UNLABELLED We developed and evaluated a simplified double-injection method for iodine-123 N-isopropyl-p-iodoamphetamine (IMP) to quantify regional cerebral blood flow (rCBF) twice in a single SPECT session. The method enabled rapid calculations of rCBF with five 10-minute SPECT scans, a fixed distribution volume (Vd), and one-point arterial blood sampling to calibrate a standard input function ...

BACKGROUND AND PURPOSE To characterize the spatial pattern of cerebral ischemic vulnerability to hypoperfusion in stroke patients. METHODS We included 90 patients who underwent admission CT perfusion and MRI within 12 hours of ischemic stroke onset. Infarcted brain lesions ("core") were segmented from admission diffusion-weighted imaging and, along with the CT perfusion parameter maps, coregi...

BACKGROUND AND PURPOSE Cerebral microangiopathy, indicated on MRI by lacunar infarctions (LI) and deep white matter lesions (DWML), is said to lead to vascular dementia. METHODS Fifty-seven patients with proven cerebral microangiopathy were assessed for changes in regional cerebral blood flow (rCBF) and glucose metabolism (rMRGlu) and compared with 19 age-matched controls. The findings were c...

PURPOSE To evaluate early perfusion changes in normal tissue following stereotactic radiosurgery (SRS). METHODS Nineteen patients harboring twenty-two brain metastases treated with SRS were imaged with dynamic susceptibility magnetic resonance imaging (DSC MRI) at baseline, 1 week and 1 month post SRS. Relative cerebral blood volume and flow (rCBV and rCBF) ratios were evaluated outside of tu...

introduction: studies with single photon emission computed tomography (spect) have revealed inconsistent changes of regional cerebral blood flow (rcbf) in schizophrenia. some studies investigated the rcbf and its relationship with psychopathology, positive and negative symptoms in treated patients. however, there is a little information about the pattern of rcbf in recently untreated or never t...

Individuals with major depressive disorder (MDD) display abnormal neurophysiological responses to psychological stress but little is known about their neurophysiological responses to physiological stressors. Using [(15)O-H(2)O] positron emission tomography we assessed whether the regional cerebral blood flow (rCBF) response to arterial cannulation differed between patients with MDD and healthy ...

99mTc-HM-PAO single photon emission computed tomography (SPECT) was used to image 30 patients referred for the assessment of dementia. SPECT images revealed various patterns of regional cerebral perfusion (rCBF) in the subgroups of patients with the clinical diagnoses of Alzheimer's disease (AD, n = 14), Pick's disease (n = 1), and multi-infarct dementia (n = 7). In three patients, SPECT clarif...

Transcranial direct current stimulation (tDCS) can up- and down-regulate cortical excitability depending on current direction, however our abilities to measure brain-tissue effects of the stimulation and its after-effects have been limited so far. We used regional cerebral blood flow (rCBF), a surrogate measure of brain activity, to examine regional brain-tissue and brain-network effects during...

The effects of caloric vestibular stimulation on regional cerebral blood flow (rCBF) of the parietal and temporal cortex were examined in 10 healthy volunteers. The consecutive 99mTe-hexamethyl-propyleneamine oxime (99mTc-HMPAO) single-photon emission computed tomography (SPECT) method with region of interest analysis was used. Changes in rCBF induced by caloric stimulation with cold air (25 de...

Positron emission tomography measurements of regional cerebral blood flow (rCBF) were performed in normal volunteers during a graded auditory-verbal memory task. Subjects were required to remember and then immediately, and freely, recall a series of auditorily presented word lists varying from two to 13 words in length. Significant regional correlations between rCBF and memory load (word list l...