[Detectability of metastatic brain tumors using gadoteridol-enhanced MRI: usefulness of standard-dose T1-weighted spin-echo image with magnetization transfer and enhanced FLAIR].
OBJECTIVE
The aim of this study was to compare the detectability and image contrast of metastatic brain tumors depicted by T1-weighted MR imaging (T1WI) with the magnetization transfer (MT) technique after the administration of a standard dose(MT-SD-T1WI) or T1WI without MT after the administration of a double dose of gadoteridol(DD-T1WI). We also assessed the usefulness of enhanced fluid attenuated inversion recovery (FLAIR) for depicting very small metastatic tumors.


METHODS
Forty-six MRI procedures were performed in 31 patients with metastatic brain tumors that had been diagnosed clinically and radiologically. An incremental dose technique was used with intravenous injections of 0.1 and 0.1 mmol/kg of gadoteridol. In 28 MRI procedures, enhanced FLAIR was carried out after an MT-SD-T1WI study.


RESULTS
Detectability was significantly greater with both MT-SD-T1WI and DD-T1WI than with SD-T1WI. However, there was no significant difference between MT-SD- and DD-T1WI. Although an MT pulse increased the contrast between the enhanced tumor and white matter, the contrast between edema and white matter was decreased. Both MT-SD- and DD-T1WI showed small but conspicuous enhanced foci, but we could not determine whether these were vessels or small metastases on the brain surface. However, enhanced FLAIR only demonstrated foci that were thought to be small metastases.


CONCLUSIONS
MT-SD- and DD-T1WI had equal ability to detect metastatic brain tumors. Enhanced FLAIR was useful for assessing very small metastases on the brain surface.
Annoura
K
K
Department of Radiology, Fukuoka University School of Medicine.
Utsunomiya
H
H
Arai
S
S
Okazaki
M
M
D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000556:secondary*; D003287:Contrast Media; D005260:Female; D005682:Gadolinium; D006571:Heterocyclic Compounds; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009942:Organometallic Compounds; D012680:Sensitivity and Specificity
D003287:Contrast Media; D006571:Heterocyclic Compounds; D009942:Organometallic Compounds; C062402:gadoteridol; D005682:Gadolinium