• The Korean Journal of Nuclear Medicine
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• v.26 no.2
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• pp.235-243
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• 1992

Patterns of abnormality in regional cerebral perfusion and its relation to clinical severity was evaluated with 32 head injury patients using $^{99m}Tc-HMPAO$ single photon emission tomography (SPECT). The findings were compared with computed tomography (CT) done within 48 hours of each SPECT study. The initial SPECT study was done within 7 days of injury in 16 cases, between 1 week and 2 months in 12, and after over 2 months in 4. Nineteen of the patients underwent followup SPECT and CT after a mean interval of 1 to 2 months. The initial SPECT showed abnormalities in 96% (31/32) of the patients while CT showed abnormal findings in only 81% (26/32). There were a total of 54 supratentorial SPECT lesions in all. Ninity percent (49/54) of these were of regional hypoperfusion, while 5 lesions showed focal hyperperfusion. The lesions were most often localized in the frontal and temporal lobes. Fifty five percent (30/54) were areas not detected as a lesion on CT. Cerebellar diaschisis was observed in 50% (16/32) of the patients. The degree of perfusion abnormality was quantified by the product of differential activity and a size factor. Correlation between the degree of perfusion abnormality and the clinical severity (Glasgow coma scale) failed to show statistical significance (p=0.053). The amount of change in the degree of perfusion abnormality on follow up SPECT was compared to the amount of change in clinical severity. Perfusion abnormality showed a tendancy to improve in most patients, and the degree of improvement showed significant correlation with the amount of clinical improvement (p < 0.01).

• Nuclear Medicine and Molecular Imaging
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• v.42 no.1
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• pp.17-28
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• 2008

Purpose: It was well known that cerebral blood perfusion is normal or diffusely decreased in the majority of patients with Parkinson's disease (PD). Actually we interpreted brain perfusion SPECT images of PD patients in the clinical situation, we observed various cerebral perfusion patterns in patients with PD. So we performed brain perfusion SPECT to know the brain perfusion patterns of PD patients and the difference of perfusion patterns according to the sex and the age. Also we classified PD patients into small groups based on the brain perfusion pattern. Methods and Materials: Two hundred nineteen patients (M: 70, F: 149, mean age: $62.9{\pm}6.9$ y/o) who were diagnosed as PD without dementia clinically and 55 patients (M:15, F:40, mean age: $61.4{\pm}9.2$ y/o) as normal controls who had no past illness history were performed $^{99m}Tc$-HMP AO brain perfusion SPECT and neuropsychological test. Results: At first, we compared all patients with PD and normal controls. Brain perfusion in left inferior frontal gyrus, left insula, left transverse temporal gyrus, left inferior parietal lobule, left superior parietal lobule, right precuneus, right caudate tail were lower in patients with PD than normal controls. Secondly, we compared male and female patients with PD and normal controls, respectively. Brain perfusion SPECT showed more decreased cerebral perfusion in left hemisphere than right side in both male and female patients compared to normal controls. And there was larger hypoperfusion area in female patients compared with male. Thirdly, we classified patients with PD and normal controls into 4 groups according to the age and compared brain perfusion respectively. In patient below fifties, brain perfusion in both occipitoparietal and left temporal lobe were lower in PD group. As the patients with PD grew older, hypoperfusion area were shown in both frontal, temporal and limbic lobes. Fourthly, We were able to divide patients into small groups based on cerebral perfusion pattern. There was normal cerebral blood perfusion in 32 (14.7%) of 219 patients with PD, decreased perfusion on the frontal lobe in 45 patients (20.6%), the temporal lobe in 39 patients (17.4%), the parietal lobe in 39 patients (17.9%), the occipital lobe in 40 patients (18.3%), diffuse area in 14 patients (6.4%) and unclassified in 10 patients (4.6%). Fifthly, we compared the results of the neuropsychological test and cerebral perfusion pattern. There was no correlation between two tests except visuospatial function. Conclusion: Various perfusion state were found in patients with PD according to the age and sex. Also we were able to classify perfusion state into several groups and compare the neuropsychological test with cerebral perfusion.

