Single-photon emission CT findings in acute Japanese encephalitis.
OBJECTIVE
To determine the usefulness of single-photon emission CT (SPECT) in the diagnosis of acute Japanese encephalitis (JE).


METHODS
We examined 10 patients (six men and four women; mean age, 69 years) with viral encephalitis. We divided the cases into two groups: the JE group (n = 4) and the non-JE group (n = 6; two with herpes simplex encephalitis and four with encephalitis of unknown origin). All cases were investigated with 99mTc-hexamethylpropyleneamine oxime (HMPAO) SPECT within 15 days after the onset of symptoms. Two patients in the JE group were also examinated by SPECT at a later stage. In all cases MR imaging was performed after the SPECT study.


RESULTS
In the acute stage, all patients in the JE group showed a marked increase of HMPAO uptake that matched the hyperintense area observed on MR images in the thalami and putamina bilaterally. Follow-up SPECT studies of two patients with JE revealed a decrease of HMPAO deposition in the areas of high uptake. None of the patients in the non-JE group had an increased accumulation of HMPAO in the thalami or the putamina.


CONCLUSIONS
SPECT is helpful in differentiating JE from herpes simplex encephalitis and other types of encephalitis. SPECT may be useful as a diagnostic tool in the early stages of JE.
Kimura
K
K
Department of Cerebrovascular Disease, Kumamoto City Hospital, Japan.
Dosaka
A
A
Hashimoto
Y
Y
Yasunaga
T
T
Uchino
M
M
Ando
M
M
D000208:Acute Disease; D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging; D003937:Diagnosis, Differential; D004672:Encephalitis, Japanese / Q000000981:diagnostic imaging*; D018792:Encephalitis, Viral / Q000000981:diagnostic imaging; D005260:Female; D006561:Herpes Simplex / Q000000981:diagnostic imaging; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015609:Organotechnetium Compounds; D010091:Oximes; D019690:Technetium Tc 99m Exametazime; D015899:Tomography, Emission-Computed, Single-Photon
D015609:Organotechnetium Compounds; D010091:Oximes; D019690:Technetium Tc 99m Exametazime