Introduction Impaired cerebral vascular reserve (CVR) in patients with symptomatic internal carotid artery (ICA) occlusion is regarded as a possible indication for performing extra-/intracranial (EC/IC) bypass surgery. As perfusion MR imaging (MRI) can demonstrate cerebral haemodynamics at capillary level, our hypothesis was that perfusion MRI could be used in these patients for the evaluation ...

BACKGROUND AND PURPOSE The clinical and hemodynamic impacts of basilar artery (BA) vasospasm (VS) after aneurysmal subarachnoid hemorrhage (SAH) are ill-defined. The purpose of the present study was to evaluate the relationship between BA-VS and regional cerebral blood flow (rCBF) with posterior circulation after aneurysmal SAH. METHODS Daily transcranial Doppler (TCD) measurements of posteri...

We have determined cerebral blood flow (CBF) and the single-pass cerebral extraction (E) of several putative agents for external imaging of CBF. Simultaneous measurements of blood flow and extraction were performed in 106 rats. For all agents, comparison of linear and exponential regressions of E on CBF indicates that this relationship can be described as linear over the range of flows studied....

OBJECTIVES Three accumulative tracers, iodine-123-labeled N-isopropyl-p-iodoamphetamine (I-123-IMP), technetium-99m-labeled hexamethylpropyleneamineoxime (Tc-99m-HMPAO), and technetium-99m-labeled ethyl cysteinate dimer (Tc-99m-ECD) are widely used to measure cerebral blood flow (CBF) in single-photon emission computed tomography (SPECT). In the present study, normal regional distribution of CB...

UNLABELLED The aim of this study was to elucidate the clinical usefulness of scatter correction with an artificial neural network (ANN) in 99mTc and 123I dual-isotope SPECT. METHODS Two algorithms for ANN scatter correction were tested: ANN-10 and ANN-3 employing 10 and 3 energy windows for data acquisition, respectively. Three patients underwent myocardial or brain SPECT with one of the foll...

OBJECTIVES Patients with idiopathic REM sleep behavior disorder (IRBD) are at risk for developing Parkinson disease (PD) and dementia with Lewy bodies (DLB). We aimed to identify functional brain imaging patterns predicting the emergence of PD and DLB in patients with IRBD, using SPECT with (99m)Tc-ethylene cysteinate dimer (ECD). METHODS Twenty patients with IRBD were scanned at baseline dur...

UNLABELLED In vitro transendothelial permeability was compared to in vivo rat single-pass cerebral extractions to evaluate which method would best estimate the blood-brain barrier (BBB) permeability of several SPECT imaging agents. METHOD Six 99mTc complexes and seven non-Tc complexes were tested in vitro using monolayers of primary bovine brain microvessel endothelial cells and in vivo using...

UNLABELLED Intra- or intersubject registration of anatomically poorly defined SPECT data, such as in neuroreceptor imaging, is important for longitudinal or group analysis. However, accurate registration is difficult with only emission CT (ECT) data. We investigated fully automated registration using transmission CT (TCT) data as an intermediary image set. METHODS The accuracy of TCT registra...