Second, time interval between symptom onset and radioexaminiation, hyperacute clot might not be show as hypointense signal on SWI, as the oxyhemoglobin remains the original status, instead of turning into deoxyhemoglobin
As the apnea period continues, C[O.sub.2] concentration increases and the concentration of deoxyhemoglobin
overcomes the concentration of oxyhemoglobin.
We could not perform group statistical analyses on the data for muscle deoxyhemoglobin
signals due to considerable between-subjects and within-subjects variability in the complexity of the signals from the NIRS unit.
In brain areas where a task activates neurons, blood flow is altered such that more oxyhemoglobin is present compared to deoxyhemoglobin
. This results in a transient task-dependent increase in magnetic resonance (MR) signal intensity within the brain regions that the task activates and this phenomenon is termed blood oxygen level dependent (BOLD) MR signal.
Cyanosis typically results from increased amounts of deoxyhemoglobin
in the bloodstream.
CT is superior to conventional MRI sequences in detecting acute SAH because the blood in acute SAH has a low hematocrit and low deoxyhemoglobin
, which makes it appear similar to brain parenchyma on T1- and T2-weighted spin echo images.
Sickle cell disease (SCD) is an inherited hematologic disorder caused by the intraerythrocytic polymerization of deoxyhemoglobin
S, which deforms the shape of red blood cells and alters their ability to circulate, particularly in narrow vascular beds.
The increase of 2,3-bisphosphoglycerate inside the red cells contributes to release of oxygen to the tissues by binding to deoxyhemoglobin
. It has been suggested that bicarbonate administration may impair tissue oxygenation by increasing the affinity of hemoglobin for oxygen, particularly in patients with diabetic ketoacidosis in whom the concentration of 2,3-bisphosphoglycerate is reduced inside the erythrocytes.
Nitrite has optimal intrinsic biological activity at low pH or deoxyhemoglobin
conditions such as those that occurred in ischemia .
In these neuroimaging techniques, fMRI has a very high spatial resolution to measure the blood oxygen level-dependent (BOLD) signal that highly correlated with deoxyhemoglobin
and becomes a gold standard for vivo imaging of brain activity [1,2].
Measurements were given as concentration change in [micro]M of oxyhemoglobin ([DELTA][O.sub.2]Hb), deoxyhemoglobin
([DELTA]HHb), and total hemoglobin ([DELTA]THb = [DELTA][O.sub.2]Hb + [DELTA]HHb) from baseline [3,9].
(172) Without the oxygen attached, the oxyhemoglobin becomes deoxyhemoglobin
, fMRI takes advantage of the "fact that oxyhemoglobin is not magnetic but deoxyhemoglobin
This potential ability of deoxyhemoglobin
to replenish NO in this fashion has led to much research into the potential role of nitrite infusions to prevent neurologic damage after SAH [17-20].
Diffuse axonal injury-related brain lesions are mainly hemorrhagic which are well recognized by this technique (7), (8) In the acute and subacute phase of hemorrhagic lesions, the existence of paramagnetic materials such as methemoglobin, deoxyhemoglobin
, hemosiderin, generates signal intensity in T2GE (9) while in spin echo imaging selective T2 relaxation enhancement of deoxyhemoglobin
is related to time varying magnetic field (10).
The AVOXimeter 4000 whole-blood oximeter is capable of multiple-band spectro-photometric analysis, which allows the researcher to quickly determine the oxyhemoglobin, deoxyhemoglobin
, methemoglobin, and carboxyhemoglobin percentage and total hemoglobin (derived/calculated) in a whole blood sample.