Better diagnosis for focal epilepsy

3T MRI is better at detecting and characterising structural brain abnormalities in patients with focal epilepsy than 1.5T MRI, leading to a better diagnosis and safer treatment of patients, according to a recent study conducted at the Oregon Health and Science University in Portland, OR. "Patients with focal epilepsy have recurrent seizures that result from a specific area of their brain, usually due to a structural brain abnormality," said Bronwyn E. Hamilton, MD, senior author of the study.

3T MRI detected 65 of 74 cases, compared to 55 of 74 cases detected by 1.5T MRI; lesions were accurately characterised in 63 of 74 cases using 3T MRI, compared to 51 of 74 cases using 1.5T MRI. "Detection refers to lesions that were found and characterisation refers to how accurately we were able to determine what type of abnormality the lesion was, such as tumour versus vascular malformation versus congenital deformity," said Dr. Hamilton.

Epilepsy is a disease with serious consequences for patients and society. Surgery offers the potential for long term cure in patients, but "surgery can only be performed in patients who have a specific structural abnormality in the brain that is detected on an imaging study (usually MRI); since insurance companies may not pay for a second scan, it is preferable to obtain a 3T MRI the first go round," said Dr. Hamilton.

"I, and most of my radiology colleagues, in conjunction with the neurologists who specialise in epilepsy at our institution, feel that a patient with focal epilepsy is incompletely assessed without a 3T MRI, and will re-image patients with prior negative 1.5T MRI in order to feel more certain an abnormality has not been missed. We have had a number of patients who had gone undiagnosed with prior negative MRI scans who later underwent 3T MRI at our institution that either disclosed a structural brain abnormality or better characterised it for the surgeon," said Dr. Hamilton.