MR assessment of changes of tumor in response to hyperbaric oxygen treatment.
Enhancement of image intensity, using the T1-weighted spoiled gradient-echo (SPGR) sequence, was measured in SCC tumor implanted in the flank of C3H mice while they were subjected to several types of oxygenation challenges inside a hyperbaric chamber designed and constructed to fit in an MRI resonator. The central portions of the tumor gave a positive enhancement, while the periphery showed signal reduction during both normobaric (NBO) and hyperbaric (HBO) oxygen challenges. In the contralateral normal leg, nearly 70% of the region showed a decrease in intensity, and the rest showed a positive enhancement. The positive signal enhancement was markedly greater under HBO compared to NBO. Calculated R1, R2, and M0 maps from multivariate fitting of images acquired by a multislice multiecho (MSME) sequence with variable TR before, during, and after HBO treatment confirm that the source of SPGR signal enhancement in the tumor is associated with shortening of T1.
Matsumoto
Ken-ichiro
K
Radiation Biology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland 20892-1002, USA.
Bernardo
Marcelino
M
Subramanian
Sankaran
S
Choyke
Peter
P
Mitchell
James B
JB
Krishna
Murali C
MC
Lizak
Martin J
MJ
D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000378:metabolism; D015687:Cell Hypoxia; D004867:Equipment Design; D005260:Female; D006931:Hyperbaric Oxygenation; D007089:Image Enhancement / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D051379:Mice; D008809:Mice, Inbred C3H; D018482:Muscle, Skeletal / Q000378:metabolism; D009369:Neoplasms / Q000378:metabolism*; D010313:Partial Pressure