive meaningful changes, and further that these changes may interact with volume effects to magnify the overall burden.


Assuntos
Tecido Adiposo , Asma , Modelos Biológicos , Obesidade , Tecido Adiposo/metabolismo , Humanos , Asma/fisiopatologia , Obesidade/fisiopatologia , Obesidade/metabolismo , Pulmão/fisiologia
3.
Am J Physiol Lung Cell Mol Physiol ; 324(2): L179-L189, 2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-36445102

RESUMO

Patients with comorbid asthma-obesity experience greater disease severity and are less responsive to therapy. We have previously reported adipose tissue within the airway wall that positively correlated with body mass index. Accumulation of biologically active adipose tissue may result in the local release of adipokines and disrupt large and small airway function depending on its anatomical distribution. This study therefore characterized airway-associated adipose tissue distribution, lipid composition, and adipokine activity in a porcine model. Airway segments were systematically dissected from different locations of the bronchial tree in inflation-fixed lungs. Cryosections were stained with hematoxylin and eosin (H&E) for airway morphology, oil red O to distinguish adipose tissue, and Nile blue A for lipid subtype delineation. Excised airway-associated adipose tissue was cultured for 72 h to quantify adipokine release using immunoassays. Results showed that airway-associated adipose tissue extended throughout the bronchial tree and occupied an area proportionally similar to airway smooth muscle within the wall area. Lipid composition consisted of pure neutral lipids (61.7 ± 3.5%), a mixture of neutral and acidic lipids (36.3 ± 3.4%), or pure acidic lipids (2.0 ± 0.8%). Following tissue culture, there was rapid release of IFN-γ, IL-1ß, and TNF-α at 12 h. Maximum IL-4 and IL-10 release was at 24 and 48 h, and peak leptin release occurred between 48 and 72 h. These data extend previous findings and demonstrate that airway-associated adipose tissue is prevalent and biologically active within the bronchial tree, providing a local source of adipokines that may be a contributing factor in airway disease.


Assuntos
Tecido Adiposo , Obesidade , Animais , Suínos , Adipocinas , Pulmão , Lipídeos
4.
Clin Sci (Lond) ; 137(19): 1547-1562, 2023 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-37732890

RESUMO

Airway-associated adipose tissue increases with body mass index and is a local source of pro-inflammatory adipokines that may contribute to airway pathology in asthma co-existing with obesity. Genetic susceptibility to airway adiposity was considered in the present study through kisspeptin/kisspeptin receptor signalling, known to modulate systemic adiposity and potentially drive airway remodelling. Therefore, the aim of the study was to determine the effects of kisspeptin/kisspeptin receptor signalling in the lung, focusing on airway-associated adipose tissue deposition and impact on airway structure-function. Wild-type, heterozygous and kisspeptin receptor knockout mice were studied at 6 or 8 weeks of age. Lung mechanics were assessed before and after methacholine challenge and were subsequently fixed for airway morphometry. A separate group of mice underwent glucose tolerance testing and bronchoalveolar lavage. At 6 weeks of age, kisspeptin/kisspeptin receptor signalling did not affect body adiposity, airway inflammation, wall structure or function. Despite no differences in body adiposity, there was a greater accumulation of airway-associated adipose tissue in knockout mice. By 8 weeks of age, female knockout mice displayed a non-diabetic phenotype with increased body adiposity but not males. Airway-associated adipose tissue area was also increased in both knockout females and males at 8 weeks of age, but again no other respiratory abnormality was apparent. In summary, airway-associated adipose tissue is decoupled from body adiposity in prepubescent mice which supports a genetic susceptibility to fatty deposits localised to the airway wall. There was no evidence that airway-associated adipose tissue drives pathology or respiratory impairment in the absence of other environmental exposures.

