Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 13.476
Filtrar
1.
Medicine (Baltimore) ; 98(45): e17940, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31702683

RESUMO

Venous air embolism (VAE) can be observed in the right heart system on contrast-enhanced computed tomography (CT), following injection of contrast media with a power injector system. Although most VAEs are mostly asymptomatic, they may result in paradoxical air embolism (PAE).To evaluate whether the incidence of VAE on coronary CT angiography is associated with the process of preparation of the intravenous access route.We retrospectively evaluated 692 coronary CT examinations at 3 institutions. Trained CT nurses placed an intravenous cannula in the forearm. Tubes connected to the cannula were prepared in the following ways: A, using an interposed three-way cock and a 20-mL syringe filled with normal saline to collect air contamination in the tube; B, through direct connection to the power injector system without the interposed 3-way cock; and C, using an interposed three-way cock and a 100-mL normal saline drip infusion bottle system to keep the tube patent. The incidence and location of VAE and preparation of intravenous injection were assessed.The overall incidence of VAE was 55.3% (383/692), most frequently observed in the right atrium (81.5%, 312/383). Its incidence varied significantly across the 3 techniques (A: 21.6% (35/162), B: 63.2% (237/375) and C: 71.6% (111/155); P < .001). No patient demonstrated any symptom associated with VAE.Using a 3-way cock with syringe demonstrated the lowest incidence of VAE on coronary CT angiography. It is thus recommended to reduce potential complication risks related to intravenous contrast media injection.


Assuntos
Angiografia por Tomografia Computadorizada/efeitos adversos , Embolia Aérea/etiologia , Embolia Paradoxal/etiologia , Átrios do Coração/diagnóstico por imagem , Idoso , Meios de Contraste/administração & dosagem , Embolia Aérea/complicações , Embolia Aérea/epidemiologia , Embolia Paradoxal/epidemiologia , Humanos , Injeções Intravenosas/efeitos adversos , Injeções Intravenosas/instrumentação , Injeções Intravenosas/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
2.
J Comput Assist Tomogr ; 43(5): 718-720, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31609292

RESUMO

Recently, a novel 3-dimensional visualization methodology for volumetric computed tomography data has become available. This method, known as cinematic rendering, uses an advanced lighting model to create photorealistic images from standard computed tomography acquisition data composed of isotropic voxels. We have observed that cinematic rendering visualizations in which patients have been administered dense, positive oral contrast do not have any substantive visual artifacts and can be used to demonstrate bowel pathology to advantage (ie, "virtual fluoroscopy"). In this technical note, we describe our acquisition and visualization parameters, and we also include demonstrative examples.


Assuntos
Meios de Contraste/administração & dosagem , Enterite/diagnóstico por imagem , Imagem Tridimensional/métodos , Intussuscepção/diagnóstico por imagem , Iohexol/administração & dosagem , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Artefatos , Feminino , Fluoroscopia , Humanos , Interpretação de Imagem Radiográfica Assistida por Computador
3.
J Comput Assist Tomogr ; 43(5): 736-740, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31609293

RESUMO

OBJECTIVE: The objective of this study was to compare enhancement of the aorta and liver on hepatic dynamic computed tomography scans acquired with contrast material doses based on the lean body weight (LBW) or the total body weight (TBW). METHODS: We randomly divided 529 patients (279 men, 250 women; median age, 66 years) scheduled for hepatic dynamic computed tomography into 2 groups. The LBW patients (n = 278) were injected with 679 mg iodine/kg (men) or 762 mg iodine/kg (women). The TBW group (n = 251) was injected with 600 mg iodine/kg TBW. Each group was subdivided into the 3 classes based on the body mass index (BMI; low, normal, high). Aortic enhancement during the hepatic arterial phase and hepatic enhancement during the portal venous phase was compared. The aortic and hepatic equivalence margins were 100 and 20 Hounsfield units, respectively. RESULTS: Comparison of the median iodine dose in patients with a normal or high BMI showed that it was significantly lower under the LBW protocol than the TBW protocol (558.2 and 507.0 mg iodine/kg, P < 0.001, respectively). However, in patients with a low BMI, the LBW protocol delivered a significantly higher dose than the TBW protocol (620.7 vs 600.0 mg iodine/kg, P < 0.001). The 95% confidence interval for the difference in aortic and hepatic enhancement between the 2 protocols was within the range of the predetermined equivalence margins in all BMI subgroups. CONCLUSIONS: Contrast enhancement was equivalent under both protocols. The LBW protocol can avoid iodine overdosing, especially in patients with a high BMI.


