, Volume 48, Issue 12, pp 875–880 | Cite as

Diffusion-weighted MR imaging of viral encephalitis

  • Yilmaz KiroğluEmail author
  • Cem Calli
  • Nilgun Yunten
  • Omer Kitis
  • Ayse Kocaman
  • Nevzat Karabulut
  • Hasan Isaev
  • Baki Yagci
Diagnostic Neuroradiology



The aim of this study was to evaluate the role of diffusion-weighted imaging (DWI) in the diagnosis of viral encephalitis and its relationship with the stage of the illness.


We performed conventional magnetic resonance imaging (MRI) including T1-W, T2-W and fluid attenuated inversion recovery (FLAIR) sequences and DWI in 18 patients with viral encephalitis diagnosed on the basis of laboratory, clinical and radiologic findings. Based on the qualitative and quantitative comparison of the conventional MRI and DWI, the patients were divided into three groups. Apparent diffusion coefficient (ADC) values of the involved and contralateral normal brain tissues were computed and compared for each group. The degree of correlation between the time (TI) from the onset of neurologic symptoms to the MR examination and ADC values was determined.


In group I (n=11) DWI was superior to conventional MRI in detecting the encephalitic involved sites and in depicting the borders of the encephalitic lesions. In group II (n=4) DWI was similar to conventional MRI. In group III (n=3) conventional MRI was superior to DWI. Mean ADC values of affected versus contralateral normal brain tissues were 0.458±0.161×10−3 versus 0.86±0.08×10−3 in group I, 0.670±0.142×10−3 versus 0.93±0.07×10−3 in group II, and 1.413±0.211×10−3 versus 1.05±0.06×10−3 in group III. Patients in group I had significantly lower ADC values than those in group II, while patients in group III had the highest ADC values (P<0.05). The ADC values were significantly lower in the affected sites than in the unaffected sites of patients in groups I and II, but were significantly higher in the affected sites than in the unaffected sites of patients in group III (P<0.05). There was an excellent correlation between ADC values and duration of the disease (r=0.874, P=0.01).


DWI is superior to other conventional diagnostic MR sequences in the detection of early viral encephalitic lesions and depiction of the lesion borders and, in combination with other sequences, DWI may contribute to the determination of the disease phase.


Diffusion-weighted imaging Viral encephalitis Magnetic resonance imaging 


Conflict of interest statement

We declare that we have no conflict of interest.


  1. 1.
    Struffert T, Reith W (2000) Herpes simplex virus encephalitis: neuroradiologic differential diagnosis. Radiologe 40:1011–1016PubMedCrossRefGoogle Scholar
  2. 2.
    Le Bihan D, Turner R, Douek P, Patronas N (1992) Diffusion MR imaging: clinical applications. AJR Am J Roentgenol 159:591–599PubMedGoogle Scholar
  3. 3.
    Guo AC, Provenzale JM, Cruz LCH Jr, Petrella JR (2001) Cerebral abscesses: investigation using apparent diffusion coefficient maps. Neuroradiology 43:370–374PubMedCrossRefGoogle Scholar
  4. 4.
    Heiner L, Demaerel P (2003) Diffusion-weighted MR imaging findings in a patient with herpes simplex encephalitis. Eur J Radiology 45:195–198CrossRefGoogle Scholar
  5. 5.
    Tsuchiya K, Katase S, Yoshino A, Hachiya J (1999) Diffusion-weighted MR imaging of encephalitis. AJR Am J Roentgenol 173:1097–1099PubMedGoogle Scholar
  6. 6.
    Whitley RJ (1990) Viral encephalitis. N Engl J Med 323:242–250PubMedCrossRefGoogle Scholar
  7. 7.
    White ML, Edwards-Brown MK (1995) Fluid attenuated inversion recovery (FLAIR) MRI of herpes encephalitis. J Comput Assist Tomogr 19:501–505PubMedCrossRefGoogle Scholar
  8. 8.
    Tsuchiya K, Inaoka S, Mizutani Y, Hachiya J (1997) Fast fluid-attenuated inversion recovery MR of intracranial infections. AJNR Am J Neuroradiol 18:909–913PubMedGoogle Scholar
  9. 9.
    Mueller-Mang C, Mang TG, Kalhs P, Thurnher MM (2006) Imaging characteristics of toxoplasmosis encephalitis after bone marrow transplantation: report of two cases and review of the literature. Neuroradiology 48:84–89PubMedCrossRefGoogle Scholar
  10. 10.
    Sener RN (2002) Diffusion MRI in Rasmussen’s encephalitis, herpes simplex encephalitis, and bacterial meningoencephalitis. Comput Med Imaging Graph 26:327–332PubMedCrossRefGoogle Scholar
  11. 11.
    Prakash M, Kumar S, Gupta RK (2004) Diffusion-weighted MR imaging in Japanese encephalitis. J Comput Assist Tomogr 28:756–761PubMedCrossRefGoogle Scholar
  12. 12.
    Miyake M (1964) The pathology of Japanese encephalitis. A review. Bull World Health Organ 30:153–160PubMedGoogle Scholar
  13. 13.
    Küker W, Nagele T, Schmidt F, Heckl S, Herrlinger U (2004) Diffusion-weighted MRI in herpes simplex encephalitis: a report of three cases. Neuroradiology 46:122–125PubMedCrossRefGoogle Scholar
  14. 14.
    Jorens PG, Parizel PM, Demey HE, Smets K, Jadoul K, Verbeek MM, Wevers RA, Cras P (2005) Meningoencephalitis caused by Streptococcus pneumonia: a diagnostic and therapeutic challenge. Diagnosis with diffusion-weighted MRI leading to treatment with corticosteroids. Neuroradiology 47:758–764PubMedCrossRefGoogle Scholar
  15. 15.
    Teixeira J, Zimmerman RA, Haselgrove JC, Bilainuk LT, Hunter JV (2001) Diffusion imaging in pediatric central nervous system infections. Neuroradiology 43:1031–1039PubMedCrossRefGoogle Scholar
  16. 16.
    Nouranifar RK, Ali M, Nath J (2003) The earliest manifestation of focal encephalitis on diffusion-weighted MRI. Clin Imaging 27:316–320PubMedCrossRefGoogle Scholar
  17. 17.
    Provanzale JM, Sorensen AG (1999) Diffusion-weighted MR imaging in acute stroke: theoretic consideration and clinical applications. AJR Am J Roentgenol 173:1459–1467Google Scholar
  18. 18.
    Le Bihan D, Breton E, Lallemand D, Grenier P, Cabanis E, Lava-Jeantet M (1986) MR imaging of intravoxel incoherent motions: application of diffusion and perfusion in neurologic disorders. Radiology 161:401–407PubMedGoogle Scholar
  19. 19.
    Provenzale JM, Engelters ST, Petrella JR, Smith JS, MacFall JR (1999) Use of MR exponential diffusion-weighted images to eradicate T2 “shine-through” effect. AJR Am J Roentgenol 172:537–539PubMedGoogle Scholar

Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  • Yilmaz Kiroğlu
    • 1
    Email author
  • Cem Calli
    • 2
  • Nilgun Yunten
    • 2
  • Omer Kitis
    • 2
  • Ayse Kocaman
    • 3
  • Nevzat Karabulut
    • 1
  • Hasan Isaev
    • 2
  • Baki Yagci
    • 1
  1. 1.Department of RadiologyPamukkale University School of MedicineDenizliTurkey
  2. 2.Department of RadiologyEge University School of MedicineİzmirTurkey
  3. 3.Department of NeurologyEge University School of MedicineİzmirTurkey

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