Authors: Paul C Schroeder M Judith Donovan Post Elizabeth Oschatz Alfred Stadler Jocelyn BruceGregorios Majda M Thurnher
Publish Date: 2006/09/01
Volume: 48, Issue: 10, Pages: 715-720
Abstract
Toxoplasmosis and lymphoma are common lesions of the central nervous system in patients with AIDS It is often difficult to distinguish between these lesions both clinically and radiographically Previous research has demonstrated restricted diffusion within cerebral lymphomas and bacterial abscesses However little work has been done to evaluate the diffusion characteristics of toxoplasmosis lesions This study was designed to explore further the utility of diffusionweighted imaging DWI and apparent diffusion coefficient ADC maps and values in making the distinction between toxoplasmosis and lymphomaThe magnetic resonance imaging MRI studies of 36 patients including 22 with toxoplasmosis all of whom had AIDS and 14 with lymphoma 8 of whom had AIDS at two institutions were reviewed retrospectively The characteristics of the lesions on DWI were evaluated and the ADC ratios of the lesions were calculated and comparedThere was significant overlap of the ADC ratios of toxoplasma and lymphoma most notably in the intermediate 10–16 range There was variability in ADC ratios even among different lesions in the same patient In only a minority of the lymphoma patients were the ADC ratios low enough to suggest the correct diagnosisOur study showed that toxoplasmosis exhibits a wide spectrum of diffusion characteristics with ADC ratios which have significant overlap with those of lymphoma Therefore in the majority of patients ADC ratios are not definitive in making the distinction between toxoplasmosis and lymphoma
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