3T MRI is better at detecting and characterizing 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 characterized 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 characterization refers to how
accurately we were able to determine what type of abnormality the
lesion was, such as tumor 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 specialize 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 characterized it for
the surgeon," said Dr. Hamilton.
This study appears in the September issue of the American Journal of Roentgenology.
Source : American Roentgen Ray Society. September 2008.