Review article

Radiological differential diagnosis of ring-enhancing lesions of the central nervous system in patients with HIV-infection

Klaudija Višković orcid.org/0000-0002-5927-3201 ; Klinika za infektivne bolesti "Dr. Fran Mihaljević", Zagreb, Hrvatska
Vedrana Hertl ; Zdravstveno veleučilište Zagreb, Zagreb, Hrvatska
Martina Mirt ; Zdravstveno veleučilište Zagreb, Zagreb, Hrvatska
Melta Tota ; Zdravstveno veleučilište Zagreb, Zagreb, Hrvatska
Marija Frković ; Zdravstveno veleučilište Zagreb, Zagreb, Hrvatska
Šime Zekan ; Klinika za infektivne bolesti "Dr. Fran Mihaljević", Zagreb, Hrvatska
Josip Begovac ; Klinika za infektivne bolesti "Dr. Fran Mihaljević", Zagreb, Hrvatska

Abstract

Understanding and recognizing the appearance of central nervous system (CNS) lessions in HIV-infected patients is important in promptly diagnosing and initiating proper treatment. The primary radiologic modalities used to evaluate CNS are: native and postcontrast computed tomography (CT) and native and postcontrast magnetic resonance imaging (MRI). The adjunctive imaging modalities are: 18 fluorodeoxyglucose positron emision tomography/Computorized Tomography 18F-FDG PET/CT; thallium-201 Single-Photon Emission Computed Tomography – 201 Tl SPECT and special MRI protocols as MRI Spectroscopy. These adjunctive modalities are not used in routine imaging or evaluation of CNS lesions in patients with HIV-infection. They are primarily used when the nature of a lesion is undetermined and additional non-invasive imaging would potentially alter treatment. 18F-FDG PET/CT and SPECT scanning are used most frequently. Diffusion Weighted Imaging (DWI) and Apparent Diffusion Coefficient – ADC map are specific application of MRI that have rezoattempted to distinguish ring-enhancing lesions of CNS. There is a well defined differential diagnosis for ring-enhancing lesions in CNS. When we consider entities that are common in HIV-infected patients we can focus on Toxoplasmosis and primary CNS lymphoma. Toxoplasmosis and primary CNS lymphoma are the two most common brain lesions but, both can have very similar clinical features and appearances on CT and MRI. Imaging features that favour Toxoplasmosis are: large number of lesions, involvment of basal ganglia and, in some cases, hemorrhagic lesion. Imaging features that favour primary CNS lymphoma are: large lesion size (>4 cm), extensive white matter involvement, periventricular location/subependymal spread, contrast enhancement along ventricular surface, extension across or involvement of corpus callosum. MRI and nuclear medicine offer non-invasive methods to facilitate the identification of CNS lesions without invasive biopsy. The definitive diagnosis is sometimes provided by brain biopsy, but biopsy is an invasive procedure and is associated with possible morbidity and mortality. Delay in diagnosis while waiting to see if the patient responds to initial therapy is a significant problem.

Keywords

HIV infection; toxoplasmosis; primary lymphoma; central nervous system

Hrčak ID:

138008

URI

https://hrcak.srce.hr/138008

Publication date:

30.9.2014.

Article data in other languages: croatian

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