Determinants of signal intensity in MRI of human astrocytomas

Autor: Marius P. Valsamis, B. Góraj, Marga Spiller, Samuel S. Kasoff, Michael S. Tenner
Rok vydání: 1995
Předmět:
Zdroj: European Radiology. 5
ISSN: 1432-1084
0938-7994
DOI: 10.1007/bf00178085
Popis: MRI studies at 1.5 T of 38 patients with histologically confirmed astrocytomas were reviewed to search for a relationship of signal intensity with grade of malignancy, rediotherapy used for recurrent tumours and calcium deposits in surgical specimens. Signal intensity of tumours compared with normal brain was rated on a scale of 1 to 5 on T1- and T2-weighted images. Surgical specimens of each tumour were graded histopathologically on a scale of I to III and examined for calcium deposits. CT scans were searched for evidence of calcification. The majority of astrocytomas appeared hypointense on T1-weighted and hyperintense on T2-weighted images. Of 18 tumours with increased signal on T1-weighted images, grade II were prevalent, followed by calcified astrocytomas. Among 14 tumours with decreased signal on T2-weighted images the order was similar, but the ratio of high-grade to low-grade tumours did not differ in relation to signal intensity, while on T1-weighted images the ratio was higher in the group with increased signal intensity. A high grade of malignancy and microcalcifications were associated with an increased signal intensity of astrocytomas on T1-weighted sequences without contrast agent. The above factors did not influence significantly the signal intensity on T2-weighted images.
Databáze: OpenAIRE
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