A Method for Attenuation Correction in Radionuclide Computed Tomography

Chang, Lee-Tzuu

doi:10.1109/tns.1978.4329385

Cited by 1,114 publications

(481 citation statements)

References 3 publications

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“…We corrected all images for attenuation using the Chang method. 20 The totalbody radiation absorbed dose after a 99mTc-HMPAO study is 2.1 mGy (0.21 rad) per 500 MBq of 99mTc, which is less than 10% of the radiation absorbed from a conventional contrast-enhanced brain radiographic computed tomography scan. 21 …”

Section: Spect Imaging Protocolmentioning

confidence: 91%

Regional differences in cerebral perfusion associated with the α-2A-adrenergic receptor genotypes in attention deficit hyperactivity disorder

Kim¹,

Kim²,

Kang

et al. 2010

jpn

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Background: Neurobiologic studies have suggested that dysregulation of central noradrenergic systems may be involved in the pathophysiology of attention deficit hyperactivity disorder (ADHD), and it has been hypothesized that genetic changes in the norepinephrine pathways might contribute to dysfunction of the prefrontal cortex circuits in ADHD. We previously reported decreased cerebral blood flow in the right lateral prefrontal cortex and both orbitofrontal cortices in children with ADHD. Genetic investigations have shown that the α-2A-adrenergic receptor gene (ADRA2A) is associated with ADHD. Our aim was to examine whether the presence of a risk allele of the ADRA2A MspI polymorphism is associated with differences in regional cerebral blood flow in boys with ADHD. Methods: We recruited 21 Korean boys with ADHD (mean age 9.9, standard deviation [SD] 2.7 yr) and 11 age-and sex-matched controls (mean age 10.6 [SD 2.1] yr). Each participant underwent technetium-99m-hexamethylpropylene amine oxime ( 99m Tc-HMPAO) single-photon emission computed tomography. We performed image analyses with voxel-wise t statistics using SPM2. Results: We found regional hypoperfusion in the prefrontal regions, including the right orbitofrontal and right medial gyri, and the bilateral putamen and cerebellum in boys with ADHD relative to controls (p < 0.0005, uncorrected for multiple comparisons). Boys with ADHD who carried the C allele (n = 13) at the ADRA2A MspI polymorphism had reduced perfusion in the bilateral orbitofrontal regions compared with those without the C allele (n = 8) (p < 0.0005, uncorrected for multiple comparisons). Limitations: This study was limited by the small sample size, and we did not obtain genetic data from the controls. Conclusion: Our findings suggest that regional differences in cerebral perfusion in the orbitofrontal cortex represent an intermediate neuroimaging phenotype associated with the ADRA2A MspI polymorphism; these data support the validity of the noradrenergic hypothesis regarding the pathophysiology of ADHD.

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Section: Spect Imaging Protocolmentioning

confidence: 91%

Regional differences in cerebral perfusion associated with the α-2A-adrenergic receptor genotypes in attention deficit hyperactivity disorder

Kim¹,

Kim²,

Kang

et al. 2010

jpn

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“…Images were reconstructed by filtered back-projection (Butterworth 3-dimensional (3-D) postfilter; 0.60 cycles/cm, 5th order) and corrected for attenuation (Chang, 1978).…”

Section: Spect Data Acquisition and Analysismentioning

confidence: 99%

Methylphenidate Effects on Brain Activity as a Function of SLC6A3 Genotype and Striatal Dopamine Transporter Availability