• The Korean Journal of Nuclear Medicine
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• v.34 no.5
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• pp.426-432
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• 2000

After surgical operation in patients with arteriovenous malformation (AVM), normal pressure perfusion breakthrough (NPPB) is one of the major complications. Brain perfusion SPECT with acetazolamide stress was known to be useful to evaluate the vascular reserve in several neurological and neurosurgical conditions. The authors performed acetazolamide brain perfusion SPECT in patients with AVM and compared the brain perfusion in the post-operative clinical courses. The acetazolamide brain perfusion SPECT was helpful in defining the prognosis of the patients with AVM. We describe 4 patients with AVM who had acetazolamide brain perfusion SPECT to examine the prognosis.

• Korean Journal of Head & Neck Oncology
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• v.14 no.2
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• pp.175-181
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• 1998

Objectives: The authors tried to analyze the results of carotid artery sacrifice with or without preoperative carotid evaluation. Materials and Methods: Thirteen patients undergone carotid sacrifice were evaluated. Carotid balloon occlusion test (BOT) and single-photon emission computed tomography (SPECT) with technetium-99m-labeled hexamethylpropyleneamineoxime ($^{99m}Tc-HMPAO$) were used for preoperative carotid evaluation. Results: The causes of carotid artery sacrifice consisted of the neck mass involving the carotid artery, spontaneous aneurysmal rupture, and traumatic pseudoaneurysm. Five patient had postoperative neurologic complications and two of them had permanent neurologic deficits. Conclusion: The authors stress that the preoperative evaluation in carotid artery sacrifice is imperable, and the BOT with SPECT can be used in selecting the method of treatment. But since these tests cannot predict the postoperative outcome perfectly, careful perioperative care of the patients should be exercised regardless of the results of the preoperative evaluation.

• The Korean Journal of Nuclear Medicine
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• v.27 no.2
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• pp.165-169
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• 1993

Functional cerebral impairments have been verified objectively by brain SPECT and q-EEG (quantitative electroencephalography). Microcerebral circulatory defects without anatomical changes can-not be detected by the brain CT or MRI. Brain SPECT using $^{99m}Tc$-HMPAO (Hexamethyl propyleneamine oxime) as a key radioisotope may be accepted as the useful method for identifying functional cerebral impairments. We studied 25 patients with mild head trauma to define whether the SPECT was helpful in detecting cerebral impairment. Results were as follows: The SPECT was positive in 23 patients out of 25, q-EEG positive in 16 patients and brain CT was positive in 3 cases. SPECT and q-EEG were more sensitive than CT, SPECT would be more useful method than brain CT to investigate cerebral function after head injury.

• Korean Journal of Psychosomatic Medicine
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• v.5 no.2
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• pp.205-213
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• 1997

The aim of this study is to find the relationship between interictal psychiatric symptoms and seizure-related variables such as structural changes, regional interictal perfusion changes, the number of interictal epileptic discharges and the presence of accompanying generalized tonic clonic seizure(GTC). The subjects were 75 patients (47 males : mean age $28.3{\pm}7.7$) with intractable epilepsy, Interictal psychiatric symptoms were rated by Symptom Checklist-90-R(SCL-90-R). Each of 4 seizure variables was measured by MRI, $^{99m}TC-HMPAO$ SPECT and the prolonged EEG monitoring. The mean SCL-90-R subscale T-scores and the ratio of the patients with definite psychiatric symptoms(T-score > 65 at any one subscale of SCL-90-R) were compared among the groups with different seizure variables. Demographic variables and clinical variables were not statistically different among the groups with different seizure variables. The patients with right mesial temporal sclerosis had higher mean SCL-90-R scores for obsessive compulsive symptom, interpersonal sensitivity, depression, hostility and psychotic symptoms than the patients with left mesial temporal sclerosis, and they also showed higher ratio of definite psychiatric symptoms. The presence of interictal epileptic discharges was related with higher T-scores of paranoid subscale. The areas of hypoperfusion, the presence of the GTC, and other clinical seizure variables showed no significant influences on the mean SCL-90-R subscale T-scores. from these results, the authors speculated that interictal subictal epileptic dischrages may be related with psychiatric symptoms of the intractable epileptic patients, especially with right mesial temporal sclerosis.

