Utilizing flip angle/TR equivalence to reduce breath hold duration in hyperpolarized 129 Xe 1‐point Dixon gas exchange imaging

2021 ◽  
Author(s):  
Peter J. Niedbalski ◽  
Junlan Lu ◽  
Chase S. Hall ◽  
Mario Castro ◽  
John P. Mugler ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Flip Angle ◽  
Breath Hold ◽  
Breath Hold Duration

Skin Cooling on Breath-Hold Duration and Predicted Emergency Air Supply Duration During Immersion

2020 ◽  
Vol 91 (7) ◽  
pp. 578-585
Author(s):  
Victory C. Madu ◽  
Heather Carnahan ◽  
Robert Brown ◽  
Kerri-Ann Ennis ◽  
Kaitlyn S. Tymko ◽  
...  
Keyword(s):  
Minute Ventilation ◽  
Hold Time ◽  
Whole Body ◽  
Breath Hold ◽  
Endurance Time ◽  
Skin Exposure ◽  
Breathing Apparatus ◽  
Air Supply ◽  
Skin Cooling ◽  
Breath Hold Duration

PURPOSE: This study was intended to determine the effect of skin cooling on breath-hold duration and predicted emergency air supply duration during immersion.METHODS: While wearing a helicopter transport suit with a dive mask, 12 subjects (29 ± 10 yr, 78 ± 14 kg, 177 ± 7 cm, 2 women) were studied in 8 and 20°C water. Subjects performed a maximum breath-hold, then breathed for 90 s (through a mouthpiece connected to room air) in five skin-exposure conditions. The first trial was out of water for Control (suit zipped, hood on, mask off). Four submersion conditions included exposure of the: Partial Face (hood and mask on); Face (hood on, mask off); Head (hood and mask off); and Whole Body (suit unzipped, hood and mask off).RESULTS: Decreasing temperature and increasing skin exposure reduced breath-hold time (to as low as 10 ± 4 s), generally increased minute ventilation (up to 40 ± 15 L · min−1), and decreased predicted endurance time (PET) of a 55-L helicopter underwater emergency breathing apparatus. In 8°C water, PET decreased from 2 min 39 s (Partial Face) to 1 min 11 s (Whole Body).CONCLUSION: The most significant factor increasing breath-hold and predicted survival time was zipping up the suit. Face masks and suit hoods increased thermal comfort. Therefore, wearing the suits zipped with hoods on and, if possible, donning the dive mask prior to crashing, may increase survivability. The results have important applications for the education and preparation of helicopter occupants. Thermal protective suits and dive masks should be provided.Madu VC, Carnahan H, Brown R, Ennis K-A, Tymko KS, Hurrie DMG, McDonald GK, Cornish SM, Giesbrecht GG. Skin cooling on breath-hold duration and predicted emergency air supply duration during immersion. Aerosp Med Hum Perform. 2020; 91(7):578–585.

scholarly journals Non‐Invasive Pulmonary Gas Exchange Measurements Following Deep Breath‐Hold Diving

2019 ◽  
Vol 33 (S1) ◽  
Author(s):  
Alexander Patrician ◽  
Ivan Drvis ◽  
Tony Dawkins ◽  
Barak Otto ◽  
Geoff Coombs ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Pulmonary Gas Exchange ◽  
Breath Hold ◽  
Deep Breath ◽  
Non Invasive

Diving and swimming performance of white whales, Delphinapterus leucas: an assessment of plasma lactate and blood gas levels and respiratory rates.

