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1.
AJR Am J Roentgenol ; 212(3): 554-561, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30620676

RESUMEN

OBJECTIVE: The purpose of this study is to determine whether second-order texture analysis can be used to distinguish lipid-poor adenomas from malignant adrenal nodules on unenhanced CT, contrast-enhanced CT (CECT), and chemical-shift MRI. MATERIALS AND METHODS: In this retrospective study, 23 adrenal nodules (15 lipid-poor adenomas and eight adrenal malignancies) in 20 patients (nine female patients and 11 male patients; mean age, 59 years [range, 15-80 years]) were assessed. All patients underwent unenhanced CT, CECT, and chemical-shift MRI. Twenty-one second-order texture features from the gray-level cooccurrence matrix and gray-level run-length matrix were calculated in 3D. The mean values for 21 texture features and four imaging features (lesion size, unenhanced CT attenuation, CECT attenuation, and signal intensity index) were compared using a t test. The diagnostic performance of texture analysis versus imaging features was also compared using AUC values. Multivariate logistic regression models to predict malignancy were constructed for texture analysis and imaging features. RESULTS: Lesion size, unenhanced CT attenuation, and the signal intensity index showed significant differences between benign and malignant adrenal nodules. No significant difference was seen for CECT attenuation. Eighteen of 21 CECT texture features and nine of 21 unenhanced CT texture features revealed significant differences between benign and malignant adrenal nodules. CECT texture features (mean AUC value, 0.80) performed better than CECT attenuation (mean AUC value, 0.60). Multivariate logistic regression models showed that CECT texture features, chemical-shift MRI texture features, and imaging features were predictive of malignancy. CONCLUSION: Texture analysis has a potential role in distinguishing benign from malignant adrenal nodules on CECT and may decrease the need for additional imaging studies in the workup of incidentally discovered adrenal nodules.


Asunto(s)
Adenoma/diagnóstico por imagen , Neoplasias de las Glándulas Suprarrenales/diagnóstico por imagen , Interpretación de Imagen Asistida por Computador/métodos , Imagen por Resonancia Magnética/métodos , Tomografía Computarizada por Rayos X/métodos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Medios de Contraste , Diagnóstico Diferencial , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos
2.
AJR Am J Roentgenol ; 210(6): 1266-1272, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29629800

RESUMEN

OBJECTIVE: The purpose of this study is to compare visualization rates of the major features covered by Liver Imaging Reporting and Data System (LI-RADS) version 2014 in patients at risk for hepatocellular carcinoma using either gadobenate dimeglumine or gadoxetate disodium IV contrast agent. MATERIALS AND METHODS: This retrospective study included liver MRI examinations performed with either gadobenate dimeglumine or gadoxetate disodium contrast enhancement. Using age, sex, underlying liver disease, and presence of cirrhosis, patients were placed into matched cohorts. All hepatic nodules 1 cm or larger (up to five per subject) were included, resulting in 63 subjects with 130 nodules (median nodule size, 1.9 cm) imaged with gadobenate and 64 subjects with 117 nodules (median nodule size, 2.0 cm) imaged with gadoxetate. Three radiologists reviewed the studies for LI-RADS major features independently. Bootstrap resampling with 10,000 repetitions was used to compare feature detection rates. RESULTS: Arterial phase hyperenhancement was seen in a similar number of nodules with gadobenate dimeglumine (mean, 91.5% [119/130]) and gadoxetate disodium (mean, 88.0% [103/117]) (p = 0.173). Dynamic phase washout was more commonly seen with gadobenate dimeglumine (mean, 60.2% [78.3/130]) than with gadoxetate disodium (mean, 45.3% [53/117]) (p = 0.006). The capsule feature was more often visualized with gadobenate dimeglumine (mean, 50.2% [65.3/130]) than with gadoxetate disodium (mean, 33.3% [39/117]) (p < 0.001). Interreader agreement for arterial phase enhancement and dynamic phase washout was almost perfect for both contrast agents (κ > 0.83). Agreement for the capsule feature was moderate for gadobenate dimeglumine (κ = 0.52) and substantial for gadoxetate disodium (κ = 0.67). CONCLUSION: The rates of visualization of arterial phase hyperenhancement are similar in studies performed with gadobenate dimeglumine and gadoxetate disodium, but dynamic phase washout and capsule appearance are more commonly visualized with gadobenate dimeglumine.


