Central haemodynamics in 23 patients with mitral stenosis and 7 control subjects were compared with the results of regional lung perfusion studied by (133)Xe, pulmonary scintigraphy with (99)mTc-labelled macro-aggregates of albumin, and regional ventilation by (133)Xe.A close correlation was found between both methods assessing regional pulmonary perfusion, i.e. pulmonary scintigraphy and (133)...

We have developed a new quantitative single-photon-emission computed tomography (SPECT) method that uses (113m)In-labeled albumin macroaggregates and Technegas ((99m)Tc) to estimate the distributions of regional ventilation and perfusion for the whole lung. The multiple inert-gas elimination technique (MIGET) and whole lung respiratory gas exchange were used as physiological evaluations of the ...

A good knowledge of clinical presentation and of risk factors for pulmonary embolism is mandatory to improve adequate clinical suspicion. Some recent improvements in diagnostic strategy have to be emphasized. A low D-dimer level has a good negative predictive value to rule out pulmonary embolism. Ventilation-perfusion lung scan is the most often used imaging technique. In case of non diagnostic...

Disturbances in the relationship of ventilation and perfusion may result in hypoxemia, a deficiency of oxygen in the blood. The four major causes of hypoxemia are hypoventilation, alveolar-capillary diffusion impairment, shunt, and ventilation perfusion mismatch.1 In this article factors which determine ventilation and gas exchange will be identified and abnormalities leading to hypoxemia will ...

The phenomenon of exercise-induced hemoptysis is still relatively underrecognised in humans. We report a case of recurrent hemoptysis brought on by vigorous exercise. A 33-year-old male presented with several episodes of intermittent fresh small-volume hemoptysis reproducible on vigorous exercise. There was no other significant medical history other than a past history of testicular tumor, trea...

INTRODUCTION The occurrence of an intravascular lymphoma with severe pulmonary involvement mimicking pulmonary embolism is described. CASE PRESENTATION A 38-year-old man was referred to our intensive care unit with acute respiratory failure and long lasting fever. Appropriate investigations failed to demonstrate any bacterial, viral, parasitic or mycobacterial infection. A chest computed tomo...

BACKGROUND We hypothesized that during demand ischemia, abnormal perfusion will precede abnormal function, the spatial extent of perfusion abnormality will be greater than that of functional abnormality, and the spatiotemporal disparity between abnormal perfusion and abnormal function will be more marked in the presence of single-vessel stenosis (SVS) versus multivessel stenosis (MVS). METHOD...

Viable tissues at risk of infarction in acute stroke patients have been hypothesized to be detectable as volumetric mismatches between lesions on perfusion-weighted (PWI) and diffusion-weighted magnetic resonance imaging (DWI). Because tissue response to ischaemic injury and to therapeutic intervention is tissue- and patient-dependent, changes in infarct progression due to treatment may be bett...

This research focuses on design of a software-based image analysis system towards facilitating automated diagnosis of Pulmonary Embolism using ventilation-perfusion scans and correlated chest x-rays. This proposed system takes the digitized ventilation-perfusion scan images of lungs as input, identify a template according to the size and shape of the lungs and thereby approximate and reconstruc...

Extrapulmonary deposition of macroaggregated albumin particles on lung perfusion scintigraphy occurs in the presence of right-to-left shunting, as demonstrated in this case of portosystemic shunting related to superior vena cava obstruction by germ cell tumor of the mediastinum. The case demonstrates the importance of examining tracer deposition within the entire field of view on (99m)Tc-macroa...