Cardiac function has traditionally been evaluated using breath-hold cine acquisitions. However, there is a great need for free breathing techniques in patients who have difficulty in holding their breath. Real-time cardiac MRI is a valuable alternative to the traditional breath-hold imaging approach, but the real-time images are often inferior in spatial and temporal resolution. This article pr...

Air pollution and cigarette smoke are recognized health risks. A method was developed for the measurement of the deposition fraction (DF) of polydisperse particulate matter (PM) in human airways. Ten normal volunteers [three females, age range 18-67 years, mean age (SD) 43.9 (14)] made single breath exhalations after inhalation to total lung capacity. The exhaled breath was diverted to a multic...

BACKGROUND AND PURPOSE A proportion of individuals with carotid artery stenosis show a reduced cerebrovascular reserve as measured by a reduced cerebral arterial vasodilatory response to carbon dioxide. Two methods of quantifying this vasodilatory response, using transcranial Doppler ultrasonography, have been in general use: the total range of vasodilation between hypocapnia, induced by hyperv...

Skow RJ, Day TA, Fuller JE, Bruce CD, Steinback CD. The ins and outs of breath holding: simple demonstrations of complex respiratory physiology. Adv Physiol Educ 39: 223–231, 2015; doi:10.1152/advan.00030.2015.—The physiology of breath holding is complex, and voluntary breath-hold duration is affected by many factors, including practice, psychology, respiratory chemoreflexes, and lung stretch. ...