Breathhold-regulated blood oxygenation level-dependent (BOLD) MRI of human brain at 3 tesla.
OBJECTIVE
To investigate the cerebrovascular response to repeated breathhold challenges using blood oxygenation level-dependent (BOLD) MRI at 3T and compare the results with previous data at 1.5T.


METHODS
Six normal volunteers and six patients with brain tumors were recruited for this 3T study. For the normal group, BOLD MRI during repeated breathholds of different durations (five to 30 seconds) were acquired. Maximum signal change, full-width at half-maximum (FWHM) and onset time (defined as the time to the first half-maximum) were determined by curve fitting. The fractional activation volume was also calculated. Patients performed a 10- or 15-second breathhold paradigm according to individual capability.


RESULTS
Significant BOLD signal increases in the gray matter for a breathhold period as short as 5 seconds at 3T, instead of 10 seconds at 1.5T. The fractional activation volume vs. breathhold duration reached a plateau of 49.54 +/- 7.26% at 15 seconds at 3T, which was higher and shorter than that at 1.5T. The maximum signal changes were significantly larger (a 69% increase) at 3T than at 1.5T. In the patient group, there were BOLD signal increases in gray matter but not in tumor bulk or perifocal edema, which agreed with the results previously found at 1.5T.


CONCLUSIONS
BOLD MRI at 3T is more sensitive for detecting breathhold-regulated signal changes than at 1.5T, which allows a shorter and more feasible breathhold paradigm for clinical applications in patients with brain tumors.
Hsu
Yuan-Yu
YY
Department of Medical Imaging, Buddhist Tzu Chi General Hospital, Taipei, Taiwan.
Kuan
Wan-Chun
WC
Lim
Kun-Eng
KE
Liu
Ho-Ling
HL
D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000378:metabolism*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption; D015203:Reproducibility of Results; D015656:Respiratory Mechanics; D012680:Sensitivity and Specificity; D055815:Young Adult
D010100:Oxygen