5.
AJR Am J Roentgenol ; 218(4): 746-755, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-34668387

RESUMO

BACKGROUND. Clinical use of the dual-energy CT (DECT) iodine quantification technique is hindered by between-platform (i.e., across different manufacturers) variability in iodine concentration (IC) values, particularly at low iodine levels. OBJECTIVE. The purpose of this study was to develop in an anthropomorphic phantom a method for reducing between-platform variability in quantification of low iodine content levels using DECT and to evaluate the method's performance in patients undergoing serial clinical DECT examinations on different platforms. METHODS. An anthropomorphic phantom in three body sizes, incorporating varied lesion types and scanning conditions, was imaged with three distinct DECT implementations from different manufacturers at varying radiation exposures. A cross-platform iodine quantification model for correcting between-platform variability at low iodine content was developed using the phantom data. The model was tested in a retrospective series of 30 patients (20 men, 10 women; median age, 62 years) who each underwent three serial contrast-enhanced DECT examinations of the abdomen and pelvis (90 scans total) for routine oncology surveillance using the same three DECT platforms as in the phantom. Estimated accuracy of phantom IC values was summarized using root-mean-square error (RMSE) relative to known IC. Between-platform variability in patients was summarized using root-mean-square deviation (RMSD). RMSE and RMSD were compared between platform-based IC (ICPB) and cross-platform IC (ICCP). ICPB was normalized to aorta and portal vein. RESULTS. In the phantom study, mean RMSE of ICPB across platforms and other experimental conditions was 0.65 ± 0.18 mg I/mL compared with 0.40 ± 0.08 mg I/mL for ICCP (38% decrease in mean RMSE; p < .05). Intrapatient between-platform variability across serial DECT examinations was higher for ICPB than ICCP (RMSD, 97% vs 88%; p < .001). Between-platform variability was not reduced by normalization of ICPB to aorta (RMSD, 97% vs 101%; p = .12) or portal vein (RMSD, 97% vs 97%; p = .81). CONCLUSION. The developed cross-platform method significantly decreased between-platform variability occurring at low iodine content with platform-based DECT iodine quantification. CLINICAL IMPACT. With further validation, the cross-platform method, which has been implemented as a web-based app, may expand clinical use of DECT iodine quantification, yielding meaningful IC values that reflect tissue biologic viability or treatment response in patients who undergo serial examinations on different platforms.


Assuntos
Iodo , Imagem Radiográfica a Partir de Emissão de Duplo Fóton , Abdome , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Imagens de Fantasmas , Imagem Radiográfica a Partir de Emissão de Duplo Fóton/métodos , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/métodos
6.
Radiology ; 298(1): 28-35, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33170103

RESUMO

Inaugural consensus statements were developed and endorsed by the American College of Radiology (ACR) and the National Kidney Foundation to improve and standardize the care of patients with kidney disease who have indication(s) to receive ACR-designated group II or group III intravenous gadolinium-based contrast media (GBCM). The risk of nephrogenic systemic fibrosis (NSF) from group II GBCM in patients with advanced kidney disease is thought to be very low (zero events following 4931 administrations to patients with estimated glomerular filtration rate [eGFR] <30 mL/min per 1.73 m2; upper bounds of the 95% confidence intervals: 0.07% overall, 0.2% for stage 5D chronic kidney disease [CKD], 0.5% for stage 5 CKD and no dialysis). No unconfounded cases of NSF have been reported for the only available group III GBCM (gadoxetate disodium). Depending on the clinical indication, the potential harms of delaying or withholding group II or group III GBCM for an MRI in a patient with acute kidney injury or eGFR less than 30 mL/min per 1.73 m2 should be balanced against and may outweigh the risk of NSF. Dialysis initiation or alteration is likely unnecessary based on group II or group III GBCM administration. This article is a simultaneous joint publication in Radiology and Kidney Medicine. The articles are identical except for stylistic changes in keeping with each journal's style. Either version may be used in citing this article.


