A comparative study of perfusion CT and 99m Tc-HMPAO SPECT measurement to assess cerebrovascular reserve capacity in patients with internal carotid artery occlusion.
OBJECTIVE
Patients with internal carotid artery (ICA) occlusion can demonstrate impaired cerebral vascular reserve (CVR). The detection of CVR using single photon emission CT (SPECT) is nowadays widely accepted as a predictor in the diagnostic pathway in patients considered for cerebral revascularization. Recently perfusion CT (PCT) gained widely acceptance in stroke imaging. The present study was aimed at comparing the results of perfusion CT (PCT) and 99m Tc-HMPAO SPECT with acetazolamide challenge in patients with ICA occlusion.


METHODS
13 patients were included in the prospective evaluation. Both PCT and 99m Tc-HMPAO SPECT were performed before and after the administration of acetazolamide. In detail, regional cerebral blood flow (rCBF), regional cerebral blood volume (rCBV), adapted time to peak (Tmax) and mean transit times (MTT) were compared with SPECT data. -


RESULTS
99m Tc-HMPAO SPECT demonstrated an impairment of CVR in six patients. A preserved CVR was present in seven patients. All patients with impaired CVR proven by SPECT had a delayed MTT (mean +2.98 s) and a delayed Tmax (mean + 5.9 s), (both p <0.005 compared with the non occluded side). 66% of patients with impaired CVR in SPECT showed a complete correlation of Tmax measurements in PCT with a high positive predictive value (PPV: 88.8%). -


CONCLUSIONS
The prospective study demonstrated a highly significant correlation of perfusion parameters as detected by 99m Tc-HMPAO SPECT and the Tmax as detected by PCT in patients with ICA occlusion. Therefore this easy-to-perform technique seems to be an adequate method for the evaluation of cerebral perfusion in patients with ICA occlusion.
Department of Neurosurgery, Heinrich-Heine-University, Düsseldorf, Germany. Sven.Eicker@med.uni-duesseldorf.de
Sven O
SO
Eicker
B
B
Turowski
H-J
HJ
Heiroth
H-J
HJ
Steiger
D
D
Hänggi
D000293:Adolescent; D000328:Adult; D000368:Aged; D001157:Arterial Occlusive Diseases / Q000000981:diagnostic imaging / Q000503:physiopathology*; D001810:Blood Volume; D001931:Brain Mapping; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010477:Perfusion / Q000379:methods*; D012039:Regional Blood Flow; D019690:Technetium Tc 99m Exametazime; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed; D055815:Young Adult
D019690:Technetium Tc 99m Exametazime