Assuntos
Índice de Massa Corporal , Meios de Contraste/administração & dosagem , Iohexol/administração & dosagem , Neoplasias Hepáticas/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Idoso , Peso Corporal , Feminino , Humanos , Injeções , Masculino , Estudos Prospectivos
4.
Nihon Hoshasen Gijutsu Gakkai Zasshi ; 75(10): 1165-1172, 2019.
Artigo em Japonês | MEDLINE | ID: mdl-31631110

RESUMO

There are many variations in branching and running of pulmonary artery (PA) and pulmonary vein (PV). It is desirable to separate as a surgical simulation of lung cancer and important to grasp before video-assisted thoracic surgery (VATS) to perform quick and safe. Therefore, the purpose of this study was to evaluate objective and subjective image quality (contrast attenuation, separation ability, and vascular visualization) of PA and PV of splitbolus single-phase protocol (SBSPP) in preoperative three-dimensional computed tomography angiography (3DCTA). CT value of PA was 410.2±71.0 Hounsfield unit (HU), PV was 245.1±24.8 HU, difference between CT value of PA and CT value of PV was 164.5±60.9 HU. Subjective image quality of PA and PV could be visualized until more than the segmental branch level. SBSPP can obtain sufficient CT value for separate visualization of PA and PV, and before VATS useful PA and PV 3D-CTA imaging.


Assuntos
Neoplasias Pulmonares , Cirurgia Torácica Vídeoassistida , Tomografia Computadorizada por Raios X , Meios de Contraste/administração & dosagem , Humanos , Imagem Tridimensional , Neoplasias Pulmonares/diagnóstico por imagem , Artéria Pulmonar , Cirurgia Torácica Vídeoassistida/métodos
5.
J Cancer Res Clin Oncol ; 145(12): 2995-3003, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31664520

RESUMO

PURPOSE: To describe the clinical characteristics and outcomes of patients with dual-phenotype hepatocellular carcinoma (DPHCC) and investigate the use of radiomics to establish an image-based signature for preoperative differential diagnosis. METHODS: This study included 50 patients with a postoperative pathological diagnosis of DPHCC (observation group) and 50 patients with CK7- and CK19-negative HCC (control group) who attended our hospital between January 2015 and December 2018. All patients underwent Gd-EOB-DTPA-enhanced MRI within 1 month before surgery. Arterial phase (AP), portal venous phase (PVP), delayed phase (DP) and hepatobiliary phase (HBP) images were transferred into a radiomics platform. Volumes of interest covered the whole tumor. The dimensionality of the radiomics features were reduced using LASSO. Four classifiers, including multi-layer perceptron (MLP), support vector machines (SVM), logistic regression (LR) and K-nearest neighbor (KNN) were used to distinguish DPHCC from CK7- and CK19-negative HCC. Kaplan-Meier survival analysis was used to assess 1-year disease-free survival (DFS) and overall survival (OS) in the observation and control groups. RESULTS: The best preoperative diagnostic power for DPHCC will likely be derived from a combination of different phases and classifiers. The sensitivity, specificity and accuracy of LR in PVP (0.740, 0.780, 0.766), DP (0.893, 0.700, 0.798), HBP (0.800, 0.720, 0.756) and MLP in PVP (0.880, 0.720, 0.798) were better performance. The 1-year DFS and OS of the patients in the observation group were 69% and 78%, respectively. The 1-year DFS and OS of the patients in the control group were 83% and 85%, respectively. Kaplan-Meier survival analysis showed no statistical difference in DFS and OS between groups (P = 0.231 and 0.326), but DFS and OS were numerically lower in patients with DPHCC. CONCLUSION: The radiomics features extracted from Gd-EOB-DTPA-enhanced MR images can be used to diagnose preoperative DPHCC. DPHCC is more likely to recur and cause death than HCC, suggesting that active postoperative management of patients with DPHCC is required.


Assuntos
Carcinoma Hepatocelular/diagnóstico , Gadolínio DTPA/administração & dosagem , Neoplasias Hepáticas/diagnóstico , Carcinoma Hepatocelular/patologia , Meios de Contraste/administração & dosagem , Diagnóstico Diferencial , Feminino , Humanos , Neoplasias Hepáticas/patologia , Imagem por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Fenótipo , Veia Porta/patologia , Prognóstico
6.
Z Gastroenterol ; 57(8): 945-951, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31398765

RESUMO

INTRODUCTION: Little is known about the imaging of omental pathologies. The aim of the current study was to determine the value of B-mode ultrasound (B-US), contrast-enhanced ultrasound (CEUS), and ultrasound-guided core needle biopsy for the differential diagnosis of benign and malignant omental pathologies. PATIENTS AND METHODS: A retrospective evaluation (2008-2017) was performed in 44 patients (median 65,5 years, mean 64 years [47-83], 27 male, 17 female) with histological (40/44 [91 %]) or cytological (4/44 [9 %]) proven omental lesions. Clinical signs and final diagnosis, size, B-US and CEUS findings, and complications were analyzed. RESULTS: Omental thickening was in n = 36 (81.8 %) of the cases malignant (mOL) and in n = 8 (18.2 %) benign (bOL). Twenty-six (59.1 %) patients had ascites (n = 24 [66.7 %] mOL, n = 2 [25 %] bOL). The average tumor thickness was 23 mm (24 mm in mOL, 20 mm in bOL). Interventional complications were not observed. DISCUSSION: The majority of omental lesions are malignant. The differentiation between a malignant or benign cause of thickening is not possible by any imaging method. CEUS is helpful to determine vital tissue before biopsy. Ultrasound-guided core-needle biopsy allows final diagnosis of omental thickening if > 10 mm and should be performed prior to the more invasive and complicative diagnostic laparoscopy.


