Regional Cerebral Blood Perfusion Research Articles

Regional cerebral blood perfusion changes in chronic stroke survivors as potential brain correlates of the functional outcome following gamified home-based rehabilitation (IntelliRehab)—a pilot study

BackgroundHospital-based stroke rehabilitation for stroke survivors in developing countries may be limited by staffing ratios and length of stay that could hamper recovery potential. Thus, a home-based, gamified rehabilitation system (i.e., IntelliRehab) was tested for its ability to increase cerebral blood flow (CBF), and the secondary impact of changes on the upper limb motor function and functional outcomes.ObjectiveTo explore the effect of IntelliRehab on CBF in chronic stroke patients and its correlation with the upper limb motor function.MethodsTwo-dimensional pulsed Arterial Spin Labelling (2D-pASL) was used to obtain CBF images of stable, chronic stroke subjects (n = 8) over 3-months intervention period. CBF alterations were mapped, and the detected differences were marked as regions of interest. Motor functions represented by Fugl-Meyer Upper Extremity Assessment (FMA) and Stroke Impact Scale (SIS) were used to assess the primary and secondary outcomes, respectively.ResultsRegional CBF were significantly increased in right inferior temporal gyrus and left superior temporal white matter after 1-month (p = 0.044) and 3-months (p = 0.01) of rehabilitation, respectively. However, regional CBF in left middle fronto-orbital gyrus significantly declined after 1-month of rehabilitation (p = 0.012). Moreover, SIS-Q7 and FMA scores significantly increased after 1-month and 3-months of rehabilitation. There were no significant correlations, however, between CBF changes and upper limb motor function.ConclusionsParticipants demonstrated improved motor functions, supporting the benefit of using IntelliRehab as a tool for home-based rehabilitation. However, within-participant improvements may have limited potential that suggests the need for a timely administration of IntelliRehab to get the maximum capacity of improvement.

Altered regional cerebral blood perfusion in mild cognitive impairment patients with dizziness

AbstractBackgroundDizziness is a common symptom presenting with lightheadedness, vertigo, or disequilibrium. Previous studies reported that the prevalence of feeling dizziness is increased with age and chronic dizziness including vestibular vertigo and orthostatic hypotension may be associated with cognitive impairment and psychiatric illness. The aim of this study was to examine regional cerebral blood flow (rCBF) in mild cognitive impairment patients with or without dizziness using single‐photon emission computed tomography (SPECT).MethodA total of 50 patients with MCI were recruited. All participants underwent brain SPECT and completed the dizziness handicap inventory (DHI, 0‐100 points, higher scores indicating more severe handicap). Participants divided into a dizziness group (DHI ≥ 1, n = 18) and a non‐dizziness group (DHI = 0, n = 32).ResultThere were no significant differences between the two groups in terms of demographics. Patients with dizziness had a mean DHI score of 16.3 ± 14.6. SPECT analysis revealed decreased rCBF in the left superior temporal gyrus, left lateral orbital gyrus, and right middle frontal gyrus in patients with dizziness compared with those without dizziness. There were no significant clusters of increased rCBF in patients with dizziness compared with those without dizziness.ConclusionMCI patients with dizziness revealed frontal and left temporal hypoperfusion compared with the patients without dizziness. This finding is similar to those of the patients with persistent postural perceptual dizziness, the representative functional dizziness. Our result suggested that the altered rCBF in the left temporal and frontal cortices might be reflecting the negative impact of dizziness in patients with MCI.

Differentiating Mild Cognitive Impairment, Alzheimer's Disease, and Dementia With Lewy Bodies Using Cingulate Island Sign on Perfusion IMP-SPECT.

The cingulate island sign (CIS) on fludeoxyglucose (FDG)-positron emission tomography (PET) is a supporting biomarker of dementia with Lewy bodies (DLB). Its diagnostic accuracy has only been investigated in FDG-PET, however. The present prospective study compared the CIS on I-iodoamphetamine-single photon emission computed tomography (SPECT) among patients with mild cognitive impairment (MCI), AD, or DLB. Fifty-eight patients with MCI, 42 with probable AD, and 58 with probable DLB were enrolled. The “CIScore” used to evaluate the CIS was defined as the ratio of volume of interest (VOI)-1 (indicating posterior cingulate gyrus [PCG]) to VOI-2 (area of significantly reduced regional cerebral blood perfusion [rCBF] in DLB patients compared with in healthy controls). It was calculated using eZIS software. The CIScore for MCI, DLB, and AD was 0.22, 0.23, and 0.28, respectively. The CIScore in the AD group was significantly higher than that in the DLB or MCI groups (AD vs. DLB: p < 0.001, AD vs. MCI: p < 0.005). This suggests that the CIScore can discriminate DLB from AD, if the decrease in rCBF in the PCG is similar between them. We believe that it is difficult to identify MCI based on the CIScore, as the decrease in rCBF in the PCG is not severe. The diagnostic accuracy of the CIScore may be low as it often shows an increase in elderly DLB patients, in whom the pathologically common form is most prevalent (1). Further study should include assessment of multiple components such as symptom classification and age.

Altered Regional Cerebral Blood Perfusion in Mild Cognitive Impairment Patients with Dizziness.

Dizziness is a common symptom among the general population, especially in the elderly. Previous studies have reported that dizziness may be associated with various cognitive functions including memory impairment. However, few studies have investigated the neural correlates of dizziness in patients with cognitive impairment. The aim of this study was to examine regional cerebral blood flow (rCBF) in mild cognitive impairment (MCI) patients with or without dizziness using single photon emission computed tomography (SPECT). A total of 50 patients with MCI were recruited. All participants underwent technetium-99m ethyl cysteinate dimer brain SPECT and a neuropsychological battery and completed the Dizziness Handicap Inventory (DHI). Participants were divided into a dizziness group (DHI ≥ 1, n = 18) and a non-dizziness group (DHI = 0, n = 32). Voxel wise differences in rCBF between the groups were estimated. SPECT analysis revealed decreased rCBF in the left superior temporal gyrus, left lateral orbital gyrus, and right middle frontal gyrus in the dizziness group compared with the non-dizziness group (p < 0.005). No significant clusters of increased rCBF were observed in the dizziness group compared with the non-dizziness group. Results of the neuropsychological tests showed a significant difference in Controlled Oral Word Association Test performance between MCI patients with and without dizziness. In conclusion, MCI patients with dizziness showed multifocal frontal and left temporal hypoperfusion compared with patients without dizziness. Our results suggest that hypoperfusion in the frontal and temporal cortices might be reflecting the negative impact of dizziness in MCI patients.

Haemodynamic analysis of adult patients with moyamoya disease: CT perfusion and DSA gradings

ObjectMoyamoya disease (MMD) is a common and chronic progressive stenotic-occlusive cerebrovascular disease in Eastern Asia. To evaluate the hemispheric haemodynamic status of adult patients with MMD, we explored the potential...

Retrograde blood flow in the internal jugular veins of humans with hypertension may have implications for cerebral arterial blood flow.