Assuntos
Meios de Contraste/administração & dosagem , Meios de Contraste/efeitos adversos , Gadolínio/administração & dosagem , Gadolínio/efeitos adversos , Nefropatias/diagnóstico por imagem , Administração Intravenosa , Consenso , Humanos , Rim/diagnóstico por imagem , Sociedades Médicas , Estados Unidos
7.
Radiology ; 298(3): 611-619, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33464180

RESUMO

Background Virtual unenhanced (VUE) images obtained by using a dual-energy CT (DECT) multimaterial decomposition algorithm hold promise for diagnostic use in the abdomen in lieu of true unenhanced (TUE) images. Purpose To assess VUE images obtained from a DECT multimaterial decomposition algorithm in patients undergoing renal mass and urinary stone evaluation. Materials and Methods In this retrospective Health Insurance Portability and Accountability Act-compliant study, DECT was performed in patients undergoing evaluation for renal mass or urinary stone. VUE images were compared quantitatively to TUE images and qualitatively assessed by four independent radiologists. Differences in attenuation between VUE and TUE images were summarized by using 95% limits of agreement. Diagnostic performance in urinary stone detection was summarized by using area under the receiver operating characteristic curve, sensitivity, and specificity. Results A total of 221 patients (mean age ± standard deviation, 61 years ± 14; 129 men) with 273 renal masses were evaluated. Differences in renal mass attenuation between VUE and TUE images were within 3 HU for both enhancing masses (95% limits of agreement, -3.1 HU to 2.7 HU) and nonenhancing cysts (95% limits of agreement, -2.9 HU to 2.5 HU). Renal mass classification as enhancing mass versus nonenhancing cyst did not change (reclassification rate of enhancing masses, 0% [0 of 78]; 95% CI: 0, 5; reclassification rate of nonenhancing cysts, 0% [0 of 193]; 95% CI: 0, 2) with use of VUE in lieu of TUE images. Among 166 urinary stones evaluated, diagnostic performance of VUE images for stone detection was lower compared with that of TUE images (area under the receiver operating characteristic curve, 0.79 [95% CI: 0.73, 0.84] vs 0.93 [95% CI: 0.91, 0.95]; P < .001) due to reduced sensitivity of VUE for detection of stones 3 mm in diameter or less compared with those greater than 3 mm (sensitivity, 23% [25 of 108; 95% CI: 12, 40] vs 88% [126 of 144; 95% CI: 77, 94]; P < .001). Conclusion Compared with true unenhanced images, virtual unenhanced (VUE) images were unlikely to change renal mass classification as enhancing mass versus nonenhancing cyst. Diagnostic performance of VUE images remained suboptimal for urinary stone detection due to subtraction of stones 3 mm or less in diameter. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Sosna in this issue.


Assuntos
Neoplasias Renais/diagnóstico por imagem , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Imagem Radiográfica a Partir de Emissão de Duplo Fóton/métodos , Tomografia Computadorizada por Raios X/métodos , Cálculos Urinários/diagnóstico por imagem , Idoso , Algoritmos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Sensibilidade e Especificidade
8.
Radiology ; 294(3): 660-668, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31961246

RESUMO

Intravenous iodinated contrast media are commonly used with CT to evaluate disease and to determine treatment response. The risk of acute kidney injury (AKI) developing in patients with reduced kidney function following exposure to intravenous iodinated contrast media has been overstated. This is due primarily to historic lack of control groups sufficient to separate contrast-induced AKI (CI-AKI; ie, AKI caused by contrast media administration) from contrast-associated AKI (CA-AKI; ie, AKI coincident to contrast media administration). Although the true risk of CI-AKI remains uncertain for patients with severe kidney disease, prophylaxis with intravenous normal saline is indicated for patients who have AKI or an estimated glomerular filtration rate less than 30 mL/min/1.73 m2 who are not undergoing maintenance dialysis. In individual high-risk circumstances, prophylaxis may be considered in patients with an estimated glomerular filtration rate of 30-44 mL/min/1.73 m2 at the discretion of the ordering clinician. This article is a simultaneous joint publication in Radiology and Kidney Medicine. The articles are identical except for stylistic changes in keeping with each journal's style. Either version may be used in citing this article.


