Neuroradiology of AIDS

Transcription

1 Neuroradiology of AIDS Frank Minja,, HMS IV Gillian Lieberman MD September 2002

2 AIDS 90% of HIV patients have CNS involvement 1 10% of AIDS patients present first with neurological symptoms % of AIDS patients have significant neuropathic lesions at autopsy 2 100% of AIDS patients must have CNS involvement HIV is a neurotropic virus 2

3 Neurotropic HIV 3 Infection of CNS cells monocyte- macrophage derivation. Astrocytes, oligodendrocytes, glial Cells and?neurons Encephalitis mediated by cytokines Neurological symptoms occur irrespective of opportunistic infxns CNS as reservoir for the HIV Lipton SA et al. NEJM 1995; 332:

4 AIDS Dementia Complex 40% of AIDS patients have neurological complaints 2 AIDS Dementia Complex: Progressive memory loss, altered mental status, arm weakness, and gait instability Focal lesions: Seizures, focal motor or sensory deficits, cranial nerve palsies Non-focal lesions: Decreased mental status, altered level of consciousness, headaches and other non-specific findings 4

5 Indications and Goals of CNS Imaging Indications: Decreased mental status, Altered level of consciousness, Headaches, Seizures, Focal motor or sensory losses, Cranial nerve palsies Accurate Diagnosis non-specific clinical features Guide therapy choice of Rx and follow-up Severity of neurologic disease correlates with imaging findings 5

6 CT vs MRI Oslen WL, Cohen W. Neuroradiology of AIDS. Radiology of AIDS

7 MR Technique T1 vs T2 spin echo sequences T1 weighting: short TR (repetition time) and short TE (echo time) T2 weighting: long TR (repetition time) and long TE (echo time) Most brain lesions increase brain water content T2 weighting more sensitive to changes in brain water content Anatomic resolution much better with T1 weighting Thus, T1 weighting only after detection of lesion by T2 weighting 7

8 Radiologic Manifestations Atrophy Mass lesion(s) White matter disease Head and Neck Neoplasms (Leptomeningeal and Ependymal disease) 8

9 Cerebral Atrophy Diffuse cerebral atrophy Enlarged ventricles and sulci of atrophy Detected equally well on CT and MRI?etiology HIV subacute encephalitis Memory loss and Psychomotor slowing T2WI demonstrating prominent sulci Progression to Dementia, Death Sakaie KE, Gonzalez RG. Imaging of Neuroaids 9

10 Ddx for Cerebral Atrophy Old Age Dehydration (esp( secondary to chronic diarrhea) Encephalitis (HIV, CMV, HSV) Cachexia 10

11 Progressive Atrophy 4 9 mos 22 mos Thurnher MM, et al. Am J Neuroradiol :

12 Mass Lesions T1WI + contrast demonstrating enhancing mass lesions Sakaie KE, Gonzalez RG. Imaging of Neuroaids 12

13 Ddx for CNS Mass Lesions Infection vs. Tumor: esp in immuno-compromised pts Infections: Toxoplasmosis, Tuberculosis, Candida albicans, Cryptococcus, HSV encephalitis, Bacterial abscesses Tumors: Lymphoma (primary CNS, Hodgkin s, Non- Hodgkin s), Glioma,, Kaposi s sarcoma, Metastatic disease Toxoplasmosis vs Primary CNS Lymphoma in AIDS patients 13

14 Toxoplasmosis Toxoplasma gondii Obligate intracellular protozoan Up to 70% adults seropositive Sub-clinical, mild infection in general population Reactivation in AIDS patients Most common mass lesion in AIDS patients Treatable CNS disease (sulfadiazine- pyrimethamine) T1WI + contrast: Multiple enhancing mass lesions Sakaie KE, Gonzalez RG. Imaging of Neuroaids 14

15 Toxoplasmosis Multiple mass lesions with surrounding vasogenic edema Ring enhancing lesions Cortex and Basal Ganglia T1: low signal intensity T2: medium high signal intensity Sakaie KE, Gonzalez RG. Imaging of Neuroaids 15

