Susceptibility weighted imaging in the diagnostic evaluation of patients with intractable epilepsy.
OBJECTIVE
Dedicated magnetic resonance imaging (MRI) protocol can diagnose epileptogenic abnormalities in patients with intractable epilepsy. However, it is not sufficiently sensitive to detect small calcified lesions that may result from infections, tumors, or vascular malformations. This study aims to study the impact of the addition of T2*gradient echo/susceptibility weighted imaging (T2*GRE/SWI) sequence to a dedicated MRI protocol.


METHODS
One hundred thirty-seven patients with intractable epilepsy underwent MRI using conventional epilepsy protocol with addition of T2*GRE/SWI sequence. Comparison of the images with and without these sequences was done for detection of calcified abnormalities/vascular abnormalities. In patients with calcified lesions, MRI findings were correlated either with histopathology or computerized tomography (CT) to confirm the presence of calcification.


RESULTS
In 16 patients the sequence gave additional information compared to conventional imaging protocol. The sequence helped in better characterization of lesions in all patients. In three patients it helped in detecting the lesion and in another three it appeared useful as it best characterized the lesions. Additional lesions were detected in two patients with old calcified granulomas. Important additional information was supplied in four patients, whereas in the remaining patients lesion conspicuity was increased.


CONCLUSIONS
T2*GRE/SWI sequence should form part of routine epilepsy protocol as it increases sensitivity by detecting occult calcified lesions or vascular malformations that may be responsible for the patient's seizures. This is especially important in patients from developing countries who have post-infective calcified lesions responsible for seizures and who undergo only MRI as the imaging modality for intractable seizures.
Saini
Jitender
J
Department of Imaging Sciences and Interventional Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India.
Kesavadas
Chandrasekhran
C
Thomas
Bejoy
B
Kapilamoorthy
Tirur Raman
TR
Gupta
Arun Kumar
AK
Radhakrishnan
Ashalatha
A
Radhakrishnan
Kurupath
K
D000293:Adolescent; D000328:Adult; D002675:Child, Preschool; D004827:Epilepsy / Q000175:diagnosis*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult