scholarly journals Tomographic Studies of rCBF with [99mTc]-HM-PAO SPECT in Patients with Brain Tumors: Comparison with C15O2 Continuous Inhalation Technique and PET

1988 ◽  
Vol 8 (1_suppl) ◽  
pp. S90-S94 ◽  
Author(s):  
K.-J. Langen ◽  
H. Herzog ◽  
T. Kuwert ◽  
N. Roosen ◽  
E. Rota ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Single Photon ◽  
Malignant Gliomas ◽  
Photon Emission ◽  
Inhalation Technique ◽  
Emission Computed Tomography ◽  
Positron Emission ◽  
Pet Scans ◽  
Photon Emission Computed Tomography

In 10 patients with malignant gliomas, the intracerebral distribution of [99mTc]–hexamethylpropyleneamine oxime ([99mTc]–HM-PAO) was studied with single photon emission computed tomography (SPECT) in comparison with C15O2 steady-state inhalation technique to measure cerebral blood flow using positron emission tomography (PET). In all instances, the cerebral [99mTc]–HM-PAO distribution was comparable with the regional pattern of cerebral blood flow (rCBF) observed with PET. This was confirmed by a significant correlation of tumor to cortex and tumor to white matter ratios between these two experimental methods. However, the contrast between high and low activity regions in the SPECT scans was significantly less than that in the PET scans. Contrast enhancement of the SPECT scans was accomplished using a correction formula proposed by Lassen.

scholarly journals Dose-dependent effects of the selective serotonin reuptake inhibitor citalopram: A combined SPECT and phMRI study

2019 ◽  
Vol 33 (6) ◽  
pp. 660-669 ◽  
Author(s):  
Anouk Schrantee ◽  
Michelle M Solleveld ◽  
Hilde Schwantje ◽  
Willem B Bruin ◽  
Henk-Jan MM Mutsaerts ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Serotonin Transporter ◽  
Single Photon ◽  
Photon Emission ◽  
Occipital Cortex ◽  
Emission Computed Tomography ◽  
Positron Emission ◽  
Pre Treatment ◽  
Dose Dependent

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.

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