To use multi-parametric magnetic resonance imaging (MRI) to test the hypothesis that hypertensives would have higher retrograde venous blood flow (RVBF) in the internal jugular veins (IJV) vs. normotensives, and that this would inversely correlate with arterial inflow and gray matter, white matter, and cerebrospinal fluid volumes. Following local institutional review board approval and written consent, a prospective observational 3-T MRI study of 42 hypertensive patients (53 ± 2years, BMI 28.2 ± 0.6kg/m2, ambulatory daytime systolic BP 148 ± 2mmHg, ambulatory daytime diastolic BP 101 ± 2mmHg) and 35 normotensive patients (48 ± 2years, BMI 25.2 ± 0.8kg/m2, ambulatory daytime systolic BP 119 ± 3mmHg, ambulatory daytime diastolic BP 90 ± 2mmHg) was performed. Phase contrast imaging calculated percentage retrograde venous blood flow (%RVBF), brain segmentation estimated regional brain volumes from 3D T1-weighted images, and pseudo-continuous arterial spin labeling measured regional cerebral blood perfusion. Statistical analysis included two-sample equal variance Student's T tests, two-way analysis of variance with Tukey's post hoc correction, and permutation-based two-group general linear modeling (p < 0.05). In the left IJV, %RVBF was higher in hypertensives (6.1 ± 1.5%) vs. normotensives (1.1 ± 0.3%, p = 0.003). In hypertensives, there was an inverse relationship of %RVBF (permutation-based general linear modeling) to cerebral blood flow in several brain regions, including the left occipital pole and the cerebellar vermis (p < 0.01). Percentage retrograde flow in the left IJV correlated inversely with the total matter volume (gray plus white matter volume) in hypertensives (r = - 0.49, p = 0.004). RVBF in the left IJV is greater in hypertensives vs. normotensives and is linked to regional hypoperfusion and brain total matter volume. • Hypertensive humans have higher retrograde cerebral venous blood flow, associated with regional brain hypoperfusion and lower tissue volume, compared with controls. • Cerebral retrograde venous blood flow may add further stress to already hypoperfused tissue in hypertensive patients. • The amount of retrograde venous blood flow in hypertensive patients may predict which patients might be at higher risk of developing cerebral pathologies.

Cognitive Performance Profile in Pediatric Moyamoya Disease Patients and Its Relationship With Regional Cerebral Blood Perfusion.

Object: Moyamoya disease affects the cognitive function of pediatric patients, and compromised cerebral blood flow might be the potential cause. We aimed to explore the specific correlation between cognitive impairment and regional perfusion status in pediatric moyamoya disease patients.Methods: We prospectively enrolled consecutive pediatric moyamoya disease patients admitted to Beijing Tiantan Hospital from July 2017 to March 2019. Arterial spin-labeling magnetic resonance and the Wechsler Intelligence Scale for Children (the 4th edition) were performed on all participants. The cognitive performance of patients was analyzed, and its correlation to cerebral perfusion status was also investigated in the region of interest-based analysis.Results: A total of 21 patients met the inclusion criteria (mean aged 11.14 ± 2.82, male: female = 11:10). Six patients (28.6%) showed no cognitive deficits in any index score, while 15 (71.4%) showed cognitive deficits with differing severity. Nine (42.9%) patients showed overall cognitive impairment, and all cognitive index scores except for Verbal Comprehension Index were significantly lower than the mean scores of normative data with corresponding age. Perceptual Reasoning Index (p = 0.019) were statistically lower in patients with radiologically confirmed cerebral infarction. Suzuki stage of the left hemisphere negatively correlated to Full-scale Intelligence Quotient (r = −0.452, p = 0.039). Region of Interest analysis showed that cerebral blood flow of the left temporal lobe independently associated with the Processing Speed Index (β = 0.535, p = 0.041).Conclusion: Pediatric moyamoya disease patients exhibited different levels of cognitive impairment. Cerebral infarction is related to poorer perceptual reasoning ability. Cerebral blood flow in the left temporal lobe positively correlates with processing speed.

Different effects of prenatal MAM vs. perinatal THC exposure on regional cerebral blood perfusion detected by Arterial Spin Labelling MRI in rats

Clinical studies consistently report structural impairments (i.e.: ventricular enlargement, decreased volume of anterior cingulate cortex or hippocampus) and functional abnormalities including changes in regional cerebral blood flow in individuals suffering from schizophrenia, which can be evaluated by magnetic resonance imaging (MRI) techniques. The aim of this study was to assess cerebral blood perfusion in several schizophrenia-related brain regions using Arterial Spin Labelling MRI (ASL MRI, 9.4 T Bruker BioSpec 94/30USR scanner) in rats. In this study, prenatal exposure to methylazoxymethanol acetate (MAM, 22 mg/kg) at gestational day (GD) 17 and the perinatal treatment with Δ-9-tetrahydrocannabinol (THC, 5 mg/kg) from GD15 to postnatal day 9 elicited behavioral deficits consistent with schizophrenia-like phenotype, which is in agreement with the neurodevelopmental hypothesis of schizophrenia. In MAM exposed rats a significant enlargement of lateral ventricles and perfusion changes (i.e.: increased blood perfusion in the circle of Willis and sensorimotor cortex and decreased perfusion in hippocampus) were detected. On the other hand, the THC perinatally exposed rats did not show differences in the cerebral blood perfusion in any region of interest. These results suggest that although both pre/perinatal insults showed some of the schizophrenia-like deficits, these are not strictly related to distinct hemodynamic features.