16 Primary CNS Lymphoma Clinical Sxs: : Encephalopathy, seizures, cranial nerve palsies, focal motor or sensory losses Extremely poor prognosis < 2 mos? Regresssion with radiation therapy Peripheral lesions - supratentorial Multiple lesions in AIDS patients T1WI + contrast: ring-enhancing lesion in medial temporal lobe Also ring enhancement Sakaie KE, Gonzalez RG. Imaging of Neuroaids 16

17 Toxoplasmosis vs Primary CNS Lymphoma Ring enhancing mass lesions Sakaie KE, Gonzalez RG. Imaging of Neuroaids 17

18 Functional MRI (fmri) 1 2 types of experiments: Regional hemodynamic changes secondary to brain activation. Studies of vision, speech, audition, and memory. Dynamic contrast fmri.. Use of injectable contrast agent. Study of neuroaids. rcbv relative Cerebral Blood Volume rcbf relative Cerebral Blood Flow 18

19 fmri 1 A. Control vs Patient High CBV = Red Mod CBV = Yellow Low CBV = White B. Patient pre vs post Rx High CBV = Red Mod CBV = Yellow Low CBV = White Sakaie KE, Gonzalez RG. Imaging of Neuroaids 19

20 fmri Primary brain lymphoma lesion Toxoplasmosis lesion Sakaie KE, Gonzalez RG. Imaging of Neuroaids 20

21 Thallium SPECT 1 Sakaie KE, Gonzalez RG. Imaging of Neuroaids 21

22 Progressive Multifocal Leukoencephalopathy (PML) 5 Post MJD et al. Am J Neuroradiol :

23 PML Papova virus (JC virus) Demyelination and necrosis of white matter T2WI: sub-cortical hyperintense signal in right hemisphere Mental status changes, visual loss, aphasia, hemiparesis,, ataxia Relentless progression Sakaie KE, Gonzalez RG. Imaging of Neuroaids Mean time to death = 18 wks 23

24 Progressive PML 8 Weeks Later 5 Post MJD et al. Am J Neuroradiol :

25 PML post 4 weeks of HAART 6 Thurnher MM et al. Am J Neuroradiol :

26 PML post 4 months and 21 months of HAART 6 HAART x 4 mos HAART x 21 mos Thurnher MM et al. Am J Neuroradiol :

27 CNS Tuberculosis 8 Right parietal tuberculoma Multiple enhancing cerebellar tuberculomas Left parietal tuberculous abscess Corr,, PD. CNS Tuberculosis. 27

28 Head and Neck Neoplasms 2 Benign Adenoid enlargement Nasopharyngeal lymphoma. Non- Hodgkin s lymphoma at surgery. Oslen WL, Cohen W. Neuroradiology of AIDS.. Radiology of 28

29 References 1. Sakaie KE, Gonzalez RG. Imaging of Neuroaids. Neuroaids :7 2. Oslen WL, Cohen W. Neuroradiology of AIDS.. Radiology of AIDS, Ch 2. Raven Press (1988) 3. Lipton SA, Gendelman HE. Seminars in Medicine of the Beth Israel Hospital, Boston: Dementia Associated with the Acquired Immunodeficiency Syndrome N Engl J Med 1995; 332: , 940, Apr 6, Thurnher MM, et al. Highly Active Antiretroviral Therapy for Patients with AIDS Dementia Complex: : Effect on MR Imaging Findings and Clinical Course AJNR Am J Neuroradiol : Post MJD et al. Progressive Multifocal Leukoencephalopathy in AIDS: : Are There Any MR Findings Useful to Patient Management and Predictive of Patient Survival? AJNR Am J Neuroradiol : Thurnher MM, Post MJD, et al. Initial and Follow-up MR Imaging Findings in AIDS-Related Progressive Multifocal Leukoencephalopathy Treated with Highly Active Antiretroviral Therapy. AJNR Am J Neuroradiol : Gupta RK, Kathuria MK, Pradhan S. Magnetization Transfer MR Imaging in CNS Tuberculosis. AJNR Am J Neuroradiol : Corr,, PD. CNS Tuberculosis. 29

30 Acknowledgements Steve Reddy MD Gillian Lieberman MD Pamela Lepowski Our Webmasters 30