RESUMEN
Fish habitat temperatures are increasing due to human impacts including climate change. For broadly distributed species, thermal tolerance can vary at the population level, making it challenging to predict which populations are most vulnerable to warming. Populations inhabiting warm range boundaries may be more resilient to these changes due to adaptation or acclimatization to warmer temperatures, or they may be more vulnerable as temperatures may already approach their physiological limits. We tested functional and critical thermal tolerance of two populations of wild Oncorhynchus mykiss near the species' southern range limit and, as predicted, found population-specific responses to temperature. Specifically, the population inhabiting the warmer stream, Piru Creek, had higher critical thermal maxima and higher functional thermal tolerance compared to the population from the cooler stream, Arroyo Seco. Arroyo Seco O. mykiss are more likely to experience a limitation of aerobic scope with warming. Piru Creek O. mykiss, however, had higher resting metabolic rates and prolonged exercise recovery, meaning that they could be more vulnerable to warming if prey or dissolved oxygen become limited. Temperature varies widely between streams near the O. mykiss southern range limit and populations will likely have unique responses to warming based on their thermal tolerances and metabolic requirements.
Asunto(s)
Oncorhynchus mykiss , Animales , Humanos , Aclimatación , Efectos Antropogénicos , Metabolismo Basal , Cambio ClimáticoRESUMEN
BACKGROUND: If compression bandaging is not performed in a professional manner, the objectives of the therapy may not be achieved and side effects or complications may result. OBJECTIVES: This cross-sectional observational survey examines the handling of the treatment options: short-stretch bandages with padding, multicomponent compression systems, and adaptive compression bandages. PARTICIPANTS AND METHODS: During several training sessions on the topic of compression therapy, 137 participants performed compression bandagings on each other. In this regard, they were asked to achieve a predetermined pressure range (short-stretch bandages: 50-60 mm Hg, multicomponent compression systems: 40-50 mm Hg, adaptive compression bandage: 35-45 mm Hg). To evaluate the efficiency, the time used for application, the achieved pressure value, and the comfort were determined. RESULTS: Of the 302 bandagings (n = 137 participants), 28.4% lay within the given target pressure value range. This included 11.2% of performed short-stretch bandages, 35.2% of multicomponent compression systems, and 85.0% of adaptive compression bandages. Significant differences in the mean deviations are found between the treatment options. The bandage was described as being comfortable by 37.7% of users of short-stretch bandages with padding, by 65.0% of those wearing a multicomponent compression system, and by 94.6% of participants with an adaptive compression bandage. CONCLUSIONS: In practice, short-stretch bandages are still the most frequently used care option for the creation of a phlebological compression bandage. In this survey, they proved to be unsafe, time-consuming, and uncomfortable in relation to other treatment options. Multicomponent compression systems and adaptive compression bandages are treatment options that may be a contemporary alternative which also bares more comfort for the patient.
Asunto(s)
Vendajes de Compresión , Dermatitis Atópica/terapia , Adulto , Vendajes de Compresión/efectos adversos , Estudios Transversales , Femenino , Humanos , Capacitación en Servicio , Masculino , Persona de Mediana Edad , Presión , Resultado del TratamientoRESUMEN
BACKGROUND: Chronic lymphoedema is characterized by a continuous need for medical treatment, many comorbidities and impaired quality of life. In Germany, about 4.5 million patients are affected by lymphoedema. Thus, lymphoedema causes high direct and indirect costs, even more in case of complications such as erysipelas and ulcers. OBJECTIVE: The aim of this study was to determine the costs of illness of community lymphoedema patients living in the metropolitan area of Hamburg, Germany. METHODS: An observational cross-sectional study in patients with lymphoedema and combined lipolymphoedema of any origin was performed analysing direct and indirect costs for the patients, the statutory health insurance and society. RESULTS: In total, 348 patients (90.8% female) were examined and interviewed. The mean age of the patients was 57.3 ± 14.5 years. On average, the total costs per patient and year were 5784, of which 4445 (76.9%) were direct costs and 1338 indirect costs. Within the direct medical costs, 3796 were accounted for the statutory health insurances and 649 for the patient. The main cost drivers were costs for manual decongestive therapy and disability costs. CONCLUSION: Chronic lymphoedema is associated with high direct and indirect costs. This community-based study is the first cost analysis of chronic lymphoedema and combined lipolymphoedema giving insights to economic impact of lymphoedema treatment. There is a high need for structured disease management programs in order to diagnose and treat lymphoedema early and to avoid complications, thus limiting socio-economic burden.