Assuntos
Injúria Renal Aguda , Meios de Contraste/efeitos adversos , Compostos de Iodo/efeitos adversos , Insuficiência Renal Crônica , Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/prevenção & controle , Administração Intravenosa , Consenso , Meios de Contraste/administração & dosagem , Humanos , Compostos de Iodo/administração & dosagem , Nefrologia/organização & administração , Guias de Prática Clínica como Assunto , Radiologia/organização & administração , Fatores de Risco
9.
AJR Am J Roentgenol ; 215(4): 896-902, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32809863

RESUMO

OBJECTIVE. The purpose of this study is to determine whether gaussian-based histogram analysis without and with noise correction can characterize indeterminate adrenal nodules (those with attenuation greater than 10 HU on unenhanced CT) as lipid-poor adenomas. MATERIALS AND METHODS. This retrospective study evaluated adrenal nodules larger than 1 cm on unenhanced CT using gaussian analysis without and with noise correction on intralesional ROIs. Two independent readers who were blinded to the final diagnoses evaluated the nodules. The final diagnosis for each nodule was determined on the basis of pathologic findings or accepted imaging criteria. Interreader agreement was assessed using the intraclass correlation coefficient. Algorithm performance was summarized using sensitivity, specificity, and the AUC. RESULTS. Ninety-four adrenal nodules in 85 patients were analyzed; 36 of these were metastases (34 of which were pathologically confirmed), and 58 were presumed adenomas. Interreader agreement was excellent for nodule size, mean attenuation, SD of attenuation, and the gaussian index. Noise-corrected gaussian analysis had significantly higher specificity (81.9% vs 55.6%; p < 0.001) and lower sensitivity (36.2% vs 56.9%; p < 0.001) for identifying adenomas than did the uncorrected gaussian analysis. The AUC of corrected gaussian analysis was 0.72, which is significantly greater than that of uncorrected gaussian analysis (0.51; p ≤ 0.001) and similar to that of mean attenuation (0.77). CONCLUSION. Noise correction is necessary when using a gaussian analysis characterization of indeterminate adrenal nodules on modern unenhanced CT examinations. This method may be able to discriminate between adenomas and nonadenomas.


Assuntos
Adenoma/diagnóstico por imagem , Adenoma/patologia , Neoplasias das Glândulas Suprarrenais/diagnóstico por imagem , Neoplasias das Glândulas Suprarrenais/patologia , Processamento de Imagem Assistida por Computador , Tomografia Computadorizada por Raios X , Algoritmos , Artefatos , Diagnóstico Diferencial , Feminino , Humanos , Lipídeos , Masculino , Distribuição Normal , Estudos Retrospectivos , Sensibilidade e Especificidade
10.
J Comput Assist Tomogr ; 44(6): 812-820, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33196593

RESUMO

OBJECTIVE: The aim of this study was to perform a meta-analysis assessing the diagnostic yield of computed tomography (CT) for the identification of coronavirus disease 2019 (COVID-19) using repeated reverse transcriptase polymerase chain reaction testing or confirmed true-negative state as reference standard. METHODS: In May 2020, we interrogated the MEDLINE, Embase, and CENTRAL databases. Pooled sensitivity, specificity, and diagnostic odds ratios of CT for COVID-19 identification were computed. Cumulative positive predictive value (PPV) and negative predictive value, stratified by disease prevalence, were calculated. RESULTS: Ten articles were included (1332 patients). Pooled sensitivity, specificity, and summary diagnostic odds ratio of CT were 82% [95% confidence interval (CI), 79%-84%], 68% (95% CI, 65%-71%), and 18 (95% CI, 9.8-32.8). The PPV and negative predictive value were 54% (95% CI, 30%-77%) and 94% (95% CI, 88%-99%) at a COVID-19 prevalence lower than 40%, and 80% (95% CI, 62%-91%) and 77% (95% CI, 68%-85%) at a prevalence higher than 40%. CONCLUSION: CT yields higher specificity and PPV, albeit lower sensitivity, than previously reported for the identification of COVID-19.