Assuntos
Meios de Contraste , Omento/patologia , Neoplasias Peritoneais/diagnóstico por imagem , Ultrassonografia/métodos , Biópsia , Meios de Contraste/administração & dosagem , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Estudos Retrospectivos , Sensibilidade e Especificidade
7.
Internist (Berl) ; 60(9): 996-1003, 2019 Sep.
Artigo em Alemão | MEDLINE | ID: mdl-31468086

RESUMO

BACKGROUND: Iodinated contrast is essential for diagnosis and treatment in contemporary interventional cardiology. An important complication of percutaneous intervention is contrast-induced nephropathy, which is associated with increased morbidity and mortality, while prolonged hospitalization is responsible for economic consequences. OBJECTIVES: This article reviews the definition of contrast-induced nephropathy, the role of biomarkers in early diagnosis to identify high-risk patients and potential therapeutic options for preventing acute nephropathy. CURRENT DATA: The optimization of patients' circulating volume remains the main aspect for preventing contrast-induced nephropathy, as recent studies confirm. Several medications are known to be nephrotoxic, whereas several are nephroprotective and the subject of recent research. CONCLUSION: Interventions to improve outcomes of established acute kidney injury have not been developed as yet. Prevention and early diagnosis are relevant factors in clinical management. It is important to identify patients at risk and to treat them preemptively.


Assuntos
Lesão Renal Aguda/induzido quimicamente , Meios de Contraste/efeitos adversos , Biomarcadores , Meios de Contraste/administração & dosagem , Humanos , Intervenção Coronária Percutânea , Fatores de Risco
8.
J Dermatol ; 46(10): 835-842, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31373042

RESUMO

Kaposiform hemangioendothelioma (KHE) and tufted angioma (TA) primarily occurring in infants are difficult to distinguish. This study evaluated ultrasonography (US) and magnetic resonance imaging (MRI) features of KHE and TA. Pathologically proven TA (n = 21) and KHE (n = 40 [11 KHE + Kasabach-Merritt phenomenon [KMP]]) occurring between January 2015 and December 2017 were reviewed. US (n = 61) and MRI (n = 50) findings were retrospectively evaluated. On US, KHE and TA lesions were subcutaneous, while 40% of KHE exhibited an infiltrative pattern extending into adjacent muscles. Of TA lesions, 42.9% were hyperechoic and 96.15% of KHE lesions exhibited mixed echogenicity. Of TA lesions, 76.2% exhibited well-defined margins and all KHE lesions exhibited ill-defined margins. The depth and vascular density of KHE and KHE + KMP were significantly increased compared with TA. The arterial peak systolic blood flow velocity of KHE + KMP was significantly higher than that in TA and KHE. KHE and KHE + KMP were significantly harder than TA on elastography. 3-D color Doppler revealed branch-shape blood flow for KHE and KHE + KMP lesions; for TA, it revealed a dot-like and striped pattern. Considering MRI findings, KHE and KHE + KMP were more likely to exhibit diffuse heterogeneous enhancement after contrast than TA. KHE was infiltrative and more likely to be thick, hypoechoic, ill-defined, richly vascular and hard than TA on US. KHE lesions were subcutaneous and reticular, with heterogeneous enhancement on MRI. Awareness of these features should prompt radiologists in the differential diagnosis of pediatric masses.


Assuntos
Hemangioendotelioma/diagnóstico por imagem , Hemangioma/diagnóstico por imagem , Síndrome de Kasabach-Merritt/diagnóstico por imagem , Sarcoma de Kaposi/diagnóstico por imagem , Neoplasias Cutâneas/diagnóstico por imagem , Adolescente , Adulto , Criança , Pré-Escolar , Meios de Contraste/administração & dosagem , Diagnóstico Diferencial , Técnicas de Imagem por Elasticidade/métodos , Feminino , Gadolínio DTPA/administração & dosagem , Hemangioendotelioma/cirurgia , Hemangioma/cirurgia , Humanos , Imagem Tridimensional , Lactente , Síndrome de Kasabach-Merritt/cirurgia , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Período Pré-Operatório , Estudos Retrospectivos , Sarcoma de Kaposi/cirurgia , Pele/irrigação sanguínea , Pele/diagnóstico por imagem , Neoplasias Cutâneas/cirurgia , Ultrassonografia Doppler em Cores , Adulto Jovem
9.
J Vet Sci ; 20(4): e38, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31364323

