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Background: Not all patients with severe chronic obstructive pulmonary disease (COPD) progressively hyperinflate during symptom limited exercise. The pattern of change in chest wall volumes (Vcw) was investigated in patients with severe COPD who progressively hyperinflate during exercise and those who do not. Methods: Twenty patients with forced expiratory volume in 1 second (FEV 1 ) 35 (2)% predicted were studied during a ramp incremental cycling test to the limit of tolerance (Wpeak). Changes in Vcw at the end of expiration (EEVcw), end of inspiration (EIVcw), and at total lung capacity (TLCVcw) were computed by optoelectronic plethysmography (OEP) during exercise and recovery. Results: Two significantly different patterns of change in EEVcw were observed during exercise. Twelve patients had a progressive significant increase in EEVcw during exercise (early hyperinflators, EH) amounting to 750 (90) ml at Wpeak. In contrast, in all eight remaining patients EEVcw remained unchanged up to 66% Wpeak but increased significantly by 210 (80) ml at Wpeak (late hyperinflators, LH). Although at the limit of tolerance the increase in EEVcw was significantly greater in EH, both groups reached similar Wpeak and breathed with a tidal EIVcw that closely approached TLCVcw (EIVcw/TLCVcw 93 (1)% and 93 (3)%, respectively). EEVcw was increased by 254 (130) ml above baseline 3 minutes after exercise only in EH. Conclusions: Patients with severe COPD exhibit two patterns during exercise: early and late hyperinflation. In those who hyperinflate early, it may take several minutes before the hyperinflation is fully reversed after termination of exercise.

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This paper reviews state-of-the-art research solutions across the spectrum of medical imaging informatics, discusses clinical translation, and provides future directions for advancing clinical practice. More specifically, it summarizes advances in medical imaging acquisition technologies for different modalities, highlighting the necessity for efficient medical data management strategies in

Measurement of respiratory muscle blood flow (RMBF) in humans has important implications for understanding patterns of blood flow distribution during exercise in healthy individuals and those with chronic disease. Previous studies examining RMBF in humans have required invasive methods on anesthetized subjects. To assess RMBF in awake subjects, we applied an indicator-dilution method using near-infrared spectroscopy (NIRS) and the light-absorbing tracer indocyanine green dye (ICG). NIRS optodes were placed on the left seventh intercostal space at the apposition of the costal diaphragm and on an inactive control muscle (vastus lateralis). The primary respiratory muscles within view of the NIRS optodes include the internal and external intercostals. Intravenous bolus injection of ICG allowed for cardiac output (by the conventional dye-dilution method with arterial sampling), RMBF, and vastus lateralis blood flow to be quantified simultaneously. Esophageal and gastric pressures were also measured to calculate the work of breathing and transdiaphragmatic pressure. Measurements were obtained in five conscious humans during both resting breathing and three separate 5-min bouts of constant isocapnic hyperpnea at 27.1 +/- 3.2, 56.0 +/- 6.1, and 75.9 +/- 5.7% of maximum minute ventilation as determined on a previous maximal exercise test. RMBF progressively increased (9.9 +/- 0.6, 14.8 +/- 2.7, 29.9 +/- 5.8, and 50.1 +/- 12.5 ml 100 ml(-1) min(-1), respectively) with increasing levels of ventilation while blood flow to the inactive control muscle remained constant (10.4 +/- 1.4, 8.7 +/- 0.7, 12.9 +/- 1.7, and 12.2 +/- 1.8 ml 100 ml(-1) min(-1), respectively). As ventilation rose, RMBF was closely and significantly correlated with 1) cardiac output (r = 0.994, P = 0.006), 2) the work of breathing (r = 0.995, P = 0.005), and 3) transdiaphragmatic pressure (r = 0.998, P = 0.002). These data suggest that the NIRS-ICG technique provides a feasible and sensitive index of RMBF at different levels of ventilation in humans.

In order to investigate underlying mechanisms, the present authors studied the effect of pulmonary rehabilitation on the regulation of total chest wall and compartmental (ribcage, abdominal) volumes during exercise in patients with chronic obstructive pulmonary disease.In total, 20 patients (forced expiratory volume in one second, mean¡SEM 39¡3% predicted) undertook high-intensity exercise 3 days?week -1 for 12 weeks. Before and after rehabilitation, the changes in chest wall (cw) volumes at the end of expiration (EEV) and inspiration (EIV) were computed by optoelectronic plethysmography during incremental exercise to the limit of tolerance (Wpeak). Rehabilitation significantly improved Wpeak (57¡7 versus 47¡5 W). In the post-rehabilitation period and at identical work rates, significant reductions were observed in minute ventilation (35.1¡2.7 versus 38.4¡2.7 L?min -1 ), breathing frequency (26¡1 versus 29¡1 breaths?min -1 ) and EEVcw and EIVcw (by 182¡79 and 136¡37 mL, respectively). Inspiratory reserve volume was significantly increased (by 148¡70 mL). Volume reductions were attributed to significant changes in abdominal EEV and EIV (by 163¡59 and 125¡27 mL, respectively). The improvement in Wpeak was similar in patients who progressively hyperinflated during exercise and those who did not (24 and 26%, respectively).In conclusion, pulmonary rehabilitation lowers chest wall volumes during exercise by decreasing the abdominal volumes. The improvement in exercise capacity following rehabilitation is independent of the pattern of exercise-induced dynamic hyperinflation.

The present study demonstrated elevated serum OPN and OPG levels in patients with carotid stenosis and documented an independent association between these biochemical markers, GSM and carotid-induced symptomatology. Therefore bone-matrix proteins combined with GSM could be potential markers for vulnerable carotid plaques.

Gender differences in resting pulmonary function are attributable to the smaller lung volumes in women relative to men. We sought to investigate whether the pattern of response in operational lung volumes during exercise is different between men and women of similar fitness levels. Breath-by-breath volume changes of the entire chest wall ( V(.)( CW)) and its rib cage ( V(.)( Rc)) and abdominal ( V(.)( Ab)) compartments were studied by optoelectronic plethysmography in 15 healthy subjects (10 men) who underwent a symptom-limited ( W (peak)) incremental bicycle test. The pattern of change in end-inspiratory and end-expiratory V(.)( CW) ( V(.)( CW,EI) and V(.)( CW,EE), respectively) did not differ between the sexes. With increasing workload the decrease in V(.)( CW,EE) was almost entirely attributable to a reduction in end-expiratory V(.)( Ab), whereas the increase in V(.)( CW,EI) was due to the increase in end-inspiratory V(.)( Rc) in both sexes. In men, at W (peak) tidal volume [ V(.)( T), 2.7 (0.2) l] and inspiratory capacity [IC, 3.4 (0.2) l] were significantly greater than in women [1.8 (0.2) and 2.6 (0.2) l, respectively]. However, after controlling for lung size using forced vital capacity (FVC) as a surrogate, the differences between men and women were eliminated [ V(.)( T) /FVC 49 (3) and 45 (3) respectively, and IC/FVC 63 (2) and 65 (3) respectively]. All data are presented as mean (SE). In both men and women the contribution of the rib cage compartment to V(.)( T) expansion was significantly greater than that of the abdominal compartment. We conclude that gender differences in operational lung volumes in response to progressive exercise are principally attributable to differences related to lung size, whereas compartmental chest wall kinematics do not differ among sexes.