Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 918
Filtrar
1.
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
2.
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
3.
Am J Vet Res ; 80(9): 885-890, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31449451

RESUMO

OBJECTIVE: To characterize abdominal lymphatic drainage in cats after thoracic duct ligation (TDL) and cisterna chyli ablation (CCA). ANIMALS: 7 purpose-bred research cats. PROCEDURES: Baseline CT lymphangiography was performed. A popliteal lymph node was injected with iohexol, and images were acquired at 5-minute intervals for 15 minutes. Cats underwent TDL and CCA; methylene blue was used to aid in identifying lymphatic vessels. The CT lymphangiography was repeated immediately after and 30 days after surgery. All cats were euthanized and necropsied. RESULTS: Results of baseline CT lymphangiography were unremarkable for all 7 cats. Only 5 cats completed the study. Leakage of contrast medium at the level of the cisterna chyli was seen on CT lymphangiography images obtained from all cats immediately after surgery. Evaluation of 30-day postoperative CT lymphangiography images revealed small branches entering the caudal vena cava in 2 cats, leakage of contrast medium into the caudal vena cava with no visible branches in 1 cat, and no contrast medium in the caudal vena cava in 2 cats. Contrast medium did not flow beyond the level of the cisterna chyli in any cat. Gross examination during necropsy revealed that all cats had small lymphatic vessels that appeared to connect to local vasculature identified in the region of the cisterna chyli. CONCLUSIONS AND CLINICAL RELEVANCE: Abdominal lymphaticovenous anastomoses formed after TDL and CCA in cats. This would support use of these procedures for treatment of cats with idiopathic chylothorax, although additional studies with clinically affected cats are warranted.


Assuntos
Gatos/cirurgia , Drenagem , Linfografia/veterinária , Ducto Torácico/cirurgia , Abdome , Animais , Quilotórax , Meios de Contraste , Iohexol/administração & dosagem , Ligadura , Linfonodos , Masculino
4.
Eur J Radiol ; 119: 108626, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31430661

RESUMO

PURPOSE: To investigate the image quality, diagnostic accuracy, and dose reduction potential of a split-bolus protocol(SBP) compared with a multiphasic protocol(MPP) in the detection of recurrent or progressive pancreatic ductal adenocarcinoma(PDAC) or cholangiocarcinoma(CC) using contrast- enhanced computed tomography(CECT). MATERIALS AND METHODS: This prospective study included 56 patients who underwent CECT, 28 with our institutional standard MPP(100 ml contrast bolus) and 28 with a novel SBP(110 ml). Radiation exposure was determined in terms of total dose- length product(DLP) and computed tomography dose index(CTDI). Image quality was measured objectively by analysis of attenuation in Hounsfield units(HU) in regions of interest(ROIs) and subjectively by two blinded readers using a Likert scale. Diagnostic accuracy and interreader variability were tested. RESULTS: The total DLP of the SBP group(498.1 ± 43.7 mGy*cm) was significantly lower than in the MPP group(1,092.5 ± 106.9 mGy*cm; p < 0.001). The SBP showed higher contrast enhancement of all critical anatomical structures including portal vein, liver, and pancreas compared with the MPP, except for the aorta(SBP: 326.9 ± 15.7 HU vs. MPP: 246.7 ± 12.2 HU; p < 0.001). Subjective analysis revealed poorer image quality ratings for important landmarks with the MPP (resection surface: p = 0.624, portal vein: p = 0.395, liver p = 0.361). The two blinded readers correlated significantly. Sensitivity, specificity, positive and negative predictive values (PPV/NPV), and overall interreader variabilities correlated significantly. Furthermore, significantly fewer slices per exam were required for the SBP(1,823 vs. 3,235; p < 0.001). CONCLUSION: The SBP provides the same image quality and diagnostic accuracy as an MPP while significantly lowering radiation exposure in CT follow-up of PDAC or CC.


Assuntos
Neoplasias dos Ductos Biliares/diagnóstico por imagem , Carcinoma Ductal Pancreático/diagnóstico por imagem , Colangiocarcinoma/diagnóstico por imagem , Meios de Contraste/administração & dosagem , Neoplasias Pancreáticas/diagnóstico por imagem , Idoso , Ductos Biliares/diagnóstico por imagem , Ductos Biliares/efeitos da radiação , Protocolos Clínicos , Feminino , Humanos , Iohexol/administração & dosagem , Iohexol/análogos & derivados , Iopamidol/administração & dosagem , Iopamidol/análogos & derivados , Fígado/diagnóstico por imagem , Fígado/efeitos da radiação , Masculino , Tomografia Computadorizada Multidetectores/métodos , Recidiva Local de Neoplasia/diagnóstico por imagem , Pâncreas/diagnóstico por imagem , Pâncreas/efeitos da radiação , Veia Porta/diagnóstico por imagem , Veia Porta/efeitos da radiação , Estudos Prospectivos , Doses de Radiação , Exposição à Radiação , Sensibilidade e Especificidade
5.
Int J Cardiovasc Imaging ; 35(12): 2239-2248, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31363878