Assuntos
Técnicas de Laboratório Clínico/métodos , Infecções por Coronavirus/diagnóstico , Pulmão/diagnóstico por imagem , Pneumonia Viral/diagnóstico , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Tomografia Computadorizada por Raios X/métodos , Betacoronavirus , COVID-19 , Teste para COVID-19 , Humanos , Pandemias , Valores de Referência , Reprodutibilidade dos Testes , SARS-CoV-2 , Sensibilidade e Especificidade
11.
FASEB J ; 32(9): 4804-4814, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29596022

RESUMO

The tendon is a mechanosensitive tissue, but little is known about how mechanical stimulation selectively signals tenogenic differentiation and neo-tendon formation. In this study, we compared the impact of uniaxial and biaxial mechanical loading on tendon-derived stem cells (TDSCs). Our data show that there are variations in cell signaling and cell differentiation of mouse TDSCs in response to uniaxial and biaxial loading in monolayer culture. Whereas uniaxial loading induced TDSCs toward tenogenic and osteogenic differentiation, biaxial loading induced osteogenic, adipogenic, and chondrogenic differentiation of TDSCs. Furthermore, by applying uniaxial loading on 3-dimensional (3D) TDSC constructs, tenogenic-specific differentiation and neo-tendon formation were observed, results that were replicated in human TDSCs. We also showed that uniaxial loading induced PKB (AKT) phosphorylation (pAKT), whereas biaxial loading induced pERK. Most importantly, we found that inhibition of the PI3K/AKT signaling pathway could attenuate tenogenic differentiation and tendon formation in 3D TDSC constructs subjected to uniaxial loading. Taken together, our study highlights the importance of appropriate mechanobiological stimulation in 3D cell niches on tendon-like tissue formation and demonstrates that uniaxial mechanical loading plays an essential role in tenogenic differentiation and tendon formation by activating the PI3K/AKT signaling pathway.-Wang, T., Thien, C., Wang, C., Ni, M., Gao, J., Wang, A., Jiang, Q., Tuan, R. S., Zheng, Q., Zheng, M. H. 3D uniaxial mechanical stimulation induces tenogenic differentiation of tendon-derived stem cells through a PI3K/AKT signaling pathway.


Assuntos
Técnicas de Cultura de Células , Diferenciação Celular/fisiologia , Transdução de Sinais/fisiologia , Células-Tronco/citologia , Tendões/citologia , Animais , Células Cultivadas , Mecanotransdução Celular/fisiologia , Camundongos Endogâmicos C57BL , Osteogênese/fisiologia , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo
12.
AJR Am J Roentgenol ; 212(5): 1044-1053, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30835518

RESUMO

OBJECTIVE. The objective of our study was to perform a systematic review and meta-analysis to evaluate the diagnostic accuracy of dual-energy CT (DECT) for renal mass evaluation. MATERIALS AND METHODS. In March 2018, we searched MEDLINE, Cochrane Database of Systematic Reviews, Embase, and Web of Science databases. Analytic methods were based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Pooled estimates for sensitivity, specificity, and diagnostic odds ratios were calculated for DECT-based virtual monochromatic imaging (VMI) and iodine quantification techniques as well as for conventional attenuation measurements from renal mass CT protocols. I2 was used to evaluate heterogeneity. The methodologic quality of the included studies and potential bias were assessed using items from the Quality Assessment Tool for Diagnostic Accuracy Studies 2 (QUADAS-2). RESULTS. Of the 1043 articles initially identified, 13 were selected for inclusion (969 patients, 1193 renal masses). Cumulative data of sensitivity, specificity, and summary diagnostic odds ratio for VMI were 87% (95% CI, 80-92%; I2, 92.0%), 93% (95% CI, 90-96%; I2, 18.0%), and 183.4 (95% CI, 30.7-1093.4; I2, 61.6%), respectively. Cumulative data of sensitivity, specificity, and summary diagnostic odds ratio for iodine quantification were 99% (95% CI, 97-100%; I2, 17.6%), 91% (95% CI, 89-94%; I2, 84.2%), and 511.5 (95% CI, 217-1201; I2, 0%). No significant differences in AUCs were found when comparing iodine quantification to conventional attenuation measurements (p = 0.79). CONCLUSION. DECT yields high accuracy for renal mass evaluation. Determination of iodine content with the iodine quantification technique shows diagnostic accuracy similar to conventional attenuation measurements from renal mass CT protocols. The iodine quantification technique may be used to characterize incidental renal masses when a dedicated renal mass protocol is not available.