Asunto(s)
Costo de Enfermedad , Linfedema/economía , Adulto , Anciano , Femenino , Alemania , Humanos , Linfedema/fisiopatología , Masculino , Persona de Mediana Edad , Calidad de VidaRESUMEN
With the shift towards patient-centered healthcare, patient- and person-reports of health-related factors, including outcomes, are seen as important determinants for evaluating and improving healthcare. However, a comprehensive, systematic categorization of patient- and person-reports is currently lacking in the literature. This study aims at developing a new classification system with well-defined constructs for patients' and persons' self-reports on health and healthcare. A literature research and evaluation by the Reported Health Outcomes (RHO) Group were used to develop this classification system. The new classification system includes patient- and person-reported preferences, outcomes, experiences, and satisfaction related to healthcare and health outcomes. Moreover, the most constitutive methods to measure these four categories - preferences, outcomes, experiences, and satisfaction - have been described in this article. Even though the value of patients' and persons' perspectives on healthcare is increasingly being recognized, its measurement and implementation presents a lasting challenge to researchers, clinicians, patients, and the general population.
RESUMEN
BACKGROUND: Guidelines provide systematically developed decision aids for medical treatment. Quality indicators are derived from recommendations of guidelines to promote the implementation of the guideline and to allow for quality management of both the guideline and the health care itself. OBJECTIVES: This study aims to describe the relevance of quality of life as a quality indicator in the development process of guidelines in the German context. METHODS: A systematic literature review was performed in the PubMed database, to highlight the current state of discussion on the use of quality indicators in the development process of guidelines. 90 articles were included in the analysis of the review. RESULTS: The focus of the evaluation of medical guidelines has changed over time. It started with the evaluation of the methodological quality. Currently, the evaluation of the effects of the guide-lines, especially the process quality but also the quality of results, is focused. Many articles merely mentioned that improving the quality of life - as well as reducing morbidity and mortality - is considered as an outcome parameter. Overall, it was obvious that quality of life is not yet considered as a quality indicator in the development of guidelines. CONCLUSIONS: A patient-oriented approach, taking into account the quality of life and not just factors of mortality and morbidity, is increasingly in demand. Therefore, quality of life should be respected in the primary studies underlying the guidelines as well as being a quality indicator.
Asunto(s)
Guías de Práctica Clínica como Asunto/normas , Garantía de la Calidad de Atención de Salud/estadística & datos numéricos , Garantía de la Calidad de Atención de Salud/normas , Indicadores de Calidad de la Atención de Salud/normas , Calidad de la Atención de Salud/normas , Calidad de Vida , Medicina Basada en la Evidencia , Garantía de la Calidad de Atención de Salud/métodos , Indicadores de Calidad de la Atención de Salud/estadística & datos numéricos , Calidad de la Atención de Salud/estadística & datos numéricosAsunto(s)
Medios de Contraste/efectos adversos , Erupciones por Medicamentos/etiología , Yohexol/análogos & derivados , Tumores Neuroendocrinos/diagnóstico por imagen , Neoplasias Pancreáticas/diagnóstico por imagen , Medicina de Precisión , Premedicación , Intensificación de Imagen Radiográfica , Tomografía Computarizada por Rayos X , Anciano , Medios de Contraste/administración & dosificación , Erupciones por Medicamentos/diagnóstico , Erupciones por Medicamentos/prevención & control , Femenino , Humanos , Pruebas Intradérmicas , Yohexol/efectos adversos , Yopamidol/efectos adversos , Yopamidol/análogos & derivados , Prevención SecundariaRESUMEN
A 4-year-old male German Hunting Terrier presented with tremor, dyspnea, trismus, spasms of the musculature of the larynx and pharynx, and hypothermia and subsequently died despite intensive clinical care. Prior clinical signs included vomitus and diarrhea. Microscopic examination of the brain revealed a multifocal nonsuppurative brain stem encephalitis; a few intralesional neurons contained intranuclear inclusions. By immunohistochemistry, Aujeszky disease virus (Suid herpesvirus 1) antigen was detected in neurons in the brain and in ganglion cells of the trigeminal ganglia. Viral culture of brain tissue confirmed the presence of Aujeszky disease virus. Histopathologic findings in the brain with the identification of Aujeszky disease virus by immunohistochemistry and polymerase chain reaction are consistent with Aujeszky disease virus-induced encephalitis. Sequencing revealed a 100% homology of the isolated Aujeszky disease virus with Aujeszky disease virus isolates of wild boar from Eastern Germany.
