Feasibility study of adenosine stress brain blood flow perfusion imaging

Objective To explore the feasibility of adenosine in stress brain blood flow perfusion imaging. Methods Between April 2008 and May 2009, thirty-two patients with non-organic mental disorders registered to our department underwent rest and adenosine stress brain blood flow perfusion imaging using two days protocol. Three reference slices in the reconstructive transverse image were selected to draw regions of interest (ROI) in bilateral symmetrical cerebellums, frontal lobes, temporal lobes, parietal lobes and occipital lobes in the normal cerebrum lobes.The size of ROI was 32.8 pixels.The radioactive counts of each ROI were calculated. Using the mean radioactive counts of bilateral cerebellum ROI as a reference,the ratio of radioactive counts of each cerebrum ROI over mean radioactive counts of bilateral cerebellum ROI was calculated. The ratio of radioactive counts of each cerebrum ROI underwent adenosine stress or rest in the same group was compared. The response to adenosine stress of cerebrums ROI in the abnormal cerebrum lobes were analyzed, which was classified by the change of the cerebral blood flow perfusion. Results All the patients underwent adenosine stress brain blood flow imaging and none withdrew due to severe adverse effects. Mild systemic adverse reactions did occur in some patients but disappeared quickly after adenosine injection. Among the 174 normal cerebrum ROI acquired, the ratio of radioactive counts of cerebrum ROI underwent rest or adenosine stress showed statistical significance in the frontal lobe (0.901±0.100 vs 0.956±0.149, P＜0.05), temporal lobe (0.923±0.070 vs 0.981±0.090, P＜0.05) and parietal lobe (0.840±0.126 vs 0.887±0.091, P＜0.05), but not in the occipital lobe (1.102±0.146 vs 1.010±0.124, P＞0.05). Of the 49 abnormal cerebrum ROI, ten showed normal regional cerebral blood flow at rest which was lowered during adenosine stress, nine had low regional cerebral blood flow at rest which was even worse during adenosine stress, twenty-seven had low regional cerebral blood flow at rest which appeared improved during adenosine stress, and three showed low regional cerebral blood flow that was comparable at rest and during adenosine stress. Conclusion Adenosine may be used for stress brain blood flow perfusion imaging with low incidence of adverse effects. Key words: Radionuclide imaging; Tomography, emission-computed, single-photon; Adenosine; Regional blood flow; Brain