RESUMO

This prospective study evaluated the image quality and accuracy of coronary computed tomography angiography (CCTA) for diagnosing coronary artery disease (CAD) in patients with atrial fibrillation (AF), in which CCTA used adaptive iterative dose reduction (AIDR) with a low tube voltage and low concentration of isotonic contrast agent. Sixty-eight consecutive patients with AF and suspected CAD were equally and randomly apportioned to two groups and underwent CCTA. In the experimental group, the contrast agent was iodixanol (270 mg I/mL), patients were scanned with 100 kV, and reconstruction was by AIDR. In the conventional scanning (control) group, the contrast agent was iopromide (370 mg I/mL), patients were scanned with 120 kV, and reconstruction was by filtered back projection. The image quality, effective radiation dose (E), and total iodine intake of the groups were compared. Thirty-nine patients with coronary artery stenosis later were given invasive coronary angiography (ICA). The groups were similar with regard to mean CT value, noise, and signal-to-noise and contrast-to-noise ratios. The figure of merit of the experimental group was significantly higher than that of the control group, while the E and total iodine were significantly lower. Using ICA as the diagnostic reference, the groups shared similar sensitivity, specificity, and false positive and false negative rates for diagnosing coronary artery stenosis. For determining CAD in patients with AF, CCTA with isotonic low-concentration contrast agent and low-voltage scanning is a feasible alternative that improves accuracy and reduces radiation dose and iodine intake.


Assuntos
Fibrilação Atrial/complicações , Angiografia por Tomografia Computadorizada , Meios de Contraste/administração & dosagem , Angiografia Coronária/métodos , Doença da Artéria Coronariana/diagnóstico por imagem , Estenose Coronária/diagnóstico por imagem , Iohexol/análogos & derivados , Ácidos Tri-Iodobenzoicos/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Fibrilação Atrial/diagnóstico , Doença da Artéria Coronariana/complicações , Estenose Coronária/complicações , Estudos de Viabilidade , Feminino , Humanos , Iohexol/administração & dosagem , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos
6.
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
8.
Radiol Med ; 124(10): 1006-1017, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31250270

RESUMO

OBJECTIVE: To evaluate the diagnostic performance of contrast-enhanced dual-energy spectral mammography (CESM) in comparison with that of full-field digital mammography (FFDM), either alone or accompanied with breast ultrasound (BUS) in a large series of patients/breast lesions (n = 644). PATIENTS AND METHODS: In this retrospective study, five radiologists evaluated the lesions by three imaging modalities: FFDM, FFDM + BUS, and CESM and compared the imaging to the gold standard (histopathology or clinical follow-up). Diagnostic performance parameters and receiver operating characteristic (ROC) curves of CESM were calculated and compared to those of FFDM or FFDM + BUS (McNemar's test). Additionally, the reliability of tumor size measurement by CESM was compared with the histopathological measurement. RESULTS: The study included 218 benign and 426 malignant lesions. 85% of benign and 93% of malignant lesions were adequately identified using CESM. With respect to FFDM and FFDM + BUS, CESM significantly increased sensitivity to 93.2% (+ 10.7% and + 3.4%, respectively); specificity to 84.4% (+ 15.8% and + 1.7%, respectively); PPV to 92.3% (+ 26.8% and + 3.6%, respectively); NPV to 86.0% (+ 1.6% and + 1.8%, respectively); and accuracy to 90.2% (+ 15.8% and + 3.2%, respectively). In the ROC curves analyses, the comparison among the three AUC values was also statistically significant (p < 0.001). Good agreement between tumor diameters measured using CESM and histopathology was observed (Spearman's rank correlation, r = 0.891, p < 0.0001), although this technique tended to produce an overestimation of the size (+ 7 mm). CONCLUSIONS: CESM has high diagnostic accuracy and can be considered as a useful technique for the assessment of breast lesions.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Meios de Contraste/administração & dosagem , Iohexol/análogos & derivados , Mamografia/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia , Neoplasias da Mama/patologia , Diagnóstico Diferencial , Feminino , Humanos , Iohexol/administração & dosagem , Pessoa de Meia-Idade , Interpretação de Imagem Radiográfica Assistida por Computador , Estudos Retrospectivos , Sensibilidade e Especificidade , Ultrassonografia Mamária
9.
J Stroke Cerebrovasc Dis ; 28(7): 2031-2037, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31047820

RESUMO

BACKGROUND: Multimodal computed tomography imaging is used to identify eligible patients for intra-arterial treatment. A concern with this method is the multiple use of iodinated contrast material which presents a possible risk of renal toxicity. We compared the safety of intra-arterial treatment versus intravenous treatment during acute ischemic stroke treatment with a focus on renal safety. METHODS: Adult acute ischemic stroke patients who underwent a baseline Multimodal computed tomography, then intra-arterial treatment and/or intravenous treatment were identified. Primary outcomes were acute kidney injury and changes in serum creatinine at 24-72 hours (Δ serum creatinine). RESULTS: A total of 184 patients received intra-arterial treatment, while 68 received intravenous treatment. There were no differences in mean serum creatinine in the 24-72-hour time period, 24-hour urine volume, or rates of acute kidney injury, dialysis, or mortality. Univariate regression analysis identified diabetes mellitus, operation duration and times of embolectomy as predictors of creatinine increase while the multiple regression model identified diabetes mellitus as the only significant predictor. CONCLUSIONS: There were no significant differences in renal safety between the intra-arterial treatment and intravenous treatment groups. Diabetes mellitus may be a predictor of acute kidney injury. The use of Multimodal computed tomography imaging in the selection of patients who could benefit from endovascular therapy is safe.


Assuntos
Lesão Renal Aguda/induzido quimicamente , Isquemia Encefálica/diagnóstico por imagem , Meios de Contraste/efeitos adversos , Procedimentos Endovasculares/métodos , Iohexol/efeitos adversos , Tomografia Computadorizada Multidetectores/efeitos adversos , Imagem de Perfusão/efeitos adversos , Acidente Vascular Cerebral/diagnóstico por imagem , Lesão Renal Aguda/sangue , Lesão Renal Aguda/diagnóstico , Idoso , Biomarcadores/sangue , Isquemia Encefálica/terapia , Tomada de Decisão Clínica , Meios de Contraste/administração & dosagem , Creatinina/sangue , Procedimentos Endovasculares/efeitos adversos , Feminino , Fibrinolíticos/administração & dosagem , Humanos , Infusões Intra-Arteriais , Infusões Intravenosas , Iohexol/administração & dosagem , Masculino , Pessoa de Meia-Idade , Imagem Multimodal/efeitos adversos , Seleção de Pacientes , Valor Preditivo dos Testes , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Acidente Vascular Cerebral/terapia , Trombectomia/métodos , Terapia Trombolítica/métodos , Resultado do Tratamento
10.
Cancer Biother Radiopharm ; 34(4): 224-230, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31070481

RESUMO

Purpose: This study is aimed to evaluate the iodine concentration in the lipid-poor portion of the renal mass as a potential tool for the differentiation between angiomyolipoma (AML) and renal cell carcinoma (RCC). Materials and Methods: There were eight cases of AML and eight cases of RCC. All patients received corticomedullary, nephrographic and excretory phase enhanced scanning. The regions of interest (ROI) were manually placed in the lipid-poor portion of the renal mass and in the abdominal aorta. Average iodine concentrations were obtained for the ROIs and abdominal aorta. Data were compared using repeated measures analysis with the Bonferroni correction for multiple comparisons. Results: At the unenhanced phase, the iodine concentration in the lipid-poor portion of the renal mass of RCC was not significantly different from that of AML (p = 0.298). At the three enhanced phases, the iodine concentrations in the renal mass of RCC were substantially elevated compared with those of AML. In addition, the CT values of the renal mass of RCC were significantly higher than those of AML at all the enhanced phases. Of note, there was a significant correlation between iodine concentrations and CT values (r = 0.919; p < 0.001) in the lipid-poor portion of the renal mass of RCC. Conclusions: Between RCC and AML there was significant difference in iodine concentrations in the lipid-poor portion of the renal masses. Iodine concentration holds promise as a diagnostic alternative to macroscopic fat for differentiation of AML from RCC.


