Kun Cao MD, Abstract Co-Author: Nothing to Disclose

Xiao-Peng Zhang MD, Abstract Co-Author: Nothing to Disclose

Ying-Shi Sun MD, Presenter: Nothing to Disclose

Lei Tang MD, Abstract Co-Author: Nothing to Disclose

To describe the characteristics of brain metastases on MR perfusion-weighted imaging, and to evaluate the potential of perfusion MR in predicting the short-term therapeutic effects.

Fifty-eight patients diagnosed as brain metastases were included in the study. Totally 92 lesions were evaluated. Five indexes of perfusion MR were derived from post-processing workstation，Mean time to enhance (MTE), Negative enhancement integral (NEI), Time to maximum (TTM), Maximum slope of increase(MSI) and Maximum slope of decrease(MSD). Comparison between metastases and contralateral normal grey matter were made. The extents of peritumoral edema were recorded in four grades from none to heavy, and correlations between perfusion MR indexes and degrees of edema were made. According to WHO criteria, tumors were divided into 3 groups based on their size change after 2-4 months therapy. Differences of perfusion MR indexes among the groups were analyzed.

MTE, NEI and TTM are all higher in metastases than those in contralateral normal grey matter. In lesions with peritumoral edema, there is a tendency that those with higher NEI and TTM have greater extent of edema, with statistical significance existing between mild and heavy degree groups. After short-term therapy, NEI in responded group is higher than in stable group and progressive group (P=0.048 and 0.039 respectively), but there is no significant difference existing between stable group and progressive group (P=0.600).

Perfusion MR could reflect the blood supply and permeability of brain metastases. The blood volume of lesions may be able to predict the short term therapeutic effects. The blood volume and time to peak may reflect the permeability of certain area, demonstrated by their correlation with peritumoral edema extents.

Brain metastases intensively affect the living qualities of people with malignancy. To tell in advance which lesions are more, or less, vulnerable to therapy may help reduce the unnecessary agony.

Cao, K, Zhang, X, Sun, Y, Tang, L, Perfusion MR in Brain Metastasis: Characteristics and Prognostic Value for Short-term Therapy.  Radiological Society of North America 2009 Scientific Assembly and Annual Meeting, November 29 - December 4, 2009 ,Chicago IL. http://archive.rsna.org/2009/8001262.html