PURPOSE: To evaluate the utility of a recently reported simple measure
of brain atrophy on MR imaging, the interuncal distance (IUD). METHOD
S: Measurements of the IUD were made over a 12-month interval in 10 pa
tients with probable early Alzheimer disease and in a comparison group
of age-matched healthy control subjects. The measurements were made i
n both the transaxial and coronal planes. RESULTS: Significant group d
ifferences for the coronal measurement of IUD were found in both the a
bsolute value of the measurement and the IUD corrected for head size.
There was overlap in IUD between the disease and the control groups. T
hese differences were not found for the transaxial IUD. Significant po
sitive correlations of the IUD with Mini-Mental State Examination scor
e and Clinical Dementia Rating Scale stage were observed. Over the age
range tested, age was not significantly correlated with IUD in the sa
mple. CONCLUSIONS: The interuncal distance IUD is not a useful screeni
ng measurement for Alzheimer disease.