RESUMO
Transposition of the great arteries is one of the most common cyanotic congenital heart diseases. It is characterised by an abnormal connection of the ventricles and great arteries, so that the aorta arises from the morphological right ventricle and the pulmonary artery arises from the morphological left ventricle. Historically, as with many congenital heart diseases, patients with transposition of the great arteries had poor life expectancy. Advances in surgical and medical management have resulted in patients surviving into adulthood. As these patients are living longer, they will be encountered more frequently in practice. The purpose of this article is to familiarise the general radiologist with the expected postoperative anatomy, and the appearance on cross-sectional imaging as well as the long-term complications in this group of patients.
Assuntos
Cardiopatias Congênitas , Situs Inversus , Transposição dos Grandes Vasos , Adulto , Ventrículos do Coração , Humanos , Artéria Pulmonar/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Transposição dos Grandes Vasos/diagnóstico por imagem , Transposição dos Grandes Vasos/cirurgiaRESUMO
The purpose of this work was to take advantage of the new clinical field strength of 3 T to implement and optimize a chemical shift imaging (CSI) acquisition protocol to produce spectra of high quality with high specificity to the myocardium within a clinically feasible scan time. Further, an analysis method was implemented dependent purely on anatomical location of spectra, and as such free from any potential user bias caused by inference from spectral information. Twenty healthy male subjects were scanned on two separate occasions using the optimized CSI protocol at 3 T. Data were analyzed for intra- and inter-subject variability, as well as intra- and inter-observer variability. The average phosphocreatine (PCr)/adenosine triphosphate (ATP) value for scan 1 was 2.07 +/- 0.38 and for scan 2 was 2.14 +/- 0.46, showing no significant difference between scans. Intra-subject variability was 0.43 +/- 0.35 (percentage difference 20%) and the inter-subject coefficient of variation was 18%. The intra-observer variability, assessed as the absolute difference between analyses of the data by a single observer, was 0.14 +/- 0.24 with no significant difference between analyses. The inter-observer variability showed no significant differences between the PCr/ATP value measured by four different observers as demonstrated by an intra-class correlation coefficient of 0.763. The increased signal available at 3 T has improved spatial resolution and thereby increased myocardial specificity without any significant decrease in reproducibility over previous studies at 1.5 T. We present an acquisition protocol that routinely provides high quality spectra and a robust analysis method that is free from potential user bias.
Assuntos
Coração/anatomia & histologia , Trifosfato de Adenosina/metabolismo , Humanos , Espectroscopia de Ressonância Magnética , Masculino , Variações Dependentes do Observador , Fosfocreatina/metabolismo , Isótopos de Fósforo , Reprodutibilidade dos Testes , Tamanho da AmostraRESUMO
PURPOSE: To investigate left atrial volumes and function and their variability in healthy volunteers using steady state free precession (SSFP) and fast low angle shot (FLASH) sequences at both 1.5 and 3 T using both the short-axis and biplane area-length methods. MATERIALS AND METHODS: Ten healthy volunteers underwent CMR at both 1.5 and 3 Tesla. The biplane area-length method utilized volumes from the horizontal and vertical long axis images. RESULTS: There were no significant differences between left atrial short-axis volumes or function between 1.5 and 3 T assessed using either FLASH or SSFP sequences. The biplane area-length method underestimated maximal left atrial volume using FLASH by 12 mL at 3 T (18%) and by 10 mL (14%) at 1.5 T (p = 0.003 and p = 0.05 respectively). Variability was larger for left atrial measurements using the biplane area-length method. CONCLUSION: Field strength had no effect on left atrial volume and function assessment using either FLASH or SSFP. The use of the short-axis method for the acquisition of left atrial parameters is more reproducible than the biplane area-length for serial measurements.
Assuntos
Átrios do Coração/anatomia & histologia , Imagem Cinética por Ressonância Magnética/métodos , Adulto , Volume Cardíaco , Feminino , Humanos , Aumento da Imagem , Processamento de Imagem Assistida por Computador , Modelos Lineares , Masculino , Tamanho do Órgão , Reprodutibilidade dos TestesRESUMO
Back pain is a major burden on the working population. It is a particular problem amongst hospital staff, especially nurses. It has been poorly studied amongst doctors. Pre-registration house officers (PRHOs) starting their careers are exposed to a number of risk factors for back problems, both physical and psychological. This questionnaire-based study investigated the prevalence of back pain and its impact on the work of new graduates from two UK medical schools. Around half of the newly qualified PRHOs had significant back pain, one-quarter at least once a week. The frequency of back pain doubled once they started work, although the overall prevalence remained static. One in 10 of them had been unable to perform their normal work activities at some stage because of back pain. One in eight had sought professional help for back problems in the previous 5 years. Fewer than 50% of newly qualified doctors could recall any formal training in lifting and handling.