13.
Radiology ; 289(2): 443-454, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30015591

RESUMO

Purpose To investigate performance in detectability of small (≤1 cm) low-contrast hypoattenuating focal lesions by using filtered back projection (FBP) and iterative reconstruction (IR) algorithms from two major CT vendors across a range of 11 radiation exposures. Materials and Methods A low-contrast detectability phantom consisting of 21 low-contrast hypoattenuating focal objects (seven sizes between 2.4 and 10.0 mm, three contrast levels) embedded into a liver-equivalent background was scanned at 11 radiation exposures (volume CT dose index range, 0.5-18.0 mGy; size-specific dose estimate [SSDE] range, 0.8-30.6 mGy) with four high-end CT platforms. Data sets were reconstructed by using FBP and varied strengths of image-based, model-based, and hybrid IRs. Sixteen observers evaluated all data sets for lesion detectability by using a two-alternative-forced-choice (2AFC) paradigm. Diagnostic performances were evaluated by calculating area under the receiver operating characteristic curve (AUC) and by performing noninferiority analyses. Results At benchmark exposure, FBP yielded a mean AUC of 0.79 ± 0.09 (standard deviation) across all platforms which, on average, was approximately 2% lower than that observed with the different IR algorithms, which showed an average AUC of 0.81 ± 0.09 (P = .12). Radiation decreases of 30%, 50%, and 80% resulted in similar declines of observer detectability with FBP (mean AUC decrease, -0.02 ± 0.05, -0.03 ± 0.05, and -0.05 ± 0.05, respectively) and all IR methods investigated (mean AUC decrease, -0.00 ± 0.05, -0.04 ± 0.05, and -0.04 ± 0.05, respectively). For each radiation level and CT platform, variance in performance across observers was greater than that across reconstruction algorithms (P = .03). Conclusion Iterative reconstruction algorithms have limited radiation optimization potential in detectability of small low-contrast hypoattenuating focal lesions. This task may be further complicated by a high degree of variation in radiologists' performances, seemingly exceeding real performance differences among reconstruction algorithms. © RSNA, 2018 Online supplemental material is available for this article.


Assuntos
Fígado/diagnóstico por imagem , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Tomografia Computadorizada por Raios X/métodos , Algoritmos , Variações Dependentes do Observador , Imagens de Fantasmas , Doses de Radiação , Reprodutibilidade dos Testes
14.
AJR Am J Roentgenol ; 211(1): W1-W12, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29812983

RESUMO

OBJECTIVE: The purpose of this article is to assess the performance of a contrast reaction management checklist for optimal management of a contrast reaction scenario created using a high-fidelity hands-on simulation. MATERIALS AND METHODS: A safety checklist was designed that presented the five adverse events that most commonly occur after administration of IV contrast medium as well as their step-by-step management. Forty-three radiology residents were randomized into two groups, a checklist group (n = 22) and a control group (n = 21), as stratified by postgraduate year. Participants took written tests involving multiple-choice questions 2 months before and immediately after participating in the high-fidelity simulation scenario, which was videotaped and independently evaluated by three graders. RESULTS: Both groups had similar scores on the multiple-choice question tests taken before and after participation in the simulation (p = 0.35 and p = 0.62, respectively). In the simulation, the checklist group scored significantly higher than the control group with regard to their overall management of a severe contrast reaction (85.1% vs 64.8%; p = 0.001), including individual scores for first-line treatment of bronchospasm (97.0% vs 91.3%; p = 0.035) and use of the correct route of administration and dose of epinephrine (77.3% vs 45.2%; p = 0.021). CONCLUSION: A standardized contrast reaction management checklist can reduce the number of treatment errors that occur during a simulated severe contrast reaction, particularly with regard to proper administration of epinephrine and treatment of bronchospasm. Such a checklist could be used by radiologists, technologists, and nurses to improve patient safety as a result of improved contrast reaction management and teamwork skills.


