PT  - JOURNAL ARTICLE
AU  - N. Sakai
AU  - S. Koizumi
AU  - S. Yamashita
AU  - Y. Takehara
AU  - H. Sakahara
AU  - S. Baba
AU  - Y. Oki
AU  - H. Hiramatsu
AU  - H. Namba
TI  - Arterial Spin-Labeled Perfusion Imaging Reflects Vascular Density in Nonfunctioning Pituitary Macroadenomas
AID  - 10.3174/ajnr.A3564
DP  - 2013 May 30
TA  - American Journal of Neuroradiology
4099  - http://www.ajnr.org/content/early/2013/05/30/ajnr.A3564.short
4100  - http://www.ajnr.org/content/early/2013/05/30/ajnr.A3564.full
AB  - BACKGROUND AND PURPOSE: Angiogenesis is very important in clinical features of pituitary adenomas. We investigated the relationship between the blood flow of nonfunctioning pituitary macroadenomas measured by arterial spin-labeled perfusion imaging and the microvessel attenuation of the tissue. MATERIALS AND METHODS: Conventional MR imaging with contrast-enhanced T1WI and arterial spin-labeled perfusion imaging were performed before surgery in 11 consecutive patients with nonfunctioning pituitary macroadenomas. ROIs were drawn on the tumors, and the degrees of enhancement were calculated by dividing the signal intensity on the contrast-enhanced T1WI by that on the nonenhanced TIWI. As an index of tumor perfusion, a quantitative analysis was performed by using normalized tumor blood flow values calculated by dividing the mean value of the tumor region of interest by the mean region of interest values in the 2 cerebellar hemispheres. The relative microvessel attenuation was determined as the total microvessel wall area divided by the entire tissue area on CD-31-stained specimens. The degree of enhancement and the normalized tumor blood flow values were compared with relative microvessel attenuation. Additionally, intra- and postoperative tumor hemorrhages were visually graded. RESULTS: The degree of enhancement was not correlated with relative microvessel attenuation. Statistically significant correlations were observed between normalized tumor blood flow values and relative microvessel attenuation (P < .05). At surgery, 3 cases were visually determined to be hypervascular tumors, and 1 of these cases had symptomatic postoperative hemorrhage. A statistically significant difference in normalized tumor blood flow values was observed visually between the intraoperative hypovascular and hypervascular groups (P < .05). CONCLUSIONS: Arterial spin-labeled perfusion imaging reflects the vascular density of nonfunctioning pituitary macroadenomas, which may be useful in the preoperative prediction of intra- and postoperative tumor hemorrhage. Abbreviations ASL-PIarterial spin-labeled perfusion imagingnTBFnormalized tumor blood flowTBFtumor blood flow%Vesselrelative microvessel attenuation