Clinical physiology and functional imaging
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Clin Physiol Funct Imaging · Jan 2012
Response patterns to bronchodilator and quantitative computed tomography in chronic obstructive pulmonary disease.
Patients with chronic obstructive pulmonary disease (COPD) show different spirometric response patterns to bronchodilator, such that some patients show improvement principally in expiratory flow (forced expiratory volume in 1 s; FEV(1)), whereas others respond by improvement of lung volume (forced vital capacity; FVC). The mechanisms of these different response patterns to bronchodilator remain unclear. We investigated the associations between bronchodilator responsiveness and quantitative computed tomography (CT) indices in patients with COPD. ⋯ The degrees of emphysema and air trapping may contribute to the different response patterns to bronchodilator in patients with COPD.
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Clin Physiol Funct Imaging · Jan 2012
Randomized Controlled TrialEffects of oxygen supplementation on cerebral oxygenation during exercise in chronic obstructive pulmonary disease patients not entitled to long-term oxygen therapy.
The rate of change (Δ) in cerebral oxygenation (COx) during exercise is influenced by blood flow and arterial O(2) content (CaO(2)). It is currently unclear whether ΔCOx would (i) be impaired during exercise in patients with chronic obstructive pulmonary disease (COPD) who do not fulfil the current criteria for long-term O(2) therapy but present with exercise-induced hypoxaemia and (ii) improve with hyperoxia (FIO(2) = 0·4) in this specific sub-population. ⋯ ΔCOx was impaired in non-hypoxaemic patients with COPD who desaturated during exercise. Hyperoxic breathing was able to correct for these abnormalities, an effect related to enhanced CaO(2) rather than improved central haemodynamics. This indicates that O(2) supplementation ameliorates exercise COx in patients with COPD who are not currently entitled to ambulatory O(2) therapy.
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Clin Physiol Funct Imaging · Jan 2012
Technetium-99m-labelled HL91 and technetium-99m-labelled MIBI SPECT imaging for the detection of ischaemic viable myocardium: a preliminary study.
The assessment of myocardial viability has become an important aspect of the diagnostic and prognostic work-up of patients with coronary artery disease. Technetium-99m labelled sestamibi ((99m)Tc-MIBI) myocardial perfusion imaging may underestimate the viability of ischaemic myocardium. Technetium-99m labelled 4,9-diaza-3,3,10,10-tetramethyldodecan-2,11-dione dioxime ((99m)Tc-HL91) is a hypoxia-avid agent which can identify acutely ischaemic viable myocardium in a canine model using a standard gamma camera. The aim of this study was to evaluate uptake character of ischaemic viable myocardium and diagnostic performance of single-photon emission computed tomography (SPECT) imaging by (99m)Tc-HL91 and (99m)Tc-MIBI in detecting ischaemic viable myocardium in coronary heart disease. ⋯ Functional SPECT imaging with (99m)Tc-HL91 and (99m)Tc-MIBI can be used to detect the seriously ischaemic but viable myocardium with a mismatched uptake character. The uptake of (99m)Tc-HL91 in the viable myocardium reached a stable level at 3-4 h after injection.
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Clin Physiol Funct Imaging · Jan 2012
Correlation between serum calcium levels and dual-phase (99m)Tc-sestamibi parathyroid scintigraphy in primary hyperparathyroidism.
The goal of the study is to correlate serum calcium levels with the results of dual-phase (99m)Tc-sestamibi parathyroid scintigraphy to find the best cut-off level of the serum calcium that correlates with a positive presurgery. ⋯ (99m)Tc-MIBI parathyroid scintigraphy is most likely to yield identification and localization of a parathyroid adenoma when both PTH and calcium are elevated; however, although there is no lower limit of PTH which can predict a negative study, we cannot recommend (99m)Tc-MIBI parathyroid scintigraphy if the serum calcium is <2·51 mmol l(-1).