Assuntos
Angiomiolipoma/diagnóstico por imagem , Carcinoma de Células Renais/diagnóstico por imagem , Processamento de Imagem Assistida por Computador/métodos , Iodo/análise , Neoplasias Renais/diagnóstico por imagem , Adulto , Idoso , Angiomiolipoma/patologia , Carcinoma de Células Renais/patologia , Meios de Contraste/administração & dosagem , Meios de Contraste/química , Diagnóstico Diferencial , Feminino , Humanos , Iohexol/administração & dosagem , Iohexol/química , Rim/diagnóstico por imagem , Rim/patologia , Neoplasias Renais/patologia , Lipídeos , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Tomografia Computadorizada por Raios X/métodos
11.
J Stroke Cerebrovasc Dis ; 28(6): 1474-1482, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30948224

RESUMO

BACKGROUND AND PURPOSE: The computed tomography angiographic (CTA) spot sign has been shown to predict hematoma expansion in patients with intracranial hemorrhage (ICH), but the significance of the spot sign density (SSD) and the spot sign ratio (SSR) has not yet been explored. METHODS: Using the institutional Neurocritical care and Stroke registry, we retrospectively reviewed patients with ICH from January-2013 to June-2017. We selected patients who had baseline CT-head (CTH), CTA with positive-spot sign within 6 hours of last known well and at least one follow-up CTH within 24 hours. Baseline demographics and variables known to affect hematoma-volume were collected. Hematoma-volumes and SSR were calculated using computer-assisted 3D-volumetric measurement and the average of the surrounding hematoma density divided by the SSD, respectively. The 2-sample t test and the area-under-the-curve (receiver operating characteristic) were used to detect the association between hematoma expansion and outcome at discharge. RESULTS: A total of 320 patients were reviewed; 22 met the inclusion criteria. Significant hematoma expansion (volume expansion ≥12.5 cc or ≥33% compared to baseline) was noted in 14 (64%) subjects. SSD was significantly higher in subjects with hematoma expansion (216 ± 66) than those without (155 ± 52, P = .036). With a cut-off SSD of ≥150 HU, we had sensitivity of 86% and specificity of 75%. For SSR, lower ratios suggested a trend toward hematoma expansion, although it was not statistically significant (P = .12). There was no significant correlation between SSD or SSR and modified ranking scale at discharge and after 3-6 months. CONCLUSION: SSD might be a good predictor of hematoma growth. Although SSR showed a trend toward expansion, results were not statistically significant.


Assuntos
Angiografia Cerebral/métodos , Angiografia por Tomografia Computadorizada , Meios de Contraste/administração & dosagem , Hematoma/diagnóstico por imagem , Hemorragias Intracranianas/diagnóstico por imagem , Iohexol/administração & dosagem , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Imagem Tridimensional , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Interpretação de Imagem Radiográfica Assistida por Computador , Sistema de Registros , Estudos Retrospectivos
12.
Eur Radiol ; 29(11): 6109-6118, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31016447

RESUMO

OBJECTIVE: To compare the effect of contrast medium iodine concentration on contrast enhancement, heart rate, and injection pressure when injected at a constant iodine delivery rate in coronary CT angiography (CTA). METHODS: One thousand twenty-four patients scheduled for coronary CTA were prospectively randomized to receive one of four contrast media: iopromide 300 mg I/ml, iohexol 350 mg I/ml, iopromide 370 mg I/ml, or iomeprol 400 mg I/ml. Contrast media were delivered at an equivalent iodine delivery rate of 2.0 g I/s. Intracoronary attenuation was measured and compared (per vessel and per segment). Heart rate before and after contrast media injection was documented. Injection pressure was recorded (n = 403) during contrast medium injection and compared between groups. RESULTS: Intracoronary attenuation values were similar for the different contrast groups. The mean attenuation over all segments ranged between 384 HU for 350 mg I/ml and 395 HU for 400 mg I/ml (p = 0.079). Dose-length product (p = 0.8424), signal-to-noise ratio (all p > 0.05), time to peak (p = 0.324), and changes in heart rate (p = 0.974) were comparable between groups. The peak pressures differed: 197.4 psi for 300 mg I/ml (viscosity 4.6 mPa s), 229.8 psi for 350 mg I/ml (10.4 mPa s), 216.1 psi for 370 mg I/ml (9.5 mPa s), and 243.7 psi for 400 mg I/ml (12.6 mPa s) (p < 0.0001). CONCLUSION: Intravascular attenuation and changes in heart rate are independent of iodine concentration when contrast media are injected at the same iodine delivery rate. Differences in injection pressures are associated with the viscosity of the contrast media. KEY POINTS: • The contrast enhancement in coronary CT angiography is independent of the iodine concentration when contrast media are injected at body temperature (37 °C) with the same iodine delivery rate. • Iodine concentration does not influence the change in heart rate when contrast media are injected at identical iodine delivery rates. • For a fixed iodine delivery rate and contrast temperature, the viscosity of the contrast medium affects the injection pressure.