Theta and alpha EEG frequency interplay in subjects with mild cognitive impairment: evidence from EEG, MRI, and SPECT brain modifications.

Background: Temporo-parietal and medial temporal cortex atrophy are associated with mild cognitive impairment (MCI) due to Alzheimer disease (AD) as well as the reduction of regional cerebral blood perfusion in hippocampus. Moreover, the increase of EEG alpha3/alpha2 power ratio has been associated with MCI due to AD and with an increase in theta frequency power in a group of subjects with impaired cerebral perfusion in hippocampus.Methods: Seventy four adult subjects with MCI underwent clinical and neuropsychological evaluation, electroencephalogram (EEG) recording and high resolution 3D magnetic resonance imaging (MRI). Among the patients, a subset of 27 subjects underwent also perfusion single-photon emission computed tomography and hippocampal atrophy evaluation. Alpha3/alpha2 power ratio as well as cortical thickness was computed for each subject. Three MCI groups were detected according to increasing tertile values of alpha3/alpha2 power ratio and difference of cortical thickness among the groups estimated.Results: Higher alpha3/alpha2 power ratio group had wider cortical thinning than other groups, mapped to the Supramarginal and Precuneus bilaterally. Subjects with higher alpha3/alpha2 frequency power ratio showed a constant trend to a lower perfusion than lower alpha3/alpha2 group. Moreover, this group correlates with both a bigger hippocampal atrophy and an increase of theta frequency power.Conclusion: Higher EEG alpha3/alpha2 power ratio was associated with temporo-parietal cortical thinning, hippocampal atrophy and reduction of regional cerebral perfusion in medial temporal cortex. In this group an increase of theta frequency power was detected inMCI subjects. The combination of higher EEG alpha3/alpha2 power ratio, cortical thickness measure and regional cerebral perfusion reveals a complex interplay between EEG cerebral rhythms, structural and functional brain modifications.

Atlas-based and DTI-guided quantification of human brain cerebral blood flow: Feasibility, quality assurance, spatial heterogeneity and age effects

Accurate and noninvasive quantification of regional cerebral blood perfusion (CBF) of the human brain tissue would advance the study of the complex interplay between human brain structure and function, in both health and disease. Despite the plethora of works on CBF in gray matter, a detailed quantitative white matter perfusion atlas has not been presented on healthy adults using the International Consortium for Brain Mapping atlases. In this study, we present a host of assurance measures such as temporal stability, spatial heterogeneity and age effects of regional and global CBF in selected deep, cortical gray matter and white matter tracts identified and quantified using diffusion tensor imaging (DTI). We utilized whole brain high-resolution DTI combined with arterial spin labeling to quantify regional CBF on 15 healthy adults aged 23.2–57.1years. We present total brain and regional CBF, corresponding volume, mean diffusivity and fractional anisotropy spatial heterogeneity, and dependence on age as additional quality assurance measures to compare with published trends using both MRI and nuclear medicine methods. Total CBF showed a steady decrease with age in gray matter (r=−0.58; P=.03), whereas total CBF of white matter did not significantly change with age (r=0.11; P=.7). This quantitative report offers a preliminary baseline of CBF, volume and DTI measurements for the design of future multicenter and clinical studies utilizing noninvasive perfusion and DT-MRI.