Asunto(s)
Enfermedades de los Perros/patología , Encefalitis/veterinaria , Herpesvirus Suido 1/aislamiento & purificación , Seudorrabia/patología , Animales , Tronco Encefálico/patología , Enfermedades de los Perros/diagnóstico , Perros , Encefalitis/diagnóstico , Encefalitis/patología , Resultado Fatal , Masculino , Seudorrabia/diagnósticoRESUMEN
Mast cells are now recognized as effective modulators of innate immunity. We recently reported that mast cells and secreted interleukin-4 (IL-4) effectively control intramacrophage replication of Francisella tularensis Live Vaccine Strain (LVS), and that mice deficient in mast cells or IL-4 receptor (IL-4R(-/-)) exhibit greater susceptibility to pulmonary challenge. In this study, we further evaluated the mechanism(s) by which mast cells/IL-4 control intramacrophage bacterial replication and host cell death, and found that IL-4R(-/-) mice exhibited significantly greater induction of active caspase-3 within lung macrophages than wild-type animals following intranasal challenge with either LVS or the human virulent type A strain SCHU S4. Treatment of LVS-infected bone-marrow-derived macrophages with a pancaspase inhibitor (zVAD) did not alter bacterial replication, but minimized active caspase-3 and other markers (Annexin V and propidium iodide) of cell death, whereas treatment with both rIL-4 and zVAD resulted in concomitant reduction of both parameters, suggesting that inhibition of bacterial replication by IL-4 was independent of caspase activation. Interestingly, IL-4-treated infected macrophages exhibited significantly increased ATP production and phagolysosomal acidification, as well as enhanced mannose receptor upregulation and increased internalization with acidification, which correlated with observations in mast cell-macrophage co-cultures, with resultant decreases in F. tularensis replication.
Asunto(s)
Adenosina Trifosfato/biosíntesis , Francisella tularensis , Interacciones Huésped-Patógeno , Interleucina-4/inmunología , Mastocitos/inmunología , Fagosomas/inmunología , Tularemia/inmunología , Animales , Caspasa 3/metabolismo , Muerte Celular/inmunología , Células Cultivadas , Activación Enzimática/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Francisella tularensis/crecimiento & desarrollo , Francisella tularensis/inmunología , Regulación de la Expresión Génica , Lectinas Tipo C/metabolismo , Macrófagos Alveolares/enzimología , Macrófagos Alveolares/inmunología , Macrófagos Alveolares/patología , Receptor de Manosa , Lectinas de Unión a Manosa/metabolismo , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Oligopéptidos/farmacología , Orgánulos/química , Orgánulos/microbiología , Fagosomas/química , Receptores de Superficie Celular/metabolismo , Receptores de Interleucina-4/genética , Receptores de Interleucina-4/inmunología , Transducción de Señal/inmunologíaRESUMEN
PURPOSE: The aim of this study was to investigate the potential dose reduction in the uterus as a result of lead apron protection during thoracic CT scans. Moreover, the distribution of the radiation dose in the uterus was determined in order to obtain information about the ratio of internally and externally scattered radiation. MATERIALS AND METHODS: The uterus doses during thoracic CT were determined by measuring organ doses using an Alderson-RANDO®-Phantom and thermoluminescent dosimeters. A 0.25 mm lead equivalent protective apron was used to shield the abdominal area. Three measurement conditions were evaluated: without lead apron, covered with lead apron and wrapped with lead apron. The uterus dose with and without shielding describes the mean value and standard deviation of all examinations and all measurement points in the organ. RESULTS: The uterus dose by thoracic CT was measured to be approximately 66.5 ± 3.1 µGy. If the abdomen is covered with a 0.25 mm Pb equivalent lead apron in the front area and on both sides, the uterus dose is reduced to 49.4 ± 2.8 µGy (26% reduction, p < 0.001). If a lead apron is wrapped around the abdomen, providing 0.50 mm Pb shielding in the anterior section due to overlap, and 0.25 mm Pb in the posterior section and on both sides, the uterus dose is reduced even more to 43.8 ± 2.5 µGy (34% reduction, p < 0.001). The dose distribution when the lead apron covers the abdomen shows that the shielding is effective for the scatter radiation that comes from the anterior part. Moreover, the wrapped apron protects the uterus from all directions and is even more effective for dose reduction than the covering apron. CONCLUSION: Our findings demonstrate that protective aprons are an effective dose reduction technique without additional costs and little effect on patient examination time.
