Diffusion‐Weighted Imaging With Calculated Apparent Diffusion Coefficient of Enhancing Extra‐Axial Masses

Abstract

ABSTRACT Background and Purpose. Sometimes intracranial contrastenhancing tumors like meningiomas, metastases, lymphomas, and schwannomas can mimic each other. It was the aim of the present study to investigate if intracranial contrast‐enhancing lesions can be reliably differentiated with the help of diffusionweighted imaging with calculated apparent diffusion coefficients (ADCs). Methods . 29 patients (ages ranging from 22 to 82 years, mean age of 58.6 years) were included. Nine meningiomas, 7 metastases, 6 lymphomas, and 7 schwannomas were investigated. The ADC value in the lesions and in the perifocal edema was analyzed. Results . For the lymphomas, the authors measured the lowest ADC values in the contrast‐enhancing part (0.59 ± 0.09 · 10 – 3mm2/sec). The meningiomas showed a mean ADC value of 0.98 ± 0.18 · 10 – 3mm2/sec. The schwannomas and metastases showed higher ADC values of 1.33 ± 0.28 · 10 – 3mm2/sec and 1.05 ± 0.20 · 10 – 3mm2/sec. The authors saw a statistically significant difference between lymphomas, meningiomas, and metastases concerning the ADC values in the contrast‐enhancing part. Conclusions . In spite of a small sample size and partly a wide range of values, the authors found statistically significant differences between meningiomas, metastases, and lymphomas concerning ADC values. Nevertheless, a differentiation of these lesions only with the help of ADC values seems questionable.