Assuntos
Angiografia por Tomografia Computadorizada/métodos , Meios de Contraste/farmacocinética , Angiografia Coronária/métodos , Doença da Artéria Coronariana/diagnóstico , Vasos Coronários/diagnóstico por imagem , Iodo/metabolismo , Iohexol/farmacocinética , Meios de Contraste/administração & dosagem , Doença da Artéria Coronariana/metabolismo , Feminino , Humanos , Injeções Intravenosas , Iohexol/administração & dosagem , Iohexol/análogos & derivados , Iopamidol/administração & dosagem , Iopamidol/análogos & derivados , Iopamidol/farmacocinética , Masculino , Pessoa de Meia-Idade
13.
BMC Cardiovasc Disord ; 19(1): 74, 2019 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-30922230

RESUMO

BACKGROUND: The usefulness of the CHA2DS2-VASC risk score (CVRS) in predicting the occurrence of contrast-induced nephropathy (CIN) among patients with chronic total occlusion (CTO) undergoing percutaneous coronary intervention (PCI) remains unclear. METHOD: A total of 239 patients with CTO who underwent PCI were included in this study. They were divided into 3 groups according to the CVRS: low-risk group (1 point, n = 64), intermediate-risk group (2 points, n = 135), and high-risk group (≥3 points, n = 40). Baseline serum creatinine was determined upon admission before the procedure. The serum creatinine level was monitored for 72 h post-procedure to determine the occurrence of CIN. RESULTS: The total incidence of CIN in patients with CTO who underwent PCI was 16.3%. The average CVRS in the CIN group was significantly higher than that in the non-CIN group (3.1 ± 1.2 VS 2.1 ± 1.1, P < 0.001). The incidence of CIN in the high-risk group was 5.6 times higher than that in the low-risk group (37.5% VS 6.3%, P < 0.001). Similar to the Mehran risk score (AUC, 0.754; 95% CI, 0.698-0.810; P < 0.001), the receiver operating characteristic curve analysis showed a good diagnostic value of the CVRS in predicting CIN among patients with CTO who underwent interventional therapy for having CVRS≥3 (sensitivity, 69.2%; specificity, 78.0%; AUC, 0.742; 95% CI, 0.682-0.797; P < 0.001). The multivariate analysis showed that the higher pulse pressure and contrast volume, lower baseline glomerular filtration rate, and CVRS ≥3 were independent predictors of CIN. CONCLUSIONS: The CVRS can be used as a simple pre-procedural predictor of CIN among patients with CTO undergoing PCI.


Assuntos
Meios de Contraste/efeitos adversos , Oclusão Coronária/terapia , Técnicas de Apoio para a Decisão , Iohexol/análogos & derivados , Nefropatias/induzido quimicamente , Rim/efeitos dos fármacos , Intervenção Coronária Percutânea/efeitos adversos , Ácidos Tri-Iodobenzoicos/efeitos adversos , Idoso , Biomarcadores/sangue , Pressão Sanguínea , China , Doença Crônica , Meios de Contraste/administração & dosagem , Angiografia Coronária/efeitos adversos , Oclusão Coronária/diagnóstico por imagem , Oclusão Coronária/fisiopatologia , Creatinina/sangue , Feminino , Taxa de Filtração Glomerular/efeitos dos fármacos , Humanos , Iohexol/administração & dosagem , Iohexol/efeitos adversos , Rim/fisiopatologia , Nefropatias/diagnóstico , Nefropatias/fisiopatologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Radiografia Intervencionista/efeitos adversos , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Ácidos Tri-Iodobenzoicos/administração & dosagem
14.
Clin Biochem ; 67: 16-23, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30905584

RESUMO

BACKGROUND: The glomerular filtration rate (GFR) is monitored clinically to follow renal function of a patient. This is commonly performed using endogenous compounds, which estimate GFR (eGFR). However, several conditions exists which may confound or render the eGFR inaccurate. In such cases, it is appropriate to perform a procedure to directly measure GFR (mGFR). Iohexol plasma disappearance is a procedure to determine mGFR and is typically performed using bolus injection of contrast media followed by timed plasma collections. The iohexol plasma concentrations are referenced to the dose given and the elimination rate of iohexol is reflective of the mGFR. Therefore, analytical bias or interference in the iohexol analytical measurement procedure will directly impact the mGFR result. METHODS: Plasma sample iohexol concentrations were measured using both high performance liquid chromatography-ultraviolet detection (HPLC-UV) and liquid chromatography tandem mass spectrometry (LC-MS/MS) measurement procedures. Results were compared on 50 patients where the mGFR was calculated from the iohexol plasma disappearance on two collection time points. RESULTS: Bland-Altman analysis illustrated <1% mean bias when comparing iohexol concentration determinations from the measurement procedures. Passing-Bablok regression revealed y = 1.028x - 0.9420 (slope 95% CI: 1.011, 1.041; Y-intercept 95% CI: -1.606, -0.1638) when comparing LC-MS/MS to HPLC-UV. CONCLUSIONS: Comparison studies of the LC-MS/MS and HPLC-UV measurement procedures displayed a mean bias of <1% by Bland Altman analysis. Measurement of iohexol by LC-MS/MS and HPLC-UV produced similar results and suggests there should be minimal bias in concentration or computed mGFR solely due to the measurement procedure employed.


Assuntos
Taxa de Filtração Glomerular , Iohexol/administração & dosagem , Iohexol/farmacocinética , Testes de Função Renal/métodos , Espectrometria de Massas/métodos , Adulto , Idoso , Cromatografia Líquida de Alta Pressão/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
15.
Radiology ; 291(2): 531-538, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30835189

RESUMO

Background Optimal timing of the CT scan relative to the contrast media bolus remains a challenging task given the shorter scan durations of modern CT scanners, as well as interpatient variability. Purpose To compare contrast opacification in CT angiography of the aorta between a cohort with fixed trigger delay and a cohort with patient-specific individualized trigger delay for contrast media timing with bolus tracking. Materials and Methods In this prospective study (January-August 2018), CT angiography of the thoracoabdominal aorta with bolus tracking was performed in two different study cohorts: one with a fixed trigger delay of 4 seconds (fixed cohort) and one with a patient-specific trigger delay (individualized cohort). All CT and contrast media protocol parameters were kept identical among cohorts. Objective image quality was evaluated by one reader; two readers assessed subjective image quality. Student t test was used to test for differences in mean attenuation; the Wilcoxon-Mann-Whitney test was used to test for differences in noise, contrast-to-noise ratio, and subjective image quality. Results The fixed cohort had 108 study participants (16 women; mean age ± standard deviation, 72 years ± 10); the individualized cohort had 108 participants (16 women; mean age, 72 years ± 12). The trigger delay in the individualized cohort ranged from 6.4-11.3 seconds (mean, 9.2 seconds). There was higher overall attenuation in the individualized cohort than in the fixed cohort (486 HU ± 92 for individualized vs 438 HU ± 99 for fixed; P < .001), with increasing differences from the aortic arch (8 HU) to the iliac arteries (95 HU). The regression model indicated uniform attenuation in the individualized cohort and decreasing attenuation in the fixed cohort (decrease of 87 HU by the iliac arteries; P < .001). There was no difference between cohorts for image noise (20 vs 19; P = .41), but contrast-to-noise ratio (21 vs 19; P = .04) and subjective image quality were higher in the individualized cohort than in the fixed cohort (excellent or good image quality, 100% vs 67%; P < .001). Conclusion Compared with a fixed delay time after bolus tracking, a patient-specific individualized trigger delay improves image quality and provides uniform contrast attenuation for CT angiography of the aorta. ©RSNA, 2019.


Assuntos
Aorta/diagnóstico por imagem , Angiografia por Tomografia Computadorizada/métodos , Meios de Contraste/administração & dosagem , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Aortografia/métodos , Feminino , Humanos , Iohexol/administração & dosagem , Iohexol/análogos & derivados , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Tempo
16.
Equine Vet J ; 51(6): 795-801, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30854693

RESUMO

BACKGROUND: Centrodistal joint injection is an important component of lameness evaluation and treatment. Successful injection is poor for the medial approach. The dorsolateral approach is an alternative but has not been validated with contrast medium. Radiograph-guidance has not been studied to determine its necessity or benefit for either approach. OBJECTIVES: To determine if the dorsolateral approach to the centrodistal joint is more successful than the medial approach. To determine if radiograph-guidance is beneficial. STUDY DESIGN: Prospective, randomised study. METHODS: Three operators injected 98 centrodistal joints in total, each horse served as its own control. In Phase 1, injections were performed by standard technique. In the Phase 2, operators were allowed to use radiography to assist needle placement. Contrast deposition was evaluated by a single radiologist. RESULTS: Without radiographic assistance, 10/25 (40%) joints were successfully injected using either the medial or dorsolateral approach. With radiographic assistance, 19/24 (79%) joints were successfully injected using the medial approach, 11/24 (46%) joints were successfully injected using the dorsolateral approach. MAIN LIMITATIONS: The population consisted of aged horses representing a variety of breeds with existing osteoarthritis, and multiple operators were recruited. CONCLUSIONS: The dorsolateral approach was equivalent to the medial approach when traditional injection techniques were used. Radiograph-guidance improved success of the medial approach, but not the dorsolateral approach. Many injections performed from the dorsolateral approach (32/49; 65%) resulted in extensive perivascular subcutaneous contrast deposition after infiltration into the tarsal canal. Further research is needed to improve injection success of the centrodistal joint when using the dorsolateral approach.