Asunto(s)
Tomografía Computarizada de Haz Cónico/efectos adversos , Tomografía Computarizada de Haz Cónico/métodos , Protección Radiológica/métodos , Radiografía Torácica/efectos adversos , Útero/efectos de la radiación , Tomografía Computarizada de Haz Cónico/instrumentación , Femenino , Humanos , Plomo , Fantasmas de Imagen , Embarazo , Radiografía Torácica/métodos , Dispersión de Radiación , Dosimetría TermoluminiscenteRESUMEN
INTRODUCTION: Heart failure is characterized by an increase in cardiac load, wall stress and autonomic dysfunction. The neurohumoral imbalance arising from adrenergic activation and parasympathetic withdrawal is associated with worse prognosis. We addressed the hypothesis that an increased left ventricular (LV) wall stress as assessed by cardiac magnetic resonance imaging (CMR) in patients with heart failure is related to a depression of heart rate variability (HRV). METHODS: Cardiac function and mass were measured in 37 individuals with suspected cardiomyopathy using CMR imaging. A thick-walled sphere model was used to calculate ventricular wall stress. Time domain analysis of HRV was obtained by long-term Holter ECG. RESULTS: Standard deviation of both normal-to-normal (NN) intervals (SDNN) and average NN intervals over 5 minutes (SDANN-i) were negatively correlated with LV enddiastolic wall stress (r = 0.42, P < 0.01). SDNN and SDANN-i were severely decreased (P < 0.01) in patients with increased enddiastolic LV wall stress > 12 kPa (vs. normal range: < 4 kPa). CONCLUSION: A relation between increased cardiac wall stress and depressed heart rate variability was observed in patients with heart failure. CMR-based measurement of LV volume and mass is appropriate to calculate LV wall stress which should be considered not only as a potential prognostic determinant but also as therapeutic target.
Asunto(s)
Insuficiencia Cardíaca/fisiopatología , Frecuencia Cardíaca/fisiología , Imagen por Resonancia Magnética/métodos , Disfunción Ventricular Izquierda/fisiopatología , Electrocardiografía/métodos , Insuficiencia Cardíaca/diagnóstico , Humanos , Disfunción Ventricular Izquierda/diagnósticoAsunto(s)
Enfermedades Inflamatorias del Intestino/diagnóstico por imagen , Colangitis/diagnóstico por imagen , Femenino , Cálculos Biliares/diagnóstico por imagen , Hepatitis Crónica/diagnóstico por imagen , Humanos , Enfermedades Inflamatorias del Intestino/complicaciones , Pruebas de Función Hepática , Masculino , UltrasonografíaRESUMEN
PURPOSE: Today healthcare policy is based on effectiveness. Diagnostic imaging became a "pacesetter" due to amazing technical developments (e. g. multislice CT), extensive data volumes, and especially the well defined workflow-orientated scenarios on a local and (inter)national level. To make centralized networks sufficient, image data compression has been regarded as the key to a simple and secure solution. In February 2008 specialized working groups of the DRG held a consensus conference. They designed recommended data compression techniques and ratios. MATERIAL AND METHOD: The purpose of our paper is an international review of the literature of compression technologies, different imaging procedures (e. g. DR, CT etc.), and targets (abdomen, etc.) and to combine recommendations for compression ratios and techniques with different workflows. The studies were assigned to 4 different levels (0 - 3) according to the evidence. 51 studies were assigned to the highest level 3. RESULTS: We recommend a compression factor of 1 : 8 (excluding cranial scans 1:5). For workflow reasons data compression should be based on the modalities (CT, etc.). PACS-based compression is currently possible but fails to maximize workflow benefits. Only the modality-based scenarios achieve all benefits. CONCLUSION: Imaging equipment manufacturers are encouraged to improve the compression technology of their imaging devices (e. g. freely selectable compression ratios in the output filter). Double compression should be strictly avoided. Lossless compression formats should be switched off.
