PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-10 (10)
 

Clipboard (0)
None

Select a Filter Below

Journals
Authors
more »
Year of Publication
Document Types
1.  Quantitative Myocardial Distribution Volume from Dynamic Contrast-Enhanced MRI 
Magnetic resonance imaging  2008;26(4):532-542.
The objective of this study was to investigate if dynamic contrast-enhanced magnetic resonance imaging (MRI) can be used to quantitate the distribution volume (ve) in regions of normal and infarcted myocardium. ve reflects the volume of the extra-cellular, extra-vascular space within the myocardial tissue. In regions of the heart where an infarct has occurred, the loss of viable cardiac cells results in an elevated ve compared to normal regions. A quantitative estimate of the magnitude and spatial distribution of ve is significant because it may provide information complementary to delayed enhancement MRI alone.
Using a hybrid gradient echo-echo planar imaging (GRE-EPI) pulse sequence on a 1.5T MRI scanner, 12 normal subjects and four infarct patients were imaged dynamically, during the injection of a contrast agent, to measure the regional blood and tissue enhancement in the left ventricular (LV) myocardium. Seven of the normal subjects and all of the infarct patients were also imaged at steady-state contrast enhancement to estimate the steady-state ratio of contrast agent in the tissue and blood (Ct/Cb)—a validated measure of ve. Normal and infarct regions of the LV were manually selected and the blood and tissue enhancement curves were fit to a compartment model to estimate ve. Also, the effect of the vascular blood signal on estimates of ve was evaluated using simulations and in the dynamic and steady-state studies.
Aggregate estimates of ve were 23.6% ± 6.3% in normal myocardium and 45.7% ± 3.4% in regions of infarct. These results were not significantly different from the reference standards of Ct/Cb (22.9% ± 6.8% and 42.6% ± 6.3%, p=0.073). From the dynamic contrast-enhanced studies, approximately one minute of scan time was necessary to estimate ve in the normal myocardium to within 10% of the steady-state estimate. In regions of infarct, up to three minutes of dynamic data was required to estimate ve to within 10% of the steady-state ve value.
By measuring the kinetics of blood and tissue enhancement in the myocardium during an extended dynamic contrast enhanced MRI study, ve may be estimated using compartment modeling.
doi:10.1016/j.mri.2007.10.003
PMCID: PMC2383320  PMID: 18068931
7.  Trampoline injury in New Zealand: emergency care. 
OBJECTIVE: To examine trampoline related injuries resulting in emergency department attendance. METHODS: Cases were identified by searching free text descriptions of the circumstances of injury contained in the records of the emergency department of a large city hospital. RESULTS: 114 cases were identified for a 12 month period, giving an incidence rate of 108 per 100,000 population per year (95% confidence interval = 89 to 129) compared with 9.3 hospital admissions per 100,000 population per year (95% confidence interval = 8.3 to 10.4) for a corresponding period reported in earlier research from New Zealand. This suggested that for every one hospital admission there are approximately 12 emergency department attendances. Of the cases, 95% were aged less than 20 years. As for the earlier research, falls from the trampoline to the surrounding surface were the commonest cause of injury. In the present study, sprains and strains were the commonest type of injury (40%), and the body site most frequently involved was the lower limb (46%). CONCLUSIONS: The findings support the conclusion from earlier research that although existing trampoline standards address many of the issues relating to trampoline safety, the need remains for measures to reduce the impact of falls from the trampoline to the ground surface and to prohibit the use of trampolines as unsupervised "play equipment".
PMCID: PMC1332419  PMID: 9015596
8.  The New Zealand rugby injury and performance project. III. Anthropometric and physical performance characteristics of players. 
OBJECTIVE: To investigate the anthropometric and physical performance characteristics of New Zealand rugby players of different ages and both sexes. METHODS: 356 rugby players (264 male, 92 female) took part in the study during a single season. Playing grade ranged from schoolboys and schoolgirls to senior men and women. Assessment of height, weight, neck circumference, and somatotype was performed before the competitive rugby season. A battery of six physical performance assessments was completed after the anthropometry. Analysis of variance was used to examine differences in these variables between field positions and grades. RESULTS: Significant differences between forwards and backs on anthropometric and physical performance variables were apparent at all grades assessed. In terms of anthropometric characteristics, forwards of a given grade were generally taller, possessed greater body mass, and were more endomorphic and less ectomorphic than backs of the same grade. The backs tended to perform better on physical performance measures than forwards, being more aerobically fit, faster, more agile, and possessing a higher degree of muscular endurance. Differences in anthropometry and physical performance attributes were also apparent between players from the various grades. The players at higher levels were generally larger, and performed better on tests of physical performance than the players at lower levels. These differences were found in both sexes. CONCLUSIONS: The greater body mass of the forwards allows them to obtain greater momentum than the backs when sprinting. The ability to obtain greater momentum is important in the body contact phases of the game. Forwards may compromise their aerobic fitness and speed to some extent in order to maintain a high body mass. The anthropometric and physical performance characteristics of players appear to reflect the demands placed on them by the sport.
PMCID: PMC1332239  PMID: 8808542
9.  Trampolines in New Zealand: a decade of injuries. 
Despite international concern about the safety of trampolines, they have become increasingly popular in New Zealand. While internationally attention has centred on a relatively few cases of catastrophic cervical spine injury, little research effort has been directed at placing these incidents in a wider context. To redress this, a descriptive epidemiological study of trampoline-related injury in New Zealand was undertaken. National hospitalization and mortality data for a 10-year period revealed 2098 hospitalizations and two deaths. The incidence rate for hospitalizations increased from 3.1 per 100,000 population per year in 1979 to 9.3 in 1988. Of the hospitalized victims, 71% were injured on home trampolines and 80% fell from the trampoline to the surrounding surface. Fractures were the commonest type of injury (68%), and the body site most frequently involved was the upper limb (53%). There was no evidence of a high incidence of severe head and neck injuries. It was concluded that, although existing trampoline standards addressed many of the issues raised by this research, measures to reduce the impact of falls from trampolines to the ground and to prohibit the provision of trampolines as 'play equipment' are required.
PMCID: PMC1332082  PMID: 7894953
10.  Urinary infection presenting with jaundice. 
British Medical Journal  1967;1(5539):539-540.
PMCID: PMC1841333  PMID: 6017155

Results 1-10 (10)