RESUMO

Use of a saline chaser has been reported to allow reduction of contrast dose and artifacts during computed tomography (CT) examination in humans. This study assesses the extent of contrast dose by using a saline chaser in abdominal CT scans of normal dogs. Five beagles underwent abdominal CT scans. Three protocols were applied: 600 mg I/kg iohexol without saline chaser (protocol 1), 30% lower dose of iohexol (420 mg I/kg) followed by a 10 mL saline chaser (protocol 2), and 40% lower dose of iohexol (360 mg I/kg) followed by a 10 mL saline chaser (protocol 3). Attenuation values were obtained from aorta, portal vein, and liver parenchyma. The maximum enhancement values (MEVs) in protocol 2 were significantly higher than those in protocols 1 and 3 in the aorta; no difference was seen in the portal vein in all protocols. The liver parenchymal MEVs in protocols 1 and 2 were significantly higher than those obtained in protocol 3. In this study, the use of a saline chaser and a reduced dose of contrast material did not affect vessel enhancement. In conclusion, use of a saline chaser for abdominal CT of dogs is recommended because it allows a 30% reduction of contrast dose without decreasing vascular and hepatic parenchymal enhancement.


Assuntos
Meios de Contraste/análise , Iohexol/análise , Radiografia Abdominal/veterinária , Cloreto de Sódio/administração & dosagem , Tomografia Computadorizada por Raios X/veterinária , Animais , Meios de Contraste/administração & dosagem , Cães , Iohexol/administração & dosagem , Radiografia Abdominal/métodos , Cloreto de Sódio/análise , Tomografia Computadorizada por Raios X/métodos
10.
Anticancer Res ; 39(8): 4219-4225, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31366509

RESUMO

BACKGROUND/AIM: The aim of the study was to evaluate surgical outcomes of patients with high-signal intensity (SI) image hepatocellular carcinoma (HCC). PATIENTS AND METHODS: Between 2008 and 2013, 257 HCC patients were retrospectively evaluated. A total of 21 patients were diagnosed as high-SI image HCC, 215 as low-SI image HCC, and 21 patients as mixed (high and low)-SI image HCC in the hepatobiliary (HB) phase of MRI. Five-year overall survival (OS) and recurrence-free survival (RFS) were compared among patient groups. RESULTS: The 5-year OS and RFS rates were significantly higher in patients with high-SI image HCC (100% and 56%) than in patients with low-SI image HCC (71%; p=0.097 and 38%; p=0.0209) and in patients with mixed-SI image HCC (73%; p=0.0329 and 9%; p=0.0021). High-SI image was an independent prognostic factor for OS (relative risk 0.167, p=0.0178) and RFS (relative risk 0.471, p=0.0322) on multivariate analysis. CONCLUSION: Patients with high-SI image HCC showed favorable long-term survival after curative surgery.


Assuntos
Sistema Biliar/diagnóstico por imagem , Carcinoma Hepatocelular/diagnóstico por imagem , Neoplasias Hepáticas/diagnóstico por imagem , Recidiva Local de Neoplasia/diagnóstico por imagem , Idoso , Idoso de 80 Anos ou mais , Sistema Biliar/patologia , Carcinoma Hepatocelular/patologia , Meios de Contraste/administração & dosagem , Intervalo Livre de Doença , Feminino , Gadolínio DTPA/administração & dosagem , Humanos , Neoplasias Hepáticas/patologia , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Estudos Retrospectivos
11.
Artigo em Japonês | MEDLINE | ID: mdl-31434848

RESUMO

PURPOSE: A three-dimensional (3D) image from computed tomography (CT) angiography is a useful method for evaluation of complex anatomy such as congenital heart disease. However, 3D imaging requires high contrast enhancement for distinguishing between blood vessels and soft tissue. To improve the contrast enhancement, many are increasing the injection rate. However, one method is the use of fenestrated catheters, it allows use of a smaller gauge catheter for high-flow protocols. The purpose of this study was to compare the pressure of injection rate and CT number of a 24-gauge fenestrated catheter with an 22-gauge non-fenestrated catheter for i.v. contrast infusion during CT. METHODS: Between December 2014 and March 2015, 50 newborn patients were randomly divided into two protocols; 22-gauge conventional non-fenestrated catheter (24 newborn; age range 0.25-8 months, body weight 3.6±1.2 kg) and 24-gauge new fenestrated catheter (22 newborn; age range 0.25-12 months, body weight 3.3±0.9 kg). Helical scan of the heart was performed using a 64-detector CT (LightSpeed VCT, GE Healthcare) (tube voltage 80 kV; detector configuration 64×0.625 mm, rotation time 0.4 s/rot, helical pitch 1.375, preset noise index for automatic tube current modulation 40 at 0.625 mm slice thickness). RESULTS: We compared the maximum pressure of injection rate, CT number of aortic enhancement, and CT number of pulmonary artery enhancement between both protocols. The median injection rate, CT number of aortic enhancement, and CT number of pulmonary artery enhancement were 0.9 (0.5-3.4) ml/s, 455.5 (398-659) HU, and 500.0 (437-701) HU in 22-gauge conventional non-fenestrated catheter and 0.9 (0.5-2.0) ml/s, 436.5 (406-632) HU, and 479.5 (445-695) HU in the 24-gauge fenestrated catheter, respectively. There are no significantly different between a 24-gauge fenestrated catheter and 22-gauge non-fenestrated catheters at injection rate and CT number. Maximum pressure of injection rate was lower with 24-gauge non-fenestrated catheters (0.33 kg/cm2) than 22-gauge non-fenestrated catheters (0.55 kg/cm2) (p<0.01Conclusion: A 24-gauge fenestrated catheter performs similarly to an 22-gauge non-fenestrated catheter with respect to i.v. contrast infusion and aortic enhancement levels and can be placed in most subjects whose veins are deemed insufficient for an 22-gauge catheter.