Kasparbauer

Rujescu²,

Riedel

et al. 2014

Neuropsychopharmacol

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We pharmacologically challenged catecholamine reuptake, using methylphenidate, to investigate its effects on brain activity during a motor response inhibition task as a function of the 3 0 -UTR variable number of tandem repeats (VNTR) polymorphism of the dopamine transporter (DAT) gene (SLC6A3) and the availability of DATs in the striatum. We measured the cerebral hemodynamic response of 50 healthy males during a Go/No-Go task, a measure of cognitive control, under the influence of 40 mg methylphenidate and placebo using 3T functional magnetic resonance imaging. Subjects were grouped into 9-repeat (9R) carriers and 10/10 homozygotes on the basis of the SLC6A3 VNTR. During successful no-go trials compared with oddball trials, methylphenidate induced an increase of blood oxygen level-dependent (BOLD) signal for carriers of the SLC6A3 9R allele but a decrease in 10/10 homozygotes in a thalamocortical network. The same pattern was observed in caudate and inferior frontal gyrus when successful no-go trials were compared with successful go trials. We additionally investigated in a subset of 35 participants whether baseline striatal DAT availability, ascertained with 123 I-FP-CIT single photon emission computed tomography, predicted the amount of methylphenidate-induced change in hemodynamic response or behavior. Striatal DAT availability was nominally greater in 9R carriers compared with 10/10 homozygotes (d ¼ 0.40), in line with metaanalyses, but did not predict BOLD or behavioral changes following MPH administration. We conclude that the effects of acute MPH administration on brain activation are dependent on DAT genotype, with 9R carriers showing enhanced BOLD following administration of a prodopaminergic compound.

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“…The acquisition parameters consisted of a rotational radius of 12.7-13 cm, a 20% energy window centered on 159 keV, 120 projection angles over 3601 (60 s per projection), and a 128 Â 128 matrix. Images were reconstructed by filtered backprojection (low-pass filter with a cutoff frequency of 0.27 Nyquist, fifth order) and corrected for attenuation according to Chang (1978) (m ¼ 0.12 cm À1 ). Voxel size in the reconstructed and reoriented images was 2.26 Â 2.26 Â 2.26 mm.…”

Section: Spect Imagingmentioning

confidence: 99%

Serotonin and Dopamine Transporter Availabilities Correlate with the Loudness Dependence of Auditory Evoked Potentials in Patients with Obsessive-Compulsive Disorder

Pogarell

Tatsch

Juckel

et al. 2004

Neuropsychopharmacol

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Brain monoaminergic function is involved in the pathophysiology of psychiatric disorders. The loudness dependence (LD) of the N1/P2 component of auditory evoked potentials has been proposed as a noninvasive indicator of central serotonergic function, whereas single photon emission computed tomography (SPECT) and [ 123 I]b-CIT can be used to visualize both serotonin (SERT) and dopamine transporters (DAT). The aim of the study was to correlate LD and SPECT measures in patients with obsessive-compulsive disorder, a condition with evidence for a serotonergic dysfunction. A total of 10 subjects received both neurophysiological and imaging investigations. Evoked potentials were recorded following the application of acoustic stimuli with increasing intensities. The LD of the relevant subcomponents (tangential dipoles) was investigated using dipole source analysis. SPECT was performed 20-24 h after injection of a mean 140 MBq [ 123 I]b-CIT. As a measure of brain SERT and DAT availabilities, a ratio of specific to nonspecific [ 123 I]b-CIT binding for the midbrain . pons region (SERT) and the striatum (DAT) was used. The LD of the right tangential dipole correlated significantly with both SERT and DAT availabilities (Pearson's correlations: r ¼ 0.69, po0.05, and r ¼ 0.80, po0.01, respectively). The correlations remained significant after controlling for the effects of age, gender, and severity of clinical symptoms. Associations between LD and both SERT and DAT availabilities further validate the use of neurophysiological approaches as noninvasive indirect measures of neurochemical brain function and point at a hypothesized interconnection of central monoaminergic systems.

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A Method for Attenuation Correction in Radionuclide Computed Tomography

Cited by 1,114 publications

References 3 publications

Regional differences in cerebral perfusion associated with the α-2A-adrenergic receptor genotypes in attention deficit hyperactivity disorder

Regional differences in cerebral perfusion associated with the α-2A-adrenergic receptor genotypes in attention deficit hyperactivity disorder

Methylphenidate Effects on Brain Activity as a Function of SLC6A3 Genotype and Striatal Dopamine Transporter Availability

Serotonin and Dopamine Transporter Availabilities Correlate with the Loudness Dependence of Auditory Evoked Potentials in Patients with Obsessive-Compulsive Disorder

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