T. Sandor et al., COMPARISON OF THE PRECISION OF 2 STANDARDIZED COORDINATE SYSTEMS FOR THE QUANTITATION OF BRAIN ANATOMY - PRELIMINARY-RESULTS, Neuroradiology, 36(7), 1994, pp. 499-503
Citations number
19
Categorie Soggetti
Radiology,Nuclear Medicine & Medical Imaging",Neurosciences
We assessed reproducible definition of two standardized co-ordinate sy
stems for intersubject analysis of brain images. The baselines in the
two co-ordinate systems were a modification of the canthomeatal (mCM)
line and the anterior-posterior commissural (AC-PC) line. Axial spin-e
cho MR images of four subjects at 1.5T were used. Operator error was c
omputed from the replicate analyses of two operators. The mCM line was
determined by the lens of the eye and the inter nai auditory canal, a
nd the AC-PC line was determined by the intersection of the AC and PC
with the interhemispheric fissure. Reproducibility of the mCM markers
(SD = 0.59 mm) did not differ significantly from that of the AC-PC lin
e (SD = 0.68 mm). The measurement error of the angle of the baseline (
delta alpha), however, was more than 7 times as large for the AC-PC li
ne as for the mCM line. An additional error affecting the rostrocaudal
rotation of the co-ordinate systems, attributable to the distance bet
ween the anatomic markers, was 2.1 and 3.6 degrees (3 mm and 5 mm slic
e thickness) for the mCM co-ordinate system and 8.2 and 11.0 degrees (
3 mm and 5 mm slice thickness) for the AC-PC system. The AC-PC line ba
sed co-ordinate system is therefore, less reproducible than the mCM li
ne based system. This could be improved if a combination of axial and
sagittal images were used for the definition of the AC-PC line.