Asunto(s)
Compresión de Datos/métodos , Diagnóstico por Imagen/métodos , Eficiencia Organizacional , Procesamiento de Imagen Asistido por Computador/métodos , Sistemas de Información Radiológica , Diagnóstico por Imagen/instrumentación , Procesamiento de Imagen Asistido por Computador/instrumentación , Sistemas de Información Radiológica/instrumentación , Tomografía Computarizada Espiral/instrumentación , Tomografía Computarizada Espiral/métodosRESUMEN
Background Although B-type natriuretic peptide (BNP) is used as complimentary diagnostic tool in patients with unknown thoracic disorders, many other factors appear to trigger its release. In particular, it remains unresolved to what extent cellular stretch or wall stress of the whole heart contributes to enhanced serum BNP concentration. Wall stress cannot be determined directly, but has to be calculated from wall volume, cavity volume and intraventricular pressure of the heart. The hypothesis was, therefore, addressed that wall stress as determined by cardiac magnetic resonance imaging (CMR) is the major determinant of serum BNP in patients with a varying degree of left ventricular dilatation or dysfunction (LVD). Methods A thick-walled sphere model based on volumetric analysis of the LV using CMR was compared with an echocardiography-based approach to calculate LV wall stress in 39 patients with LVD and 21 controls. Serum BNP was used as in vivo marker of a putatively raised wall stress. Nomograms of isostress lines were established to assess the extent of load reduction that is necessary to restore normal wall stress and related biochemical events. Results Both enddiastolic and endsystolic LV wall stress were correlated with the enddiastolic LV volume (r = 0.54, P < 0.001; r = 0.81, P < 0.001). LV enddiastolic wall stress was related to pulmonary pressure (capillary: r = 0.69, P < 0.001; artery: r = 0.67, P < 0.001). Although LV growth was correlated with the enddiastolic and endsystolic volume (r = 0.73, P < 0.001; r = 0.70, P < 0.001), patients with LVD exhibited increased LV wall stress indicating an inadequately enhanced LV growth. Both enddiastolic (P < 0.05) and endsystolic (P < 0.01) wall stress were increased in patients with increased BNP. In turn, BNP concentration was elevated in individuals with increased enddiastolic wall stress (>8 kPa: 587 +/- 648 pg/ml, P < 0.05; >12 kPa: 715 +/- 661 pg/ml, P < 0.001; normal < or =4 kPa: 124 +/- 203 pg/ml). Analysis of variance revealed LV enddiastolic wall stress as the only independent hemodynamic parameter influencing BNP (P < 0.01). Using nomograms with "isostress" curves, the extent of load reduction required for restoring normal LV wall stress was assessed. Compared with the CMR-based volumetric analysis for wall stress calculation, the echocardiography based approach underestimated LV wall stress particularly of dilated hearts. Conclusions In patients with LVD, serum BNP was increased over the whole range of stress values which were the only hemodynamic predictors. Cellular stretch appears to be a major trigger for BNP release. Biochemical mechanisms need to be explored which appear to operate over this wide range of wall stress values. It is concluded that the diagnostic use of BNP should primarily be directed to assess ventricular wall stress rather than the extent of functional ventricular impairment in LVD.