Assuntos
Angiografia por Tomografia Computadorizada , Meios de Contraste , Cardiopatias , Angiografia , Angiografia por Tomografia Computadorizada/métodos , Meios de Contraste/administração & dosagem , Cardiopatias/congênito , Cardiopatias/diagnóstico por imagem , Humanos , Lactente , Recém-Nascido , Tomografia Computadorizada por Raios X
12.
Am J Vet Res ; 80(9): 825-831, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31449446

RESUMO

OBJECTIVE: To assess effects of catheter diameter and injection rate of flush solution (saline [0.9% NaCl] solution) on renal contrast-enhanced ultrasonography (CEUS) with perfluorobutane in dogs. ANIMALS: 5 healthy Beagles. PROCEDURES: CEUS of the kidneys was performed by IV injection of contrast medium (0.0125 mL/kg) followed by injection of 5 mL of saline solution at rates of 1, 3, and 5 mL/s through a 20-gauge or 24-gauge catheter; thus, CEUS was repeated 3 times for each catheter diameter. Time-intensity curves were created for regions of interest drawn in the renal cortex and medulla. Repeatability was determined by calculating the coefficient of variation (CV). Statistical analysis was used to assess whether perfusion variables or CV of the perfusion variables was associated with catheter diameter or injection rate. RESULTS: Perfusion variables did not differ significantly between catheter diameters. Time to peak enhancement (TTP) in the renal cortex was affected by injection rate, and there were significantly lower values for TTP at higher injection rates. The CEUS variables with the lowest CVs among injection rates were TTP for the renal cortex; the CV for TTP of the renal cortex was the lowest at an injection rate of 5 mL/s. CONCLUSIONS AND CLINICAL RELEVANCE: Use of a 24-gauge catheter did not alter CEUS with perfluorobutane; therefore, such catheters could be used for CEUS of the kidneys of small dogs. Moreover, a rate of 5 mL/s is recommended for injection of flush solution to obtain greater accuracy for renal CEUS in Beagles.


Assuntos
Cateteres de Demora , Cães , Fluorcarbonetos/administração & dosagem , Rim/diagnóstico por imagem , Ultrassonografia/veterinária , Animais , Meios de Contraste/administração & dosagem , Feminino , Injeções Intravenosas , Rim/metabolismo , Masculino , Perfusão
13.
J Comput Assist Tomogr ; 43(5): 741-746, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31356524

RESUMO

OBJECTIVE: To identify the computed tomographic features to differentiate gastric schwannoma from gastric gastrointestinal stromal tumor. METHODS: Computed tomographic images of 103 pathologically confirmed patients with gastric schwannoma (n = 23) or gastric gastrointestinal stromal tumor (n = 80) were retrospectively studied. Sex, morphology, location, border, growth pattern, enhancement pattern, necrosis, calcification, ulceration, and perigastric lymph nodes were analyzed. Age, short diameter, long diameter, and the degree of enhancement were measured. Statistical analyses were performed, and receiver operating characteristic curve, sensitivity, and specificity values were analyzed. RESULTS: Female, age younger than 57.5 years, round or ovoid morphology, extraluminal growth, homogeneous enhancement, lack of necrosis, presence of perigastric lymph nodes, and an enhancement degree of less than 15.4 Hounsfield units in the arterial phase were significant variables for differentiating gastric schwannoma from gastric gastrointestinal stromal tumor (P < 0.05). CONCLUSIONS: Dual-phase contrast-enhanced computed tomography can help to differentiate gastric schwannoma from gastric gastrointestinal stromal tumor.


