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1.
AJR Am J Roentgenol ; 214(4): 775-785, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32045305

RESUMO

OBJECTIVE. The purpose of this article is to outline the utility of iodine density maps for evaluating cardiothoracic disease and abnormalities. Multiple studies have shown that the variety of images generated from dual-energy spectral detector CT (SDCT) improve identification of cardiothoracic conditions. CONCLUSION. Understanding the technique of SDCT and being familiar with the features of different cardiothoracic conditions on iodine density map images help the radiologist make a better diagnosis.


Assuntos
Doenças Cardiovasculares/diagnóstico por imagem , Meios de Contraste/farmacocinética , Iodo/farmacocinética , Imagem Radiográfica a Partir de Emissão de Duplo Fóton/métodos , Radiografia Torácica/métodos , Doenças Respiratórias/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Humanos , Interpretação de Imagem Radiográfica Assistida por Computador
3.
Eur Radiol ; 30(1): 1-10, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31278580

RESUMO

OBJECTIVES: Various imaging methods have been evaluated regarding non-invasive differentiation of renal cell carcinoma (RCC) subtypes. Dual-energy computed tomography (DECT) allows iodine concentration (IC) analysis as a correlate of tissue perfusion. Microvascular density (MVD) in histopathology specimens is evaluated to determine intratumoral vascularization. The objective of this study was to assess the potential of IC and MVD regarding the differentiation between papillary and clear cell RCC and between well- and dedifferentiated tumors. Further, we aimed to investigate a possible correlation between these parameters. METHODS: DECT imaging series of 53 patients with clear cell RCC (ccRCC) and 15 with papillary RCC (pRCC) were analyzed regarding IC. Histology samples were stained using CD31/CD34 monoclonal antibodies; MVD was evaluated digitally. Statistical analysis included performance of Mann-Whitney U test, ROC analysis, and Spearman rank correlation. RESULTS: Analysis of IC demonstrated significant differences between ccRCC and pRCC (p < 0.001). A cutoff value of ≤ 3.1 mg/ml at IC analysis allowed identification of pRCC with an accuracy of 86.8%. Within the ccRCC subgroup, G1/G2 tumors could significantly be differentiated from G3/G4 carcinomas (p = 0.045). A significant positive correlation between IC and MVD could be determined for the entire RCC cohort and the ccRCC subgroup. Limitations include the small percentage of pRCCs. CONCLUSIONS: IC analysis is a useful method to differentiate pRCC from ccRCC. The significant positive correlation between IC and MVD indicates valid representation of tumor perfusion by DECT. KEY POINTS: • Analysis of iodine concentration using DECT imaging could reliably distinguish papillary from clear cell subtypes of renal cell cancer (RCC). • A cutoff value of 3.1 mg/ml allowed a distinction between papillary and clear cell RCCs with an accuracy of 86.8%. • The positive correlation with microvascular density in tumor specimens indicates correct display of perfusion by iodine concentration analysis.


Assuntos
Carcinoma Papilar/patologia , Carcinoma de Células Renais/patologia , Neoplasias Renais/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Papilar/irrigação sanguínea , Carcinoma Papilar/diagnóstico por imagem , Carcinoma de Células Renais/irrigação sanguínea , Carcinoma de Células Renais/diagnóstico por imagem , Transformação Celular Neoplásica/patologia , Meios de Contraste/farmacocinética , Feminino , Humanos , Iodo/farmacocinética , Neoplasias Renais/irrigação sanguínea , Neoplasias Renais/diagnóstico por imagem , Masculino , Microvasos/diagnóstico por imagem , Microvasos/patologia , Pessoa de Meia-Idade , Estudos Retrospectivos , Estatísticas não Paramétricas , Tomografia Computadorizada por Raios X/métodos , Carga Tumoral
4.
Am J Clin Nutr ; 110(1): 102-110, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-31788697

RESUMO

BACKGROUND: Milk and dairy products are considered important dietary sources of iodine in many countries. However, to our knowledge, iodine bioavailability from milk has not been directly measured in humans. OBJECTIVE: The aim of this study was to compare iodine bioavailability in iodine-replete adults from: 1) cow milk containing a high concentration of native iodine; 2) milk containing a low concentration of native iodine, with the addition of potassium iodide (KI) to assess a potential matrix effect; and 3) an aqueous solution of KI as a comparator; with all 3 containing equal amounts of total iodine (263 µg/250 mL). We also speciated iodine in milk. DESIGN: We conducted a 3-wk, randomized, crossover balance study in adults (n = 12) consuming directly analyzed, standardized diets. During the 3 test conditions - high intrinsic iodine milk (IIM), extrinsically added iodine in milk (EIM), and aqueous iodine solution (AIS) - subjects collected 24-h urine over 3 d and consumed the test drink on the second day, with 3- or 4-d wash-out periods prior to each treatment. Iodine absorption was calculated as the ratio of urinary iodine excretion (UIE) to total iodine intake. Milk iodine speciation was performed using ion chromatography-mass spectrometry. RESULTS: Iodine intake from the standardized diet was 195 ± 6 µg/d for males and 107 ± 6 µg/d for females; the test drinks provided an additional 263 µg. Eleven subjects completed the protocol. There was a linear relation between iodine intake and UIE (ß = 0.89, SE = 0.04, P < 0.001). There were no significant differences in UIE among the 3 conditions (P = 0.24). Median (range) fractional iodine absorption across the 3 conditions was 91 (51-145), 72 (48-95), and 98 (51-143)% on days 1, 2, and 3, respectively, with day 2 significantly lower compared with days 1 and 3 (P < 0.001). In milk, 80-93% of the total iodine was inorganic iodide. CONCLUSION: Nearly all of the iodine in cow milk is iodide and although fractional iodine absorption from milk decreases with increasing dose, its bioavailability is high. The trial was registered at clinicaltrials.gov as NCT03590431.


Assuntos
Iodo/farmacocinética , Leite/química , Adulto , Animais , Disponibilidade Biológica , Índice de Massa Corporal , Bovinos , Estudos Cross-Over , Dieta , Feminino , Humanos , Iodo/administração & dosagem , Iodo/urina , Masculino , Estado Nutricional , Iodeto de Potássio/administração & dosagem
5.
Eur J Radiol ; 120: 108698, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31600640

RESUMO

PURPOSE: The aim of the study is to explore the patient's and scan's parameters that affect the iodine concentration in the abdomen using dual energy computed tomography (DECT) in an oncologic population. METHOD: This is a retrospective study with consecutive patients with different cancers who underwent a single-source DECT (ssDECT) examinations at our institution between years 2015 and 2017. On axial IODINE images, the radiologist manually drew a circular ROI along the inner contour of the aorta. Mean iodine concentration and ROI areas were recorded. Body mass index for every patient was recorded. Descriptive statistics were summarized for iodine concentration and patient/scan characteristics. Linear regression was used to examine associations between iodine concentration in aorta and studied characteristics. Statistical significance was set at a p value < 0.05. RESULTS: The univariate analysis, showed a statistically significant association between iodine concentration within the aorta and the area of ROI (Estimated Coefficient ß: -0.013), the rate of injection (Estimated Coefficient ß: 2.09), the acquisition time (Estimated Coefficient ß: -0.195). In multivariable analysis iodine concentration in the aorta increased with higher rate of injection (4 ml/sec), smaller ROI area and lower BMI. CONCLUSION: Our results showed how iodine concentration is highly dependent on some intrinsic and extrinsic parameters of the examination. These parameters should be taken into account since lower concentration of iodine decrease contrast-to-noise ratio, and in longitudinal follow up studies, they would affect iodine quantitive assessments in cancer patients with frequent chemotherapy-induced variations in BMI and cardiac function.


Assuntos
Meios de Contraste/farmacocinética , Iodo/farmacocinética , Neoplasias/diagnóstico por imagem , Intensificação de Imagem Radiográfica/métodos , Imagem Radiográfica a Partir de Emissão de Duplo Fóton/métodos , Tomografia Computadorizada por Raios X/métodos , Adulto , Aorta/metabolismo , Índice de Massa Corporal , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
6.
Curr Med Sci ; 39(5): 825-830, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31612403

RESUMO

To explore the feasibility and superiority of iodine delivery rate (IDR) and tube voltage determined by patients' body mass index (BMI) in coronary CT angiography (CCTA), a total of 1567 patients undertaking CCTA during Feb. and Dec. 2016 were enrolled and divided into two groups. In the control group, the IDR and tube voltage were fixed, while in the experimental group, the IDR and tube voltage were determined by patients' BMI. The volume of iodinated contrast media (ICM), extravasation rate, extravasation volume, extravasation recovery interval, incidence rate of adverse reactions, effective dose (ED) and image quality of the two groups were compared. The experiments demonstrated that the ICM volume, extravasation rate, extravasation volume, extravasation recovery interval, incidence of adverse reactions and ED were lower or shorter in the experimental group than in the control group, and the differences were statistically significant (all P<0.05). However, there were no significant differences in the mean CT value, image noise, signal to noise ratio and contrast to noise ratio between the two groups (all P<0.05), which were consistent with the diagnosticians' subjective evaluation outcomes. Our findings suggested that in CCTA, it is feasible to determine the IDR and tube voltage based on patients' BMI; low tube voltage and IDR are superior to the fixed tube voltage and IDR and are worthy of clinical promotion.


Assuntos
Angiografia por Tomografia Computadorizada/métodos , Meios de Contraste/farmacocinética , Angiografia Coronária/métodos , Doença da Artéria Coronariana/diagnóstico por imagem , Extravasamento de Materiais Terapêuticos e Diagnósticos/diagnóstico por imagem , Iodo/farmacocinética , Índice de Massa Corporal , Doença da Artéria Coronariana/sangue , Extravasamento de Materiais Terapêuticos e Diagnósticos/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Razão Sinal-Ruído
7.
Food Chem ; 300: 125202, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31330374

RESUMO

The aim of a three-year study was to assess the effect of combined biofortification with I and Se in carrot. Four cultivars ('Askona' F1, 'Samba' F1, 'Kazan' F1 and 'White Satin') were grown in soil fertilized with KI (4 kg I ha-1) and Na2SeO4 (0.25 kg Se ha-1). The I + Se fertilization did not affect yield but the plants of all cultivars accumulated both elements in leaves and roots. On average, the I and Se contents in roots increased 7.7-times for I and 4.9-times for Se as well as the average I:Se molar ratio was 0.28:1. The contents of both elements in roots remained well below the hazard threshold thus the intake of 100 g of biofortified carrot would substantially cover the RDA for I and Se. The changes in chemical composition of roots (nitrates, phenolic compounds, sugars, carotenoids, macro-, microelements and cadmium) were rather year-dependent than affected by the applied I + Se fertilization.


Assuntos
Biofortificação/métodos , Daucus carota/química , Iodo/farmacologia , Raízes de Plantas/química , Selênio/farmacologia , Cádmio/análise , Carotenoides/análise , Daucus carota/efeitos dos fármacos , Daucus carota/crescimento & desenvolvimento , Fertilizantes , Alimentos Fortificados/análise , Iodo/análise , Iodo/farmacocinética , Polônia , Selênio/análise , Selênio/farmacocinética , Solo/química
8.
Food Chem ; 301: 125197, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31357004

RESUMO

The present study aimed to evaluate the changes in total iodine and iodine species (iodide, iodate, 3-iodo-l-tyrosine, and 3,5-diiodo-l-tyrosine) content in abalone after different treatments (raw, semi-drying, steaming, grilling, and boiling) and in-vitro digestion using high-performance liquid chromatography-inductively coupled plasma-mass spectroscopy (HPLC-ICP-MS). The highest reduction in iodine content was found in boiled abalone (64.95%), followed by steamed (32.40%) and grilled (32.11%) abalones. There is no significant difference between iodine content of raw and semi-dried abalone. Absorption efficiency was determined by an in vitro digestion procedure using simulated gastro/intestinal solutions. Unlike total iodine content after cooking, absorption efficiency increased after cooking. Absorption efficiency of semi-dried abalone is the highest (28.53%), followed by boiled (23.85%), grilled (22.62%), steamed (21.51%), and raw (12.20%) abalones. Iodide was the major form of iodine present in the abalone after cooking and in vitro digestion. No iodate was observed, and the organic iodine content was very low.


Assuntos
Culinária , Iodo/análise , Frutos do Mar/análise , Animais , Disponibilidade Biológica , Cromatografia Líquida de Alta Pressão , Digestão , Gastrópodes , Iodetos/análise , Iodetos/farmacocinética , Iodo/farmacocinética , Espectrometria de Massas , Monoiodotirosina/análise , Monoiodotirosina/farmacocinética , Vapor
9.
Invest Radiol ; 54(11): 689-696, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31335633

RESUMO

OBJECTIVES: Using dual-energy computed tomography (DECT) for quantifying iodine content after injection of contrast agent could provide a quantitative basis for dynamic computed tomography (CT) perfusion measurements by means of established mathematical models of contrast agent kinetics, thus improving results by combining the strength of both techniques, which was investigated in this study. MATERIALS AND METHODS: A dynamic DECT acquisition over 51 seconds performed at 80/Sn140 kVp in 17 patients with pancreatic carcinoma was used to calculate iodine-enhancement images for each time point by means of 3-material decomposition. After motion correction, perfusion maps of blood flow were calculated using the maximum-slope model from both 80 kVp image data and iodine-enhancement images. Blood flow was measured in regions of interest placed in healthy pancreatic tissue and carcinoma for both of the derived perfusion maps. To assess image quality of input data, an adjusted contrast-to-noise ratio was calculated for 80 kVp images and iodine-enhancement images. Susceptibility of perfusion results to residual patient breathing motion during acquisition was investigated by measuring blood flow in fatty tissue surrounding the pancreas, where blood flow should be negligible compared with the pancreas. RESULTS: For both 80 kVp and iodine-enhancement images, blood flow was significantly higher in healthy tissue (114.2 ± 37.4 mL/100 mL/min or 115.1 ± 36.2 mL/100 mL/min, respectively) than in carcinoma (46.5 ± 26.6 mL/100 mL/min or 49.7 ± 24.7 mL/100 mL/min, respectively). Differences in blood flow between 80 kVp image data and iodine-enhancement images were statistically significant in healthy tissue, but not in carcinoma. For 80 kVp images, adjusted contrast-to-noise ratio was significantly higher (1.3 ± 1.1) than for iodine-enhancement images (1.1 ± 0.9). When evaluating fatty tissue surrounding the pancreas for estimating influence of patient motion, measured blood flow was significantly lower for iodine-enhancement images (30.7 ± 12.0 mL/100 mL/min) than for 80 kVp images (39.0 ± 19.1 mL/100 mL/min). Average patient radiation exposure was 8.01 mSv for dynamic DECT acquisition, compared with 4.60 mSv for dynamic 80 kVp acquisition. DISCUSSION: Iodine enhancement images can be used to calculate CT perfusion maps of blood flow, and compared with 80 kVp images, results showed only a small difference of 1 mL/100 mL/min in blood flow in healthy tissue, whereas patient radiation exposure was increased for dynamic DECT. Perfusion maps calculated based on iodine-enhancement images showed lower blood flow in fatty tissues surrounding the pancreas, indicating reduced susceptibility to residual patient breathing motion during the acquisition.


Assuntos
Meios de Contraste/farmacocinética , Iodo/farmacocinética , Neoplasias Pancreáticas/diagnóstico por imagem , Intensificação de Imagem Radiográfica/métodos , Tomografia Computadorizada por Raios X/métodos , Absorciometria de Fóton/métodos , Humanos , Pâncreas/diagnóstico por imagem , Estudos Retrospectivos
10.
Br J Nutr ; 122(2): 172-185, 2019 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-31182169

RESUMO

The contribution of milk and dairy products to daily iodine intake is high but variable in many industrialised countries. Factors that affect iodine concentrations in milk and dairy products are only poorly understood. Our aim was to: (1) assess the effect of feed iodine concentration on milk iodine by supplementing five groups of five cows each with one of five dosages from 0-2 mg iodine/kg DM; (2) quantify iodine losses during manufacturing of cheese and yogurt from milk with varying iodine concentrations and assess the effect of cellar-ripening; and (3) systematically measure iodine partitioning during heat treatment and skimming of milk. Milk iodine reached a near-steady state after 3 weeks of feeding. Median milk iodine (17-302 µg/l for 0-2 mg iodine/kg DM) increased linearly with feed iodine (R2 0·96; P < 0·001). At curd separation, 75-84 % of iodine was lost in whey. Dairy iodine increased linearly with milk iodine (semi-hard cheese: R2 0·95; P < 0·001; fresh cheese and yogurt: R2 1·00; P < 0·001), and cellar-ripening had no effect. Heat treatment had no significant effect, whereas skimming increased (P < 0·001) milk iodine concentration by only 1-2 µg/l. Mean daily intake of dairy products by Swiss adults is estimated at 213 g, which would contribute 13-52 % of the adults' RDA for iodine if cow feed is supplemented with 0·5-2 mg iodine/kg DM. Thus, modulation of feed iodine levels can help achieve desirable iodine concentrations in milk and dairy products, and thereby optimise their contribution to human iodine nutrition to avoid both deficiency and excess.


Assuntos
Ração Animal/análise , Bovinos , Laticínios/análise , Manipulação de Alimentos/métodos , Iodo/administração & dosagem , Leite/química , Adulto , Animais , Dieta , Feminino , Temperatura Alta , Humanos , Iodo/análise , Iodo/farmacocinética , Recomendações Nutricionais , Suíça
11.
Eur Radiol ; 29(12): 6581-6590, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31175416

RESUMO

OBJECTIVES: The objective of this study was to evaluate the intra-individual, longitudinal consistency of iodine measurements regarding the vascular and renal blood pool in patients that underwent repetitive spectral detector computed tomography (SDCT) examinations to evaluate their utility for oncologic imaging. METHODS: Seventy-nine patients with two (n = 53) or three (n = 26) clinically indicated biphasic SDCT scans of the abdomen were retrospectively included. ROI-based measurements of Hounsfield unit (HU) attenuation in conventional images and iodine concentration were performed by an experienced radiologist in the following regions (two ROIs each): abdominal aorta, vena cava inferior, portal vein, and renal cortices. Modified variation coefficients (MVCs) were computed to assess intra-individual longitudinal between the different time points. RESULTS: Variation of HU attenuation and iodine concentration measurements was significantly lower in the venous than in the arterial phase images (attenuation/iodine concentration: arterial - 4.2/- 3.9, venous 0.4/1.0; p ≤ 0.05). Regarding attenuation in conventional images of the arterial phase, the median MVC was - 1.8 (- 20.5-21.3) % within the aorta and - 6.5 (- 44.0-25.0) % within the renal cortex while in the portal venous phase, it was 0.62 (- 11.1-11.7) % and - 1.6 (- 16.2-10.6) %, respectively. Regarding iodine concentration, MVC for arterial phase was - 2.5 (- 22.9-28.4) % within the aorta and - 5.8 (- 55.9-29.6) % within the renal cortex. The referring MVCs of the portal venous phase were - 0.7 (- 17.9-16.9) % and - 2.6 (- 17.6-12.5) %. CONCLUSIONS: Intra-individual iodine quantification of the vascular and cortical renal blood pool at different time points works most accurately in venous phase images whereas measurements conducted in arterial phase images underlay greater variability. KEY POINTS: • There is an intra-individual, physiological variation in iodine map measurements from dual-energy computed tomography. • This variation is smaller in venous phase examinations compared with arterial phase and therefore venous phase images should be preferred to minimize this intra-individual variation. • Care has to be taken, when considering iodine measurements for clinical decision-making, particularly in the context of oncologic initial or follow-up imaging.


Assuntos
Artérias/metabolismo , Iodo/farmacocinética , Rim/metabolismo , Tomografia Computadorizada por Raios X/métodos , Artérias/diagnóstico por imagem , Meios de Contraste/farmacocinética , Humanos , Rim/diagnóstico por imagem , Veia Porta , Estudos Retrospectivos
12.
ACS Appl Mater Interfaces ; 11(21): 18953-18959, 2019 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-31062589

RESUMO

Emerging tumor treatment demands high sensitivity and high-spatial resolution diagnosis in combination with targeted therapy. Here, we report that iodine-rich polymersomes (I-PS) enable versatile single-photon emission computed tomography (SPECT)/computed tomography (CT) dual-modal imaging and potent radioisotope therapy for breast cancer in vivo. Interestingly, I-PS could be easily and stably labeled with radioiodine, 125I and 131I. Dynamic light scattering and transmission electron microscopy showed that 125I-PS had a size of 106 nm and vesicular morphology, similar to those of the parent I-PS. Methyl thiazolyl tetrazolium assays displayed that I-PS and 125I-PS were noncytotoxic, whereas 131I-PS caused significant death of 4T1 cells at 5 mg PS/mL with a radioactivity of 12 µCi. Pharmacokinetic and biodistribution studies showed that 125I-PS has a prolonged circulation and distributes mainly in tumor and the reticuloendothelial system. The intravenous injection of 125I-PS to 4T1 murine breast tumor-bearing mice allowed simultaneous high sensitivity and high-spatial resolution imaging of tumor by SPECT and CT, respectively. The therapeutic studies revealed that 131I-PS could effectively retard the growth of 4T1 breast tumor and significantly prolong mice survival time. The hematoxylin and eosin staining assay proved that 131I-PS induced tumor cell death. I-PS emerges as a robust and versatile platform for dual-modal imaging and targeted radioisotope therapy.


Assuntos
Iodo/química , Neoplasias/radioterapia , Polímeros/química , Tomografia Computadorizada de Emissão de Fóton Único , Tomografia Computadorizada por Raios X , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Morte Celular , Linhagem Celular Tumoral , Iodo/farmacocinética , Radioisótopos do Iodo/farmacocinética , Camundongos Endogâmicos BALB C , Neoplasias/patologia , Distribuição Tecidual
13.
Eur J Radiol ; 112: 136-143, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30777202

RESUMO

BACKGROUND: The aim of this study was to assess the potential of rest-stress DECT iodine quantification to discriminate between normal, ischemic, and infarcted myocardium. METHODS: Patients who underwent rest-stress DECT on a 2nd generation dual-source system and cardiac magnetic resonance (CMR) were retrospectively included from a prospective study cohort. CMR was performed to identify ischemic and infarcted myocardium and categorize patients into ischemic, infarcted, and control groups. Controls were analyzed on a per-slice and per-segment basis. Regions of interest (ROIs) were placed in ischemic and infarcted areas based on CMR. Additionally, ROIs were placed in the septal area to assess normal and remote myocardium. RESULTS: We included 42 patients: 10 ischemic, 17 infarcted, and 15 controls. Iodine concentrations showed no significant between segments in controls. Iodine concentrations for normal myocardium increased significantly from rest to stress (median 3.7 mg/mL (interquartile range 3.5-3.9) vs. 4.5 mg/mL (4.3-4.9)) (p < 0.001). Iodine concentrations in diseased myocardium were significantly lower than in normal myocardium; 1.3 mg/mL (0.9-1.8) and 0.6 mg/mL (0.4-0.8) at rest and stress in ischemic myocardium, and 0.3 mg/mL (0.3-0.5) and 0.5 mg/mL (0.5-0.7) at rest and stress in infarcted myocardium (p < 0.005 and p < 0.001). At rest only, iodine concentrations were significantly lower in infarcted vs. ischemic myocardium (p < 0.001). The optimal threshold for differentiating diseased from normal myocardium was 2.5 mg/mL and 2.1 mg/mL for rest and stress (AUC 1.00). To discriminate ischemic from infarcted myocardium, the optimal threshold was 1.0 mg/ml (AUC 0.944) at rest. CONCLUSION: DECT iodine concentration from rest-stress imaging can potentially differentiate between normal, ischemic, and infarcted myocardium.


Assuntos
Meios de Contraste/farmacocinética , Iodo/farmacocinética , Isquemia Miocárdica/diagnóstico , Idoso , Estudos de Casos e Controles , Teste de Esforço/métodos , Feminino , Coração/fisiologia , Humanos , Angiografia por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/diagnóstico , Imagem de Perfusão do Miocárdio/métodos , Miocárdio/química , Estudos Prospectivos , Descanso , Estudos Retrospectivos , Tomografia Computadorizada por Raios X/métodos
14.
PLoS One ; 14(2): e0212679, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30802258

RESUMO

OBJECTIVES: To evaluate the accuracy of Spectral Photon-Counting Computed Tomography (SPCCT) in the quantification of iodine concentrations and its potential for the differentiation between blood and iodine. METHODS: Tubes with blood and a concentration series of iodine were scanned with a preclinical SPCCT system (both in vitro and in an ex vivo bovine brain tissue sample). Iodine density maps (IDM) and virtual non-contrast (VNC) images were generated using the multi-bin spectral information to perform material decomposition. Region-of-interest (ROI) analysis was performed within the tubes to quantitatively determine the absolute content of iodine (mg/ml). RESULTS: In conventional CT images, ROI analysis showed similar Hounsfield Unit (HU) values for the tubes with blood and iodine (59.9 ± 1.8 versus 59.2 ± 1.5). Iodine density maps enabled clear differentiation between blood and iodine in vitro, as well as in the bovine brain model. Quantitative measurements of the different iodine concentrations matched well with those of actual known concentrations even for very small iodine concentrations with values below 1mg/ml (RMSE = 0.19). CONCLUSIONS: SPCCT providing iodine maps and virtual non-contrast images allows material decomposition, differentiation between blood and iodine in vitro and ex vivo in a bovine brain model and reliably quantifies the iodine concentration.


Assuntos
Sangue/metabolismo , Encéfalo/diagnóstico por imagem , Meios de Contraste/farmacocinética , Iodo/farmacocinética , Fótons , Tomografia Computadorizada de Emissão , Animais , Encéfalo/metabolismo , Bovinos , Meios de Contraste/farmacologia , Iodo/farmacologia
15.
Invest Radiol ; 54(3): 177-182, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30721159

