Perfusion SPECT in the Differential Diagnosis of Dementia

2017 ◽  
Vol 41 (S1) ◽  
pp. S627-S627
Author(s):  
D. Brigadeiro ◽  
J. Nunes ◽  
T. Ventura Gil ◽  
P. Costa
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Differential Diagnosis ◽  
Emission Tomography ◽  
Emission Computed Tomography ◽  
World Population ◽  
Positron Emission ◽  
Diagnosis Of Dementia ◽  
Perfusion Spect ◽  
Differential Diagnosis Of Dementia

Dementia is a syndrome–usually of a chronic or progressive nature–in which there is deterioration in cognitive function beyond what might be expected from normal ageing (WHO). As the world population ages, the number of people afflicted with dementing illnesses will increase. This neurodegenerative disease is one of the major causes of disability and dependency among older people worldwide. Brain single-photon emission computed tomography (SPECT) allows the study of regional cerebral blood flow, providing functional information. Each of the different types of dementia has a distinct blood flow pattern that is revealed with SPECT imaging and which can be used for differential diagnoses. This imaging technique can also be used to differentiate dementia from pseudodementia. The use of SPECT has been recommended in various guidelines to help in differential diagnosis of dementia. The National Institute for Health and Clinical Excellence in the UK recommend the use of SPECT or positron emission tomography (PET) to help differentiate Alzheimer's disease (AD) from frontotemporal dementia and vascular dementia when there is diagnostic doubt (NICE, 2006). The European Federation of the Neurological Societies guidelines for diagnosis also supports the use of FDG-PET (18F fluorodeoxyglucose positron emission tomography) or perfusion SPECT when clarifying a diagnosis of AD. This review describes the utility of perfusion SPECT in differential diagnosis of neurodegenerative dementias.Disclosure of interestThe authors have not supplied their declaration of competing interest.

scholarly journals Linearization Correction of 99mTc-Labeled Hexamethyl-Propylene Amine Oxime (HM-PAO) Image in Terms of Regional CBF Distribution: Comparison to C15O2 Inhalation Steady-State Method Measured by Positron Emission Tomography

1988 ◽  
Vol 8 (1_suppl) ◽  
pp. S52-S60 ◽  
Author(s):  
Atsushi Inugami ◽  
Iwao Kanno ◽  
Kazuo Uemura ◽  
Fumio Shishido ◽  
Matsutaro Murakami ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Steady State ◽  
Emission Tomography ◽  
Emission Computed Tomography ◽  
Whole Brain ◽  
Steady State Method ◽  
Positron Emission ◽  
State Method

The radioisotope distribution following intravenous injection of 99mTc-labeled hexamethylpropyleneamine oxime (HM-PAO) in the brain was measured by single photon emission computed tomography (SPECT) and corrected for the nonlinearity caused by differences in net extraction. The “linearization” correction was based on a three compartment model, and it required a region of reference to normalize the SPECT image in terms of regional cerebral blood flow distribution. Two different regions of reference, the cerebellum and the whole brain, were tested. The uncorrected and corrected HM-PAO images were compared with cerebral blood flow (CBF) image measured by the C15O2 inhalation steady state method and positron emission tomography (PET). The relationship between uncorrected HM-PAO and PET–CBF showed a correlation coefficient of 0.85 but tended to saturate at high CBF values, whereas it was improved to 0.93 after the “linearization” correction. The whole-brain normalization worked just as well as normalization using the cerebellum. This study constitutes a validation of the “linearization” correction and it suggests that after linearization the HM-PAO image may be scaled to absolute CBF by employing a global hemispheric CBF value as measured by the nontomographic 133Xe clearance method.

scholarly journals Synthesis and evaluation of N-isopropyl-p-[11C]methylamphetamine as a novel cerebral blood flow tracer for positron emission tomography

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jun Toyohara ◽  
Norihiro Harada ◽  
Takeharu Kakiuchi ◽  
Hiroyuki Ohba ◽  
Masakatsu Kanazawa ◽  
...  
Keyword(s):  
Positron Emission Tomography ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Emission Tomography ◽  
Emission Computed Tomography ◽  
Normal Brain ◽  
Brain Uptake ◽  
Pet Tracer ◽  
Positron Emission ◽  
The Brain

Abstract Introduction Increases in fasting plasma glucose (PG) levels lead to a decrease in 2-deoxy-2-[18F]fluoro-d-glucose ([18F]FDG) uptake in the normal brain, especially in the precuneus, resulting in an Alzheimer’s disease (AD)-like uptake pattern. Therefore, patients with higher PG levels, such as those with diabetes, can be erroneously diagnosed with AD when positron emission tomography (PET) imaging is done using [18F]FDG, due to reduced uptake of [18F]FDG in the precuneus. To help avoid an erroneous diagnosis of AD due to differences in glucose metabolism, evaluating cerebral blood flow (CBF) in the brain is useful. However, current techniques such as single photon emission computed tomography (SPECT) and [15O]H2O PET have limitations regarding early diagnosis of AD because the images they produce are of low resolution. Here, we developed a novel CBF PET tracer that may be more useful than [18F]FDG for diagnosis of AD. Methods We synthesized and evaluated N-isopropyl-p-[11C]methylamphetamine ([11C]4) as a carbon-11-labeled analogue of the standard CBF SPECT tracer N-isopropyl-p-[123I]iodoamphetamine. Fundamental biological evaluations such as biodistribution, peripheral metabolism in mice, and brain kinetics of [11C]4 in non-human primates with PET with successive measurement of [15O]H2O were performed. Results [11C]4 was synthesized by methylation of the corresponding tributyltin precursor (2) with [11C]MeI in a palladium-promoted Stille cross-coupling reaction. The brain uptake of [11C]4 in mice peaked at 5–15 min after injection and then promptly decreased. Most radioactivity in the brain was detected in the unchanged form, although in the periphery, [11C]4 was rapidly metabolized to hydrophilic components. Acetazolamide (AZM) treatment significantly increased the brain uptake of [11C]4 without affecting the blood levels of radioactivity in mice. Preliminary kinetics analysis showed that the K1 of [11C]4 reflected regional CBF in a vehicle-treated monkey, but that the K1 did not reflect CBF in higher flow regions after AZM loading. Conclusion [11C]4 is a potential novel CBF PET tracer. Further validation studies are needed before [11C]4 can be used in humans.

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