Single breath-holding scans of the abdomen using FISP and FLASH at 1.5 T

Single breath-holding gradient echo techniques fast imaging with steady-state free precession (FISP) and fast low angle shot (FLASH) images were evaluated in the study of the abdomen in 16 patients (13 liver, two kidney, and one pancreas examinations). Gradient echo images were compared retrospectively with conventional spin echo images for image quality (depiction of pathology and representation of anatomic detail), and contrast characteristics were evaluated. All lesions were shown on gradient echo images, and in three of 16 cases gradient echo images were more diagnostic than spin echo images. On both FISP and FLASH images, most hepatic metastases were hyperintense relative to normal liver. The predicted flip angles for maximal contrast for the liver were modeled from signal intensity equations for FISP and FLASH and yielded predicted flip angles of approximately 40-55 degrees for FISP and 15-25 degrees for FLASH. Peak signal-to-noise ratio in liver of normal volunteers occurred at approximately 30 degrees for both FISP and FLASH. Single breath-holding gradient echo images are useful in the evaluation of abdominal structures and this study provides a framework for future work.     

Anti‐neutrophil cytoplasmic antibody‐associated systemic vasculitis: nature or nurture?

This review examines the environmental and genetic contributions to the anti-neutrophil cytoplasmic antibody-associated systemic vasculitides. The dominant environmental risk factors appear to be silica exposure for all three syndromes, and vitamin D deficiency is strongly suggested by the latitude and ultraviolet radiation gradient observed for Wegener's granulomatosis and Churg-Strauss syndrome. Genetic factors are generally not very strong, consistent with the rarity of these conditions in children. However, multiple genetic factors, each with a relatively small effect, may combine to create a state of susceptibility towards autoimmunity. With infection as a triggering agent, it is possible to synthesise a pathogenetic hypothesis that accounts for both environmental and genetic effects in regard to both necrotising vasculitis and granuloma formation.     

Detection of functional connectivity using temporal correlations in MR images

Functional connectivity among brain regions has been investigated via an analysis of correlations between regional signal fluctuations recorded in magnetic resonance (MR) images obtained in a steady state. In comparison with studies of functional connectivity that utilize task manipulations, the analysis of correlations in steady state data is less susceptible to confounds arising when functionally unrelated brain regions respond in similar ways to changes in task. A new approach to identifying interregional correlations in steady state data makes use of two independent data sets. Regions of interest (ROIs) are defined and hypotheses regarding their connectivity are generated in one data set. The connectivity hypotheses are then evaluated in the remaining (independent) data set by analyzing low frequency temporal correlations between regions. The roles of the two data sets are then reversed and the process repeated, perhaps multiple times. This method was illustrated by application to the language system. The existence of a functional connection between Broca's area and Wernicke's area was confirmed in healthy subjects at rest. An increase in this functional connection when the language system was actively engaged (when subjects were continuously listening to narrative text) was also confirmed. In a second iteration of analyses, a correlation between Broca's area and a region in left premotor cortex was found to be significant at rest and to increase during continuous listening. These findings suggest that the proposed methodology can reveal the presence and strength of functional connections in high-level cognitive systems.     

Pregnancy Loss with Phospholipid Antibodies: Improved Outcome with Aspirin Containing Treatment

Summary: The obstetric outcome in 37 patients with antiphospholipid antibodies (APAs) is described. The APAs were measured by the lupus anticoagulant assay and/or more recently anticardiolipin antibodies. There were 15 patients with SLE who without therapy had 51/58 pregnancy failures, either abortion or fetal death in utero, a failure rate of 88%. Likewise, 22 patients without definite SLE lost 69/87 pregnancies, a failure rate of 79%. After treatment the pregnancy wastage rate was 55% and 25% in the 2 groups respectively. When treatment regimens used were examined in detail the improvement with therapy was most clearly evident in the group who received low dose aspirin (75–150mg) in association with immunosup-pression. This improvement was most apparent in the patients without definite SLE.     

CT-guided needle localization for intraoperative biopsy of the head and neck

Needle-localized intraoperative biopsy was first described for the nonpalpable breast mass using mammography for needle placement. This technique can be adapted by substituting CT (or MRI) for mammography. It can be a valuable tool in localizing the nonpalpable areas of concern in the head and neck, especially when the location is obscure or the patient has undergone previous radiation and/or surgical therapy.     

A comparison of bound and unbound audio-visual information processing in the human cerebral cortex

Recently, the technique of single-trial fMRI was introduced, which allows the assessment of hemodynamic responses to single task executions (e.g. sensory, motor, or cognitive). In this study, single-trial fMRI was used to examine regional differences in the inter-trial consistency (ITC) of brain activity related to the processing of a dynamic visuo-spatial imagery task. For every single trial, a t-statistic assessing task-related activation was calculated and thresholded at a p-value of P < or =l0.05 (uncorrected). The percentage of trials with t-values above the threshold was used to assess differences in the consistency of brain activity in occipital, parietal, premotor and prefrontal regions of interest. While most of these regions showed activation which was highly consistent across trials, the consistency of activation was significantly reduced in the dorsolateral prefrontal cortex. We hypothesize that the consistency of activation across trials may be interpreted as an indicator of the functional relevance of a brain region for processing and solving a cognitive task. Thus, the analysis concept presented here has the potential to provide new insights into the neuro-cognitive mechanisms of human information processing. In addition, the results of this study confirm that averaging across trials might result in a significant loss of information about functional neuroanatomy. Regions which are active in some trials only, which show only weak activity increases, or whose activity is not constant and time-locked, might not show up in averaged activation maps and could thus erroneously be interpreted as irrelevant for task processing.     

"First Aid for Scalds" campaign: reaching Sydney''s Chinese, Vietnamese, and Arabic speaking communities

OBJECTIVES: As a serious yet preventable problem, scald injuries in children have been a priority for prevention in Australia and other developed countries. Not only can the occurrence of scalds be prevented, but immediate first aid treatment offers an effective method for secondary prevention, reducing the severity of scalds. Despite the success of scald prevention initiatives, local evidence suggested that first aid knowledge was lacking in some minority ethnic groups. To redress this gap, the "First Aid for Scalds" campaign for those from a non-English speaking background was specifically targeted to three ethnic groups (Vietnamese, Chinese, and Arabic), with the aim of increasing the proportions of parents and caregivers who had correct knowledge of first aid treatment for scalds. The primary strategy was a media campaign, including advertisements on ethnic radio and in ethnic newspapers. METHODS: The evaluation design included formative research and impact evaluation. The impact evaluation study involved random population based telephone surveys with each of the three language groups, before and after the campaign, to assess the reach and effectiveness of the campaign. RESULTS: After the campaign, there were significant increases in the proportion of people who knew the correct first aid treatment for scalds. There were substantial variations in campaign recall and knowledge between each of the three language groups. The largest improvement was found in the Vietnamese group. CONCLUSION: The association between campaign recall and increase in correct knowledge, and the absence of any similar interventions during the campaign period, give credence to the conclusion that the changes observed were a result of the campaign. The results demonstrate the value of community based injury prevention campaigns specifically targeting linguistically diverse communities.     

Why do cancers have high aerobic glycolysis?

If carcinogenesis occurs by somatic evolution, then common components of the cancer phenotype result from active selection and must, therefore, confer a significant growth advantage. A near-universal property of primary and metastatic cancers is upregulation of glycolysis, resulting in increased glucose consumption, which can be observed with clinical tumour imaging. We propose that persistent metabolism of glucose to lactate even in aerobic conditions is an adaptation to intermittent hypoxia in pre-malignant lesions. However, upregulation of glycolysis leads to microenvironmental acidosis requiring evolution to phenotypes resistant to acid-induced cell toxicity. Subsequent cell populations with upregulated glycolysis and acid resistance have a powerful growth advantage, which promotes unconstrained proliferation and invasion.