RESUMO

OBJECTIVES: The aim of the present study was to evaluate the attenuation and image quality (IQ) of a body weight-adapted contrast media (CM) protocol compared with a fixed injection protocol in computed tomography (CT) of the liver at 90 kV. MATERIALS AND METHODS: One hundred ninety-nine consecutive patients referred for abdominal CT imaging in portal venous phase were included. Group 1 (n = 100) received a fixed CM dose with a total iodine load (TIL) of 33 g I at a flow rate of 3.5 mL/s, resulting in an iodine delivery rate (IDR) of 1.05 g I/s. Group 2 (n = 99) received a body weight-adapted CM protocol with a dosing factor of 0.4 g I/kg with a subsequent TIL adapted to the patients' weight. Injection time of 30 seconds was kept identical for all patients. Therefore, flow rate and IDR changed with different body weight. Patients were divided into 3 weight categories; 70 kg or less, 71 to 85 kg, and 86 kg or greater. Attenuation (HU) in 3 segments of the liver, signal-to-noise ratio, and contrast-to-noise ratio were used to evaluate objective IQ. Subjective IQ was assessed by a 5-point Likert scale. Differences between groups were statistically analyzed (P < 0.05 was considered statistically significant). RESULTS: No significant differences in baseline characteristics were found between groups. The CM volume and TIL differed significantly between groups (P < 0.01), with mean values in group 1 of 110 mL and 33 g I, and in group 2 of 104.1 ± 21.2 mL and 31.2 ± 6.3 g I, respectively. Flow rate and IDR were not significantly different between groups (P > 0.05). Body weight-adapted protocoling led to more homogeneous enhancement of the liver parenchyma compared with a fixed protocol with a mean enhancement per weight category in group 2 of 126.5 ± 15.8, 128.2 ± 15.3, and 122.7 ± 21.2 HU compared with that in group 1 of 139.9 ± 21.4, 124.6 ± 24.8, and 116.2 ± 17.8 HU, respectively. CONCLUSIONS: Body weight-adapted CM injection protocols result in more homogeneous enhancement of the liver parenchyma at 90 kV in comparison to a fixed CM volume with comparable objective and subjective IQ, whereas overall CM volume can be safely reduced in more than half of patients.


Assuntos
Peso Corporal , Meios de Contraste/farmacocinética , Iodo/farmacocinética , Fígado/diagnóstico por imagem , Intensificação de Imagem Radiográfica/métodos , Tomografia Computadorizada por Raios X/métodos , Meios de Contraste/administração & dosagem , Feminino , Humanos , Iodo/administração & dosagem , Masculino , Pessoa de Meia-Idade , Razão Sinal-Ruído
17.
ACS Appl Mater Interfaces ; 11(1): 403-416, 2019 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-30541280

RESUMO

Noninvasive diagnostic by imaging combined with a contrast agent (CA) is by now the most used technique to get insight into human bodies. X-ray and magnetic resonance imaging (MRI) are widely used technologies providing complementary results. Nowadays, it seems clear that bimodal CAs could be an emerging approach to increase the patient compliance, accessing different imaging modalities with a single CA injection. Owing to versatile designs, targeting properties, and high payload capacity, nanocarriers are considered as a viable solution to reach this goal. In this study, we investigated efficient superparamagnetic iron oxide nanoparticle (SPION)-loaded iodinated nano-emulsions (NEs) as dual modal injectable CAs for X-ray imaging and MRI. The strength of this new CA lies not only in its dual modal contrasting properties and biocompatibility, but also in the simplicity of the nanoparticulate assembling: iodinated oily core was synthesized by the triiodo-benzene group grafting on vitamin E (41.7% of iodine) via esterification, and SPIONs were produced by thermal decomposition during 2, 4, and 6 h to generate SPIONs with different morphologies and magnetic properties. SPIONs with most anisotropic shape and characterized by the highest r2/ r1 ratio once encapsulated into iodinated NE were used for animal experimentation. The in vivo investigation showed an excellent contrast modification because of the presence of the selected NEs, for both imaging techniques explored, that is, MRI and X-ray imaging. This work provides the description and in vivo application of a simple and efficient nanoparticulate system capable of enhancing contrast for both preclinical imaging modalities, MRI, and computed tomography.


Assuntos
Meios de Contraste , Iodo , Imagem por Ressonância Magnética/métodos , Nanopartículas de Magnetita , Tomografia Computadorizada por Raios X/métodos , Animais , Meios de Contraste/química , Meios de Contraste/farmacocinética , Meios de Contraste/farmacologia , Emulsões , Células HeLa , Humanos , Iodo/química , Iodo/farmacocinética , Iodo/farmacologia , Nanopartículas de Magnetita/química , Nanopartículas de Magnetita/uso terapêutico , Camundongos
18.
Acad Radiol ; 26(7): 872-877, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30262328

