Perfusion computed tomographic measurements of cerebral blood flow variables in live Holstein calves

OBJECTIVE To measure cerebral blood flow (CBF) and cerebral blood volume (CBV) by means of perfusion CT in clinically normal Holstein calves. ANIMALS 9 Holstein calves. PROCEDURES Each of the 9 calves (mean age, 20.2 days) was anesthetized and received an injection of iodinated contrast medium into the right jugular vein at a rate of 4.0 mL/s. Dynamic CT scanning of the head at a level that included the mandibular condyle was initiated at the time of the contrast medium injection and continued for 100 seconds. A deconvolution method was used as an analytic algorithm. RESULTS Among the 9 calves, the mean ± SD CBF in the cerebral cortex, white matter, and thalamus was 44.3 ± 10.3 mL/100 g/min, 36.1 ± 7.5 mL/100 g/min, and 40.3 ± 7.5 mL/100 g/min, respectively. The CBF in white matter was significantly lower than that in the cerebral cortex or thalamus. The mean CBV in the cerebral cortex, white matter, and thalamus was 6.8 ± 1.0 mL/100 g, 5.2 ± 1.0 mL/100 g, and 5.7 ± 0.7 mL/100 g, respectively. The CBV in the cerebral cortex was significantly higher than that in the white matter or thalamus. CONCLUSIONS AND CLINICAL RELEVANCE Measurement of CBF and CBV in clinically normal calves by means of perfusion CT was feasible. The data obtained may be useful as baseline values for use in future research or for comparison with findings from calves with CNS diseases. Investigations to determine the lower limit of blood flow at which brain function can still be restored are warranted.