MR and TL-201 SPECT imaging with pathologic correlation for the assessment of CNS lymphoma vs. Toxoplasmosis in AIDS patients

L. Ketonen, R. C. De La Pena, Javier Villanueva-Meyer

Research output: Contribution to journalArticle


Purpose: Analyze the value of Tl-201 (Tl) brain single photon emission computed tomography (SPECT), to differentiate CNS lymphoma from toxoplasmosis in AIDS patients. Material and Methods: Twenty-four AIDS patients with MR enhancing lesion(s), underwent a brain Tl SPECT. Final diagnosis was established by pathology and clinical/MR follow-up. Results: Nine patients had CNS tumor, 9 toxoplasmosis and 6 other non-tumorous lesions. The sensitivity of Tl to diagnose CNS tumor was 77% and the specificity 93%. Two false negative studies corresponded to tumors with significant necrosis. Conclusions: Tl proved useful for differentiating brain neoplasm from toxoplasmosis. Tumors with significant necrosis, did not show the expected increase in Tl uptake. Determination of Tl uptake ratios help detect tumor with faint tracer uptake.

Original languageEnglish (US)
Pages (from-to)21-42
Number of pages22
JournalJournal of Neuro-AIDS
Issue number1
StatePublished - Jul 1 1998



  • AIDS
  • CNS lymphoma
  • Magnetic resonance
  • Thallium-201
  • Toxoplasmosis

ASJC Scopus subject areas

  • Clinical Neurology

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