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1.
Mult Scler Relat Disord ; 56: 103274, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34583214

RESUMO

BACKGROUND: multiple sclerosis (MS) is a complex disease sustained by several pathogenic mechanisms. As such, combination therapy strategies, targeting a range of disease mechanisms, might represent the ideal therapeutic approach. Here we investigated the efficacy of curcumin, a naturally occurring poly-phenolic phytochemical with potent anti-inflammatory and antioxidant properties, in subjects under treatment with IFN ß-1a, to test the effects of this combination therapy on clinical and MRI parameters of inflammation and neurodegeneration in relapsing MS (RMS). METHODS: eighty active RMS were prospectively enrolled, randomized (1:1) to either the IFN-curcumin or the IFN-placebo group and followed up longitudinally with clinical and MRI assessments for 24 months. Primary endpoint was the efficacy of curcumin versus placebo as add-on therapy on new/enlarging T2 lesions in RMS subjects under treatment with subcutaneous IFN ß-1a 44 mcg TIW. Efficacy on clinical parameters (relapses and disability progression), other MRI parameters of inflammation (T1 Gd-enhancing lesions, combined unique active-CUA lesions) and neurodegeneration (T1-hypointense lesions, grey matter loss and white matter microstructural damage) as well as safety and tolerability of curcumin were explored as secondary endpoints. RESULTS: ten subjects dropped out from the study by month 12 (6 in the IFN-curcumin group and 4 in the IFN-placebo group), and 27 by month 24 (11 in the IFN-curcumin group and 16 in the IFN-placebo group). Although no between-group difference was present in terms of proportion of subjects free from new/enlarging T2 lesions, a lower proportion of patients with CUA lesions was noted at month 12 in the IFN-curcumin group in comparison with the IFN-placebo group (7.5% vs 17.5%, χ² test p= 0.0167). This result was not confirmed at month 24. The statistical analysis failed to reveal any difference between the two treatment groups - IFN-curcumin and IFN-placebo - in terms of relapses, disability progression, other MRI metrics of inflammation and MRI changes suggestive of ongoing neurodegeneration. No difference in the rate and nature of adverse events was observed between the two treatment groups. CONCLUSION: Although the study drop-out rate was too high to allow definite conclusions, our findings suggest that curcumin might add to IFN ß-1a efficacy on radiological signs of inflammation in MS, while it did not seem to exert any neuroprotective effect as assessed by clinical and MRI parameters. (NCT01514370).


Assuntos
Curcumina , Esclerose Múltipla Recidivante-Remitente , Esclerose Múltipla , Adjuvantes Imunológicos , Curcumina/efeitos adversos , Suplementos Nutricionais , Humanos , Interferon beta-1a/efeitos adversos , Imageamento por Ressonância Magnética , Esclerose Múltipla Recidivante-Remitente/diagnóstico por imagem , Esclerose Múltipla Recidivante-Remitente/tratamento farmacológico , Estudos Prospectivos , Recidiva , Resultado do Tratamento
2.
Ultrasound Med Biol ; 44(8): 1585-1596, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29735312

RESUMO

Non-alcoholic fatty liver disease is becoming a global epidemic. The aim of this study was to develop a system for assessing liver fat content based on ultrasound images. Magnetic resonance spectroscopy measurements were obtained in 61 patients and the controlled attenuation parameter in 54. Ultrasound images were acquired for all 115 participants and used to calculate the hepatic/renal ratio, hepatic/portal vein ratio, attenuation rate, diaphragm visualization and portal vein wall visualization. The Steato-score was obtained by combining these five parameters. Magnetic resonance spectroscopy measurements were significantly correlated with hepatic/renal ratio, hepatic/portal vein ratio, attenuation rate, diaphragm visualization and portal vein wall visualization; Steato-score was dependent on hepatic/renal ratio, attenuation rate and diaphragm visualization. Area under the receiver operating characteristic curve was equal to 0.98, with 89% sensitivity and 94% specificity. Controlled attenuation parameter values were significantly correlated with hepatic/renal ratio, attenuation rate, diaphragm visualization and Steato-score; the area under the curve was 0.79. This system could be a valid alternative as a non-invasive, simple and inexpensive assessment of intrahepatic fat.


Assuntos
Fígado Gorduroso/diagnóstico por imagem , Ultrassonografia/métodos , Estudos de Avaliação como Assunto , Feminino , Humanos , Itália , Fígado/diagnóstico por imagem , Espectroscopia de Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Índice de Gravidade de Doença
3.
J Comput Assist Tomogr ; 42(2): 222-229, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29489589

RESUMO

OBJECTIVE: To evaluate the accuracy of single-source dual-energy computed tomography (ssDECT) in iodine quantification using various segmentation methods in an ex vivo model. METHODS: Ten sausages, injected with variable quantities of iodinated contrast, were inserted into 2 livers and scanned with ssDECT. Material density iodine images were reconstructed. Three radiologists segmented each sausage. Iodine concentration, volume, and absolute quantity were measured. Agreement between the measured and injected iodine was assessed with the concordance correlation coefficient (CCC). Intrareader agreement was assessed using the intraclass correlation coefficient (ICC). RESULTS: Air bubbles were observed in sausage (IX). Sausage (X) was within the same view as hyper-attenuating markers used for localization. With IX and X excluded, CCC and ICC were greater than 0.98 and greater than 0.88. When included, CCC and ICC were greater than 0.94 and greater than 0.79. CONCLUSIONS: Iodine quantification was reproducible and precise. However, accuracy reduced in sausages consisting of air filled cavities and within the same view as hyperattenuating markers.


Assuntos
Iodo/análise , Fígado/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Animais , Bovinos , Imagem Radiográfica a Partir de Emissão de Duplo Fóton/métodos , Reprodutibilidade dos Testes
4.
Acad Radiol ; 25(7): 825-832, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29373213

RESUMO

RATIONALE AND OBJECTIVES: To determine the impact of second-opinion assessment on cancer staging and patient management in patients with pancreatic ductal adenocarcinoma. METHODS AND MATERIALS: This retrospective study was approved by our institutional review board with a waiver of informed consent. Second-opinion reports between January 1, 2009 and December 31, 2013, alongside outside reports for 65 consecutive cases of biopsy-proven pancreatic adenocarcinomas, were presented in random order to two experienced abdominal surgeons who independently reviewed them blinded to the origin of the report, images of the examinations, and patient identifier. Each surgeon filled in a questionnaire for each report recommending cancer staging and patient management. Recommended patient management and staging were evaluated against reference standards (actual patient management at 6 months following second-opinion assessment, and pathology or other clinical and imaging reference standards at 6 months or longer, respectively) using Cohen kappa. RESULTS: Cancer staging differed in 13% (9 of 65) of cases for surgeon 1 and in 18.4% (12 of 65) for surgeon 2. Patient management changed in 38.4% (25 of 65) of cases for surgeon 1 and in 20% (13 of 65) for surgeon 2. When compared to the pathologic staging gold standard, second opinion was correct in 85.7% (six of seven) of the time for both surgeons. Recommended patient management from second-opinion reports showed good agreement with the reference standard (weighted k = 0.6467 [0.4014-0.892] and weighted k = 0.6262 [0.3954-0.857] for surgeon 2). CONCLUSION: Second-opinion review by subspecialized oncologic radiologists can impact patient care, specifically in terms of management decision.


Assuntos
Carcinoma Ductal Pancreático/diagnóstico por imagem , Carcinoma Ductal Pancreático/terapia , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/terapia , Encaminhamento e Consulta , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Ductal Pancreático/patologia , Tomada de Decisão Clínica , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Variações Dependentes do Observador , Neoplasias Pancreáticas/patologia , Estudos Retrospectivos , Tomografia Computadorizada por Raios X
6.
Q J Nucl Med Mol Imaging ; 62(1): 112-117, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26329495

RESUMO

BACKGROUND: In-vivo imaging of dopamine transporter (DAT), a reliable marker of degeneration of nigrostriatal dopaminergic innervation, has gained increasing interest in preclinical neurodegenerative research for studying disease mechanisms and testing new therapeutic strategies. We assessed the feasibility and the reliability of in vivo and ex vivo quantification of Methyl (3S,4S,5R)-8-(3-fluoropropyl)-3-(4-iodophenyl)-8-azabicyclo[3.2.1]octane-4-carboxylate ([123I]FP-CIT) binding to striatal DAT sites in mouse brain. METHODS: Dedicated small animal single-photon emission computed tomography (SPECT) images of [123I]FP-CIT binding were obtained in 3 groups of healthy mice: untreated (N.=6), pre-treated with lugol solution (N.=4), and pre-treated with selective dopamine transporter uptake inhibitor GBR12909 (N.=4). Ex-vivo autoradiography studies were performed at the end of SPECT studies with phosphor image system in 4 out of the 6 untreated mice and in all mice pre-treated with lugol. Regions of interest were defined over the striatum. The specific binding (SB) was calculated using the cerebral cortex as reference region. RESULTS: SPECT images in untreated mice showed high [123I]FP-CIT uptake in the striatum and extracerebral regions. Lugol pretreatment improved striatal images quality decreasing salivary and thyroid glands uptake. SB was higher (P<0.0001) in mice pre-treated with lugol (5.97±0.60) than in untreated mice (2.25±0.28). Autoradiography showed similar SB findings in untreated (2.27±0.33) and lugol-treated (4.27±0.57) mice (P<0.0001). In-vivo striatal 123I-FP-CIT SB and ex-vivo striatal 123I-FP-CIT SB were significantly correlated (r=0.87; P<0.0001). SPECT competition studies showed a significant (P<0.0001) reduction of [123I]FP-CIT SB in the striatum after GBR12909. CONCLUSIONS: We demonstrated the feasibility of [123I]FP-CIT imaging of the normal mouse brain using small-animal SPECT without pinhole collimators. The reliability of quantitative measurement of striatal [123I]FP-CIT SB is supported by competition studies showing measurable inhibition of uptake induced by GBR12909 and by the strong correlation between in vivo and ex vivo striatal [123I]FP-CIT SB. Our data also demonstrate that pre-treatment with lugol might improve striatal [123I]FP-CIT SB in mice.


Assuntos
Proteínas da Membrana Plasmática de Transporte de Dopamina/metabolismo , Neostriado/diagnóstico por imagem , Neostriado/metabolismo , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Tropanos/metabolismo , Animais , Transporte Biológico , Dopamina/metabolismo , Estudos de Viabilidade , Camundongos , Ligação Proteica , Reprodutibilidade dos Testes
7.
PLoS One ; 12(10): e0185391, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29023554

RESUMO

The presence of significant fibrosis is an indicator for liver disease staging and prognosis. The aim of the study was to determine reproducibility of real-time shear wave elastography using a hepatic biopsy as the reference standard to identify patients with chronic liver disease. Forty patients with chronic liver disease and 12 normal subjects received shear wave elastography performed by skilled operators. Interoperator reproducibility was studied in 29 patients. Fibrosis was evaluated using the Metavir score. The median and range shear wave elastography values in chronic liver disease subjects were 6.15 kPa and 3.14-16.7 kPa and were 4.49 kPa and 2.92-7.32 kPa in normal subjects, respectively. With respect to fibrosis detected by liver biopsy, shear wave elastography did not change significantly between F0 and F1 (p = 0.334), F1 and F2 (p = 0.611), or F3 and F4 (0.327); a significant difference was observed between the F0-F2 and F3-F4 groups (p = 0.002). SWE also correlated with inflammatory activity (Rs = 0.443, p = 0.0023) and ALT levels (Rs = 0.287, p = 0.0804). Age, sex and body mass index did not affect shear wave elastography measurements. Using receiver operator characteristic curves, two threshold values for shear wave elastography were identified: 5.62 kPa for patients with fibrosis (≥F2; sensitivity 80%, specificity 69.4%, and accuracy 77%) and 7.04 kPa for patients with severe fibrosis (≥F3; sensitivity 88.9%, specificity 81%, and accuracy 89%). Overall interobserver agreement was excellent and was analysed using an interclass correlation coefficient (0.94; CI 0.87-0.97).This study shows that shear wave elastography executed by skilled operators can be performed on almost all chronic liver disease patients with high reproducibility. It is not influenced by age, sex or body mass index, identifies severely fibrotic patients and is also related to inflammatory activity.


Assuntos
Técnicas de Imagem por Elasticidade/métodos , Hepatopatias/diagnóstico por imagem , Fígado/diagnóstico por imagem , Índice de Gravidade de Doença , Adulto , Idoso , Área Sob a Curva , Estudos de Casos e Controles , Doença Crônica , Feminino , Humanos , Hepatopatias/patologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Curva ROC , Reprodutibilidade dos Testes , Adulto Jovem
8.
Clin Nucl Med ; 42(11): e482-e483, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28872552

RESUMO

A previously healthy 4-year-old girl presented with petechial rash and low platelet count. There were no other symptoms. On abdominal ultrasound, a 4.7-cm heterogeneous mass was demonstrated anterior to the left kidney. An abdominal MRI subsequently performed demonstrated a heterogeneously enhancing mass at the same location extending to the pancreas and spleen. A surgical biopsy of the mass was obtained. Pathology reported a malignant epithelioid neoplasm consistent with pancreatoblastoma. The mass demonstrated intense FDG uptake on PET and an FDG avid retrocaval lymph node.


Assuntos
Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/patologia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Pré-Escolar , Feminino , Fluordesoxiglucose F18 , Humanos , Metástase Linfática , Imageamento por Ressonância Magnética , Espaço Retroperitoneal/patologia , Ultrassonografia
9.
Clin Nucl Med ; 41(1): e68-9, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26462043

RESUMO

A 72-year-old man with history of lung cancer and melanoma was referred for routine follow-up with 18F-FDG PET/CT. CT images showed a new mass in the right groin associated with mild FDG activity on 18F-FDG PET images. Subsequent ultrasound obtained the same day demonstrated flow within the lesion to be a pseudoaneurysm of the right femoral artery.


Assuntos
Falso Aneurisma/diagnóstico por imagem , Artéria Femoral , Fluordesoxiglucose F18 , Achados Incidentais , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X , Idoso , Humanos , Neoplasias Pulmonares/diagnóstico por imagem , Masculino , Melanoma/diagnóstico por imagem , Imagem Multimodal , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos , Tomografia Computadorizada por Raios X/métodos
10.
Reprod Sci ; 22(12): 1649-55, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26142278

RESUMO

An accurate diagnosis of congenital heart defects during fetal development is critical for interventional planning. Mice can be used to generate animal models with heart defects, and high-frequency ultrasound (HFUS) imaging enables in utero imaging of live mouse embryos. A wide range of physiological measurements is possible using Doppler-HFUS imaging; limitations of any single measurement warrant a multiparameter approach to characterize cardiovascular function. Doppler-HFUS was used to explore the embryonic (heart, aorta) and extraembryonic (umbilical blood flow) circulatory systems to create a database in normal mouse embryos between 9.5 and 16.5 days of gestation. Multivariate analyses were performed to explore correlations between gestational age and embryo echocardiographic parameters. Heart rate and peak velocity in the aorta were positively correlated with gestational time, whereas cardiac cycle length, isovolumetric relaxation time, myocardial performance index, and arterial deceleration time of the umbilical cord were negatively correlated with it. Doppler-HFUS facilitated detailed characterization of the embryonic mouse circulation and represents a useful tool for investigation of the early mouse embryonic cardiovascular system.


Assuntos
Sistema Cardiovascular/diagnóstico por imagem , Ecocardiografia Doppler de Pulso/métodos , Ultrassonografia Pré-Natal/métodos , Animais , Aorta/diagnóstico por imagem , Aorta/embriologia , Velocidade do Fluxo Sanguíneo , Sistema Cardiovascular/embriologia , Feminino , Idade Gestacional , Camundongos , Análise Multivariada , Gravidez , Fluxo Sanguíneo Regional , Artérias Umbilicais/diagnóstico por imagem , Artérias Umbilicais/embriologia
11.
PLoS One ; 10(6): e0129912, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26067061

RESUMO

To characterize the anatomy of the venous outflow of the mouse brain using different imaging techniques. Ten C57/black male mice (age range: 7-8 weeks) were imaged with high-frequency Ultrasound, Magnetic Resonance Angiography and ex-vivo Microcomputed tomography of the head and neck. Under general anesthesia, Ultrasound of neck veins was performed with a 20 MHz transducer; head and neck Magnetic Resonance Angiography data were collected on 9.4 T or 7 T scanners, and ex-vivo Microcomputed tomography angiography was obtained by filling the vessels with a radiopaque inert silicone rubber compound. All procedures were approved by the local ethical committee. The dorsal intracranial venous system is quite similar in mice and humans. Instead, the mouse Internal Jugular Veins are tiny vessels receiving the sigmoid sinuses and tributaries from cerebellum, occipital lobe and midbrain, while the majority of the cerebral blood, i.e. from the olfactory bulbs and fronto-parietal lobes, is apparently drained through skull base connections into the External Jugular Vein. Three main intra-extracranial anastomoses, absent in humans, are: 1) the petrosquamous sinus, draining into the posterior facial vein, 2) the veins of the olfactory bulb, draining into the superficial temporal vein through a foramen of the frontal bone 3) the cavernous sinus, draining in the External Jugular Vein through a foramen of the sphenoid bone. The anatomical structure of the mouse cranial venous outflow as depicted by Ultrasound, Microcomputed tomography and Magnetic Resonance Angiography is different from humans, with multiple connections between intra- and extra-cranial veins.


Assuntos
Veias Cerebrais/anatomia & histologia , Ecocardiografia Doppler em Cores/métodos , Cabeça/irrigação sanguínea , Veias Jugulares/anatomia & histologia , Angiografia por Ressonância Magnética/métodos , Pescoço/irrigação sanguínea , Microtomografia por Raio-X/métodos , Animais , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Ultrassom/métodos
12.
Int J Food Sci Nutr ; 66(4): 466-70, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26017320

RESUMO

BACKGROUND: Atherosclerosis begins in childhood and develops silently for decades before clinical events such as myocardial infarction or stroke occur. Only few studies have evaluated the relationship between CVD risk factors and carotid artery Intimal Media Thickness (IMT) in young asymptomatic people. AIM: The aim of this study is to investigate risk factors for cardiovascular disease associated with higher Carotid Intimal Media Thickness (IMT) in healthy young subjects. METHODS: A cohort of 106 healthy young men, mean age 21 ± 2 years (mean ± SD), BMI 24.4 ± 2.8 (kg/m(2)), on military duty, participated in this cross-sectional study. Waist circumference, carotid intima-media thickness (IMT), blood pressure, and plasma concentrations of relevant metabolic parameters were measured at fasting. Smoking and habitual dietary patterns were evaluated by a semiquantitative questionnaire. RESULTS: The population was divided into two groups on the basis of IMT values: the lowest three quartiles versus the highest quartile (cut-off value = 0.7 mm). BMI, waist circumference, systolic (SBP), and diastolic (DBP) blood pressure were significantly higher in the group with higher IMT (p = 0.02). All other variables, including dietary parameters and smoking, were similar in the two groups. Data analysis showed that IMT values correlated positively with SBP (r = 0.22; p = 0.025), DBP (r = 0.27; p = 0.005), waist circumference (r = 0.29; p = 0.002), and fat mass (r = 0.24; p = 0.01), and negatively with kcal/kg of body weight (r = -0.220.22; p = 0.022) - an indirect marker of physical activity. Based on multiple regression analysis, waist circumference and DBP were the only variables independently associated with IMT (p = 0.029). CONCLUSIONS: In a non-selected sample of healthy young adult males, a larger waist circumference and a higher diastolic blood pressure - albeit within normal values - are the only parameters independently associated with higher IMT.


Assuntos
Adiposidade/fisiologia , Aterosclerose/epidemiologia , Espessura Intima-Media Carotídea/estatística & dados numéricos , Adulto , Aterosclerose/fisiopatologia , Pressão Sanguínea/fisiologia , Índice de Massa Corporal , Estudos de Coortes , Estudos Transversais , Humanos , Itália/epidemiologia , Masculino , Fatores de Risco , Circunferência da Cintura/fisiologia , Adulto Jovem
13.
Abdom Imaging ; 40(1): 167-80, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25063236

RESUMO

A heterogeneous group of uncommon neoplastic and non-neoplastic pancreatic pathologies exists that can mimic pancreatic adenocarcinoma. These "imitators" are unique and may demonstrate characteristic clinical and imaging features. Imaging characteristics of some of these diverse lesions are not well described in the literature, and erroneous diagnoses of these entities as pancreatic carcinoma may be responsible for unnecessary surgeries. Knowledge of these selected pancreatic pathologies is essential to facilitate optimal patient management.


Assuntos
Diagnóstico por Imagem , Pancreatopatias/diagnóstico , Neoplasias Pancreáticas/diagnóstico , Diagnóstico Diferencial , Humanos , Pâncreas/diagnóstico por imagem , Pâncreas/patologia , Tomografia Computadorizada por Raios X , Ultrassonografia
14.
Radiol Med ; 120(1): 158-70, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25115293

RESUMO

Radiologists are familiar with the use of radiographs, computed tomography, magnetic resonance imaging and ultrasound in the acute clinical setting. However, there are some specific clinical scenarios which may be found in nuclear medicine imaging problem-solving tools. These clinical scenarios and imaging techniques are less frequent, and the referring clinician from the emergency department may not consider these alternatives. It is important for the radiologist to be aware of these techniques to be able to guide the clinician to use those tools, which may result in optimal patient care. In this article, we will discuss those nuclear medicine studies which have application in the setting of an emergency radiology practice.


Assuntos
Medicina de Emergência/métodos , Serviço Hospitalar de Emergência , Medicina Nuclear/métodos , Diagnóstico por Imagem , Humanos , Interpretação de Imagem Assistida por Computador , Compostos Radiofarmacêuticos
15.
Eur Radiol ; 25(5): 1238-46, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25537980

RESUMO

PURPOSE: We compared carotid plaque calcification detection sensitivity and apparent cross-sectional area on CT as a function of CT beam energy using conventional CT techniques and virtual mono-energetic CT images generated from dual-energy acquisitions. METHODS & MATERIALS: Five ex-vivo carotid endarterectomy (CEA) specimens were imaged with dual-energy computed tomography. Virtual monochromatic spectrum (VMS) CT images were reconstructed at energies between 40-140 keV. The same specimens were imaged using conventional polyenergetic spectrum (PS) CT with peak beam energies 80, 100, 120, and 140 kVp. The histological calcium areas on each corresponding CEA specimen were traced manually on digitized images of Toluidine-Blue/Basic-Fuchsin stained plastic sections. RESULTS: 40 keV VMS CT images provided high detection sensitivity (97 %) similar to conventional PS CT images (~96 %). The calcification size measured on CT decreased systematically with increasing CT beam energy; the rate of change was larger for the VMS images than for PS images. CONCLUSION: From a single dual-energy CT, multiple VMS-CT images can be generated, yielding equivalent detection sensitivity and size correlations as conventional PS-CT in CEA calcification imaging. VMS-CT at 80-100 keV provided the most accurate estimates of calcification size, as compared to histology, but detection sensitivity was reduced for smaller calcifications on these images. KEY POINTS: • Calcifications depicted at 80-100 keV were most similar to the histology standard. • Conventional polychromatic images demonstrated excellent correlation with plaque size at pathology. • Conventional polychromatic images systematically overestimate plaque size. • Plaque calcifications can be missed on high energy monochromatic images.


Assuntos
Placa Aterosclerótica/diagnóstico por imagem , Intensificação de Imagem Radiográfica/métodos , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Tomografia Computadorizada por Raios X/métodos , Dissecação , Endarterectomia das Carótidas , Humanos , Masculino , Pessoa de Meia-Idade , Placa Aterosclerótica/patologia , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
16.
PLoS One ; 9(10): e111852, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25360557

RESUMO

The heartbeat has been proposed as an intrinsic source of motion that can be used in combination with tagged Magnetic Resonance Imaging (MRI) to measure displacements induced in the liver as an index of liver stiffness. Optimizing a tagged MRI acquisition protocol in terms of sensitivity to these displacements, which are in the order of pixel size, is necessary to develop the method as a quantification tool for staging fibrosis. We reproduced a study of cardiac-induced strain in the liver at 3T and simulated tagged MR images with different grid tag patterns to evaluate the performance of the Harmonic Phase (HARP) image analysis method and its dependence on the parameters of tag spacing and grid angle. The Partial Volume Effect (PVE), T1 relaxation, and different levels of noise were taken into account. Four displacement fields of increasing intensity were created and applied to the tagged MR images of the liver. These fields simulated the deformation at different liver stiffnesses. An Error Index (EI) was calculated to evaluate the estimation accuracy for various parameter values. In the absence of noise, the estimation accuracy of the displacement fields increased as tag spacings decreased. EIs for each of the four displacement fields were lower at 0° and the local minima of the EI were found to correspond to multiples of pixel size. The accuracy of the estimation decreased for increasing levels of added noise; as the level increased, the improved estimation caused by decreasing the tag spacing tended to zero. The optimal tag spacing turned out to be a compromise between the smallest tag period that is a multiple of the pixel size and is achievable in a real acquisition and the tag spacing that guarantees an accurate liver displacement measure in the presence of realistic levels of noise.


Assuntos
Simulação por Computador , Fígado/fisiopatologia , Imageamento por Ressonância Magnética/métodos , Algoritmos , Fenômenos Biomecânicos , Humanos , Processamento de Imagem Assistida por Computador
17.
Neuroimage ; 101: 390-403, 2014 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-25026156

RESUMO

Large-scale longitudinal neuroimaging studies with diffusion imaging techniques are necessary to test and validate models of white matter neurophysiological processes that change in time, both in healthy and diseased brains. The predictive power of such longitudinal models will always be limited by the reproducibility of repeated measures acquired during different sessions. At present, there is limited quantitative knowledge about the across-session reproducibility of standard diffusion metrics in 3T multi-centric studies on subjects in stable conditions, in particular when using tract based spatial statistics and with elderly people. In this study we implemented a multi-site brain diffusion protocol in 10 clinical 3T MRI sites distributed across 4 countries in Europe (Italy, Germany, France and Greece) using vendor provided sequences from Siemens (Allegra, Trio Tim, Verio, Skyra, Biograph mMR), Philips (Achieva) and GE (HDxt) scanners. We acquired DTI data (2 × 2 × 2 mm(3), b = 700 s/mm(2), 5 b0 and 30 diffusion weighted volumes) of a group of healthy stable elderly subjects (5 subjects per site) in two separate sessions at least a week apart. For each subject and session four scalar diffusion metrics were considered: fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD) and axial (AD) diffusivity. The diffusion metrics from multiple subjects and sessions at each site were aligned to their common white matter skeleton using tract-based spatial statistics. The reproducibility at each MRI site was examined by looking at group averages of absolute changes relative to the mean (%) on various parameters: i) reproducibility of the signal-to-noise ratio (SNR) of the b0 images in centrum semiovale, ii) full brain test-retest differences of the diffusion metric maps on the white matter skeleton, iii) reproducibility of the diffusion metrics on atlas-based white matter ROIs on the white matter skeleton. Despite the differences of MRI scanner configurations across sites (vendors, models, RF coils and acquisition sequences) we found good and consistent test-retest reproducibility. White matter b0 SNR reproducibility was on average 7 ± 1% with no significant MRI site effects. Whole brain analysis resulted in no significant test-retest differences at any of the sites with any of the DTI metrics. The atlas-based ROI analysis showed that the mean reproducibility errors largely remained in the 2-4% range for FA and AD and 2-6% for MD and RD, averaged across ROIs. Our results show reproducibility values comparable to those reported in studies using a smaller number of MRI scanners, slightly different DTI protocols and mostly younger populations. We therefore show that the acquisition and analysis protocols used are appropriate for multi-site experimental scenarios.


Assuntos
Imagem de Tensor de Difusão/normas , Substância Branca/anatomia & histologia , Idoso , Idoso de 80 Anos ou mais , Imagem de Tensor de Difusão/instrumentação , Imagem de Tensor de Difusão/métodos , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes
18.
PLoS One ; 9(3): e92730, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24675965

RESUMO

The aim of the study was to investigate the Internal Jugular Veins dynamics using contrast enhanced ultrasonography in Multiple Sclerosis patients, clinically isolated syndrome patients and healthy controls. Contrast enhanced ultrasonography imaging of the Internal Jugular Vein was performed in fifty-eight patients with Multiple Sclerosis, seven clinically isolated syndrome patients and in thirteen healthy controls. Time-intensity curves were quantified using a semi-automated method and compared with clinical disease outcomes. Wash-out parameters were calculated and six Time-intensity curves shapes were created. Significantly reduction of wash-out rate in Internal Jugular Veins was detected in Multiple Sclerosis patients compared to healthy controls [22.2% (2.7%-65.9%) vs. 33.4% (16.2%-76.8%); P<0.005]. Internal Jugular Vein enhancement was heterogeneous in patients with Multiple Sclerosis and consisted of slow wash-out Time-intensity curves shapes, compared with almost only one type of Time-intensity curves shape in control subjects that correspond to fast enhancement and fast wash-out. The vein wash-in parameters were similar in Multiple Sclerosis group compared with controls. A significant correlation was found between Internal Jugular Vein wash-out and level of disability (R =  -0.402, p<0.05). Contrast enhanced ultrasonography of the Internal Jugular Vein with time intensity curve analysis revealed alterations of cerebral venous outflow in Multiple Sclerosis patients, however mechanisms that determine this condition remains unclear.


