Pituitary macroadenomas: preoperative evaluation of consistency with diffusion-weighted MR imaging--initial experience.
OBJECTIVE
To prospectively evaluate use of diffusion-weighted (DW) magnetic resonance (MR) images and apparent diffusion coefficient (ADC) maps for determination of the consistency of macroadenomas.


METHODS
The study protocol was approved by the institutional ethics committee, and informed consent was obtained from all patients. Twenty-two patients with pituitary macroadenoma (10 men, 12 women; mean age, 54 years +/- 17.09 [standard deviation]; range, 21-75 years) were examined. All patients underwent MR examination, which included T1-weighted spin-echo and T2-weighted turbo spin-echo DW imaging with ADC mapping and contrast material-enhanced T1-weighted spin-echo imaging. Regions of interest (ROIs) were drawn in the macroadenomas and in normal white matter on DW images, ADC maps, and conventional MR images. Consistency of macroadenomas was evaluated at surgery and was classified as soft, intermediate, or hard. Histologic examination was performed on surgical specimens of macroadenomas. Mean ADC values, signal intensity (SI) ratios of tumor to white matter within ROIs on conventional and DW MR images, and degree of enhancement were compared with tumor consistency and with percentage of collagen content at histologic examination by using analysis of variance for linear trend.


RESULTS
The mean value of ADC in the soft group was (0.663 +/- 0.109) x 10(-3) mm(2)/sec; in the intermediate group, (0.842 +/- 0.081) x 10(-3) mm(2)/sec; and in the hard group, (1.363 +/- 0.259) x 10(-3) mm(2)/sec. Statistical analysis revealed a significant correlation between tumor consistency and ADC values, DW image SI ratios, T2-weighted image SI ratios, and percentage of collagen content (P < .001, analysis of variance). No other statistically significant correlations were found.


CONCLUSIONS
Findings in this study suggest that DW MR images with ADC maps can provide information about the consistency of macroadenomas.
Pierallini
Alberto
A
Neuroradiology Section and Neuroradiology Unit, Department of ENS and Neurology, University of Rome La Sapienza, Viale dell'Università 30, 00185 Rome, Italy. alberto.pierallini@uniroma1.it
Caramia
Francesca
F
Falcone
Carlo
C
Tinelli
Emanuele
E
Paonessa
Amalia
A
Ciddio
Alessia Bernardo
AB
Fiorelli
Marco
M
Bianco
Federico
F
Natalizi
Stefania
S
Ferrante
Luigi
L
Bozzao
Luigi
L
D000236:Adenoma / Q000473:pathology* / Q000601:surgery; D000328:Adult; D000368:Aged; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010911:Pituitary Neoplasms / Q000473:pathology* / Q000601:surgery; D011300:Preoperative Care; D011446:Prospective Studies