Assuntos
Tumores do Estroma Gastrointestinal/diagnóstico por imagem , Neurilemoma/diagnóstico por imagem , Neoplasias Gástricas/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Meios de Contraste/administração & dosagem , Diagnóstico Diferencial , Feminino , Tumores do Estroma Gastrointestinal/patologia , Humanos , Iopamidol/administração & dosagem , Masculino , Pessoa de Meia-Idade , Neurilemoma/patologia , Estudos Retrospectivos , Sensibilidade e Especificidade , Neoplasias Gástricas/patologia
14.
J Comput Assist Tomogr ; 43(5): 762-769, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31356526

RESUMO

OBJECTIVE: The objective of this study was to evaluate the imaging features of a hepatic sclerosed hemangioma by comparing them with those of a cavernous hemangioma using magnetic resonance imaging with gadoxetic acid enhancement. METHODS: Nine patients with hepatic sclerosed hemangiomas and 36 patients with cavernous hemangiomas (control group) who underwent gadoxetic acid-enhanced magnetic resonance imaging were included. Qualitative values (imaging findings and enhancement pattern [typical vs atypical enhancement]) and quantitative values (apparent diffusion coefficient) were evaluated. RESULTS: Patients with sclerosed hemangiomas showed significantly more irregular tumor margin on hepatobiliary phase images, peritumoral arterial enhancement, and a lower proportion of hyperintensity on heavily T2-weighted images compared with controls (all P values <0.05). In addition, the sclerosed hemangioma group had significantly more frequent atypical enhancement patterns than did the control group (88.9% vs 33.3%; P = 0.006). However, the mean apparent diffusion coefficient value of hemangiomas was not significantly different between the 2 groups (P = 0.639). CONCLUSIONS: Gadoxetic acid-enhanced magnetic resonance images can help in differentiating between hepatic sclerosed hemangiomas and cavernous hemangiomas.


Assuntos
Meios de Contraste/administração & dosagem , Gadolínio DTPA/administração & dosagem , Hemangioma/diagnóstico por imagem , Neoplasias Hepáticas/diagnóstico por imagem , Imagem por Ressonância Magnética/métodos , Adulto , Idoso , Diagnóstico Diferencial , Feminino , Hemangioma Cavernoso/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
15.
Int Braz J Urol ; 45(5): 1022-1032, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31268642

RESUMO

PURPOSE: This hybrid retrospective and prospective study performed on 200 consecutive patients undergoing renal CTA, investigates the opacification of renal vasculature, radiation dose, and reader confidence. MATERIALS AND METHODS: 100 patients were assigned retrospectively to protocol A and the other 100 were allocated prospectively to protocol B. Both protocols implemented a contrast material and saline flow rate of 4.5 mL/sec. Protocol A utilized a 100 mL of low-osmolar nonionic IV contrast material (Ioversol 350 mg I/mL) while protocol B employed a patient-tailored contrast media formula using iso-osmolar non-ionic (Iodixanol 320 mg I/mL). RESULTS: Arterial opacification in the abdominal aorta and in the bilateral main proximal renal arteries demonstrated no statistical significance (p>0.05). Only the main distal renal artery of the left kidney in protocol B was statistically significant (p<0.046). In the venous circulation, the IVC demonstrated a significant reduction in opacification in protocol B (59.39 HU ± 19.39) compared to A (87.74 HU ± 34.06) (p<0.001). Mean CNR for protocol A (22.68 HU ± 13.72) was significantly higher than that of protocol B (14.75 HU ± 5.76 p<0.0001). Effective dose was significantly reduced in protocol B (2.46 ± 0.74 mSv) compared to A (3.07 ± 0.68 mSv) (p<0.001). Mean contrast media volume was reduced in protocol B (44.56 ± 14.32 mL) with lower iodine concentration. ROC analysis demonstrated significantly higher area under the ROC curve for protocol B (p<0.0001), with inter-reader agreement increasing from moderate to excellent in renal arterial visualization. CONCLUSION: Employing a patient-tailored contrast media injection protocol shows a significant refinement in the visualization of renal vasculature and reader confidence during renal CTA.


Assuntos
Angiografia por Tomografia Computadorizada/métodos , Meios de Contraste/administração & dosagem , Rim/irrigação sanguínea , Rim/diagnóstico por imagem , Adulto , Idoso , Angiografia por Tomografia Computadorizada/normas , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Curva ROC , Doses de Radiação , Valores de Referência , Artéria Renal/diagnóstico por imagem , Veias Renais/diagnóstico por imagem , Reprodutibilidade dos Testes , Estudos Retrospectivos , Ácidos Tri-Iodobenzoicos/administração & dosagem
16.
J Comput Assist Tomogr ; 43(4): 612-618, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31268876

RESUMO

OBJECTIVE: The aim of this study was to determine if computed tomography (CT) angiography using an individualized transition delay (CTA-ID) would facilitate reductions in injection rate and iodine dose. METHODS: The CTA-ID was performed in 20 patients with routine injection rate and iodine dose; 20 patients with injection rate lowered by 1 mL/s; and 40 patients with injection rate lowered by 1 mL/s with 29% less iodine. Routine CTAs in the same or size-matched patients served as controls. Diagnostic image quality and intra-arterial CT numbers were assessed. RESULTS: The median transition delay between aortic threshold and CTA-ID image acquisition was significantly longer than with conventional bolus tracking (mean increase, 13.3 seconds; P < 0.0001), with image quality being the same or better. Intra-arterial CT numbers were 200 Hounsfield units or greater for 80 of 80 CTA-ID, but not for 6 of 49 (12%) internal control or for 11 of 80 (14%) size-matched control patients. CONCLUSION: The CTA-ID bolus-tracking software alters transition delays to permit diagnostic CTA examinations despite slower injection rate and less iodine.