Assuntos
Doenças dos Cavalos/diagnóstico , Injeções Intra-Articulares/veterinária , Iohexol/administração & dosagem , Coxeadura Animal/diagnóstico , Animais , Meios de Contraste/administração & dosagem , Cavalos , Estudos Prospectivos , Tarso Animal
17.
PLoS One ; 14(1): e0209501, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30653521

RESUMO

PURPOSE: To evaluate CF800, a novel lipid-based liposomal nanoparticle that co-encapsulates indocyanine green (ICG) and iohexol, for CT imaging of pulmonary vasculature in minimally-invasive thoracic surgery planning. METHODS: CF800 was intravenously administered to 7 healthy rabbits. In vivo CT imaging was performed 15 min post-injection, with a subset of animals imaged at 24h, 48h, and 72h post injection. Signal-to-background ratios (SBR) were calculated at the inferior vena cava and compared across time-points. A similar protocol was applied to 2 healthy pigs to evaluate the feasibility and efficacy in a large animal model. To evaluate the feasibility of clinical application, a survey was completed by 7 surgical trainees to assess pre- and post-injection CT images of rabbits and pigs. Responses on the discernibility of pulmonary vasculature sub-branches and comfort level to use the images for pre-operative planning were collected and analyzed. RESULTS: CF800 injection improved visualization of pulmonary vessels in both rabbit and pig models. The SBR of rabbit pulmonary vasculature was significantly higher after CF800 injection (range 3.7-4.4) compared to pre-injection (range 3.3-3.8, n = 7; p<0.05). SBR remained significantly different up to 24 hours after injection (range 3.7-4.3, n = 4; p<0.05). Trainees' evaluation found the post-injection CT images had significantly higher discernibility at the second vessel branch generation in both rabbit and pig models. Trainees identified smaller vasculature branch generations in the post-injection images compared to the pre-treatment images in both rabbit (mean 6.7±1.8 vs 5.4±2.1; p<0.05) and pig (mean 6.7±1.8 vs 5.4±2.1; p<0.05). Trainees were significantly more comfortable using post-injection images for surgical planning compared to the pre-injection images (rabbit: 8.1±1.1 vs. 4.7±2.1; pig: 7.6±2.1 vs. 4.9±2.2; p<0.05). CONCLUSION: CF800 provides SBR and contrast enhancement of pulmonary vasculature which may assist in pre-surgical CT planning of minimally invasive thoracic surgery.


Assuntos
Pulmão/irrigação sanguínea , Pulmão/diagnóstico por imagem , Procedimentos Cirúrgicos Torácicos , Tomografia Computadorizada por Raios X/métodos , Animais , Meios de Contraste/administração & dosagem , Humanos , Imagem Tridimensional , Verde de Indocianina/administração & dosagem , Iohexol/administração & dosagem , Lipossomos/administração & dosagem , Pulmão/cirurgia , Neoplasias Pulmonares/irrigação sanguínea , Neoplasias Pulmonares/diagnóstico por imagem , Neoplasias Pulmonares/cirurgia , Masculino , Procedimentos Cirúrgicos Minimamente Invasivos , Modelos Animais , Nanopartículas/administração & dosagem , Coelhos , Razão Sinal-Ruído , Sus scrofa , Tomografia Computadorizada por Raios X/estatística & dados numéricos , Pesquisa Médica Translacional
18.
Interv Neuroradiol ; 25(1): 102-110, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30231798

RESUMO

OBJECTIVE: Contrast-enhanced cone-beam computed tomography (CBCT) imaging is commonly used for evaluating neurovascular stents and their relationship to the parent artery or vascular pathologies such as arteriovenous malformations (AVMs) and dural arteriovenous fistulas (dAVFs) in the context of surrounding anatomical structures. The purpose of this study was to understand the effects of varying concentrations of contrast medium used in CBCT imaging for optimal visualization of various endovascular devices and anatomical pathologies. METHODS: Thirty-five patients with various neurovascular pathologies were included in the study. Contrast-enhanced CBCT images (20 s DR, Siemens syngo DynaCT, Siemens AG, Forchheim, Germany) were acquired in all cases, with varying dilutions of contrast medium, from 1% to 30%. The injection rate was kept constant at 3 cc/sec with an X-ray delay of two sec, and a total volume of 66 cc of diluted contrast was administered. Results from visual and quantitative analysis were reported. RESULTS: Ten percent dilution of contrast medium resulted in the best image differentiation between flow-diverter devices and the parent artery. Concentrations as low as 2.5% contrast medium also resulted in identifying AVMs in the context of the surrounding brain parenchyma, whereas 20% to 30% dilution provided the best visualization of residual AVMs with prior Onyx embolization and dAVFs in the presence of bony structures. CONCLUSIONS: Simultaneous visualization of brain parenchyma, bony structures, devices, and pathological anatomy using contrast-enhanced CBCT imaging is feasible with appropriate doses of iodinated contrast, and should be tailored to the individual case based on the goals of CBCT.