Asunto(s)
Cardiomiopatía Dilatada/diagnóstico , Hemodinámica , Péptido Natriurético Encefálico/sangre , Adulto , Cardiomiopatía Dilatada/sangre , Cardiomiopatía Dilatada/patología , Cardiomiopatía Dilatada/fisiopatología , Ecocardiografía , Femenino , Pruebas de Función Cardíaca , Ventrículos Cardíacos/patología , Humanos , Masculino , Persona de Mediana Edad , Tamaño de los Órganos , Pronóstico , Estrés Mecánico , Disfunción Ventricular Izquierda/diagnóstico por imagen , Disfunción Ventricular Izquierda/patología , Disfunción Ventricular Izquierda/fisiopatología , Función Ventricular Izquierda/fisiologíaRESUMEN
OBJECTIVE: Adrenal lesion is one of the features of multiple endocrine neoplasia type 1 (MEN1). This study aimed to assess prevalence, natural course and clinical relevance of small adrenal lesions without clinical symptoms, endocrine activity, or mechanical problems and thus without clear indication for surgical therapy by endoscopic ultrasound (EUS). DESIGN AND METHODS: Forty-nine patients with familial MEN1 were studied. Twenty-seven of these with adrenal lesions were detected by EUS and at least two performed EUS examinations were included into a subgroup where changes in adrenal morphology were studied by measuring changes in the largest diameter of the dominant adrenal tumour. RESULTS: EUS detected adrenal lesions in 36 (73%) patients: 6 (12%) plump adrenals, 17 (35%) nodular hyperplasia, 12 (24%) adenomas and 1 (2%) cyst. Bilateral adrenal lesions were detected in 17 patients and unilateral in 19 patients. A change in the largest tumour diameter was found to be for nodular hyperplasia -0.02+/-1.41% per month (range -2.56 to 4.58%) and for adenomas -0.61+/-1.95% per month (range -6.25 to 1.15%). One patient had an adrenal cyst with significant growth. There was no evidence of carcinoma or metastatic disease during the study. CONCLUSIONS: The prevalence of adrenal lesions in MEN1 is higher than that reported earlier. Except one cystic lesion, no significant change in the tumour size was observed over a mean observation period of more than 2 years. In a typical situation, small adrenal lesions in MEN1 seem to be constant in their morphology.
Asunto(s)
Adenoma/diagnóstico por imagen , Adenoma/epidemiología , Neoplasias de las Glándulas Suprarrenales/diagnóstico por imagen , Neoplasias de las Glándulas Suprarrenales/epidemiología , Neoplasia Endocrina Múltiple Tipo 1/diagnóstico por imagen , Neoplasia Endocrina Múltiple Tipo 1/epidemiología , Glándulas Suprarrenales/diagnóstico por imagen , Adulto , Síndrome de Cushing/diagnóstico por imagen , Síndrome de Cushing/epidemiología , Endosonografía , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , PrevalenciaRESUMEN
In experimental animals, cardiac work is derived from pressure-volume area and analyzed further using stress-length relations. Lack of methods for determining accurately myocardial mass has until now prevented the use of stress-length relations in patients. We hypothesized, therefore, that not only pressure-volume loops but also stress-length diagrams can be derived from cardiac volume and cardiac mass as assessed by cardiac magnetic resonance imaging (CMR) and invasively measured pressure. Left ventricular (LV) volume and myocardial mass were assessed in seven patients with aortic valve stenosis (AS), eight with dilated cardiomyopathy (DCM), and eight controls using electrocardiogram (ECG)-gated CMR. LV pressure was measured invasively. Pressure-volume curves were calculated based on ECG triggering. Stroke work was assessed as area within the pressure-volume loop. LV wall stress was calculated using a thick-wall sphere model. Similarly, stress-length loops were calculated to quantify stress-length-based work. Taking the LV geometry into account, the normalization with regard to ventricular circumference resulted in "myocardial work." Patients with AS (valve area 0.73+/-0.18 cm(2)) exhibited an increased LV myocardial mass when compared with controls (P<0.05). LV wall stress was increased in DCM but not in AS. Stroke work of AS was unchanged when compared with controls (0.539+/-0.272 vs 0.621+/-0.138 Nm, not significant), whereas DCM exhibited a significant depression (0.367+/-0.157 Nm, P<0.05). Myocardial work was significantly reduced in both AS and DCM when compared with controls (129.8+/-69.6, 200.6+/-80.1, 332.2+/-89.6 Nm/m(2), P<0.05), also after normalization (7.40+/-5.07, 6.27+/-3.20, 14.6+/-4.07 Nm/m(2), P<0.001). It is feasible to obtain LV pressure-volume and stress-length diagrams in patients based on the present novel methodological approach of using CMR and invasive pressure measurement. Myocardial work was reduced in patients with DCM and noteworthy also in AS, while stroke work was reduced in DCM only. Most likely, deterioration of myocardial work is crucial for the prognosis. It is suggested to include these basic physiological procedures in the clinical assessment of the pump function of the heart.
