OBJECTIVES To assess the likelihood ratios of diagnostic strategies for pulmonary embolism and to determine their clinical application according to pretest probability. DATA SOURCES Medline, Embase, and Pascal Biomed and manual search for articles published from January 1990 to September 2003. STUDY SELECTION Studies that evaluated diagnostic tests for confirmation or exclusion of pulmonary...

Several authors have described methods to track perfusion and cardiac surgical morbidity and mortality as well as perfusion accidents. There is currently not a standard definition of a perfusion accident nor is there a standard reporting threshold for events which do not directly cause known morbidity. We propose the term non-routine events (NREs) instead of accidents, and provide a working def...

BACKGROUND The way in which hyperoxia affects pulmonary ventilation and perfusion is not fully understood. We investigated how an increase in oxygen partial pressure in healthy young volunteers affects pulmonary ventilation and perfusion measured by thoracic electrical impedance tomography (EIT). METHODS Twelve semi-supine healthy male volunteers aged 21-36 years were studied while breathing ...

Five women and three men, all obese and weighing 95 to 140 kg, were studied by routine pulmonary function tests and by a radioactive xenon technique, while seated upright at rest, to measure the regional ventilation and perfusion distribution in the lung. In four subjects in whom the expiratory reserve volume averaged 49% of predicted normal, the ventilation distribution as measured with (133)x...

Cardiopulmonary exercise testing has previously demonstrated a reduced maximum oxygen uptake and anaerobic threshold, as well as abnormal wasted ventilation fraction and gas exchange after unilateral lung transplantation. To further explain the mechanisms of these abnormalities, we assessed the regional distribution of pulmonary blood flow and ventilation at rest and during steady-state exercis...

OBJECTIVE To determine the frequency of different risk factors for pulmonary embolism with particular reference to high altitude as one of the factors. STUDY DESIGN Cross sectional, analytical study. PLACE AND DURATION OF STUDY Department of Pulmonology, Military Hospital Rawalpindi, from December 2006 to December 2007. METHODOLOGY A total of 50 serving soldiers suspected of pulmonary emb...

BACKGROUND Ventilation/perfusion single-emission photon CT (V/P-SPECT) is widely used to detect pulmonary embolism (PE). Any pathological deficit on P-SPECT with a corresponding unremarkable V-SPECT is considered an embolism. This means that a deficit on P-SPECT with a corresponding deficit on the ventilation scan correlates with other lung pathologies such as pneumonia, bullous emphysema or tu...

THE lung is a large organ (over 30 cm in height, in man) perfused with blood at a relatively low pressure. Thus the influence of gravity on the distribution of blood flow and ventilation is considerable. In normal lungs significant differences in perfusion, ventilation and ventilation/perfusion ratio exist between apex and base (West 1g62), and in disease mismatching of ventilation and perfusio...

introduction: it seems that demographic and clinical features of patients referred for myocardial perfusion scintigraphy (mps) is different among populations and healthcare settings. the purpose of the current study is to evaluate the clinical features and risk factors of patients referred for myocardial perfusion scintigraphy to a military hospital. methods: as a cross-sectional study, the cli...

The authors introduce a novel coding technique which significantly improves the performance of the traditional vector quantisation (VQ) schemes at low bit rates. High interblock correlation in natural images results in a high probability that neighbouring image blocks are mapped to small subsets of the VQ codebook, which contains highly correlated codevectors. If, instead of the whole VQ codebo...