Asunto(s)
Carcinoma Hepatocelular/diagnóstico por imagen , Medios de Contraste/administración & dosificación , Gadolinio DTPA/administración & dosificación , Neoplasias Hepáticas/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Meglumina/análogos & derivados , Compuestos Organometálicos/administración & dosificación , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma Hepatocelular/patología , Femenino , Humanos , Neoplasias Hepáticas/patología , Masculino , Meglumina/administración & dosificación , Persona de Mediana Edad , Estudios Retrospectivos
3.
J Comput Assist Tomogr ; 42(2): 197-203, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-28991065

RESUMEN

OBJECTIVE: This study aimed to determine potential radiation dose reduction of contrast-enhanced computed tomography (CECT) for imaging necrotizing pancreatitis (NP) using a noise addition tool. METHODS: Eighty-four patients were identified with at least 1 abdominopelvic CECT for NP within a 2-year period. Sixty consecutive scans were selected as reference radiation dose data sets. A noise addition software was used to simulate 4 data sets of increased noise. Readers rated confidence for identifying (i) anatomic structures, (ii) complications of NP, and (iii) diagnostic acceptability. Noise and dose levels were identified at acceptability threshold where observer scores were statistically indistinguishable from full-dose computed tomographies. RESULTS: Observers' perception of image tasks decreased progressively with increasing noise (P < 0.05). Acceptability and statistical analysis indicated that noise can be increased from 10 to 25 HU corresponding to an 84% reduction in dose without change in observer perception (P < 0.05). CONCLUSIONS: Higher image noise levels may be tolerated in CECT in patients with NP.


Asunto(s)
Medios de Contraste , Pancreatitis Aguda Necrotizante/diagnóstico por imagen , Dosis de Radiación , Intensificación de Imagen Radiográfica/métodos , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Tomografía Computarizada por Rayos X/métodos , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Páncreas/diagnóstico por imagen
4.
Radiology ; 274(2): 445-54, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25207467

RESUMEN

PURPOSE: To determine whether contrast material-enhanced dual-energy multidetector computed tomography (CT) with material decomposition analysis allows differentiation of adrenal adenomas from nonadenomatous lesions and to compare findings with those of nonenhanced multidetector CT. MATERIALS AND METHODS: This retrospective HIPAA-compliant study was approved by the institutional review board of Duke University, with waiver of informed consent. Thirty-eight nonconsecutive patients (22 men and 16 women; mean age, 65 years) with 47 adrenal nodules underwent nonenhanced and contrast-enhanced dual-energy multidetector CT of the abdomen. For each adrenal nodule, nonenhanced attenuation values were recorded; dual-energy density measurements were obtained by using fat-iodine and fat-water material density basis pairs. Mean and median values of nonenhanced attenuation and material densities were compared between adenomas and nonadenomas by using the two-sample t test and Wilcoxon rank sum test, respectively. The diagnostic performance of nonenhanced multidetector CT and dual-energy material densities was assessed by setting the specificity for diagnosis of adenomas at 100%. RESULTS: Adenomas (lipid rich and lipid poor) displayed significantly different mean density values (in milligrams per cubic centimeter) than those of nonadenomas on fat-iodine (970.4 ± 17.2 vs 1012.3 ± 9.3), iodine-fat (2.5 ± 0.3 vs 4.5 ± 1.5), fat-water (-666.7 ± 154.8 vs -2141.8 ± 953.2), and water-fat (1628.4 ± 177.3 vs 3225 ± 986.1) images, respectively (P < .0001). For diagnosis of adenomas, dual-energy material density analysis showed a sensitivity of 96% (23 of 24 lesions) at a specificity of 100% (23 of 23 lesions), yielding significantly improved diagnostic performance compared with nonenhanced multidetector CT attenuation (sensitivity of 67% [16 of 24 lesions] at a specificity of 100% [23 of 23 lesions]) (P = .035). CONCLUSION: Contrast-enhanced dual-energy multidetector CT with material density analysis allows differentiation between adrenal adenomas and nonadenomas, reflecting an improved ability over nonenhanced multidetector CT for diagnosis of lipid-poor adenoma.


Asunto(s)
Adenoma/diagnóstico por imagen , Neoplasias de las Glándulas Suprarrenales/diagnóstico por imagen , Medios de Contraste , Hallazgos Incidentales , Tomografía Computarizada Multidetector/métodos , Anciano , Femenino , Humanos , Masculino , Estudios Retrospectivos , Sensibilidad y Especificidad
5.
AJR Am J Roentgenol ; 205(2): 421-8, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26204296

RESUMEN

OBJECTIVE: Many radiologists are unfamiliar with the new antithrombogenic medications and how to modify patient management before nonvascular percutaneous procedures performed in a radiology department. In this article, we review the indications for use, mechanism of action, pharmacokinetics, dosing, and recommendations for periprocedural management of patients using these medications. CONCLUSION: To improve patient safety, radiologists involved in percutaneous procedures should have knowledge of the antithrombotics that will be encountered routinely in clinical practice.