Asunto(s)
Estenosis de la Válvula Aórtica/diagnóstico , Cateterismo Cardíaco , Cardiomiopatía Dilatada/diagnóstico , Pruebas de Función Cardíaca/métodos , Hipertrofia Ventricular Izquierda/etiología , Imagen por Resonancia Cinemagnética , Modelos Cardiovasculares , Contracción Miocárdica , Estenosis de la Válvula Aórtica/complicaciones , Estenosis de la Válvula Aórtica/patología , Estenosis de la Válvula Aórtica/fisiopatología , Presión Sanguínea , Cardiomiopatía Dilatada/complicaciones , Cardiomiopatía Dilatada/patología , Cardiomiopatía Dilatada/fisiopatología , Estudios de Casos y Controles , Electrocardiografía , Estudios de Factibilidad , Humanos , Hipertrofia Ventricular Izquierda/patología , Hipertrofia Ventricular Izquierda/fisiopatología , Valor Predictivo de las Pruebas , Estudios Prospectivos , Estrés Mecánico , Presión VentricularRESUMEN
PURPOSE: The lens of an eye is a particularly radiosensitive organ. This study investigates two different materials for eye shielding during CT scanning, i. e. a commercially available bismuth protector and a newly developed material for eye shielding, comprised of an alloy of Bi/Sb/Gd/W. MATERIALS AND METHODS: The radiation dose during head CT scanning was measured using thermoluminescence dosimeters and an anthropomorphic Alderson-RANDO phantom. A radiation dose reduction was compared to two shielding materials and to the condition without any eye shielding. The effect of gantry angulation that excludes the eyes from beam path was also investigated. Radiation dose measurements were validated using a Monte-Carlo simulation. For this simulation we used the EGSsnr code system, and a new application CTDOSPP was developed for simulation of the computed tomography examination. Eight radiologists evaluated the diagnostic quality of the images. RESULTS: Dose measurements and Monte-Carlo simulations are in good agreement. If the eye shields are placed in the primary beam path, bismuth eye shielding and the new material reduce the dose by up to 38 % and 48 %, respectively. Angling the gantry causes an 88 % reduction in radiation dose. All shielding materials generate beam hardening artifacts located close to the protector, but the artifacts do not spread into the brain. CONCLUSION: The application of eye shields during CT examination of a head causes a significant reduction in radiation dose. The new protector material shows a significantly higher dose reduction in contrast to the commercially available bismuth shield. The best protection from radiation dose can be attained using gantry angulation.
Asunto(s)
Bismuto , Látex , Cristalino/efectos de la radiación , Método de Montecarlo , Fantasmas de Imagen , Protección Radiológica/instrumentación , Dosimetría Termoluminiscente , Tomografía Computarizada por Rayos X , Relación Dosis-Respuesta en la Radiación , Diseño de Equipo , HumanosRESUMEN
Ventricular loading conditions are crucial determinants of cardiac function and prognosis in heart failure. B-type natriuretic peptide (BNP) is mainly stored in the ventricular myocardium and is released in response to an increased ventricular filling pressure. We examined, therefore, the hypothesis that BNP serum concentrations are related to ventricular wall stress. Cardiac magnetic resonance imaging (MRI) was used to assess left ventricular (LV) mass and cardiac function of 29 patients with dilated cardiomyopathy and 5 controls. Left ventricular wall stress was calculated by using a thick-walled sphere model, and BNP was assessed by immunoassay. LV mass (r = 0.73, p < 0.001) and both LV end-diastolic (r = 0.54, p = 0.001) and end-systolic wall stress (r = 0.66, p < 0.001) were positively correlated with end-diastolic volume. LV end-systolic wall stress was negatively related to LV ejection fraction (EF), whereas end-diastolic wall stress was not related to LVEF. BNP concentration correlated positively with LV end-diastolic wall stress (r = 0.50, p = 0.002). Analysis of variance revealed LV end-diastolic wall stress as the only independent hemodynamic parameter influencing BNP (p < 0.001). The present approach using a thick-walled sphere model permits determination of mechanical wall stress in a clinical routine setting using standard cardiac MRI protocols. A correlation of BNP concentration with calculated LV stress was observed in vivo. Measurement of BNP seems to be sufficient to assess cardiac loading conditions. Other relations of BNP with various hemodynamic parameters (e.g., EF) appear to be secondary. Since an increased wall stress is associated with cardiac dilatation, early diagnosis and treatment could potentially prevent worsening of the outcome.
