Reliability of stereotactic coordinates of 1.5-tesla and 3-tesla MRI in radiosurgery and functional neurosurgery.
OBJECTIVE
The aims of this study are to identify interpersonal differences in defining coordinates and to figure out the degree of distortion of the MRI and compare the accuracy between CT, 1.5-tesla (T) and 3.0T MRI.


METHODS
We compared coordinates in the CT images defined by 2 neurosurgeons. We also calculated the errors of 1.5T MRI and those of 3.0T. We compared the errors of the 1.5T with those of the 3.0T. In addition, we compared the errors in each sequence and in each axis.


RESULTS
The mean difference in the CT images between the two neurosurgeons was 0.48±0.22 mm. The mean errors of the 1.5T were 1.55±0.48 mm (T1), 0.75±0.38 (T2), and 1.07±0.57 (FLAIR) and those of the 3.0T were 2.35±0.53 (T1), 2.18±0.76 (T2), and 2.16±0.77 (FLAIR). The smallest mean errors out of all the axes were in the x axis : 0.28-0.34 (1.5T) and 0.31-0.52 (3.0T). The smallest errors out of all the MRI sequences were in the T2 : 0.29-0.58 (1.5T) and 0.31-1.85 (3.0T).


CONCLUSIONS
There was no interpersonal difference in running the Gamma Plan® to define coordinates. The errors of the 3.0T were greater than those of the 1.5T, and these errors were not of an acceptable level. The x coordinate error was the smallest and the z coordinate error was the greatest regardless of the MRI sequence. The T2 sequence was the most accurate sequence.
Gamma Knife Center, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea. ; Department of Neurosurgery, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea.
Hae Yu
HY
Kim
Gamma Knife Center, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea. ; Department of Neurosurgery, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea.
Sun-Il
SI
Lee
Gamma Knife Center, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea.
Seong Jin
SJ
Jin
Department of Neurosurgery, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea.
Sung-Chul
SC
Jin
Department of Neurosurgery, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea.
Jung Soo
JS
Kim
Department of Neurosurgery, Haeundae Paik Hospital, Inje University College of Medicine, Busan, Korea.
Kyoung Dong
KD
Jeon
Functional neurosurgery; MRI; Stereotactic radiosurgery