Asunto(s)
Anticoagulantes/farmacología , Endoscopía , Hemorragia/etiología , Hemorragia/prevención & control , Inhibidores de Agregación Plaquetaria/farmacología , Radiografía Intervencional , Anticoagulantes/administración & dosificación , Anticoagulantes/farmacocinética , Humanos , Seguridad del Paciente , Inhibidores de Agregación Plaquetaria/administración & dosificación , Inhibidores de Agregación Plaquetaria/farmacocinética , Guías de Práctica Clínica como Asunto
6.
Abdom Imaging ; 40(8): 3052-61, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26350286

RESUMEN

OBJECTIVE: To determine the diagnostic performance of imaging criteria for distinguishing Ig-G4-associated autoimmune cholangiopathy (IAC) from primary sclerosing cholangitis (PSC) and bile duct malignancy. METHODS: A medical records search between January 2008 and October 2013 identified 10 patients (8 M, 2 F, mean age 61 years, range 34-82) with a clinical diagnosis of IAC. Fifteen cases of PSC (6 M, 9 F, mean age 50, range 22-65) and 15 cases of biliary malignancy (7 M, 8 F, mean age 65, range 48-84) were randomly selected for comparative analysis. Three abdominal radiologists independently reviewed MRI with MRCP (n = 32) or CT (n = 8) and ERCP (n = 8) for the following IAC imaging predictors: single-wall bile duct thickness >2.5 mm, continuous biliary involvement, gallbladder involvement, liver disease, peribiliary mass, or pancreatic and renal abnormalities. Each radiologist provided an imaging-based diagnosis (IAC, PSC, or cancer). Imaging predictor sensitivity, specificity, accuracy, and association with IAC using Fisher's exact test. Inter-reader agreement determined using Fleiss' kappa statistics. RESULTS: For diagnosis of IAC, sensitivities and specificities were high (70-93%). Pancreatic abnormality was strongest predictor for distinguishing IAC from PSC and cancer, with high diagnostic performance (70-80% sensitivity, 87-97% specificity), significant association (p < 0.01), and moderate inter-reader agreement (κ = 0.59). Continuous biliary involvement was moderately predictive (50-100% sensitivity, 53-83% specificity) and trended toward significant association in distinguishing from PSC (p = 0.01-0.19), but less from cancer (p = 0.06-0.62). CONCLUSION: It remains difficult to distinguish IAC from PSC or bile duct malignancy based on imaging features alone. The presence of pancreatic abnormalities, including peripancreatic rind, atrophy, abnormal enhancement, or T2 signal intensity, strongly favors a diagnosis of IAC.


Asunto(s)
Enfermedades Autoinmunes/patología , Enfermedades de los Conductos Biliares/patología , Neoplasias de los Conductos Biliares/patología , Colangitis Esclerosante/patología , Imagen por Resonancia Magnética , Adulto , Anciano , Anciano de 80 o más Años , Sistema Biliar/patología , Diagnóstico Diferencial , Femenino , Humanos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Reproducibilidad de los Resultados , Estudios Retrospectivos , Sensibilidad y Especificidad , Adulto Joven
7.
Abdom Imaging ; 40(7): 2850-60, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25783958

RESUMEN

PURPOSE: To prospectively evaluate whether clinical experience with an adaptive statistical iterative reconstruction algorithm (ASiR) has an effect on radiologists' diagnostic performance and confidence for the diagnosis of hypervascular liver tumors, as well as on their subjective perception of image quality. MATERIALS AND METHODS: Forty patients, having 65 hypervascular liver tumors, underwent contrast-enhanced MDCT during the hepatic arterial phase. Image datasets were reconstructed with filtered backprojection algorithm and ASiR (20%, 40%, 60%, and 80% blending). During two reading sessions, performed before and after a three-year period of clinical experience with ASiR, three readers assessed datasets for lesion detection, likelihood of malignancy, and image quality. RESULTS: For all reconstruction algorithms, there was no significant change in readers' diagnostic accuracy and sensitivity for the detection of liver lesions, between the two reading sessions. However, a 60% ASiR dataset yielded a significant improvement in specificity, lesion conspicuity, and confidence for lesion likelihood of malignancy during the second reading session (P < 0.0001). The 60% ASiR dataset resulted in significant improvement in readers' perception of image quality during the second reading session (P < 0.0001). CONCLUSIONS: Clinical experience using an ASiR algorithm may improve radiologists' diagnostic performance for the diagnosis of hypervascular liver tumors, as well as their perception of image quality.


Asunto(s)
Neoplasias Hepáticas/diagnóstico por imagen , Hígado/diagnóstico por imagen , Tomografía Computarizada Multidetector , Anciano , Algoritmos , Competencia Clínica , Medios de Contraste , Femenino , Humanos , Aumento de la Imagen , Hígado/irrigación sanguínea , Masculino , Persona de Mediana Edad , Neovascularización Patológica/diagnóstico por imagen , Estudios Prospectivos , Interpretación de Imagen Radiográfica Asistida por Computador
8.
J Ultrasound ; 27(2): 329-334, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38332311