Assuntos
Hemodinâmica , Veias Jugulares , Esclerose Múltipla/sangue , Esclerose Múltipla/fisiopatologia , Fluxo Sanguíneo Regional , Adulto , Idade de Início , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/diagnóstico , Adulto Jovem
19.
PLoS One ; 8(10): e77205, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24155928

RESUMO

BACKGROUND: Ultrasound is a valuable non-invasive tool used in obstetrics and gynecology to monitor the growth and well being of the human fetus. The laboratory mouse has recently emerged as an appropriate model for fetal and perinatal studies because morphogenetic processes in mice exhibit adequate homology to those in humans, and genetic manipulations are relatively simple to perform in mice. High-frequency ultrasound (HFUS) has recently become available for small animal preclinical imaging and can be used to study pregnancy and development in the mouse. The objective of the current study was to assess the main applications of HFUS in the evaluation of fetal growth and placental function and to better understand human congenital diseases. METHODOLOGY/PRINCIPAL FINDINGS: On each gestational day, at least 5 dams were monitored with HFUS; a total of ∼200 embryos were examined. Because it is not possible to measure each variable for the entire duration of the pregnancy, the parameters were divided into three groups as a function of the time at which they were measured. Univariate analysis of the relationship between each measurement and the embryonic day was performed using Spearman's rank correlation (Rs). Continuous linear regression was adopted for multivariate analysis of significant parameters. All statistical tests were two-sided, and a p value of 0.05 was considered statistically significant. CONCLUSIONS/SIGNIFICANCE: The study describes the main applications of HFUS to assess changes in phenotypic parameters in the developing CD1 mouse embryo and fetus during pregnancy and to evaluating physiological fetal and placental growth and the development of principal organs such as the heart, kidney, liver, brain and eyes in the embryonic mouse. A database of normal structural and functional parameters of mouse development will provide a useful tool for the better understanding of morphogenetic and cardiovascular anomalies in transgenic and mutant mouse models.


Assuntos
Desenvolvimento Fetal , Placenta/diagnóstico por imagem , Ultrassonografia Pré-Natal , Animais , Embrião de Mamíferos/diagnóstico por imagem , Feminino , Humanos , Camundongos , Gravidez , Análise de Regressão , Estatísticas não Paramétricas
20.
J Ultrasound Med ; 32(6): 1033-40, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23716525

RESUMO

OBJECTIVES: The purpose of this study was to evaluate the renal volume and intrarenal hemodynamics with duplex sonography in a group of diabetic patients with normal renal function in comparison to nondiabetic controls. METHODS: The renal volume and resistive index (RI) of segmental arteries were assessed by duplex sonography in 88 diabetic patients (44 male and 44 female; median age, 58 years [range, 37-69 years]) and 73 nondiabetic control participants (48 male and 25 female; median age, 53 years [range, 27-75 years]) without renal artery stenosis. RESULTS: Both renal volume and RI values in the diabetic patients were significantly higher compared to the controls (mean volume ± SD: diabetic patients, 197.3 ± 47.6 mL; controls, 162.5 ± 35.2 mL; P < .0001; RI: diabetic patients, 0.70 ± 0.05; controls, 0.59 ± 0.06; P < .0001). Renal hypertrophy was present even in diabetic patients without proteinuria (renal volume: patients without proteinuria, 198.3 ± 45.9 mL; controls, 162.5 ± 35.2 mL; P < .005). Patients with higher RI values had significantly greater proteinuria (RI <0.75, 15.9 mg/g [range, 4.2-1718.9 mg/g]; RI >0.75, 37.9 mg/g [range, 11.34-2087.0 mg/g]; P < .02). CONCLUSIONS: Changes in renal volume and hemodynamics are detectable on sonography in diabetic patients. Those changes are also present in patients without proteinuria or signs of renal atherosclerosis and with both normal and increased glomerular filtration rates. These results indicate a potential role of duplex sonography in the early identification of morphologic and hemodynamic renal changes in type 2 diabetic patients.


Assuntos
Diabetes Mellitus Tipo 2/diagnóstico por imagem , Diabetes Mellitus Tipo 2/epidemiologia , Nefropatias Diabéticas/diagnóstico por imagem , Nefropatias Diabéticas/epidemiologia , Rim/diagnóstico por imagem , Ultrassonografia Doppler Dupla/estatística & dados numéricos , Adulto , Idoso , Causalidade , Comorbidade , Feminino , Humanos , Incidência , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Medição de Risco , Sensibilidade e Especificidade
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