Gliomas: classification with MR imaging.

Abstract

The findings at magnetic resonance (MR) imaging in a group of 36 pathologically verified supratentorial gliomas were analyzed and compared with the biopsy diagnoses (a) to determine whether MR imaging could be used to classify astrocytic-series tumors into a three-tiered system of low-grade astrocytoma, anaplastic astrocytoma, and glioblastoma multiforme; and (b) to evaluate MR imaging features that may aid in this classification. The MR characteristics evaluated were crossing of the midline, edema, tumor signal heterogeneity, hemorrhage, border definition, cyst formation or necrosis, and mass effect. The statistically significant MR characteristics (positive predictors) were mass effect (P = .0000) and cyst formation or necrosis (P = .0512). The MR accuracy rate approached that of neuropathologic diagnosis, which is subject to sampling errors. MR imaging may serve as an adjunct in case management when the clinical course and MR findings appear to be at odds with the neuropathologic diagnosis.

Perfusion, diffusion and spectroscopy values in newly diagnosed cerebral gliomas

“…In a study by Dean et al (6), only approximately 82% of the tumor grades estimated by MR were correct and the main two parameters suggestive of high-grade lesions were mass effect and intra-tumoral necrosis or cyst formation. Although enhancement was more often characteristic of high-grade lesions, 10 to 38% of the high-grade gliomas did not enhance (7) and 15 to 20% of low-grade gliomas did enhance.…”

“Dazed and diffused”: making sense of diffusion abnormalities in neurologic pathologies

“…Glioblastoma is an aggressive World Health Organization Grade IV malignancy with a survival rate of less than 1 year [47]. Patients are typically older than 40 years and present with symptoms of headache, memory loss, motor or language deficits, personality change or seizure [47].…”

“…Patients are typically older than 40 years and present with symptoms of headache, memory loss, motor or language deficits, personality change or seizure [47]. Imaging of glioblastoma typically demonstrates an infiltrating, heterogeneously enhancing lesion with mass effect within the supratentorial white matter that may cross the midline [47].…”

Three-dimensional magnetic resonance reconstruction images before and after surgical therapy of spontaneous canine brain tumors

“…Edema may be present with meningiomas (DEAN et al, 1990), whereas minimal peritumoral edema was observed in choroid plexus tumors (TURREL et al, 1986). T2-weighted images were used to reconstruct edema volume because edema is better seen in T2-weighted sequence (DEAN et al, 1990).…”

“…T2-weighted images were used to reconstruct edema volume because edema is better seen in T2-weighted sequence (DEAN et al, 1990). On the other hand, the software used offers various methods that facilitate the evaluation of the difference between two volumes by combining of the volumes into a single view.…”