The response to rapid infusion of fentanyl in the human brain measured using pulsed arterial spin labelling

We evaluated the sensitivity of pulsed Arterial Spin Labelling (pASL) for the detection of changes in regional cerebral blood perfusion (CBP) during and after intra-venous (i.v.) infusion of an opioid agonist (fentanyl) and an opioid antagonist (naloxone). Twenty-three subjects were scanned four times, receiving i.v. infusion of fentanyl, naloxone, placebo and a second fentanyl administration, in four separate scanning sessions in randomised order. End-tidal CO(2), respiration rate and heart rate were recorded continuously throughout each scan. pASL time series were collected using single shot EPI for 15min (including 5min of baseline prior to infusion). Significant increases in CBP were detected during and after administration of fentanyl, (when compared to placebo and naloxone), in most areas of high concentration of mu-opioid receptors (thalamus, lingual gyrus, para-hippocampal gyrus, and insula); near-significant increases were also observed in the insula. No increases in perfusion were observed during or after naloxone infusion. No correlation was found between regional rCBF changes and end-tidal CO(2), respiration rate or heart rate. Good reliability was found between the first and second fentanyl sessions but the regions of high reliability did not overlap completely with those of highest perfusion change. pASL is a suitable method for examining rapid, dynamic effects of opioid administration on brain physiology.

Normal reference ranges of fetal regional cerebral blood perfusion as measured by fractional moving blood volume

To establish normal reference intervals of fetal regional brain blood perfusion using power Doppler ultrasound as measured by fractional moving blood volume (FMBV). A cohort of consecutive singleton normally grown fetuses was selected including at least 12 fetuses for each completed week of gestation between 24 and 41 weeks. Cerebral blood perfusion was estimated using conventional power Doppler ultrasound in the following brain regions: frontal area, basal ganglia and posterior brain. Five consecutive good-quality images were recorded in each area and the region of interest was delineated offline. The FMBV was quantified as the average of all images and expressed as a percentage. Normal reference ranges were constructed by means of the LMS (lambda-mu-sigma) method. A total of 230 fetuses were included. The median gestational age at evaluation and at delivery was 33.1 (range, 24.0-41.0) and 39.7 (range, 34.9-42.3) weeks, respectively. From 24 to 41 weeks' gestation, the mean FMBV increased from 13.21 to 14.97% in the frontal area, 11.17 to 14.86% in the basal ganglia and 4.83 to 6.70% in the posterior brain. Normal data of fetal cerebral blood perfusion in the frontal area, basal ganglia and posterior brain are provided, which could be of clinical use in the assessment of fetal brain circulation.

Regional reproducibility of pulsed arterial spin labeling perfusion imaging at 3T

Arterial spin labeling (ASL) is a promising non-invasive magnetic resonance imaging (MRI) technique for measuring regional cerebral blood flow (rCBF) or perfusion in vivo. To evaluate the feasibility of ASL as a biomarker for clinical trials, it is important to examine test-retest reproducibility. We investigated both inter- and intra-session reproducibility of perfusion MRI using a pulsed ASL (PASL) sequence PICORE Q2TIPS with an echo-planar imaging (EPI) readout. Structural MRI regions of interest (ROIs) were extracted individually by automated parcellation and segmentation methods using FreeSurfer. These cortical and subcortical ROIs were used to assess regional perfusion stability. Our results indicated regional variability in grey matter rCBF. Although rCBF measurements were characterized by intersubject variation, our results also indicated relatively less within-subject variability estimated as within-subject standard deviation (SDW) (intersession SDW: 2.0 to 8.8; intrasession SDW: 2.8 to 9.6) and acceptable reliabilities as measured using intraclass correlation coefficient (ICC) (intersession ICC: 0.68 to 0.94; intrasession ICC: 0.66 to 0.95) for regional MRI perfusion measurements using the PICORE Q2TIPS technique. Overall, our findings suggest that PASL is a technique with good within and between session reproducibility. Further reproducibility studies in target populations relevant for specific clinical trials of neurovascular related agents will be important and the present results provide a framework for such assessments.