Assuntos
Transtornos Cerebrovasculares/diagnóstico por imagem , Tomografia Computadorizada de Feixe Cônico/métodos , Meios de Contraste/administração & dosagem , Iohexol/administração & dosagem , Prótese Vascular , Transtornos Cerebrovasculares/terapia , Diagnóstico Diferencial , Relação Dose-Resposta a Droga , Humanos
19.
AJR Am J Roentgenol ; 212(1): 117-123, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30422713

RESUMO

OBJECTIVE: The purpose of this study was to compare dual-energy CT (DECT) urography with a 50% reduced iodine dose to single-energy CT (SECT) urography with a standard iodine dose with respect to attenuation of renal vascular and urinary tract structures and with respect to image quality. SUBJECTS AND METHODS: The study included 62 patients undergoing evaluation of urinary tract lithiasis, tumor, or hematuria. Thirty-one patients underwent DECT urography with a 50% reduced iodine dose and reconstruction at 50 and 77 keV. These subjects were sex, age, and size matched to a group of 31 patients who underwent 120-kVp SECT urography with a standard iodine dose. The mean iodine dose was 22 g for DECT and 44 g for SECT. Attenuation was measured at seven locations in the renal arteries, renal veins, and urinary tract. Two reviewers subjectively scored the image quality parameters image noise, sharpness of urinary tract contours, enhancement of urinary structures, and streak artifacts. RESULTS: Mean DECT attenuation at 50 keV was the same as or greater than SECT attenuation at each of the seven locations. Measured image noise was highest at 50-keV DECT but was the same for 77-keV DECT and 120-kVp SECT. Mean subjective scores for DECT image quality parameters were the same as or higher than those of SECT, except for streak artifact and sharpness of urinary tract contours. CONCLUSION: DECT urography with a 50% reduced iodine dose may result in measured renal vascular and urinary tract attenuation the same as or higher than and image quality measurements and scores similar to those obtained with 120-kVp SECT urography with a standard iodine dose.


Assuntos
Meios de Contraste/administração & dosagem , Iohexol/administração & dosagem , Imagem Radiográfica a Partir de Emissão de Duplo Fóton/métodos , Tomografia Computadorizada por Raios X/métodos , Ácidos Tri-Iodobenzoicos/administração & dosagem , Urografia/métodos , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Interpretação de Imagem Radiográfica Assistida por Computador
20.
J Cardiovasc Comput Tomogr ; 13(1): 81-84, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30377090

RESUMO

ObjectiveTo assess the feasibility of dual energy CT (DECT) to derive myocardial extracellular volume (ECV) and detect myocardial ECV differences without a non-contrast acquisition, compared to single energy CT (SECT). MethodsSubjects (n = 35) with focal fibrosis (n = 17), diffuse fibrosis (n = 10), and controls (n = 9) underwent non-contrast and delayed acquisitions to calculate SECT-ECV. DECT-ECV was calculated using the delayed acquisition and the derived virtual non-contrast images. In the control and diffuse fibrotic groups, the entire myocardium of the left ventricle was used to calculate ECV. Two ROIs were placed in the focal fibrotic group, one in normal and one in fibrotic myocardium. ResultsMedian ECV was 33.4% (IQR, 30.1-37.4) using SECT and 34.9% (IQR, 31.2-39.2) using DECT (p = 0.401). For both techniques, focal and diffuse fibrosis had significantly higher ECV values (all p < 0.021) than normal myocardium. There was no systematic bias between DECT and SECT (p = 0.348). SECT had a higher radiation dose (1.1 mSv difference) than DECT (p < 0.001). ConclusionECV can be measured using a DECT approach with only a delayed acquisition. The DECT approach provides similar results at a lower radiation dose compared to SECT.


Assuntos
Cardiomiopatias/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Idoso , Cardiomiopatias/patologia , Estudos de Casos e Controles , Meios de Contraste/administração & dosagem , Estudos de Viabilidade , Feminino , Fibrose , Humanos , Iohexol/administração & dosagem , Iohexol/análogos & derivados , Masculino , Pessoa de Meia-Idade , Miocárdio/patologia , Valor Preditivo dos Testes , Doses de Radiação , Exposição à Radiação/efeitos adversos , Exposição à Radiação/prevenção & controle , Tomografia Computadorizada por Raios X/efeitos adversos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA