RESUMEN
OBJECTIVE: To investigate the test-retest precision and to report the longitudinal change in cartilage thickness, the percentage of knees with progression and the predictive value of the machine-learning-estimated structural progression score (s-score) for cartilage thickness loss in the IMI-APPROACH cohort - an exploratory, 5-center, 2-year prospective follow-up cohort. DESIGN: Quantitative cartilage morphology at baseline and at least one follow-up visit was available for 270 of the 297 IMI-APPROACH participants (78% females, age: 66.4 ± 7.1 years, body mass index (BMI): 28.1 ± 5.3 kg/m2, 55% with radiographic knee osteoarthritis (OA)) from 1.5T or 3T MRI. Test-retest precision (root mean square coefficient of variation) was assessed from 34 participants. To define progressor knees, smallest detectable change (SDC) thresholds were computed from 11 participants with longitudinal test-retest scans. Binary logistic regression was used to evaluate the odds of progression in femorotibial cartilage thickness (threshold: -211 µm) for the quartile with the highest vs the quartile with the lowest s-scores. RESULTS: The test-retest precision was 69 µm for the entire femorotibial joint. Over 24 months, mean cartilage thickness loss in the entire femorotibial joint reached -174 µm (95% CI: [-207, -141] µm, 32.7% with progression). The s-score was not associated with 24-month progression rates by MRI (OR: 1.30, 95% CI: [0.52, 3.28]). CONCLUSION: IMI-APPROACH successfully enrolled participants with substantial cartilage thickness loss, although the machine-learning-estimated s-score was not observed to be predictive of cartilage thickness loss. IMI-APPROACH data will be used in subsequent analyses to evaluate the impact of clinical, imaging, biomechanical and biochemical biomarkers on cartilage thickness loss and to refine the machine-learning-based s-score. GOV IDENTIFICATION: NCT03883568.
Asunto(s)
Cartílago Articular , Osteoartritis de la Rodilla , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Cartílago Articular/diagnóstico por imagen , Progresión de la Enfermedad , Articulación de la Rodilla/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Osteoartritis de la Rodilla/diagnóstico por imagen , Estudios ProspectivosRESUMEN
PURPOSE: The purpose of this study was to quantify the distribution of trabeculated (T) and compact (C) left ventricular (LV) myocardium masses in a healthy Caucasian population against age, gender and LV parameters, and to provide normal values for T, C and T/C. MATERIALS AND METHODS: One hundred and forty healthy subjects were prospectively recruited and underwent cardiac MRI at 1.5T with a stack of short-axis cine sequences covering the entire LV. End-diastolic volume (EDV), C and T masses were quantified using a semi-automatic method. Ejection fraction (EF) and T/C ratio were computed. RESULTS: We included 70 men and 70 women with a mean age of 44±14 (SD) years (range: 20-69 years). The mean EF was 63.7±6.3 (SD) % (range: 50.7-82.0%), the mean EDV was 75.9±16.2 (SD) mL/m2 (range: 36.4-112.2mL/m2), the mean C mass was 53.9±11.2 (SD) g/m2 (range: 26.5-93.4g/m2) and the mean T mass was 4.9±2.4 (SD) g/m2 (range: 1.1-11.4g/m2). The T/C ratio was 9.2±4.5% (range: 2.0-29.4%). Multivariate ANOVA test showed that the compact mass was influenced by EDV (P<0.0001), EF (P=0.001) and gender (P<0.0001), and the trabeculated mass depended on EDV (P<0.0001), gender (P=0.002) and age (P<0.0001), while the T/C ratio was only influenced by age (P=0.0003). Spearman test showed a correlation between EDV and C (r=0.60; P<0.0001),T (r=0.46; P<0.0001) and T/C ratio (r=0.26; P=0.0023).T and T/C ratio correlated with EF (r=-0.18, P=0.0373; r=-0.18, P=0.0321, respectively). CONCLUSION: While the compact and trabeculated myocardium masses appear to relate separately to the cardiac function, age and gender, their ratio T/C appears to only decrease with age. Furthermore, we propose here normal values for T, C and T/C in a cohort of healthy Caucasians subjects.
Asunto(s)
Técnicas de Imagen Cardíaca , Ventrículos Cardíacos/diagnóstico por imagen , Imagen por Resonancia Magnética , Adulto , Factores de Edad , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valores de Referencia , Factores Sexuales , Población Blanca , Adulto JovenRESUMEN
UNLABELLED: Young mice over-expressing Runx2 fail to gain bone relative to wild type mice with growth and present spontaneous fractures. It allows, for the first time in rodents, direct assessment of anti-fracture efficacy of strontium ranelate which was able to decrease caudal vertebrae fracture incidence through an improvement of trabecular and cortical architecture. INTRODUCTION: The aim was to investigate whether strontium ranelate was able to decrease fracture incidence in mice over-expressing Runx2, model of severe developmental osteopenia associated with spontaneous vertebral fractures. METHODS: Transgenic mice and their wild type littermates were treated by oral route with strontium ranelate or vehicle for 9 weeks. Caudal fracture incidence was assessed by repeated X-rays, resistance to compressive loading by biochemical tests, and bone microarchitecture by histomorphometry. RESULTS: Transgenic mice receiving strontium ranelate had significantly fewer new fractures occurring during the 9 weeks of the study (-60%, p < 0.05). In lumbar vertebrae, strontium ranelate improves resistance to compressive loading (higher ultimate force to failure, +120%, p < 0.05) and trabecular microarchitecture (higher bone volume and trabecular number, lower trabecular separation, +60%, +50%, -39%, p < 0.05) as well as cortical thickness (+17%, p < 0.05). In tibiae, marrow cavity cross-section area and equivalent diameter were lower (-39%, -21%, p < 0.05). The strontium level in plasma and bone was in the same range as the values measured in treated postmenopausal women. CONCLUSIONS: This model allows, for the first time, direct assessment of anti-fracture efficacy of strontium ranelate treatment in rodents. In these transgenic mice, strontium ranelate was able to decrease caudal vertebral fracture incidence through an improvement of trabecular and cortical architecture.
Asunto(s)
Conservadores de la Densidad Ósea/uso terapéutico , Fracturas Espontáneas/prevención & control , Compuestos Organometálicos/uso terapéutico , Osteoporosis/tratamiento farmacológico , Fracturas de la Columna Vertebral/prevención & control , Tiofenos/uso terapéutico , Animales , Calcio/sangre , Cauda Equina/lesiones , Subunidad alfa 1 del Factor de Unión al Sitio Principal/metabolismo , Modelos Animales de Enfermedad , Evaluación Preclínica de Medicamentos/métodos , Femenino , Fracturas Espontáneas/metabolismo , Fracturas Espontáneas/patología , Vértebras Lumbares/efectos de los fármacos , Vértebras Lumbares/patología , Vértebras Lumbares/fisiopatología , Ratones , Ratones Transgénicos , Osteoporosis/metabolismo , Osteoporosis/patología , Fracturas Osteoporóticas/metabolismo , Fracturas Osteoporóticas/patología , Fracturas Osteoporóticas/prevención & control , Fracturas de la Columna Vertebral/etiología , Fracturas de la Columna Vertebral/metabolismo , Fracturas de la Columna Vertebral/patología , Estrés Mecánico , Estroncio/metabolismo , Tibia/efectos de los fármacos , Tibia/patologíaRESUMEN
PURPOSE: To evaluate aortic elasticity with MRI on young asymptomatic individuals with mutation of the smooth muscle myosin heavy chain in whom aortic enlargement is not present. MATERIALS AND METHODS: Aortic compliance, aortic distensibility, and pulse wave velocity (PWV) were semiautomatically measured from MRI in 8 asymptomatic subjects having a mutation of the MYH11 gene (M+) and 21 nonmutated relatives (M-) of similar age, sex, and blood pressure characteristics. RESULTS: Despite a similar aortic diameter in both groups, the aortic compliance and distensibility were significantly lower in M+ subjects compared with M- (0.84+/-0.33 versus 2.03+/-0.54 mm2/mmHg, 1.18+/-0.62 10(-3) versus 5.11+/-1.58 10(-3) mmHg(-1), respectively), and PWV was significantly higher (5.35+/-1.53 versus 3.60+/-0.64 m.s(-1)). A threshold aortic compliance value of 1.3 mm2/mmHg separated the two groups. The receiver operating characteristics curve analysis indicated an optimal threshold of 2.9 10(-3) mmHg(-1) for aortic distensibility (sensitivity: 87.5%, specificity: 90%), and of 4.4 m.s(-1) for PWV (sensitivity: 75%, specificity: 100%). CONCLUSION: Young asymptomatic adults with MYH11 mutation have an aortic compliance impairment which is not detectable by the sole measurement of the aortic size. Aortic compliance measurement might be part of routine examination in patients suspected of inherited aortic disease even with a normal aortic diameter.
Asunto(s)
Insuficiencia de la Válvula Aórtica/diagnóstico , Insuficiencia de la Válvula Aórtica/fisiopatología , Estenosis de la Válvula Aórtica/diagnóstico , Estenosis de la Válvula Aórtica/fisiopatología , Diagnóstico por Imagen de Elasticidad/métodos , Interpretación de Imagen Asistida por Computador/métodos , Cadenas Pesadas de Miosina/genética , Adulto , Algoritmos , Velocidad del Flujo Sanguíneo , Módulo de Elasticidad , Femenino , Predisposición Genética a la Enfermedad/genética , Humanos , Aumento de la Imagen/métodos , Masculino , Mutación , Pronóstico , Flujo Pulsátil , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Adulto JovenRESUMEN
The aim of this work is to evaluate the relationship between improvement of regional myocardial function and visual analysis of contrast-enhanced (CE) MRI in patients after acute myocardial infarction. MRI was performed on 19 patients 1 and 11 weeks after a reperfused acute myocardial infarction. Perfusion data (first-pass images [FPI] and delayed CE images) were acquired after an intravenous bolus of gadolinium-DTPA and visually analyzed using a 17 segment model. Each segment was then classified in 3 groups, according to the presence or absence of FPI and CE patterns at baseline study: group 0: normal-appearing segments; group 1: segments with delayed hyper-enhancement but no early hypo-enhancement; group 2: segments with early hypoenhancement. Relative Wall thickening (RWT) was analyzed in each segment and its improvement evaluated in each group. Between first MRI and follow-up study, a significant improvement of RWT occurred in group 1 (mean +/- SD) [from 43.43 +/- 26.59% to 76.71 +/- 47.38%; p = 0.001] but not in group 2 (from 32.73 +/- 25.58% to 39.57 +/- 30.57%; p = NS). In group 0, RWT despite normal value at baseline study exhibited a significant improvement at follow-up (from 65.23 +/- 46.52% to 79.73 +/- 48.46%; p = 0.0015). In conclusion, the combined analysis of early and delayed perfusion abnormalities in MRI in the week following myocardial infarction can predict myocardial viability and allows in the future an evaluation of the efficacy of perfusion therapy.
Asunto(s)
Imagen por Resonancia Magnética , Infarto del Miocardio/diagnóstico , Miocardio/patología , Anciano , Angioplastia de Balón/métodos , Medios de Contraste/administración & dosificación , Estudios de Evaluación como Asunto , Femenino , Gadolinio DTPA/administración & dosificación , Humanos , Aumento de la Imagen , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/patología , Infarto del Miocardio/rehabilitación , Infarto del Miocardio/terapia , Reperfusión Miocárdica/rehabilitación , Recuperación de la Función , Estudios RetrospectivosRESUMEN
OBJECTIVES: Analysis of dose-area product (DAP) in cerebral angiography, according to the type of pathology and technique used. MATERIALS AND METHODS: Use of dosimetric and clinical data resulting from 84 diagnostic cerebral angiograms and 32 cerebral embolizations. RESULTS: The diagnostic angiography data were divided into three categories: A/ When a secondarily embolized aneurysm was diagnosed: n=17. B/ When the final diagnosis was an arteriovenous malformation (AVM): n=10. C/ In the case where the diagnosis was neither AVM, nor aneurysm to embolize: n=57. The cerebral embolizations were classified in two sub-groups: K/ When the embolization immediately followed the diagnostic angiogram: n=15. L/ When the embolization of the aneurysm took place 24 to 48H after the angiography: n=17. The mean DAP of group B containing the AVM is higher than mean DAP values in groups A and C, because of the increased cinegraphic time. There is a strong correlation between the duration of the fluoroscopy and the DAP (n=116; r=0.931; p<0.0001). Addition of runs in the group L contributes to the augmentation of the exposure time (significant difference in time: p=0.0054) and thus with the fact that DAP L>DAPK. CONCLUSION: Radiation dose during diagnostic cerebral angiography is increased in the presence of AVM. DAP of embolizations are higher when diagnostic and therapeutic phases are separated in time.
Asunto(s)
Encéfalo/efectos de la radiación , Angiografía Cerebral/efectos adversos , Fluoroscopía/efectos adversos , Aneurisma Intracraneal/terapia , Malformaciones Arteriovenosas Intracraneales/terapia , Traumatismos por Radiación/etiología , Radiometría , Adulto , Anciano , Anciano de 80 o más Años , Relación Dosis-Respuesta en la Radiación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Traumatismos por Radiación/prevención & control , Radiodermatitis/etiología , Estudios Retrospectivos , RiesgoRESUMEN
Structural changes that might influence the structural integrity of the vessel in response to intravascular brachytherapy (IVB) and stenting were examined, focus being on the importance of neovascularization in rabbit stented arteries. Stents were implanted in the infrarenal aortas of rabbits, immediately followed by gamma IVB or a sham radiation procedure, and the arteries harvested at 6 months. Labelling for von Willebrand factor showed an increase in adventitial and medial neovascularization in irradiated versus control arteries group (5.04+/-0.89 versus 1.51+/-0.23 mm(-2), respectively; p=0.004). Moreover, intramedial haemorrhages (free hemosiderin deposition) and inflammation (macrophages) were only observed in irradiated arteries. No significant change in expression of matrix metalloproteinase 1, 2 or 3 was observed between the irradiated and control group while collagen content decreased in the irradiated versus the control group (10.05%+/-1.48% versus 31.92%+/-3.12%, respectively; p<0.001). The study supports the hypothesis that IVB associated with stenting induces late deleterious effects on the medial layer, characterized by formation of intramural neovessels, haemorrhages and a decrease in collagen content.
Asunto(s)
Aorta Abdominal/patología , Aorta Abdominal/efectos de la radiación , Braquiterapia/efectos adversos , Hemorragia/etiología , Neovascularización Patológica/etiología , Stents/efectos adversos , Enfermedades Vasculares/etiología , Animales , Aorta Abdominal/metabolismo , Aorta Abdominal/cirugía , Colágeno/metabolismo , Reestenosis Coronaria/prevención & control , Reestenosis Coronaria/radioterapia , Rayos gamma/efectos adversos , Hemorragia/metabolismo , Hemorragia/patología , Masculino , Metaloproteasas/metabolismo , Conejos , Valores de Referencia , Enfermedades Vasculares/metabolismo , Enfermedades Vasculares/patologíaRESUMEN
Magnetic resonance imaging allows an accurate calculation of the left ventricular ejection fraction and left ventricular volumes. Additionally, it makes possible to assess myocardial perfusion after gadolinium chelate injection. Late after the injection, the presence of a myocardial hyper-enhancement can be visualized. The present study has used the 17 segment standardized nomenclature for tomographic imaging of the heart as recommended for all cardiac imaging modalities. Sixty nine patients were studied after a revascularised myocardial infarction. All patients had Timi grade 3 flow in the infarct-related artery after therapy. Regional and global function was studied using cine MR short axis slices. The gadolinium chelate first pass was scored using a 5 level scale reflecting the transmural extent of the segmental myocardial enhancement. The delayed enhancement due to gadolinium accumulation in the myocardium 10 min post injection was scored in the same manner. Left ventricular ejection fraction was 51 +/- 13%. Segmental thickening parameters (systolic thickness, absolute thickening and relative thickening) appeared statistically related to the hypoperfusion and delayed enhancement scores. Absolute myocardial thickening varied from 4.8 +/- 2.7 mm in the myocardial segments free of any delayed enhancement to 2.4 +/- 2.1 mm in segments presenting with a transmural extent of the delayed hyper-enhancement. Scores obtained after gadolinium injection were also well correlated with the global left ventricular function (r = 0.65, p < 0.01 for late enhancement). Magnetic resonance imaging of the heart allows a precise characterisation of revascularised myocardium which makes this technique very attractive for evaluating the treatments designed to improve myocardial microperfusion.
Asunto(s)
Medios de Contraste , Gadolinio DTPA , Imagen por Resonancia Cinemagnética/métodos , Infarto del Miocardio/patología , Volumen Sistólico/fisiología , Enfermedad Aguda , Femenino , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/fisiopatología , Miocardio/patología , Factores de Tiempo , Función Ventricular Izquierda/fisiologíaRESUMEN
The aim of this work is to study the regional myocardial perfusion by MRI early after revascularised myocardial infarction and to compare it with regional function. This prospective work has included 15 patients with acute first myocardial infarction that was precociously revascularised. A myocardial MRI was performed between D2 and D10 after myocardial infarction. The regional myocardial thickening was evaluated from cine-MRI sequences. For the study of myocardial perfusion, the first pass of the contrast agent was analysed from curves of the signal evolution versus time. The signal enhancement on late images acquired 10 minutes after the perfusion of the contrast agent was also evaluated. Among 384 studied myocardial segments, those with a normal gadolinium first pass curve had a relative thickening of 46 +/- 38%. The segments with a severely reduced first pass kinetic have a markedly reduced relative thickening (14 +/- 20%) in relation with myocardial hypoperfusion. The myocardial enhancement is frequently seen in the infarct territory and appears related to a reduced regional contractility. The myocardium is enhanced on late images in 12% of the normally perfused segments. These segments have a mildly reduced wall thickening (3.36 +/- 2.84 mm vs 4.42 +/- 2.83 mm). The segmental contractility in a reperfused myocardial infarction appears to depend both on the myocardial perfusion which reflects the microvascularisation and on the myocardial enhancement which is linked to myocardial structural alterations. MRI appears to be an adequate method to evaluate these abnormalities and allows an easy assessment of the no-reflow phenomenon, if present.
Asunto(s)
Infarto del Miocardio/cirugía , Reperfusión Miocárdica , Revascularización Miocárdica , Adulto , Anciano , Femenino , Hemodinámica , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Contracción Miocárdica , Infarto del Miocardio/patología , Estudios Prospectivos , Flujo Sanguíneo RegionalRESUMEN
We recently showed that indapamide (IDP), a thiazide-related diuretic, increases bone mass and decreases bone resorption in spontaneously hypertensive rats supplemented with sodium. In the present study, we evaluated the in vitro effects of this diuretic on bone cells, as well as those of hydrochlorothiazide (HCTZ), the reference thiazide, and acetazolamide (AZ), a carbonic anhydrase (CA) inhibitor. We showed that 10(-4) M IDP and 10(-4) M AZ, as well as 10(-5) M pamidronate (APD), decreased bone resorption in organ cultures and in cocultures of osteoblast-like cells and bone marrow cells in the presence of 10(-8) M 1,25-dihydroxyvitamin D3 [1,25(OH)2D3]. We investigated the mechanism of this antiresorptive effect of IDP; IDP decreased osteoclast differentiation as the number of osteoclasts developing in coculture of marrow and osteoblast-like cells was decreased markedly. We then investigated whether IDP affected osteoblast-like cells because these cells are involved in the osteoclast differentiation. Indeed, IDP increased osteoblast-like cell proliferation and alkaline phosphatase (ALP) expression. Nevertheless, it did not modify the colony-stimulating factor 1 (CSF-1) production by these cells. In addition, osteoblast-like cells expressed the Na+/Cl- cotransporter that is necessary for the renal action of thiazide diuretics, but IDP inhibited bone resorption in mice lacking this cotransporter, so the inhibition of bone resorption and osteoclast differentiation did not involve this pathway. Thus, we hypothesized that IDP may act directly on cells of the osteoclast lineage. We observed that resorption pits produced by spleen cells cultured in the presence of soluble osteoclast differentiation factor (sODF) and CSF-1 were decreased by 10(-4) M IDP as well as 10(-5) M APD. In conclusion, in vitro IDP increased osteoblast proliferation and decreased bone resorption at least in part by decreasing osteoclast differentiation via a direct effect on hematopoietic precursors.
Asunto(s)
Benzotiadiazinas , Resorción Ósea/prevención & control , Indapamida/farmacología , Inhibidores de los Simportadores del Cloruro de Sodio/farmacología , Simportadores , Animales , Secuencia de Bases , Células de la Médula Ósea/citología , Células de la Médula Ósea/efectos de los fármacos , Proteínas Portadoras/metabolismo , División Celular/efectos de los fármacos , Técnicas de Cocultivo , Cartilla de ADN , Diuréticos , Factor Estimulante de Colonias de Macrófagos/biosíntesis , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Ratones , Técnicas de Cultivo de Órganos , Osteoclastos/citología , Osteoclastos/efectos de los fármacos , Ratas , Ratas Wistar , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Simportadores del Cloruro de SodioRESUMEN
BACKGROUND AND PURPOSE: To evaluate the functional prognostic value of proton magnetic resonance spectroscopy performed within the 5 days of an infarction of the middle cerebral artery territory, compared with previously demonstrated prognostic factors. METHODS: Proton magnetic resonance spectroscopy was performed on 77 consecutive non-comatosed patients during the acute stage of middle cerebral artery infarction. The functional status was determined for each patient via the Orgogozo score. Proton magnetic resonance spectroscopic data were acquired in the infarction and in contra-lateral normal tissue and the results were expressed as metabolite ratios. Correlations were evaluated between the Orgogozo score at day 1 and day 30, the age, the sex, the volume of the infarction, and the metabolic ratios. RESULTS: In a monovariate analysis, the decrease of the NAA/choline ratio was correlated with a low Orgogozo score at days 1 and 30 (P<0.05) and with a large infarction (P<0.05). A stepwise analysis showed a significant relationship between the Orgogozo score at day 30 and the Orgogozo score at day 1, the sex, the volume of infarction, and the NAA/Cho ratio within the infarction. CONCLUSIONS: Our work demonstrates that a good clinical outcome at day 30 depends on a good initial clinical score at day 1, a small volume of infarction, a small decrease of NAA/Cho, and being of the female gender.