RESUMO

PURPOSE: To investigate the hemodynamic changes in liver cirrhosis by comparing iodine density in hepatic and splenic parenchyma with 8 cm detector dual energy CT (DECT). MATERIALS AND METHODS: Forty-six consecutive patients with liver cirrhosis and 22 healthy volunteers were recruited in this study, and they were all performed contrast enhanced examination with 8 cm detector DECT. All raw data were reconstructed with 1.25 mm slice thickness, Iodine density (in milligrams per milliliter) were measured on iodine-based material decomposition images. Quantitative indices of iodine density (ID), including normalized ID of liver parenchyma for arterial phase (NIDLAP), ID of liver parenchyma for venous phase (IDLVP), ID of splenic parenchyma for arterial phase (IDSAP), ID of splenic parenchyma for venous phase (IDSVP), ID of portal vein in venous phase (IDPVP) and Liver arterial iodine density fraction (AIF) were measured and compared between two groups. The correlation between Child-Pugh grade and other quantitative indices were calculated, with statistical significance as P<0.05. RESULTS: For all 46 liver cirrhosis patients, 10 were classified in grade A, 24 in Grade B and 12 in Grade C. Compared with control group, patients with liver cirrhosis showed (1) no statistical difference in general data (age, gender, height and weight) (all P>0.05), (2) higher iodine density of NIDLAP, IDSVP, IDPVP and AIF, and lower NIDSAP (all P<0.01), (3) NIDLAP, AIF, IDSVP and IDPVP in grade A were all lower than Grade B and C (all P<0.01). (4) AIF and NIDLAP showed positive correlation with Child-Pugh grade, with coefficient of R = 0.71 and R = 0.46, respectively. CONCLUSION: Based on iodine density measurement in DECT, it is possible to evaluate the hemodynamic changes in liver and spleen parenchyma in liver cirrhosis. Quantitative indices of AIF and NIDLAP demonstrate positive correlation with Child-Pugh grade, which accommodates potential possibility for DECT as a noninvasive tool in assessing the severity of liver cirrhosis.


Assuntos
Meios de Contraste/farmacocinética , Iodo/farmacocinética , Cirrose Hepática/diagnóstico por imagem , Intensificação de Imagem Radiográfica/métodos , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Feminino , Humanos , Fígado/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Veia Porta , Imagem Radiográfica a Partir de Emissão de Duplo Fóton , Baço/diagnóstico por imagem
20.
Cancer Imaging ; 18(1): 42, 2018 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-30413174

RESUMO

BACKGROUND: Computed tomography (CT) imaging is the most common imaging modality for the diagnosis and staging of gastric cancer. The aim of this study is was to prospectively explore the ability of quantitative spectral CT parameters in the detection of gastric cancer and its histologic types. METHODS: A total of 87 gastric adenocarcinoma (43 poorly and 44 well-differentiated) patients and 36 patients with benign gastric wall lesions (25 inflammation and 11 normal), who underwent dual-phase enhanced spectral CT examination, were retrospectively enrolled in this study. Iodine concentration (IC) and normalized iodine concentration (nIC) during arterial phase (AP) and portal venous phase (PP) were measured thrice in each patient by two blinded radiologists. Moreover, intraclass correlation coefficient (ICC) was used to assess the interobserver reproducibility. Differences of IC and nIC values between gastric cancer and benign lesion groups were compared using Mann-Whitney U test. Furthermore, the gender, age, location, thickness and histological types of gastric adenocarcinoma were analyzed by Mann-Whitney U test or Kruskal-Wallis H test. Receiver operating characteristic (ROC) curves were used to evaluate the diagnostic efficacy of IC and nIC values, and the optimal cut-off value was calculated with Youden J. RESULTS: An excellent interobserver agreement (ICC >  0.6) was achieved for IC. Notably, the values of ICAP, ICPP, nICAP and nICPP were significantly higher in gastric cancer group (Z = 5.870, 3.894, 2.009 and 10.137, respectively; P < 0.05) than those in benign lesion group. Additionally, the values of ICAP, ICPP, nICAP and nICPP were significantly higher in poorly differentiated gastric adenocarcinoma group (Z = 4.118, 5.637, 6.729 and 2.950, respectively; P < 0.005) than those in well-differentiated gastric adenocarcinoma group. There were no statistically significant differences in the values of ICAP, ICPP, nICAP and nICPP between age, gender, tumor thickness and tumor location. Furthermore, the area under the curve (AUC) values of ICAP, nICAP, ICPP and nICPP were 0.745, 0.584, 0.662, and 0.932, respectively, for gastric cancer detection; while 0.756, 0.919, 0.851 and 0.684, respectively, in discriminating poorly differentiated gastric adenocarcinoma. CONCLUSION: IC values exhibited great potential in the preoperative and non-invasive diagnosis of gastric cancer and its histological types. In particular, nICPP is more effective for the identification of gastric cancer, whereas nICAP is more effective in discriminating poorly differentiated gastric adenocarcinoma.


Assuntos
Adenocarcinoma/diagnóstico por imagem , Meios de Contraste/farmacocinética , Iodo/farmacocinética , Neoplasias Gástricas/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adenocarcinoma/patologia , Adulto , Idoso , Meios de Contraste/administração & dosagem , Feminino , Humanos , Iodo/administração & dosagem , Masculino , Pessoa de Meia-Idade , Neoplasias Gástricas/patologia , Tomografia Computadorizada por Raios X/normas
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