[A study on the vascular permeability of brain tumors using dynamic CT]

The vascular permeability of 50 brain tumors of various kinds was examined by means of dynamic CT. The degree of the vascular permeability within the tumor was evaluated according to the theoretical basis that the regression of the time-density curve after the peak to the base line became less in accord with the increase in vascular permeability. The time-density curves obtained from dynamic CT were classified into the following four types. Type 1; This type shows a similar pattern to normal brain tissue and is thought to reveal the normal vascular permeability. Type 2; this type shows intermediate pattern between type 1 and type 3. And the vascular permeability is thought to have been moderately increased. Type 3; This type shows the flattening or gradual increase in the time-density curve after forming the peak. The vascular permeability is thought to have increased markedly. Type 4; The peak of the time-density curve is lower than that of the white matter. This type of tumor is regarded to be least vascularized. All tumors except for gliomas and AVMs showed type 2 or 3 and their vascular permeability was thought to be increased. Most of the gliomas showed type 2 or 3, although some gliomas showed type 1 even in the lesion with positive contrast enhancement. In the lesions of such cases, it was thought that the vascular permeability was not affected significantly, so that blood brain barrier modification therapy by intraarterial mannitol infusion may be quite effective. All AVMs showed type 1.(ABSTRACT TRUNCATED AT 250 WORDS)