BACKGROUND AND PURPOSE Visualization of the peripheral arteries on single-slab 3D time-of-flight (TOF) MR angiography (MRA) can reflect blood flow velocity. The velocity in the middle cerebral artery (MCA) may correlate with cerebrovascular reactivity (CVR) to acetazolamide, which can be used to assess hemodynamic impairment. The goal of this study was to compare the signal intensity of the MCA...

OBJECTIVE To determine the reliability of radionuclide cerebral blood perfusion imaging in confirming brain death irrespective of continued heartbeat. SUBJECTS AND METHODS Twenty-eight patients (19 male and 9 female, aged 17-63 years) with severe brain injury and fully supported until the final cardiac asystole were included in the study. Two sets of clinical tests aimed at ascertaining brain...

BACKGROUND Several biomarkers have been proposed for detecting Alzheimer's disease (AD) in its earliest stages, that is, in the predementia stage. In an attempt to find noninvasive biomarkers, researchers have investigated the feasibility of neuroimaging tools, such as MRI, SPECT as well as neurophysiological measurements using EEG. Moreover, the increase of EEG alpha3/alpha2 frequency power ra...

UNLABELLED In selecting patients for epilepsy surgery, it is important to distinguish mesial temporal seizures from seizures originating in the posterolateral cortex. We studied ictal cerebral perfusion in five patients with complex partial seizures with clear posterior EEG ictal onsets and clinical seizures semiology suggesting seizure origin in the posterolateral cortex. METHODS Ictal SPECT...

OBJECTIVE The response of cerebral blood flow (CBF) to acetazolamide (ACZ) challenge is frequently determined in clinical settings to evaluate cerebrovascular reserve (CVR). A reduced CVR can indicate patients with occlusive cerebrovascular disease and compromised hemodynamics who may be at increased risk of cerebral ischemia. However, how precisely ACZ reflects cerebral hemodynamic impairment ...

BACKGROUND AND PURPOSE Reliability of CT perfusion (CTP) algorithms has not been fully validated. We investigated whether the cerebral blood flow (CBF) values obtained by using a dynamic CTP technique with a tracer delay-insensitive deconvolution algorithm are more accurate than those obtained by using CTP with delay-sensitive algorithms in unilateral cerebrovascular steno-occlusive disease, wh...

Thallium-201 diethyldithiocarbamate ([201TI]DDC) was studied in humans as an agent for cerebral blood flow imaging. Brain uptake proved to be complete 90 sec after injection with no appreciable washout or redistribution for hours. Intracarotid injection suggested an almost 100% extraction during the first passage. Whole-body distribution studies demonstrated a brain uptake of 4.3% of the dose c...

BACKGROUND Partial volume effects in atrophied areas should be taken into account when interpreting brain perfusion single photon emission computed tomography (SPECT) images of neurodegenerative diseases. To evaluate both perfusion and atrophy using brain SPECT alone, we developed a new technique applying tensor-based morphometry (TBM) to SPECT. METHODS After linear spatial normalization of b...

This study evaluated the relationship between the location of the most severe coronary artery stenosis and the subsequent acute myocardial infarction (AMI). Methods: Of 1590 patients who were admitted with a diagnosis of AMI, we identified 44 patients who had undergone previous myocardial perfusion SPECT. Thirty-one of these patients also had previous coronary angiography. The relationshi...

Cerebral perfusion single photon emission computed tomography (SPECT) has been used to confirm the localization of the epileptic focus and the evaluation of seizure. Recently, diffusion-weighted MR imaging (DWI) has been recognized for evaluation of seizure activity. We describe a case of transient seizure activity demonstrated by Tc-99m HMPAO SPECT and DWI. This patient was a 61-year-old woman...