Asunto(s)
Cardiomiopatía Dilatada/fisiopatología , Imagen por Resonancia Magnética , Péptido Natriurético Encefálico/sangre , Función Ventricular Izquierda , Adulto , Anciano , Cardiomiopatía Dilatada/sangre , Diástole , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estrés MecánicoRESUMEN
Endoscopic ultrasound (EUS) enables detection and localization of pancreatic neuroendocrine tumours. Even small tumours down to a diameter of 1-2 mm can be visualized. Since such small tumours usually cannot be detected by computed tomography (ct), magnetic resonance imaging (mri) and somatostatin receptor scintigraphy (srs), and experience with EUS imaging is limited, there is no clear evidence for clinical management in multiple endocrine neoplasia type 1 (MEN1). Knowledge about the natural course of growth and metastatic distribution is mandatory to come to appropriate clinical decisions and guidelines. This prospective study was aimed to assess the natural course of small (<15 mm) neuroendocrine pancreatic tumours without clinical symptoms due to endocrine activity or mechanical problems and without clear indication for surgical therapy in MEN1 by EUS. A total of 82 asymptomatic tumours<15 mm (5.9+/-3.2 mm diameter at baseline) in 20 patients with MEN1-disease (8 female/12 male, 43+/-13 years) were studied over a period of 20+/-12 months (33.8 patient years, 106.7 tumour years) by EUS. Change in largest diameter of each tumour and annual tumour incidence rate in the patients' cohort were calculated. Increase of largest tumour diameter was found to be 1.3+/-3.2% per month, annual tumour incidence rate 0.62 new tumours per patient year. In one patient, rapid progressive pancreatic manifestation of MEN1 was observed. There was no evidence in ct and/or srs and/or mri for metastatic disease in all patients. Only 4/84 (4.8%) pancreatic tumours could be visualized by computed tomography, 5/79 (6.3%) by somatostatin receptor imaging and 4/39 (10.3%) by magnetic resonance imaging. Small asymptomatic neuroendocrine pancreatic tumours in MEN1 usually seem to grow slowly. Annual tumour incidence rate is low. However, faster growing tumours and patients with rapidly progressive disease can be observed. Risk for obvious metastatic disease from asymptomatic neuroendocrine pancreatic tumours<15 mm in MEN1 seems to be low.
Asunto(s)
Carcinoma Neuroendocrino/diagnóstico por imagen , Endosonografía , Neoplasia Endocrina Múltiple Tipo 1/diagnóstico por imagen , Neoplasias Pancreáticas/diagnóstico por imagen , Adulto , Anciano , Carcinoma Neuroendocrino/patología , Estudios de Cohortes , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Neoplasias Pancreáticas/patología , Tomografía de Emisión de Positrones , Estudios Prospectivos , Radiografía , Receptores de Somatostatina/metabolismo , Tomografía Computarizada de EmisiónRESUMEN
PURPOSE: It is evident that there is a growing need for Internet-based reference databases for reasons of practicability and due to the increasing use of reporting on digital workstations. The main advantages of online databases are expected with respect to plain film radiography and cross-sectional imaging. A reference database of skeletal plain film radiography was to be created using the Orthorad program. MATERIALS AND METHODS: The most important standard settings and special images of young and healthy adults in plain film radiography were collected over one year. All samples were approved for the Orthorad database by a board qualified radiologist. Based on the workflows of radiographers and radiologists, the records were organized by body part ( http://www.idr.med.uni-erlangen.de/orthorad/orthorad.htm ). This logical data structure will ensure that the tool serves as a source of information in two ways: On the one hand, the radiographer can access information on positioning, tube voltage and cassette format. On the other hand, the radiologist receives important knowledge regarding X-ray anatomy, reference data regarding the human skeleton, and information about the correct reporting for an image. RESULTS AND CONCLUSION: Orthorad is used as an online reference database for traumatologic plain film radiography to support radiographers and radiologists in their daily working routines. To date, user feedback has been positive.