Xenon contrast-enhanced CT imaging of supratentorial hypoperfusion in patients with brain stem infarction

BACKGROUND AND PURPOSE: The characteristics of hypoperfusion in the suprate ntorial region of patients with brain stem infarction are unclear. We inves tigated the relationships between the presence of hypoperfusion and the loc ation, number, and size of the infarcts with xenon contrast-enhanced CT. METHODS: One hundred five patients with brain stem infarction detected by M R imaging underwent xenon contrast-enhanced CT to measure the regional CBF (rCBF) in the frontal, temporal, parietal, and occipital regions and in the putamen and thalamus, A decrease of more than 10% from the mean rCBF value for normal individuals was considered to indicate hypoperfusion. RESULTS: Thirty-six patients had supratentorial hypoperfusion. The mean rCB F values (measured in mL/100 g/minute) were as follows: frontal region, 36. 2 +/- 5.1 (-14.8%, n = 28); parietal region, 42.3 +/- 4.7 (-19.1%, n = 29); temporal region, 41.5 +/- 2.8 (-12.6%, n = 12); and thalamus, 50.1 +/- 3.2 (-19.6%, n = 7), Supratentorial hypoperfusion was associated with pontine infarction in 33 patients (upper pens in 15, middle pens in 18, and lower p ens in seven), midbrain infarction in two, and medulla infarction in one. T wenty-three patients had infarcts that were larger than 5 mm, and 11 had in farcts that were 2 to 5 mm, Only two had infarcts that were smaller than 2 mm, Seven patients each had one infarct, 13 each had two, and 16 each had t hree. CONCLUSION: Supratentorial hypoperfusion was associated with larger infarct s, with more infarcts, and with pontine infarction.