Assuntos
Abdome , Aorta/diagnóstico por imagem , Angiografia por Tomografia Computadorizada , Meios de Contraste , Iodo , Abdome/irrigação sanguínea , Abdome/diagnóstico por imagem , Idoso , Angiografia por Tomografia Computadorizada/métodos , Angiografia por Tomografia Computadorizada/estatística & dados numéricos , Meios de Contraste/administração & dosagem , Meios de Contraste/uso terapêutico , Humanos , Iodo/administração & dosagem , Iodo/uso terapêutico , Masculino , Radiografia Abdominal , Estudos Retrospectivos , Fatores de Tempo
17.
Br J Radiol ; 92(1103): 20190302, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31271535

RESUMO

OBJECTIVES: To compare a low-dose dynamic contrast-enhanced breast MRI protocol (LITE MRI) to standard-dosage using a dual-dose injection technique. METHODS: 8 females with a total of 10 lesions with imaging features compatible with fibroadenoma were imaged using a dual-dose dynamic contrast-enhanced-MRI (DCE-MRI) technique. After pre-contrast scans, 15% of a standard dose of contrast was administered; approximately 10 min later, the remaining 85% of the standard dose was administered. Enhancement kinetic parameters, conspicuity and signal-to-noise ratio were measured quantitatively. RESULTS: One lesion showed no enhancement in either DCE series. All nine of the enhancing lesions were visualized in both the low-dose and standard-dose images. While the (low-to-standard) ratio of contrast doses was roughly 0.18, this did not match the ratios of kinetic parameters. Lesion conspicuity and enhancement rate were both higher in the low-dose images, with (low-to-standard) ratios 1.5 ± 0.1 and 1.2 ± 0.4, respectively. The upper limit of enhancement (ratio 0.3 ± 0.1) and signal-to-noise ratio (ratio 0.5 ± 0.1) were higher in the standard-dose images, but less than expected based on the ratio of the doses. CONCLUSIONS: This preliminary study demonstrates that LITE MRI has the potential to match standard DCE-MRI in the detection of enhancing lesions. Additionally, LITE MRI may enhance sensitivity to contrast media dynamics. ADVANCES IN KNOWLEDGE: Lower doses of MRI contrast media may be equally effective in the detection of breast lesions, and increase sensitivity to contrast media dynamics. LITE MRI may help increase screening compliance and long-term patient safety.


Assuntos
Neoplasias da Mama/diagnóstico , Fibroadenoma/diagnóstico , Adolescente , Adulto , Meios de Contraste/administração & dosagem , Meios de Contraste/farmacocinética , Relação Dose-Resposta a Droga , Feminino , Gadolínio/administração & dosagem , Gadolínio/farmacocinética , Humanos , Imagem por Ressonância Magnética/métodos , Pessoa de Meia-Idade , Razão Sinal-Ruído , Adulto Jovem
18.
Vet Anaesth Analg ; 46(4): 510-515, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31155379

RESUMO

OBJECTIVE: To compare the cranial spread of epidural injectates between lumbosacral (LS) and sacrococcygeal (SCo) approaches in order to guide volume selection for SCo epidural anaesthesia in the dog. STUDY DESIGN: Prospective, randomized cadaveric experimental study. ANIMAL: A group of 13 adult greyhound cadavers. METHODS: The greyhound cadavers were randomly allocated to receive an epidural injection of diluted contrast via the LS or SCo approach. Incremental volumes (0.1, 0.2, 0.4 and 0.6 mL kg-1) were injected consecutively, and a computed tomography (CT) scan was completed following every volume increment. Cranial spread of contrast was recorded by counting the number of vertebrae cranial to the LS space that the injectate had reached, expressed as a vertebral value (n). This vertebral value was measured taking into consideration the percentage of the cord surrounded by contrast (vertebral canal coverage, %). RESULTS: The cranial spread of contrast was similar at 0.1 mL kg-1 [1 (0-3) versus 2 (1-3) n], 0.2 mL kg-1 [3 (0-10) versus 3 (1-5) n], 0.4 mL kg-1 [12 (9-18) versus 11 (3-19) n] and 0.6 mL kg-1 [18 (12-20) versus 15 (10-23) n] for the LS and SCo injections, respectively (p = 0.945). There was a significant interaction between the volume injected and vertebral canal coverage (p < 0.001). CONCLUSIONS AND CLINICAL RELEVANCE: The cranial spread of contrast was similar, independent of whether the epidural injection was performed in the LS or SCo intervertebral space. Current volume guidelines used for the LS approach may produce similar distribution patterns when the SCo approach is used. Further studies are required in order to evaluate the in vivo effectiveness and the adequacy in differently sized dogs of the results found herein.


Assuntos
Meios de Contraste/administração & dosagem , Cães , Injeções Epidurais/veterinária , Região Lombossacral , Região Sacrococcígea , Animais , Cadáver , Espaço Epidural , Estudos Prospectivos
19.
Int J Cardiovasc Imaging ; 35(10): 1935-1942, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31172392

RESUMO

The aim of this study was to compare the radiation dose and image quality of two CT protocols using a wide-detector computed tomography (WDCT) scanner with single contrast injection for simultaneous evaluation of the aorta and coronary artery. We retrospectively included 104 consecutive patients who underwent coronary and aorta CT angiography. CT Protocols were divided as follows: protocol I, variable helical pitch scan (VHP, n = 31); protocol II, volume scan for coronary artery following helical scan for aorta (VFH, n = 73). Vascular attenuation, noise, signal-to-noise (SNR), and contrast-to-noise ratios (CNR) were compared. Image parameters were measured at coronary artery, thoracic aorta, abdominal aorta, and iliofemoral arteries. Subjective image quality was assessed by two observers. The patient characteristics between groups were similar (P ≥ 0.384). There were no significant differences in any of the quantitative image parameters between the two groups except for the thoracic aorta. Vascular attenuation (469.2 ± 133.6 vs. 605.9 ± 140.2 HU), CNR (24.8 ± 11.4 vs. 37.3 ± 18.5), and SNR (28.4 ± 12.0 vs. 40.6 ± 19.5 ml) were higher in the VHP protocol (P < 0.001 for each) for covering the thoracic aorta. However, all subjective image scores guaranteed diagnostic image quality. The effective radiation dose of the VFH protocol was reduced to 27.2% compared with that of the VHP protocol (443.8 ± 115.8 vs. 706.7 ± 163.7 mGy·cm, P < 0.001). WDCT with single contrast injection allows assessment of both the coronary artery and aorta. The VFH protocol can reduce the radiation dose and preserve the image quality compared with that of the VHP protocol.


Assuntos
Aorta/diagnóstico por imagem , Aortografia/métodos , Angiografia por Tomografia Computadorizada , Meios de Contraste/administração & dosagem , Angiografia Coronária/métodos , Vasos Coronários/diagnóstico por imagem , Iopamidol/análogos & derivados , Tomografia Computadorizada Espiral , Adulto , Idoso , Feminino , Humanos , Iopamidol/administração & dosagem , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Doses de Radiação , Exposição à Radiação , Interpretação de Imagem Radiográfica Assistida por Computador , Reprodutibilidade dos Testes , Estudos Retrospectivos
20.
J Comput Assist Tomogr ; 43(4): 634-640, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31162241

RESUMO

BACKGROUND: Noninvasive blood oxygen level-dependent imaging and intravoxel incoherent motion sequences were used to assess bilateral renal oxygenation, hemodynamics, and proton diffusion in iodixanol renal artery first-pass in rabbit model. METHODS: Forty-two rabbits were divided into 2 groups. Saline and iodixanol (1 g iodine/kg, left renal artery) were administered. Magnetic resonance imaging scans were acquired longitudinally at 24 hours prior to and 1, 24, 48, and 72 hours after administration to assess apparent diffusion coefficient, pure molecular diffusion (D), perfusion-related diffusion (D*), volume fraction (f), and relative spin-spin relaxation rate (R2*) values, respectively. The experiment evaluated serum creatinine, histological, and hypoxia-inducible factor 1α immunoexpression. RESULTS: During 1 to 48 hours, the values of D, f, and D* significantly decreased (P < 0.05), but R2* values significantly increased (P < 0.05) in cortex, outer medulla, and inner medulla after administration of iodixanol through left renal artery, which showed in the 72 hours. The change of the left kidney is noteworthy. Significant negative correlations were observed between apparent diffusion coefficient, D, f, and R2* in cortex, outer medulla, and inner medulla (all P < 0.001, r = -0.635-0.697). CONCLUSIONS: The first-pass effect of the contrast agent significantly reduces ipsilateral renal perfusion and renal oxygenation, and noninvasive monitoring can be performed by using blood oxygen level-dependent magnetic resonance imaging and intravoxel incoherent motion.


Assuntos
Lesão Renal Aguda , Meios de Contraste/efeitos adversos , Imagem por Ressonância Magnética/métodos , Oxigênio/sangue , Ácidos Tri-Iodobenzoicos/efeitos adversos , Lesão Renal Aguda/induzido quimicamente , Lesão Renal Aguda/diagnóstico por imagem , Animais , Meios de Contraste/administração & dosagem , Interpretação de Imagem Assistida por Computador/métodos , Rim/irrigação sanguínea , Rim/diagnóstico por imagem , Rim/efeitos dos fármacos , Masculino , Coelhos , Artéria Renal/diagnóstico por imagem , Ácidos Tri-Iodobenzoicos/administração & dosagem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA