Validation of in vivo MR measurement of oxygen saturation after resuscitation with a hemoglobin-based oxygen carrier in a rabbit model.
OBJECTIVE
The authors tested whether noninvasive magnetic resonance (MR) oximetry is accurate in the in vivo measurement of oxygen saturation in a stroma-free, hemoglobin-based oxygen carrier (HBOC).


METHODS
A central venous catheter was placed in the inferior vena cava (IVC) of 10 New Zealand white rabbits (weight range, 2.5-3.2 kg). Each rabbit underwent removal of 20% of blood volume followed by resuscitation with 10 mL/kg of bovine HBOC-200. Oxygen saturation of the blood mixture was measured in vivo at the IVC with MR oximetry, with separate in vitro calibration for each animal. Blood drawn from the IVC was measured with ex vivo oximetry, which was used as the standard of reference. The in vivo and ex vivo measurements were compared.


RESULTS
There was no significant difference (P > .1) between measurements obtained with MR oximetry and ex vivo oximetry. The results with in vivo MR oximetry demonstrated excellent correlation with those from ex vivo oximetry (r = 0.99) over a wide range of physiologic oxygen saturation values (16.7%-74.9%) in venous blood.


CONCLUSIONS
Noninvasive in vivo MR measurement of oxygen saturation is valid for whole blood mixed with stroma-free hemoglobin. Therefore, MR oximetry may be clinically useful for assessing the oxygenation status in patients resuscitated with a HBOC.
Chan
F P
FP
Department of Radiology, Stanford University Medical Center, CA 94305-5105, USA.
Jahr
J S
JS
Driessen
B
B
Daunt
D A
DA
Li
K C
KC
D000818:Animals; D001802:Blood Substitutes / Q000378:metabolism*; D006454:Hemoglobins / Q000378:metabolism*; D008279:Magnetic Resonance Imaging; D010092:Oximetry / Q000379:methods*; D010100:Oxygen / Q000097:blood*; D011817:Rabbits; D012151:Resuscitation
D001802:Blood Substitutes; D006454:Hemoglobins; C402601:hemoglobin glutamer-200; C096798:HBOC 201; D010100:Oxygen