Asunto(s)
Infarto de la Arteria Cerebral Media/diagnóstico , Espectroscopía de Resonancia Magnética , Adulto , Anciano , Femenino , Humanos , Infarto de la Arteria Cerebral Media/terapia , Masculino , Persona de Mediana Edad , Análisis Multivariante , Valor Predictivo de las Pruebas , Estudios Prospectivos , Protones , Factores de Tiempo , Resultado del TratamientoRESUMEN
The term non-invasive and non-echographic myocardial imaging is used to describe the advances in nuclear cardiology and magnetic resonance imaging underlying the most recent developments in investigating the myocardium. The value of new techniques such as rapid CT scan and cardiological applications of the synchroton are described. The main clinical applications of these techniques in the present and future are reviewed, especially with regards to ischaemic heart disease.
Asunto(s)
Imagen por Resonancia Magnética , Espectroscopía de Resonancia Magnética , Isquemia Miocárdica/diagnóstico , Humanos , Miocardio/patología , Sensibilidad y Especificidad , Tomografía Computarizada por Rayos XRESUMEN
PURPOSE: To determine the extent to which the number of planes imaged at magnetic resonance (MR) imaging could be reduced without modifying the calculated volume and thickness of the left ventricle. MATERIALS AND METHODS: Sixty-one patients were examined after a myocardial infarction. The whole left ventricle was imaged by using 5-mm contiguous breath-hold cine MR short-axis sections with no gap (SAng) (two-dimensional fast low-angle shot sequence, 9/4.8 [repetition time msec/echo time msec]). The effect of omitting one section in two (short-axis sections with 5-mm gap [SA5 mm]) or two sections in three (short-axis sections with 10-mm gap [SA10 mm]) was studied. RESULTS: In the comparison of SA5 mm or SA10 mm with respect to the reference SAng, the standard error of the estimate (SEE) for the diastolic volume did not exceed the 6.1% interobserver SEE, and the SEE for the ejection fraction remained lower than the 3% interobserver SEE. The measured wall thickness was not affected. In addition, six simple geometric models were compared with SAng and yielded an SEE of 9.5%-28.1% for the diastolic volume and 3.8%-13.3% for the ejection fraction. CONCLUSION: In the study of left ventricles with heterogeneous contractility, short-axis imaging is more accurate than geometric modeling and permits wall thickness measurements when an intersection gap of 5 or 10 mm is used.
Asunto(s)
Imagen por Resonancia Magnética , Infarto del Miocardio/patología , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Ventrículos Cardíacos/patología , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/fisiopatología , Miocardio/patología , Volumen SistólicoRESUMEN
The introduction of fuzzy logic improves a system for the automatic quantification of renal artery lesions seen in digital subtraction angiograms. A two-step approach has been followed. An earlier system based on non-fuzzy syntactic analysis provided a clear symbolic description of the stenotic lesions. Although this system worked correctly, it did not take into account the variability and uncertainty inherent to image processing and to knowledge on the reference diameter. This system has been improved by the introduction of fuzzy logic in the representation of the reference diameter. It provides a description of the stenosis in terms of fuzzy quantities. To illustrate the benefits of the fuzzy approach, the results of the two systems have been compared by plotting the differences of an index of variability. It appears that the differences are statistically different when using a two-tailed paired t-test (t = 2.37; p = 0.025). The result shows that the fuzzy approach is better than a non-fuzzy approach in the sense that the index of variability is reduced significantly.
Asunto(s)
Angiografía de Substracción Digital , Lógica Difusa , Interpretación de Imagen Radiográfica Asistida por Computador , Obstrucción de la Arteria Renal/diagnóstico por imagen , Arteria Renal/diagnóstico por imagen , HumanosRESUMEN
Metabolic changes induced by cerebral infarction or by stenosis and occlusion of the internal carotid artery have been previously described in 1H Magnetic Resonance Spectroscopy (1H MRS). These changes are essentially characterized by decreased N-acetyl-aspartate (NAA) and increased lactate concentration. Little is known about the metabolic changes observed in the three days following a transient ischemic attack (TIA), in the absence of stenosis or occlusion of the internal carotid artery, and without visible infarction on Magnetic Resonance Imaging (MRI). We studied five patients with a TIA lasting between 30 min and 3 h, affecting the sensory and motor functions of the brachio-facial territory with or without aphasia. A Computerized Tomography Scan (CT-scan), an electro-encephalogram, cervical Doppler ultrasound and MRI with proton magnetic resonance spectroscopy were performed on the affected cerebral area and on the normal contralateral homologous cerebral area within three days of the onset of TIA. None of the five patients had stenosis or occlusion of the internal carotid artery on Doppler ultrasound, or cerebral infarction on MRI. From 1H MRS ratio measurements, we did not observe any significant changes in the NAA/Creatine ratio. However, a rise in Lactate/Creatine ratio was observed in the symptomatic non-infarcted area compared with the normal cerebral tissue. During the first three days following a transient ischemic attack, there is an increase in lactate production. This change may reflect transient local hypoperfusion which could be long enough to stimulate lactate production, but short enough not to induce infarction. This region could be at risk from infarction in the long term.
