scholarly journals Assessment of informative value of effective cerebral blood flow calculation technique according to 99mTc-HMPAO polyphase scintigraphy data

Author(s):  
N. A. Nikolov ◽  
T. H. Novikova ◽  
S. S. Makeуev

Background. According to single-photon emission computed tomography (SPECT) data, the most common technique to calculate volume cerebral blood flow (VCBF) is N.A. Lassen method. Following it, VCBF in different segments of the brain is assessed in comparison with blood flow in the cerebellum, where it is considered to be constant. However, this approach does not take into account that in some pathologies, in particular, injuries, occlusions of blood vessels, VCBF of the cerebellum also does change. Therefore, an original technique of calculating regional VCBF based on polyphase scintigraphy has been developed, which will make it possible to make a more accurate assessment of the effective perfusion of the brain. Purpose – to evaluate the clinical informative value of the developed technique for calculating effective cerebral blood flow according to 99mTc-HMPAO (hexamethylpropyleneaminoxime) polyphase brain scintigraphy data. Materials and methods. The study is focused on analyzing two groups of patients: Group A represented by patients with signs of chronic cerebral ischemia and Group B enrolling patients in the interim and long term of explosive minor brain injury (n=22). Group A patients were divided into two subgroups, depending on the presence of structural and hemodynamic changes in the vertebral arteries (VA) according to ultrasound (US) of the major vessels of the brain. I-A subgroup (n=13) was made up by those patients who had structural lesions of the vertebrobasilar basin; II-A (n=27) patients had no relevant signs. All patients underwent a comprehensive clinical examination including neuropsychological testing, ultrasound of major vessels, magnetic resonance imaging, single-photon emission computed tomography (SPECT). Effective volume cerebral blood flow (VCBF), according to the SPECT data, was calculated based on the original technique (VCBFSB). VCBFSB values were compared with the SPECT data using N.A. Lassen (VCBFLassen) method and the ultrasound data. Results and discussion. Analysing the data of the groups of patients with hemodynamic impairment in the vertebro-basilar basin shows that, according to the scintigraphy of VCBF, I-A group patients differ from II-A group on average 1.82± 0.06 times the amount for CBFSB and 0.95± 0.04 for CBFLassen. The total mean blood flow   in   the   carotid   and   vertebral   arteries   of I-A group patients was 748.19±198.42 mL/min, II-A group patients – 1112.23±63.71 mL/min. Comparing the mean values of the hemodynamic parameters of the brain of Group B patients with the data of Group II-A patients, VCBFSB was 1.33±0.25-fold decreased, while CBFLassen showed 1.03±0.14-fold decrease of perfusion (in total average blood flow of vertebral and carotid arteries according to US of Group B – 1760±580 ml/min). Conclusions. Preliminary clinical studies, using the developed technique for calculating volume cerebral blood flow according to 99mTc-HMPAO scintigraphy data with the corresponding software, showed a rather high sensitivity in assessing VCBF in case of pathological changes in the brain, especially, in occlusion of the major vessels of the brain and contusions resulting from battle trauma, whereas N.A. Lassen method was insufficiently informative. The regression analysis of US data, SPECT data and neuropsychological testing shows clear linear correlation relationships, but they do also differ in sign depending on the diagnosis and the degree of pathological changes.

1998 ◽  
Vol 18 (4) ◽  
pp. 457-462 ◽  
Author(s):  
Dominique Cardebat ◽  
Jean-François Démonet ◽  
Michèle Puel ◽  
Alain Agniel ◽  
Gerard Viallard ◽  
...  

Task-induced changes in regional cerebral blood flow (rCBF) during verbal episodic memory activation were compared in 17 right-handed patients with dementia of the Alzheimer's type (DAT) and 20 healthy volunteers. Regional cerebral blood flow was assessed using single photon emission computed tomography (SPECT) and an injection of 133Xe (xenon, isotope of mass 133) in 21 regions of interest (ROI) during rest, passive listening to 36 words, and memorizing of a 12-word list repeated three times. In healthy subjects, memory—listening comparison showed activation of a distributed system involving several left-sided ROI, especially the posterior inferior frontal region. In patients with DAT, the same pattern of activation was found for listening—rest comparison, and no significant changes were found in memory—listening comparison. During listening compared with rest, significant activation was observed in left-sided hypoperfused regions. A significant correlation between memory performance and rCBF recorded in patients with DAT during the memory task was found only in the right lateral frontal region, a region that was not hypoperfused significantly in patients. The involvement of this region might relate to either retrieval effort or actual performance of patients with DAT on the memory task.


2019 ◽  
Vol 33 (6) ◽  
pp. 660-669 ◽  
Author(s):  
Anouk Schrantee ◽  
Michelle M Solleveld ◽  
Hilde Schwantje ◽  
Willem B Bruin ◽  
Henk-Jan MM Mutsaerts ◽  
...  

Background: Serotonin transporter blockers, like citalopram, dose-dependently bind to the serotonin transporter. Pharmacological magnetic resonance imaging (phMRI) can be used to non-invasively monitor effects of serotonergic medication. Although previous studies showed that phMRI can measure the effect of a single dose of serotoninergic medication, it is currently unclear whether it can also detect dose-dependent effects. Aims: To investigate the dose-dependent phMRI response to citalopram and compared this with serotonin transporter occupancy, measured with single photon emission computed tomography (SPECT). Methods: Forty-five healthy females were randomized to pre-treatment with placebo, a low (4 mg) or clinically standard (16 mg) oral citalopram dose. Prior to citalopram, and 3 h after, subjects underwent SPECT scanning. Subsequently, a phMRI scan with a citalopram challenge (7.5 mg intravenously) was conducted. Change in cerebral blood flow in response to the citalopram challenge was assessed in the thalamus and occipital cortex (control region). Results: Citalopram dose-dependently affected serotonin transporter occupancy, as measured with SPECT. In addition, citalopram dose-dependently affected the phMRI response to intravenous citalopram in the thalamus (but not occipital cortex), but phMRI was less sensitive in distinguishing between groups than SPECT. Serotonin transporter occupancy showed a trend-significant correlation to thalamic cerebral blood flow change. Conclusion: These results suggest that phMRI likely suffers from higher variation than SPECT, but that these techniques probably also assess different functional aspects of the serotonergic synapse; therefore phMRI could complement positron emission tomography/SPECT for measuring effects of serotonergic medication.


Neurosurgery ◽  
1988 ◽  
Vol 22 (5) ◽  
pp. 913-919 ◽  
Author(s):  
Hunt H. Batjer ◽  
Michael D. Devous ◽  
Phillip D. Purdy ◽  
Bruce Mickey ◽  
Frederick J. Bonte ◽  
...  

Abstract Regional cerebral blood flow was measured with xenon-133 inhalation single photon emission computed tomography in a patient who developed a neurological deficit after carotid ligation. Hemispheric hypoperfusion was noted in resting studies and impaired vasoreactivity was suggested by lack of symmetrical flow augmentation after acetazolamide administration. Because of progressive neurological deterioration, an extracranial-intracranial bypass was performed. After prompt neurological improvement, repeat cerebral blood flow measurements at 1 and 9 weeks postoperatively confirmed improvement in resting flow and vasoreactivity. It is possible that decreased cerebrovascular reserve implied by measurements of vasoreactivity can identify patients who will benefit from surgical revascularization.


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