Changes in regional fetal cerebral blood flow perfusion in relation to hemodynamic deterioration in severely growth‐restricted fetuses

To study regional cerebral blood perfusion with power Doppler ultrasound (PDU) imaging in appropriate-for-gestational age (AGA) fetuses and those with intrauterine growth restriction (IUGR) at different hemodynamic stages of fetal deterioration. Brain blood perfusion was studied with PDU imaging, and the fractional moving blood volume (FMBV) was estimated in 56 growth-restricted and 56 AGA matched fetuses at 26-32 weeks of gestation. Fetuses with IUGR were classified according to progression of hemodynamic deterioration as follows: Group 1, abnormal umbilical artery (UA) pulsatility index (PI) (mean > 2 SD, n = 13); Group 2, abnormal UA-PI and middle cerebral artery (MCA) PI (mean < 2 SD, n = 15); Group 3, abnormal UA-PI, MCA-PI and ductus venosus (DV) PI (mean > 2 SD) but atrial (a-wave) flow present (n = 16); and Group 4, absent or reversed DV atrial flow (n = 12). FMBV was calculated in the complete mid-sagittal, frontal, basal ganglia and cerebellar regions. In all growth-restricted fetuses, FMBV was significantly increased in all regions. Fetuses in Group 1 showed considerable increments in FMBV values in the frontal, complete mid-sagittal and cerebellar regions, and a mild increase in the basal ganglia. From Groups 2 to 4, there was a steady reduction (compared with Group 1) in frontal FMBV values (F = 3.25, P = 0.027) together with a significant increment in the basal ganglia values (F = 11.61, P < 0.001). A trend for increasing FMBV values was also observed in the cerebellum, whereas a decreasing trend was noted in the complete mid-sagittal area. Brain perfusion in growth-restricted fetuses shows clear regional variations, which change with progression of hemodynamic deterioration. After an initial and early increase in the frontal area, progression of fetal deterioration was rapidly associated with a pronounced decrease in frontal perfusion, together with an increase towards the basal ganglia.

Simplified quantitative determination of cerebral perfusion reserve with H2(15)O PET and acetazolamide.

The measurement of regional cerebral blood flow (rCBF) and perfusion reserve (PR) with H2(15)O positron emission tomography (PET) and acetazolamide challenge is of importance in evaluating patients with cerebrovascular disease and is thought to be useful in selecting patients for possible vascular surgery. Full quantitative assessment of rCBF with PET requires arterial blood sampling, which is inconvenient in a clinical setting. In this work, we present a simple non-invasive method with which to quantitatively evaluate PR in one PET session lasting no more than 30 min. In ten patients with cerebrovascular disease, rCBF was measured with H2(15)O PET under the baseline condition and after administration of 1 g acetazolamide using a standard technique involving arterial blood sampling. The activity accumulated over 60 s was normalized to injected activity per kilogram body weight (nAA) and compared with rCBF in eight different brain regions. A high linear correlation was found for PR based on nAA (PRnAA) and rCBF (PRrCBF) (PRnAA=0.843 PRrCBF + 0.092, r=-0.83, Pearson's correlation coefficient). Bland-Altman analyses further confirmed that PRnAA reflects PR in a quantitative manner. These results demonstrate that the method based on normalized counts allows the quantitative assessment of PR without blood sampling.

Epilepsy accompanied by intracranial arachnoid cysts: studies on volume and regional cerebral blood perfusion using MRI and SPECT

To evaluate whether arachnoid cysts (ACs) can directly cause epilepsy by cortical compression, we studied the relationships among seizures, the volume of ACs, and regional cerebral blood perfusion around ACs. Subjects were 11 patients (10.5 ± 7.2 years) with primary intracranial ACs. The AC volume was calculated from axial T 1-weighted magnetic resonance imaging (MRI). N-isopropyl p-iodoamphetamine ( 123I-IMP) single photon emission computed tomography (SPECT) was used to evaluate cerebral blood perfusion. The lesional side to normal side ratio (L/N ratio) was calculated from rectangular and irregular region of interests (ROIs) in frontal and temporal area around the ACs. The volume of ACs in nonepileptic patients was significantly larger than in epileptic patients. In nonepileptic patients, SPECT demonstrated hyperperfusion around ACs, whereas in epileptic patients it showed hypoperfusion. The L/N ratio of rectangular ROIs in the posterior temporal area and irregular ROIs in the temporal area were significantly lower in epileptic patients than in nonepileptic ones. Our results suggest that epilepsy with ACs is related to the cerebral blood perfusion in the surrounding brain structures rather than to the volume of the ACs. Not only compression but also complicated brain parenchymal lesions may participate in the development of epilepsy.

Regional cerebral blood perfusion in children with hemiplegia: A SPECT study.

Fourteen children with spastic hemiplegia of various etiology: cerebral palsy (seven cases, five with porencephalic cyst); stroke with small deep infarcts (two); hemiconvulsion-hemiplegia-epilepsy syndrome (three); traumatic brain injury (two), were investigated by 99mTc-HMPAO SPECT. Localized and remote perfusion abnormalities were studied. Hypoperfusion corresponding to CT abnormalities was found in each group, but the perfusion deficit extended beyond the boundaries of anatomical defects, most prominently in cases with widespread unilateral epileptic discharges. Ipsilateral cerebellar diaschisis was observed in patients with early cerebral insult (who had porencephalic cyst of pre- or perinatal onset) and crossed cerebellar diaschisis was noted in a patient who sustained traumatic brain injury at a later age. Diaschisis in the overlying cortex, thalamus and basal ganglia was noticed in several cases. Although clinical symptoms or signs could not be unequivocally attributed either to the size of the perfusion defects beyond the boundaries of lesions shown by CT or to the diaschisis, the findings may contribute to reveal age-related abnormal perfusion patterns.

A method of regional cerebral blood perfusion measurement using dynamic CT with an iodinated contrast medium.

Acta Neurologica ScandinavicaVolume 93, Issue s166 p. 28-31 A method of regional cerebral blood perfusion measurement using dynamic CT with an iodinated contrast medium Kyojiro Nambu, Kyojiro Nambu Medical Systems Engineering Department II, Nasu Works, Toshiba CorporationSearch for more papers by this authorRie Takehara, Rie Takehara Department of Neurosurgery, Wakayama Rosai HospitalSearch for more papers by this authorTomoaki Terada, Tomoaki Terada Department of Neurosurgery, Wakayama Medical CollegeSearch for more papers by this author Kyojiro Nambu, Kyojiro Nambu Medical Systems Engineering Department II, Nasu Works, Toshiba CorporationSearch for more papers by this authorRie Takehara, Rie Takehara Department of Neurosurgery, Wakayama Rosai HospitalSearch for more papers by this authorTomoaki Terada, Tomoaki Terada Department of Neurosurgery, Wakayama Medical CollegeSearch for more papers by this author First published: July 1996 https://doi.org/10.1111/j.1600-0404.1996.tb00537.xCitations: 17AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume93, Issues166July 1996Pages 28-31 RelatedInformation

Error analysis of the double-integral method for calculating brain blood perfusion from inert gas clearance data.

A single-photon dynamic computer-assisted tomograph (DSPECT) has been built and is currently being used to evaluate regional cerebral blood perfusion in patients and volunteers. A computer simulation of the system was created to analyze the effects of data collection, Poisson noise, attenuation compensation, and the reconstruction technique now employed in the DSPECT. Several methods of attenuation compensation were used to generate perfusion images from both ideal and noisy data. The results indicate that the mean perfusion is calculated to within 10.4% accuracy for all perfusion rates in a region of interest if attenuation correction is used. Without attenuation correction, perfusions are underestimated by as much as 27%. The three correctors tested have different effects on the calculated perfusion value, depending on the location of the region of interest in the picture. The algorithm introduces random noise that is proportional to both the random error in the input data and the perfusion rate. Air-curve delay errors result in inaccuracies in the final perfusion picture that are proportional to perfusion rate. Physiological values (0.8-1.5) of the partition coefficient cause overestimation of both gray (0-34%) and white (7-67%) matter perfusion values. Compton scatter and collimator effects were not addressed in this study.

Three-dimensional regional cerebral blood perfusion images with single-photon emission computed tomography.

Twenty-seven patients were studied for cerebral blood perfusion abnormalities using krypton 81m. A solution of 81mKr was continuously infused into an internal carotid artery, and single-photon emission computed tomograms were recorded. The transverse section images using 81mKr represented the three-dimensional regional cerebral blood perfusion, and this technique seemed to be useful for evaluating the regional cerebral blood perfusion in the deep brain.