RESUMEN

RATIONAL AND OBJECTIVES: To increase utilization of contrast-enhanced ultrasound (CEUS) during ultrasound-guided targeted liver biopsies. MATERIAL AND METHODS: Two educational training interventions performed to increase use of CEUS. First, 14 radiologists (fellowship-trained in Abdominal Imaging) given didactic teaching and case presentations on the use of CEUS. Second, hands-on teaching on how to use CEUS provided to the same group. To determine the efficacy of these two interventions, radiologists completed anonymous surveys to determine the level of understanding and acceptability of using CEUS before and 6 months after CEUS training. In addition, the percentage of CEUS assisted liver biopsies was compared for the 6 months before and 6 months after the training. RESULTS: Pre-training survey completed by 11 radiologists and post-training survey completed by 9 radiologists. Before training, 11% survey responders use CEUS routinely, whereas 89% never or rarely used it. After training, 54% of respondents were new users and 100% reported they planned to use CEUS in the future. Unfamiliarity (71%) was the main reason for not using it. After training, 25% reported lack of comfort with using CEUS as the main reason for not using CEUS. During six months before training, CEUS was administered in 6% (10/172) of targeted liver biopsies. Six months after training, CEUS was used nearly twice as often (10%, 16/160, P = 0.09, 1-sided Boschloo test). The number of radiologists using CEUS increased to 57% (8/14) after training compared to 20% (3/14, P = 0.03, 1-sided Boschloo) before training. CONCLUSION: Educational training intervention increases use of CEUS during ultrasound-guided targeted liver biopsies.


Asunto(s)
Medios de Contraste , Hígado , Humanos , Hígado/diagnóstico por imagen , Hígado/patología , Biopsia Guiada por Imagen , Ultrasonografía/métodos , Abdomen/diagnóstico por imagen , Ultrasonografía Intervencional , Encuestas y Cuestionarios , Radiología/educación
9.
J Magn Reson Imaging ; 37(2): 398-406, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23011874

RESUMEN

PURPOSE: To evaluate the value of hepatobiliary phase imaging for detection and characterization of hepatocellular carcinoma (HCC) in liver MRI with Gd-EOB-DTPA, in a North American population. MATERIALS AND METHODS: One hundred MRI examinations performed with the intravenous injection of Gd-EOB-DTPA in patients with cirrhosis were reviewed retrospectively. Nodules were classified as HCC (n = 70), indeterminate (n = 33), or benign (n = 22). Five readers independently reviewed each examination with and without hepatobiliary phase images (HBP). Lesion conspicuity scores were compared between the two readings. Lesion detection, confidence scores, and receiver operating characteristic (ROC) analysis were compared. RESULTS: Lesion detection was slightly improved for all lesion types with the inclusion of the HBP, and was substantially higher for small HCCs (96.0% versus 85.3%). Mean confidence scores for the diagnosis of HCC increased for HCCs overall and each size category (P < 0.001). Diagnostic performance improved with the addition of the HBP (aggregate AROC 87.7% versus 80.0%, P < 0.01), and sensitivity for characterization improved (90.9% versus 78.3%, P < 0.01) while specificity was unchanged. CONCLUSION: Hepatobiliary phase imaging may improve small lesion detection (<1 cm) and characterization of lesions in general, in MRI of the cirrhotic liver with Gd-EOB-DTPA.


Asunto(s)
Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/epidemiología , Gadolinio DTPA , Cirrosis Hepática/diagnóstico , Cirrosis Hepática/epidemiología , Imagen por Resonancia Magnética/estadística & datos numéricos , Adulto , Anciano , Anciano de 80 o más Años , Comorbilidad , Medios de Contraste , Femenino , Humanos , Masculino , Persona de Mediana Edad , North Carolina/epidemiología , Prevalencia , Reproducibilidad de los Resultados , Factores de Riesgo , Sensibilidad y Especificidad
10.
Eur Radiol ; 23(12): 3325-35, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23832320

RESUMEN

OBJECTIVES: To investigate the impact of an adaptive statistical iterative reconstruction (ASiR) algorithm on diagnostic accuracy and confidence for the diagnosis of hypervascular liver tumours, as well as the reader's perception of image quality, using a low tube voltage (80 kVp), high tube current computed tomography (CT) technique. METHODS: Forty patients (29 men, 11 women) with 65 hypervascular liver tumours underwent dual energy CT. The 80 kV set of the dual energy acquisition was reconstructed with standard filtered backprojection (FBP) and ASiR at different blending levels. Lesion contrast-to-noise ratio (CNR), reader's confidence for lesion detection and characterisation, and reader's evaluation of image quality were recorded. RESULTS: ASiR yielded significantly higher CNR values compared with FBP (P < 0.0001 for all comparisons). Reader's perception of lesion conspicuity and confidence in the diagnosis of malignancy were also higher with 60 % and 80 % ASiR, compared with FBP (P = 0.01 and < 0.001, respectively). Compared with FBP, ASiR yielded nearly significantly lower specificity for lesion detection and a substantial decrease in the reader's perception of image quality. CONCLUSIONS: Compared with the standard FBP algorithm, ASiR significantly improves conspicuity of hypervascular liver lesions. This improvement may come at the cost of decreased specificity and reader's perception of image quality.


Asunto(s)
Algoritmos , Carcinoma Hepatocelular/irrigación sanguínea , Carcinoma Hepatocelular/diagnóstico por imagen , Neoplasias Hepáticas/irrigación sanguínea , Neoplasias Hepáticas/diagnóstico por imagen , Tomografía Computarizada Multidetector/métodos , Intensificación de Imagen Radiográfica/métodos , Anciano , Carcinoma Hepatocelular/patología , Carcinoma Hepatocelular/secundario , Carcinoma de Células Renales/secundario , Medios de Contraste , Diagnóstico Precoz , Femenino , Humanos , Neoplasias Hepáticas/patología , Neoplasias Hepáticas/secundario , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Dosis de Radiación , Interpretación de Imagen Radiográfica Asistida por Computador , Sensibilidad y Especificidad
11.
AJR Am J Roentgenol ; 201(1): 223-9, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23789679

RESUMEN

OBJECTIVE: The objective of this article is to review the MRI and ultrasound appearances of incarcerated uterus. CONCLUSION: Incarcerated uterus is a rare but serious complication of pregnancy in which the gravid uterus becomes trapped in the posterior pelvis. Characteristic MRI and ultrasound imaging features enable definitive diagnosis of incarcerated uterus, which reduces risks of complications that can lead to maternal and fetal morbidity and mortality.


Asunto(s)
Imagen por Resonancia Magnética/métodos , Complicaciones del Embarazo/diagnóstico , Ultrasonografía Prenatal/métodos , Retroversión Uterina/diagnóstico , Adulto , Diagnóstico Diferencial , Femenino , Humanos , Embarazo , Complicaciones del Embarazo/diagnóstico por imagen , Factores de Riesgo , Retroversión Uterina/diagnóstico por imagen
12.
J Comput Assist Tomogr ; 37(3): 408-14, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23674013

RESUMEN

OBJECTIVE: The objectives of this study were to explore utilization of multi-detector row computed tomography (MDCT) in screening for hepatocellular carcinoma (HCC) and to modify a liver CT protocol with a goal of dose reduction. METHODS: An electronic mail survey querying HCC surveillance practices was sent. One hundred forty consecutive patients referred for HCC indications underwent 4-phase MDCT of the liver. The unenhanced and delayed phases were evaluated by 3 readers for identification of HCC and reader confidence. The estimated effective dose (ED) was calculated. RESULTS: Computed tomography is primarily used to screen for HCC. Average estimated ED was 35.5 mSv. Unenhanced phase did not add to reader confidence; delayed phase increased confidence in 47% of cases. Thirty-two percent of the screening population had cumulative ED of greater than 200 mSv. CONCLUSIONS: Multi-detector row CT of the liver is used frequently in screening for HCC. Unenhanced phase imaging does not add to HCC detection and may be eliminated to reduce radiation dose.


Asunto(s)
Carcinoma Hepatocelular/diagnóstico por imagen , Hepatopatías/diagnóstico por imagen , Hepatopatías/cirugía , Neoplasias Hepáticas/diagnóstico por imagen , Trasplante de Hígado , Tomografía Computarizada Multidetector/métodos , Pautas de la Práctica en Medicina/estadística & datos numéricos , Dosis de Radiación , Adulto , Biopsia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Interpretación de Imagen Radiográfica Asistida por Computador , Sensibilidad y Especificidad , Encuestas y Cuestionarios
13.
Clin Imaging ; 99: 60-66, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-37116263

RESUMEN

OBJECTIVES: The purpose is to apply a previously validated deep learning algorithm to a new thyroid nodule ultrasound image dataset and compare its performances with radiologists. METHODS: Prior study presented an algorithm which is able to detect thyroid nodules and then make malignancy classifications with two ultrasound images. A multi-task deep convolutional neural network was trained from 1278 nodules and originally tested with 99 separate nodules. The results were comparable with that of radiologists. The algorithm was further tested with 378 nodules imaged with ultrasound machines from different manufacturers and product types than the training cases. Four experienced radiologists were requested to evaluate the nodules for comparison with deep learning. RESULTS: The Area Under Curve (AUC) of the deep learning algorithm and four radiologists were calculated with parametric, binormal estimation. For the deep learning algorithm, the AUC was 0.69 (95% CI: 0.64-0.75). The AUC of radiologists were 0.63 (95% CI: 0.59-0.67), 0.66 (95% CI:0.61-0.71), 0.65 (95% CI: 0.60-0.70), and 0.63 (95%CI: 0.58-0.67). CONCLUSION: In the new testing dataset, the deep learning algorithm achieved similar performances with all four radiologists. The relative performance difference between the algorithm and the radiologists is not significantly affected by the difference of ultrasound scanner.


Asunto(s)
Aprendizaje Profundo , Nódulo Tiroideo , Humanos , Nódulo Tiroideo/diagnóstico por imagen , Nódulo Tiroideo/patología , Estudios Retrospectivos , Ultrasonografía/métodos , Redes Neurales de la Computación
14.
AJR Am J Roentgenol ; 199(5 Suppl): S64-70, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23097169

RESUMEN

OBJECTIVE: The purpose of this article is to give a brief overview of the technical background of dual-energy CT (DECT) imaging and to review various DECT applications in the abdomen that are currently available for clinical practice. In a review of the recent literature, specific DECT applications available for abdominal organs, liver, pancreas, kidneys including renal stones, and adrenal glands, will be discussed in light of reliability and clinical usefulness in replacing true unenhanced imaging, increased lesion conspicuity, iodine extraction, and improved tissue/material characterization (e.g., renal stone composition). Radiation dose considerations will be addressed in comparison with standard abdominal imaging protocols. CONCLUSION: Modern DECT applications for the abdomen expand the use of CT and enable advanced quantitative methods in the clinical routine on the basis of differences in material attenuation observed by imaging at two different distinct photon energies.


Asunto(s)
Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Radiografía Abdominal/métodos , Imagen Radiográfica por Emisión de Doble Fotón/métodos , Tomografía Computarizada por Rayos X/métodos , Humanos
15.
AJR Am J Roentgenol ; 198(2): 377-83, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22268181

RESUMEN

OBJECTIVE: The objective of our study was to retrospectively determine whether minimal fat renal angiomyolipoma can be differentiated from clear cell or papillary renal cell carcinoma (RCC) in small renal masses using attenuation measurement histogram analysis on unenhanced CT. MATERIALS AND METHODS: Twenty minimal fat renal angiomyolipomas were compared with 22 clear cell RCCs and 23 papillary RCCs using an institutional database. All masses were histologically confirmed and all minimal fat renal angiomyolipomas lacked radiographic evidence of macroscopic fat. Using attenuation measurement histogram analysis, two blinded radiologists determined the percentage of negative pixels within each renal mass. The percentages of negative pixels below attenuation thresholds of 0, -5, -10, -15, -20, -25, and -30 HU were recorded. Sensitivity, specificity, positive predictive value, negative predictive value, and receiver operator characteristic curves for the diagnosis of minimal fat renal angiomyolipoma were generated for each threshold. The Student t test was used to compare radiologists and cohorts. Previously published attenuation and pixel-counting thresholds reported as having a specificity of near 100% for discriminating between minimal fat renal angiomyolipomas and RCCs were analyzed. RESULTS: The mean maximal transverse lesion diameter was 1.8 cm for minimal fat renal angiomyolipomas (SD, 0.5 cm; range, 1.1-3.0 cm), 2.1 cm for clear cell RCCs (SD, 0.5 cm; range, 1.0-2.9 cm), and 2.1 cm for papillary RCCs (SD, 0.7 cm; range, 1.3-3.9 cm). No significant difference in the percentage of negative pixels was found between minimal fat renal angiomyolipomas and clear cell RCCs or between minimal fat renal angiomyolipomas and papillary RCCs at any of the selected attenuation thresholds for either radiologist (p = 0.210-0.499). Radiologist 1 and radiologist 2 used significantly different region-of-interest sizes (p < 0.001), but neither radiologist could differentiate minimal fat renal angiomyolipoma from RCC. No previously published threshold allowed discrimination between minimal fat renal angiomyolipoma and RCC with 100% specificity. CONCLUSION: Attenuation measurement histogram analysis cannot reliably differentiate minimal fat renal angiomyolipoma from RCC.


Asunto(s)
Angiomiolipoma/diagnóstico por imagen , Carcinoma de Células Renales/diagnóstico por imagen , Neoplasias Renales/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Adulto , Anciano , Angiomiolipoma/patología , Carcinoma de Células Renales/patología , Diagnóstico Diferencial , Femenino , Humanos , Neoplasias Renales/patología , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Interpretación de Imagen Radiográfica Asistida por Computador , Estudios Retrospectivos , Sensibilidad y Especificidad
16.
AJR Am J Roentgenol ; 198(4): 840-5, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22451549

RESUMEN

OBJECTIVE: The purpose of our study was to investigate whether virtual unenhanced adrenal nodule attenuation values can replace true noncontrast attenuation values. MATERIALS AND METHODS: Twenty-three incidentally discovered adrenal nodules (19 adenomas and four metastases) were identified in 19 patients (11 men and eight women; mean age, 65 years; age range, 38-84 years) who underwent unenhanced single-energy CT followed by contrast-enhanced dual-energy CT on the same scanner. A virtual unenhanced imaging dataset was generated from each dual-energy CT dataset. CT attenuation of each adrenal nodule was measured at the same location on virtual unenhanced images and true unenhanced images by three radiologists and mean values compared using the Student t test. Correlation between virtual unenhanced and true unenhanced values was determined using linear regression analysis. The mean difference and percentage of diagnostic agreement were also determined. Interreader variability was assessed using the intraclass correlation coefficient (ICC). RESULTS: The mean ± SD attenuation values for virtual unenhanced images and true unenhanced images were 14.7 ± 15.1 HU and 12.9 ± 13.4 HU, respectively (p = 0.2). Strong positive correlation was observed between virtual unenhanced images and true unenhanced images (R = 0.83-0.87). The mean difference between virtual unenhanced images and true unenhanced images was 1.8 ± 1.7 HU. Diagnostic agreement between virtual unenhanced images and true unenhanced images was 83-91% for three radiologists. No malignant nodules were misclassified as benign on virtual unenhanced images. The ICC was 0.88 and 0.96 for virtual unenhanced images and true unenhanced images, respectively, indicating high interreader agreement. CONCLUSION: Virtual unenhanced and true unenhanced attenuation measurements of adrenal nodules were not significantly different and showed strongly positive linear correlation. This finding resulted in substantial diagnostic agreement between virtual unenhanced images and true unenhanced images for distinguishing benign from malignant nodules.


Asunto(s)
Enfermedades de las Glándulas Suprarrenales/diagnóstico por imagen , Imagen Radiográfica por Emisión de Doble Fotón/métodos , Tomografía Computarizada por Rayos X/métodos , Neoplasias de las Glándulas Suprarrenales/diagnóstico por imagen , Adulto , Anciano , Anciano de 80 o más Años , Medios de Contraste , Femenino , Humanos , Hallazgos Incidentales , Yopamidol , Modelos Lineales , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Técnica de Sustracción
17.
Abdom Radiol (NY) ; 47(8): 2623-2631, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-34128102

RESUMEN

PURPOSE: To identify commonly used needle types in cross-sectional interventional radiology (CSIR) and to review features and safety profiles of those needles. METHODS: Members of the Society of Abdominal Radiology (SAR) emerging technologies commission (ETC) on CSIR were sent a 13-question survey about what needles they use for common CSIR procedures: random and targeted solid organ biopsy, ultrasound-guided paracentesis, and ultrasound-guided thyroid fine needle aspiration (FNA). Results were compiled with descriptive statistics, and features of the most commonly used needles were reviewed. RESULTS: 19 surveys were completed (response rate 57.6%, 19/33) from 16 institutions. For solid organ biopsies, the majority of respondents reported using an 18-gauge needle with an automatic firing mechanism and a variable throw length option. The most commonly used needle for both random and targeted biopsies was the Argon BioPince (26.3%, 5/19) The three most commonly used needles for solid organ biopsies all featured automatic firing, variable throw length options, and 18-gauge size. A 5 French Cook Yueh needle was most the most commonly used paracentesis needle (36.8%, 7/19). For thyroid FNA, all respondents used spinal needles, and 25-gauge was the most common size (72.2%, 13/18). CONCLUSION: Abdominal radiologists use a variety of needles when performing common interventional procedures. Members of the SAR CSIR ETC commonly use automatic, 18-gauge, variable throw length needles for solid organ biopsies, 5 French catheter style needles for paracentesis, and 25-gauge spinal needles for thyroid FNA.


Asunto(s)
Neoplasias Pancreáticas , Radiología Intervencionista , Biopsia con Aguja Fina , Estudios Transversales , Equipos y Suministros , Humanos , Neoplasias Pancreáticas/patología , Paracentesis , Encuestas y Cuestionarios , Tecnología
18.
Abdom Radiol (NY) ; 47(8): 2632-2639, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-34181039

RESUMEN

PURPOSE: To compare clinical efficacy, subjective radiologist preference, and complication rates for two different core biopsy needles, the Achieve® and Marquee®. METHODS: Retrospective review included consecutive patients who underwent 18 gauge non-targeted core liver biopsy, 30 with Achieve® (Merit Medical) and 30 with Marquee® (BD Bard) Pathologist (blinded to needle type) reviewed specimen total length, maximum width, and portal triad count. Sixteen radiologists subjectively rated (1 to 5(best)) each needle for cocking, firing, recoil, chamber exposure, handling, and overall. A medical records search of all (targeted and non-targeted) core liver biopsies 1/1/17-9/30/2020 compared rates of major (requiring transfusion and/or embolization) and minor (self-limited bleeding) hemorrhagic complications. Comparison between needle types was performed using t-test. RESULTS: For Achieve® and Marquee® needles, the respective mean (SD) for total length(mm) was 29.7(7.0) and 31.9(4.6), p = 0.1; max width(mm) was 0.78(0.1) and 0.85(0.1), p < 0.01; and number of portal triads was 15.3(5.3) and 17.3(5.3), p = 0.2. Radiologists subjectively preferred the Marquee® for several measures including cocking, chamber exposure, and overall (p < 0.02 for each), while the needles were rated similarly for firing, recoil, and handling. Review of 800 cases showed no difference in major (1.0% Achieve®, 1.9% Marquee®, p = 0.5) or minor (1.5% Achieve®, 0.5% Marquee®, p = 0.3) rates of hemorrhagic complications. CONCLUSION: Liver biopsy specimens were significantly wider with Marquee® compared to Achieve®. Radiologists preferred the Marquee® for multiple tactile measures, while the major complication rate was not significantly different. While both needles have a similar side-notch design, the Marquee® needle demonstrates better sample quality and higher user preference, without compromising safety.


Asunto(s)
Hígado , Agujas , Biopsia , Biopsia con Aguja Gruesa/efectos adversos , Humanos , Hígado/diagnóstico por imagen , Hígado/patología , Resultado del Tratamiento
19.
J Am Coll Radiol ; 18(2): 265-273, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32818484

RESUMEN

PURPOSE: To compare the effectiveness of different reporting templates using the ACR Thyroid Imaging Reporting and Data System (TI-RADS) for thyroid ultrasound. METHODS: In this retrospective study, four radiologists implemented ACR TI-RADS while dictating 20 thyroid ultrasounds for each of four different templates: free text, minimally structured, fully structured, fully structured and automated (embedded software automatically sums TI-RADS points, correlates with nodule size, and inserts appropriate recommendation into report impression). In total, 80 reports were constructed per template type. Frequencies of different errors related to ACR TI-RADS were recorded: errors in point assignment, point addition, risk-level assignment, and recommendation. Reporting times were recorded, and a survey about using the template was administered. Differences in error rates were compared using χ2 and Fisher's exact tests, and differences in reporting times were compared using Kruskal-Wallis tests. RESULTS: Across all readers, errors were identified in 27.5% of reports (22 of 80) for the free text template, 28.8% (23 of 80) for the minimally structured template, 18.8% (15 of 80) for the fully structured template, and 0% (0 of 80) for the fully structured and automated template (P < .0001). Frequency of each error type (number assignment, addition, TR categorization, recommendation) decreased across the four templates (P < .0005 to P < .005). Median reporting times for the less complex templates were 210 to 240 seconds, whereas the median automated template reporting time was 180 seconds (P = .41). Radiologists subjectively preferred using the automated template. CONCLUSION: A structured reporting template for thyroid ultrasound that automatically executed steps of ACR TI-RADS resulted in fewer reporting errors for radiologists.


Asunto(s)
Nódulo Tiroideo , Humanos , Radiólogos , Estudios Retrospectivos , Ultrasonografía
20.
Radiology ; 256(2): 450-9, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20656835

RESUMEN

PURPOSE: To intraindividually compare a low-tube-voltage (80 kVp), high-tube-current (675 mA) computed tomographic (CT) technique with a high-tube-voltage (140 kVp) CT protocol for the detection of pancreatic tumors, image quality, and radiation dose during the pancreatic parenchymal phase. MATERIALS AND METHODS: This prospective, single-center, HIPAA-compliant study was approved by the institutional review board, and written informed consent was obtained. Twenty-seven patients (nine men, 18 women; mean age, 64 years) with 23 solitary pancreatic tumors underwent dual-energy CT. Two imaging protocols were used: 140 kVp and 385 mA (protocol A) and 80 kVp and 675 mA (protocol B). For both protocols, the following variables were compared during the pancreatic parenchymal phase: contrast enhancement for the aorta, the pancreas, and the portal vein; pancreas-to-tumor contrast-to-noise ratio (CNR); noise; and effective dose. Two blinded, independent readers qualitatively scored the two data sets for tumor detection and image quality. Random-effect analysis of variance tests were used to compare differences between the two protocols. RESULTS: Compared with protocol A, protocol B yielded significantly higher contrast enhancement for the aorta (508.6 HU vs 221.5 HU, respectively), pancreas (151.2 HU vs 67.0 HU), and portal vein (189.7 HU vs 87.3 HU), along with a greater pancreas-to-tumor CNR (8.1 vs 5.9) (P < .001 for all comparisons). No statistically significant difference in tumor detection was observed between the two protocols. Although standard deviation of image noise increased with protocol B (11.5 HU vs 18.6 HU), this protocol significantly reduced the effective dose (from 18.5 to 5.1 mSv; P < .001). CONCLUSION: A low-tube-voltage, high-tube-current CT technique has the potential to improve the enhancement of the pancreas and peripancreatic vasculature, improve tumor conspicuity, and reduce patient radiation dose during the pancreatic parenchymal phase.


Asunto(s)
Carga Corporal (Radioterapia) , Páncreas/diagnóstico por imagen , Neoplasias Pancreáticas/diagnóstico por imagen , Dosis de Radiación , Protección Radiológica/métodos , Tomografía Computarizada por Rayos X/métodos , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Proyectos Piloto , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
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