Assuntos
Lista de Checagem , Meios de Contraste/efeitos adversos , Manequins , Radiologia/educação , Educação de Pós-Graduação em Medicina , Avaliação Educacional , Humanos , Internato e Residência
15.
AJR Am J Roentgenol ; 206(5): 924-32, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26998884

RESUMO

OBJECTIVE: Soft-tissue sarcomas are a diverse group of malignancies, and our rapidly improving understanding of their molecular pathogenesis and treatment is leading to better clinical outcomes. The revised 2013 World Health Organization (WHO) classification of soft-tissue sarcomas introduced several important changes. We provide a comprehensive overview of the relevant changes for radiologists. CONCLUSION: Rapid advances in the understanding of the pathogenesis and molecular biology of soft-tissue sarcomas led to major revisions in the 2013 WHO classification. To provide optimal multidisciplinary patient care, radiologists must remain up-to-date with the latest developments in the field of soft-tissue sarcomas to best correlate the histologic and imaging features of the various types of tumors and understand the unique patterns of treatment response and disease recurrence.


Assuntos
Sarcoma/classificação , Sarcoma/diagnóstico , Humanos , Sarcoma/genética , Sarcoma/patologia , Organização Mundial da Saúde
16.
Radiographics ; 36(7): 2141-2153, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27768542

RESUMO

Optimal treatment of thyroid cancer is highly dependent on accurate staging of the extent of disease at presentation. Preoperative ultrasonography (US) is the most sensitive method for detecting metastatic lymph nodes and is recommended as part of the standard preoperative workup. Missed findings on preoperative scans may lead to understaging and inadequate surgical management, which subsequently predispose these patients to residual disease postoperatively and a higher risk for recurrence, possibly requiring repeat surgery. Traditionally, thyroid US for pre- and postoperative staging has been performed by radiologists. However, there is a growing trend away from radiologist-performed US in favor of surgeon-performed US. Recent surgical and endocrinology literature has shown that, when compared with surgeon-performed US, radiologist-performed preoperative staging US is less accurate and is inadequate for presurgical planning, with higher local recurrence rates. This review highlights the importance of accurate preoperative US for patients with differentiated thyroid cancer, with specific attention to deficiencies that exist in general radiology department thyroid US reports. We present a standardized approach to neck US reporting that incorporates the newly updated 2015 recommendations from the American Thyroid Association and also addresses the pertinent questions for thyroid surgeons. By ensuring comprehensive preoperative assessment and improving thyroid US reporting, we seek to improve patient access to optimized care. ©RSNA, 2016.


Assuntos
Assistência Perioperatória/normas , Radiologistas/normas , Radiologia/normas , Neoplasias da Glândula Tireoide/diagnóstico por imagem , Neoplasias da Glândula Tireoide/cirurgia , Ultrassonografia/normas , Competência Clínica/normas , Humanos , Prognóstico , Resultado do Tratamento , Estados Unidos
17.
AJR Am J Roentgenol ; 203(1): W21-33, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24951226

RESUMO

OBJECTIVE: Hepatic malignancy is a common and lethal disease, whether due to a primary tumor or metastasis. There are numerous treatment options available depending on the stage of the disease and medical condition of the patient, including systemic chemotherapy, transcatheter embolization, thermal ablation, and surgical resection. In a subset of patients with liver malignancy, surgical resection can offer the best chance of long-term survival and potentially even cure. This article reviews the major indications and contraindications for resection, basic surgical techniques and terminology, key clinical and imaging preoperative workup, and pertinent interventional oncology procedures in the management of hepatic malignancy. CONCLUSION: Diagnostic and interventional radiology plays an important role in the assessment and treatment of malignant hepatic lesions. Radiologists should be familiar with how surgeons select, work up, and treat candidates for liver resection to provide the most clinically valuable service.


Assuntos
Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/cirurgia , Colangiocarcinoma/diagnóstico por imagem , Colangiocarcinoma/cirurgia , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/cirurgia , Adulto , Idoso , Biópsia , Carcinoma Hepatocelular/patologia , Ablação por Cateter/métodos , Colangiocarcinoma/patologia , Contraindicações , Detecção Precoce de Câncer , Feminino , Hepatectomia/métodos , Humanos , Testes de Função Hepática , Neoplasias Hepáticas/patologia , Transplante de Fígado , Masculino , Pessoa de Meia-Idade , Terapia Neoadjuvante , Estadiamento de Neoplasias , Complicações Pós-Operatórias/diagnóstico , Prognóstico , Radiografia Intervencionista
18.
AJR Am J Roentgenol ; 203(1): W34-47, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24951228