Asunto(s)
Corteza Cerebral/metabolismo , Ataque Isquémico Transitorio/metabolismo , Anciano , Corteza Cerebral/diagnóstico por imagen , Corteza Cerebral/patología , Creatina/análisis , Femenino , Humanos , Ataque Isquémico Transitorio/fisiopatología , Ácido Láctico/análisis , Imagen por Resonancia Magnética , Espectroscopía de Resonancia Magnética , Masculino , Persona de Mediana Edad , Protones , Tomografía Computarizada por Rayos XRESUMEN
RATIONALE AND OBJECTIVES: Gated cardiac cine magnetic resonance imaging provides accurate dynamic data of the left ventricular function. However, the manual extraction of important physiologic parameters such as myocardium wall thickness and left ventricular volumes is invariably time consuming and subjective. To reduce the variability and time constraints inherent in observer contour tracing, the authors developed an automatic left ventricle contour-detection method. METHODS: The purpose was to apply fuzzy logic-based automatic contour detection to identification of endocardial and epicardial borders in short-axis magnetic resonance images. The automatic contouring was compared with manual tracing using the calculated ejection fraction as the comparison criterion. RESULTS: A good correlation was found between the two approaches (r2 = 0.98). CONCLUSIONS: The ejection fraction can be obtained using this automatic contouring method.
Asunto(s)
Lógica Difusa , Imagen por Resonancia Cinemagnética , Infarto del Miocardio/fisiopatología , Volumen Sistólico , Función Ventricular , Adulto , Anciano , Humanos , Procesamiento de Imagen Asistido por Computador , Persona de Mediana EdadRESUMEN
Clinical and epidemiological studies suggest that thiazide diuretics can prevent bone loss and decrease the incidence of hip fractures. However, the mechanism of the effect of diuretics on bone is not clearly established. Indapamide (IDP), a sulfonamide diuretic related to thiazides, is used to treat hypertension. Sixty spontaneously hypertensive rats (SHRs) were divided into four groups and treated with or without IDP (1.5 mg/kg/day) during 8 weeks in the presence or absence of a high sodium load (8% NaCl supplementation in the diet). Sodium and calcium excretions were increased in the rats receiving the high sodium load (SHR + 8% NaCl) comparatively with control rats (SHR). IDP decreased and increased, respectively, calcium and sodium excretions. Serum parathyroid hormone (PTH) was unchanged in any group. Bone density was measured at the femur, tibia, and vertebrae, and bone morphometry was performed at the metaphysis of the femur to evaluate bone architecture. Rats fed a high sodium diet had an average 5.5% decreased bone density at every site except the femoral diaphysis. The trabecular bone volume was also decreased (SHR + 8% NaCl vs. SHR, 11.99+/-0.78 vs. 17.51+/-1.5%, p < 0.05). An increase in trabecular separation suggested that these changes were due to increased bone resorption. In the SHR + 8% NaCl + IDP group, IDP increased bone density and trabecular bone volume (SHR + 8% NaCl + IDP vs. SHR + 8% NaCl, 16.52+/-1.04 vs. 11.99+/-0.78%, p < 0.05). Trabecular separation and pyridinoline/creatinine excretion (SHR + 8% NaCl + IDP vs. SHR + 8% NaCl, 136.39+/-9.62 vs. 195.18+/-22.34 nmol/mmol, p < 0.05) were also decreased by IDP. These results show that in rats receiving a high sodium diet, IDP can reverse sodium-induced bone loss and increased bone resorption independently of changes in serum PTH.