1997 ◽  
Vol 200 (24) ◽  
pp. 3091-3099 ◽  
Author(s):  
S A Shaffer ◽  
D P Costa ◽  
T M Williams ◽  
S H Ridgway
Keyword(s):  
High Speed ◽  
Swimming Performance ◽  
Lactate Concentration ◽  
Delphinapterus Leucas ◽  
Breath Hold ◽  
Plasma Lactate ◽  
Post Exercise ◽  
Test Platform ◽  
Plasma Lactate Concentration ◽  
Breath Hold Duration

The white whale Delphinapterus leucas is an exceptional diver, yet we know little about the physiology that enables this species to make prolonged dives. We studied trained white whales with the specific goal of assessing their diving and swimming performance. Two adult whales performed dives to a test platform suspended at depths of 5-300 m. Behavior was monitored for 457 dives with durations of 2.2-13.3 min. Descent rates were generally less than 2 m s-1 and ascent rates averaged 2.2-3 m s-1. Post-dive plasma lactate concentration increased to as much as 3.4 mmol l-1 (4-5 times the resting level) after dives of 11 min. Mixed venous PO2 measured during voluntary breath-holds decreased from 79 to 20 mmHg within 10 min; however, maximum breath-hold duration was 17 min. Swimming performance was examined by training the whales to follow a boat at speeds of 1.4-4.2 m s-1. Respiratory rates ranged from 1.6 breaths min-1 at rest to 5.5 breaths min-1 during exercise and decreased with increasing swim speed. Post-exercise plasma lactate level increased to 1.8 mmol l-1 (2-3 times the resting level) following 10 min exercise sessions at swimming speeds of 2.5-2.8 m s-1. The results of this study are consistent with the calculated aerobic dive limit (O2 store/metabolic rate) of 9-10 min. In addition, white whales are not well adapted for high-speed swimming compared with other small cetaceans.

Case studies in Physiology: Breath-hold diving beyond 100 meters - cardiopulmonary responses in world champion divers

2021 ◽  
Author(s):  
Alexander Patrician ◽  
Christopher Gasho ◽  
Boris Spajić ◽  
Hannah G. Caldwell ◽  
Darija Bakovic-Kramaric ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Airway Resistance ◽  
Physiological Stress ◽  
Structural Characteristics ◽  
Compressive Strain ◽  
Pulmonary Gas Exchange ◽  
Arterial Oxygen ◽  
Breath Hold ◽  
Valuable Insight ◽  
World Champion

In this case study, we evaluate the unique physiological profiles of two world-champion breath-hold divers. At close-to current world record depths, the extreme physiological responses to both exercise and asphyxia during progressive elevations in hydrostatic pressure are profound. As such, these professional athletes must be highly capable of managing such stress, to maintain performing at the forefront human capacity. In both divers, pulmonary function before and after deep dives to 102 and 117 meters in the open sea were assessed using non-invasive pulmonary gas exchange (indexed via the O2 deficit, which is analogous to the traditional alveolar to arterial oxygen difference), ultrasound B-line scores, airway resistance and airway reactance. Hydrostatic-induced lung compression was also quantified via spirometry. Both divers successfully performed their dives. Pulmonary gas exchange efficiency was impaired in both divers at 10 min, but had mostly restored within a few hours. Mild hemoptysis was transiently evident immediately following the 117m dive, whereas both divers experienced nitrogen narcosis. Although B-lines were only elevated in one diver post-dive, reductions in airway resistance and reactance occurred in both divers, suggesting the compressive strain on the structural characteristics of the airways can persist for up to 3.5hrs. Marked echocardiographic dyssynchrony was evident in one diver after 10m of descent, which persisted until resolving at ~77m during ascent. In summary, despite the enormous hydrostatic and physiological stress to diving beyond 100m on a single breath, these data provide valuable insight into the extraordinary capacity of those at the pinnacle of apneic performance.

Single breath‐hold measurement of pulmonary gas exchange and diffusion in humans with hyperpolarized 129 Xe MR

2019 ◽  
Vol 32 (5) ◽  
pp. e4068 ◽  
Author(s):  
Junshuai Xie ◽  
Haidong Li ◽  
Huiting Zhang ◽  
Xiuchao Zhao ◽  
Lei Shi ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Pulmonary Gas Exchange ◽  
Breath Hold ◽  
Single Breath ◽  
Single Breath Hold ◽  
And Diffusion

Navigator assessment of breath-hold duration: impact of supplemental oxygen and hyperventilation.

1998 ◽  
Vol 171 (2) ◽  
pp. 395-397 ◽  
Author(s):  
P G Danias ◽  
M Stuber ◽  
R M Botnar ◽  
K V Kissinger ◽  
M L Chuang ◽  
...  
Keyword(s):  
Supplemental Oxygen ◽  
Breath Hold ◽  
Breath Hold Duration

Simultaneous assessment of both lung morphometry and gas exchange function within a single breath-hold by hyperpolarized 129 Xe MRI

2017 ◽  
Vol 30 (8) ◽  
pp. e3730 ◽  
Author(s):  
Jianping Zhong ◽  
Huiting Zhang ◽  
Weiwei Ruan ◽  
Junshuai Xie ◽  
Haidong Li ◽  
...  
Keyword(s):  
Gas Exchange ◽  
Breath Hold ◽  
Single Breath ◽  
Single Breath Hold ◽  
Lung Morphometry ◽  
Exchange Function ◽  
Simultaneous Assessment

scholarly journals Fast Determination of Flip Angle and T1 in Hyperpolarized Gas MRI During a Single Breath-Hold

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Jianping Zhong ◽  
Weiwei Ruan ◽  
Yeqing Han ◽  
Xianping Sun ◽  
Chaohui Ye ◽  
...  
Keyword(s):  
Flip Angle ◽  
Breath Hold ◽  
Fast Determination ◽  
Single Breath ◽  
Single Breath Hold ◽  
Hyperpolarized Gas ◽  
Hyperpolarized Gas Mri

Unsteady-state gas exchange and storage in diving marine mammals: the harbor porpoise and gray seal

2001 ◽  
Vol 281 (2) ◽  
pp. R490-R494 ◽  
Author(s):  
R. G. Boutilier ◽  
J. Z. Reed ◽  
M. A. Fedak
Keyword(s):  
Gas Exchange ◽  
Marine Mammals ◽  
Lung Ventilation ◽  
The Body ◽  
Breath Hold ◽  
Unsteady State ◽  
Harbor Porpoise ◽  
Per Se ◽  
End Tidal ◽  
And Storage

Breath-by-breath measurements of end-tidal O2 and CO2 concentrations in harbor porpoise reveal that the respiratory gas exchange ratio (RR; CO2 output/O2 uptake) of the first lung ventilation in a breathing bout after a prolonged breath-hold is always well below the animal's metabolic respiratory quotient (RQ) of 0.85. Thus the longest apneic pauses are always followed by an initial breath having a very low RR(0.6–0.7), which thereafter increases with each subsequent breath to values in excess of 1.2. Although the O2 stores of the body are fully readjusted after the first three to four breaths following a prolonged apneic pause, a further three to four ventilations are always needed, not to load more O2 but to eliminate built-up levels of CO2. The slower readjustment of CO2 stores relates to their greater magnitude and to the fact that they must be mobilized from comparatively large and chemically complex HCO[Formula: see text]/CO2 stores that are built up in the blood and tissues during the breath-hold. These data, and similar measurements on gray seals (12), indicate that it is the readjustment of metabolic RQ and not O2 stores per se that governs the amount of time an animal must spend ventilating at the surface after a dive.

Lung visualisation on PET/MRI: implementing a protocol with a short echo-time and low flip-angle volumetric interpolated breath-hold examination sequence

2020 ◽  
Vol 75 (3) ◽  
pp. 239.e15-239.e21
Author(s):  
F. Crimì ◽  
A. Varotto ◽  
G. Orsatti ◽  
C. Lacognata ◽  
D. Cecchin ◽  
...  
Keyword(s):  
Flip Angle ◽  
Breath Hold ◽  
Echo Time ◽  
Short Echo Time
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