RESUMO

OBJECTIVE: Hepatocellular carcinomas (HCCs) that arise in noncirrhotic livers have several histologic and biochemical features that distinguish them from HCCs occurring in the setting of cirrhosis. Because the presentation, management, and prognosis of these entities are distinct, the accurate preoperative characterization of these lesions is of great clinical significance. We review the pathogenesis, imaging appearance, and clinical implications of noncirrhotic HCCs as they pertain to the clinical radiologist. CONCLUSION: HCCs that develop in noncirrhotic patients have distinct etiologic, cytogenetic, histopathologic, and clinical features. Despite a larger tumor burden at the time of HCC diagnosis, noncirrhotic patients with HCC have better overall survival and disease-free survival than cirrhotic patients with HCC. Knowledge of the precise clinical and imaging features of this entity and of other diagnostic considerations for the noncirrhotic liver is essential for improved patient care.


Assuntos
Carcinoma Hepatocelular/patologia , Diagnóstico por Imagem , Neoplasias Hepáticas/patologia , Biomarcadores Tumorais/análise , Carcinoma Hepatocelular/etiologia , Carcinoma Hepatocelular/terapia , Meios de Contraste , Diagnóstico Diferencial , Humanos , Cirrose Hepática/patologia , Neoplasias Hepáticas/etiologia , Neoplasias Hepáticas/terapia , Prognóstico , Fatores de Risco , Análise de Sobrevida
19.
Abdom Imaging ; 39(5): 1127-33, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25237003

RESUMO

PURPOSE: To determine the most common errors of epinephrine administration during severe allergic-like contrast reaction management using high-fidelity simulation surrogates. MATERIALS AND METHODS: IRB approval and informed consent were obtained for this HIPAA-compliant bi-institutional prospective study of 40 radiology residents, fellows, and faculty who were asked to manage a structured high-fidelity severe allergic-like contrast reaction scenario (i.e., mild hives progressing to mild bronchospasm, then bronchospasm unresponsive to bronchodilators, and finally anaphylactic shock) on an interactive manikin. Intravenous (IV) and intramuscular epinephrine ampules were available to all participants, and the manikin had a functioning intravenous catheter for all scenarios. Video recordings of their performance were reviewed by experts in contrast reaction management, and errors in epinephrine administration were recorded and characterized. RESULTS: No participant (0/40) failed to give indicated epinephrine, but more than half (58% [23/40]) committed an error while doing so. The most common mistake was to administer epinephrine as the first-line treatment for mild bronchospasm (33% [13/40]). Other common errors were to administer IV epinephrine without a subsequent IV saline flush or concomitant IV fluids (25% [10/40]), administer an overdose of epinephrine (8% [3/40]), and administer epinephrine 1:1000 intravenously (8% [3/40]). CONCLUSION: Epinephrine administration errors are common. Many radiologists fail to administer albuterol as the first-line treatment for mild bronchospasm and fail to flush the IV catheter when administering IV epinephrine. High-fidelity contrast reaction scenarios can be used to identify areas for training improvement.


Assuntos
Meios de Contraste/efeitos adversos , Epinefrina/uso terapêutico , Hipersensibilidade Imediata/tratamento farmacológico , Manequins , Erros de Medicação/estatística & dados numéricos , Radiologia/educação , Administração Intravenosa , Agonistas alfa-Adrenérgicos/uso terapêutico , Epinefrina/administração & dosagem , Humanos , Hipersensibilidade Imediata/induzido quimicamente , Estudos Prospectivos
20.
Abdom Radiol (NY) ; 49(3): 823-841, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38017112

RESUMO

With advancements in cancer treatment, the survival rates for many malignancies have increased. However, both the primary tumors and the treatments themselves can give rise to various complications. Acute symptoms in oncology patients require prompt attention. Abdominopelvic oncologic emergencies can be classified into four distinct categories: vascular, bowel, hepatopancreatobiliary, and bone-related complications. Radiologists need to be familiar with these complications to ensure timely diagnosis, which ultimately enhances patient outcomes.


Assuntos
Emergências , Neoplasias , Humanos , Diagnóstico por Imagem , Oncologia
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