Asunto(s)
Antihipertensivos/farmacología , Densidad Ósea/efectos de los fármacos , Diuréticos/farmacología , Hipertensión/tratamiento farmacológico , Indapamida/farmacología , Absorciometría de Fotón , Animales , Antihipertensivos/administración & dosificación , Biomarcadores/sangre , Biomarcadores/orina , Resorción Ósea/diagnóstico por imagen , Resorción Ósea/tratamiento farmacológico , Diuréticos/administración & dosificación , Fémur/diagnóstico por imagen , Fémur/efectos de los fármacos , Hipertensión/inducido químicamente , Indapamida/administración & dosificación , Masculino , Distribución Aleatoria , Ratas , Ratas Endogámicas SHR , Cloruro de Sodio , Columna Vertebral/diagnóstico por imagen , Columna Vertebral/efectos de los fármacos , Tibia/diagnóstico por imagen , Tibia/efectos de los fármacosRESUMEN
The effect of prostaglandin E2 (PGE2) on osteoclast (OC) differentiation is unclear, either stimulator or inhibitor, depending on the in vitro system used. This probably reflects indirect mechanisms through intermediate cells. We have investigated the direct effect of PGE2 on human OC differentiation from cord blood monocytes (CBMs) in the absence of stromal cells. Macrophages and multinucleated cells (MNCs) resembling OCs form in cultures of CBMs stimulated by 1,25-dihydroxyvitamin D3. In the present study, CBMs were cultured for 3 weeks, as previously described, in the presence or absence of PGE2. The number of MNCs was significantly reduced in the presence of PGE2 as was the proliferation of cultured CBMs, assessed on day 7. Immunohistochemistry was performed to evaluate macrophage markers (CD11b and CD14) and OC marker (beta3-chain). PGE2 significantly increased the numbers of CD11b-positive and CD14-positive cells, whereas the number of beta3-chain-positive cells was significantly decreased. beta3-Chain, c-fos, and human calcitonin receptor (h-CTR) messenger RNA (mRNA) expressions were evaluated by reverse transcription-PCR with RNA extracted from cultured CBMs. In the presence of PGE2, expression of beta3-chain and c-fos mRNA was reduced from the first week of culture. h-CTR mRNA expression was also reduced, and only the h-CTR1 isoform was detected in the presence of PGE2. In addition, when PGE2 was added only during the last week of culture, when no CBM proliferation occurred, the number of CD11b- and beta3-positive cells was unchanged compared to that in the control culture, as were the proportion of MNCs, the fusion index, and the expression of c-fos mRNA. In conclusion, our results suggest that PGE2 has an inhibitory effect on human OC differentiation from CBMs, possibly by reducing precursor proliferation in these cultures. We also hypothesize that PGE2 may reduce OC differentiation by increasing the proportion of precursor cells that differentiate into macrophages. In addition, this may be the result of inhibition of the c-fos expression in CBMs.
Asunto(s)
Dinoprostona/farmacología , Células Madre Hematopoyéticas/efectos de los fármacos , Osteoclastos/citología , Calcitriol/farmacología , Diferenciación Celular/efectos de los fármacos , Genes fos , Células Madre Hematopoyéticas/citología , Humanos , Receptores de Lipopolisacáridos/análisis , Antígeno de Macrófago-1/análisis , Monocitos/citología , Monocitos/efectos de los fármacos , Osteoclastos/efectos de los fármacos , Reacción en Cadena de la Polimerasa , ARN Mensajero/metabolismo , Receptores de Calcitonina/análisis , Receptores de Calcitonina/genéticaRESUMEN
This paper deals with the use of fuzzy logic and dynamic programming in the detection of cardiac contours in MR Images. The definition of two parameters for each pixel allows the construction of the fuzzy set of the cardiac contour points. The first parameter takes into account the grey level, and the second the presence of an edge. A corresponding fuzzy matrix is derived from the initial image. Finally, a dynamic programming with graph searching is performed on this fuzzy matrix. The method has been tested on several MR images and the results of the contouring were validated by an expert in the domain. This preliminary work clearly demonstrates the interest of this method, although a formal evaluation has to be done.
Asunto(s)
Lógica Difusa , Corazón/anatomía & histología , Interpretación de Imagen Asistida por Computador , Imagen por Resonancia Magnética , HumanosRESUMEN
OBJECTIVE: Rheumatic fever has become infrequent in developed countries. Recent regional epidemics, particularly in North America, brought our attention to this disease in our area. In the French Caribbean Islands, rheumatic fever remains an important health problem despite much progress in the last 15 years. METHODS: A retrospective survey over the last 5 years identified 19 cases of rheumatic fever in Guadeloupe in subjects over 19 years of age. RESULTS: Among these subjects 4 cases of rheumatic fever beginning in adulthood were analysed and compared with data in the literature. CONCLUSION: The diagnosis of rheumatic fever beginning in adulthood is difficult to establish. Joint symptoms are variable and cardiac involvement, which occurs in 30 to 40% of the cases, is highly suggestive. The kinetics of antistreptococci antibodies confirms the diagnosis.