Detection of lung cancer on the chest radiograph: a study on observer performance

STUDY OBJECTIVES: to study the validity and observers consistency in the detection of lung cancer on the chest radiograph. MATERIALS AND METHODS: the chest radiographs of 100 clinical cases were interpreted by 14 observers. The radiographs were obtained from 30 patients with initially missed but histopathologically proven non-small cell lung cancer (NSCLC), 35 patients with other cardiopulmonary diseases and 35 patients with no abnormalities. The observers consisted of ten experienced radiologists, two-experienced chest physicians and two residents in radiology. All observers were unaware of the study design. The validity and observer consistency was determined for each observer. RESULTS: the mean sensitivity and specificity of the ten radiologists were 0.36 and 0.90. For the two chest physicians, the mean sensitivity and specificity were 0.29 and 0.96. For the two residents in radiology, mean sensitivity and specificity were 0.25 and 0.94. The mean interobserver kappa and mean intraobserver kappa for the radiologists were 0.38 and 0.54. For the two chest physicians, the mean interobserver kappa was 0.43, while the intraobserver kappa was 0.59. For the two residents in radiology, mean interobserver kappa was 0.35 and the intraobserver kappa was 0.42. There was no significant relation between the consistency parameters and validity parameters. The interobserver and intraobserver kappa values showed good correlation. CONCLUSION: the validity of the chest radiograph and observers consistency in the detection of nodular lung cancer varies widely. The level of experience is likely to influence the diagnostic performance.     

Methionine loading does not enhance the predictive value of homocysteine serum testing for all-cause mortality or major adverse cardiac events

Background: Hyperhomocysteinaemia is independently associated with atherosclerotic disease. Methionine loading could improve the predictive value of hyperhomocysteinaemia by detecting mild disturbances in enzyme activity. The aims of this study were to determine the beneficial effect of methionine loading on the predictive value of homocysteine testing for long‐term mortality and major adverse cardiac events (MACE). Methods: In an observational study, 1122 patients with suspected or known vascular disease, underwent homocysteine testing, which was measured fasting and again 6 h after methionine loading. Hyperhomocysteinaemia was defined as a fasting level ≥15 μmol/L and post‐methionine loading level ≥45 μmol/L or an increase of ≥30 μmol/L above fasting levels. Primary end‐points were death and MACE. Multivariate Cox regression analysis was used, adjusting for all cardiac risk factors. Results: During follow up (mean 8.9 ± 3.4 years), 98 patients died (8.7%), 86 had a MACE (7.7%), 579 patients had normal tests, 134 patients had only fasting hyperhomocysteinaemia, 226 only post‐methionine hyperhomocysteinaemia and 183 patients had both. In multivariate analysis, overall survival and MACE‐free survival were significantly worse for those with fasting hyperhomocysteinaemia, with hazard ratios of 1.86 (95% confidence interval (CI) 1.20–2.87) and 2.24 (95%CI 1.41–3.53), respectively. The addition of hyperhomocysteinaemia after methionine loading did not significantly increase the risk of death or MACE, with hazard ratios of 0.97 (95%CI 0.52–1.81) and 0.89 (95%CI 0.47–1.69), respectively. Conclusion: The presence of post‐methionine hyperhomocysteinaemia did not significantly alter risk of death or MACE in patients with normal or increased fasting homocysteine levels, respectively. In conclusion, methionine loading does not improve the predictive value of homocysteine testing with regard to long‐term mortality or MACE.     

Concussion causes transient dysfunction in cortical inhibitory networks but not the corpus callosum

The corpus callosum (CC) is thought to be especially vulnerable in traumatic brain injury. Bimanual cost (a slowing of reaction time with bimanual compared to unimanual responses) is a sensitive indicator of CC function. To determine whether CC dysfunction is a significant feature of mild traumatic brain injury, unimanual and bimanual reaction times were studied in 10 recently concussed patients and 10 healthy participants. Reaction times were studied within 1 week of concussion and again after 1 month. Concussion symptoms were assessed with the Rivermead Postconcussion Symptoms Questionnaire. The bimanual cost was present at both testing sessions in patients and healthy controls. Although overall reaction times were slower in concussed patients during session 1, these had improved by session 2, as did the symptom scores. These findings suggest that the pathogenesis of mild traumatic brain injury involves intrahemispheric cortical networks rather than impaired interhemispheric communication via the CC.     

Circulatory responses to simulated gravitational shifts of blood in man induced by exposure of the body below the iliac crests to sub-atmospheric pressure

1. Exposure of the body from iliac crests to feet of a horizontal subject to a pressure 70 mm Hg below atmospheric causes a displacement of about 10 g of blood/kg total body weight from the upper to the lower part of the body. Much of this blood is returned very rapidly at the end of suction.2. During suction, the changes in the circulation resemble those during a foot-down tilt. After suction, the changes resemble to some extent those following the Valsalva manoeuvre.3. The overshoot of forearm blood flow following suction is caused by variations in the activity of adrenergic vasoconstrictor nerves. The receptors for this reflex have not been identified, but their stimulation depends upon a rapid and large return of blood to the central circulation.     

Application of hydrosurgery for burn wound debridement: An 8-year cohort analysis

Introduction

During the last decade, the Versajet? hydrosurgery system has become popular as a tool for tangential excision in burn surgery. Although hydrosurgery is thought to be a more precise and controlled manner for burn debridement prior to skin grafting, burn specialists decide individually whether hydrosurgery should be applied in a specific patient or not. The aim of this study was to gain insight in which patients hydrosurgery is used in specialized burn care in the Netherlands.