Clinical physiology and functional imaging
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Clin Physiol Funct Imaging · May 2012
Functional assessment of high-grade ICA stenosis with duplex ultrasound and transcranial Doppler.
Duplex ultrasound (DUS) has shown a >90% accuracy compared to angiography, concerning the degree of internal carotid artery (ICA) stenosis. However, uncertainty may occur in a severe stenosis, in which peak systolic velocity (PSV) may decrease owing to high flow resistance or high backward pressure. We investigated intracranial collateral flows using transcranial Doppler (TCD) to further evaluate the hemodynamic significance of high-grade ICA stenosis. ⋯ Transcranial Doppler helps to determine whether an ICA stenosis is of hemodynamic significance and to assess collateral patterns. Established collateral blood flow will help to identify patients with ≥70% (ECST) carotid artery disease. TCD might be of value when flow velocity criteria combined with plaque assessment by DUS are inclusive. Other diagnostic methods may also be considered.
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Clin Physiol Funct Imaging · Mar 2012
Atherosclerotic plaques in the internal carotid artery and associations with lung function assessed by different methods.
Previous studies on associations between reduced lung function and cardiovascular disease (CVD) have mainly been based on forced expiratory volume in 1-s (FEV(1) ) and vital capacity (VC). This study examined potential associations between five different lung function variables and plaques in the internal carotid artery (ICA). ⋯ The occurrence of plaques in the ICA was associated with low D(L,CO) and high RV, but not significantly with FEV(1) or COPD status. The results suggest that the relationships between reduced lung function, COPD and CVD are complex and not only linked to bronchial obstruction and low-grade systemic inflammation.
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Clin Physiol Funct Imaging · Mar 2012
The washout rate of a subcutaneous 99mTc-HSA depot in lower extremity lymphoedema.
Lymphoscintigraphy is currently the leading diagnostic modality of lower extremity lymphoedema but has been criticized for being unreliable. Washout rate constants have been investigated and proven to be of diagnostic value in several studies of breast-cancer-related lymphoedema; however, the applicability in lower extremity lymphoedema needs further evaluation. The aim of the study was to verify if washout of (99m) Tc-human serum albumin ((99m) Tc-HSA) is a reliable diagnostic tool in lower extremity lymphoedema. ⋯ The washout rate of a subcutaneous (99m) Tc-HSA depot is not a reliable diagnostic tool in examination of lower extremity lymphoedema. Additional examinations revealed in vivo instability of the utilized (99m) Tc-HSA as the likely reason.
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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.