• The Korean Journal of Nuclear Medicine
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• v.27 no.1
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• pp.22-27
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• 1993

Drug abuse is widespread in worldwide and has been associated with neurologic complication. Zipeprol is one of the drugs which been abused for psychological satisfaction in some adolescents. This agent is non-opioid antitussive agent, which is not legally considered as being capable of creating dependence or abuse liability at therapeutic serum levels. But it has been reported that acute or chronic overdose create neurologic complication such as convulsion as well as dependence. Recently we experienced six zipeprol abusers who admitted due to convulsion and variable neurologic symptoms. The aim of our study was to determine the role of $^{99m}Tc$-HMPAO brain SPECT in those patients. EEG and brain CT showed no abnormal finding, but brain SPECT showed focal or multiple perfusion abnormalities in frontal, parietal, occipital cortex, basal ganglia, thalamus and especially at temporal cortex. These results suggest that brain SPECT may be a useful diagnostic tool to evaluate the cerebral dysfunction infused by zipeprol abuse.

• The Korean Journal of Nuclear Medicine
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• v.31 no.3
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• pp.330-338
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• 1997

This study investigated the method to adjust acquisition time(a) and injection dose (i) to make the best basal and subtraction images in consecutive SPECT. Image quality was assumed to be mainly affected by signal to noise ratio(S/N). Basal image was subtracted from the second image consecutively acquired at the same position. We calculated S/N ratio in basal SPECT images($S_1/N_1$) and subtraction SPECT images(Ss/Ns) to find a(time) and i(dose) to maximize S/N of both images at the same time. From phantom images, we drew the relation of image counts and a(time) and i(dose) in our system using fanbeam-high-resolution collimated triple head SPECT. Noise by imaging process depended on Poisson distribution. We took maximum tolerable duration of consecutive acquisition as 30 minutes and maximum injectible dose as 1,850MBq(50 mCi)(sum of two injections) per study. Counts of second-acquired image($S_2$), counts($S_s$) and noise($N_s$) of subtraction SPECT were as follows. $C_1$ was the coefficient of measurement with our system. $$S_2=S_1{\cdot}(\frac{30-a}{a})+background{\cdot}(1-\frac{30-a}{a})+C_1{\cdot}(30-a){\cdot}{\epsilon}{\cdot}(50-i)$$ $$Ss=S_2-\{S_1{\cdot}(\frac{30-a}{a})+background{\cdot}(1-\frac{(30-a)}{a})\}$$ $$Ns={\sqrt{N_2^2+N_1^2{\cdot}\frac{(30-a)^2}{a^2}}={\sqrt{S_2+S_1{\cdot}\frac{(30-a)^2}{a^2}}$$ In case of rest/acetazolamide study, effect(${\epsilon}$) of acetazolamide to increase global brain uptake of Tc-99m-HMPAO could be 1.5 or less. Varying ${\epsilon}$ from 1 to 1.5, a(time) and i(dose) pair to maximize both $S_1/N_l$ and Ss/Ns was determined. 15 mCi/17 min and 35mCi/13min was the best a(time) and i(dose) pair for rest/acetazolamide study(when ${\epsilon}$ were 1.2) and came to be used for our clinical routine after this study. We developed simple method to maximize S/N ratios of basal and subtraction SPECT from consecutive acquisition. This method could be applied to ECD/HMPAO and brain activation studies as well as rest/acetazolamide studies.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.20 no.3
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• pp.122-128
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• 2009

Objectives : Autism is a well-known psychiatric disorder that is presumed to have a neural basis. To investigate the underlying neurofunctional abnormalities of autism, the authors performed single photon emission computed tomography (SPECT) on children with autism. Methods : Fifty-five children with untreated autism (47 boys and 8 girls, mean age=$50.6{\pm}20.28$ months) were selected from among the patients visiting the child and adolescent psychiatric clinic of Seoul National University Hospital. Psychiatrists had diagnosed the participants according to the DSM-IV criteria for autistic disorder and the Childhood Autism Rating Scale (CARS) criteria for a diagnosis of autism. All participants were examined using 99mTC-HMPAO Brain SPECT. Using statistical parametric mapping (SPM) analysis, we compared the participants' SPECT images to standardized SPECT images of normal children, which had been retrospectively selected by the authors, on a voxel by voxel basis. Voxels with a p-value less than .001 were considered to be significantly different. Results : The autistic group showed significant hypoperfusion in the right medial frontal gyrus, right precentral gyrus, and left precuneus gyrus. In addition, they showed no significant hyperperfusion areas when compared to the control group. Conclusion : The findings of hypoperfusion in the medial-frontal lobe and precuneus are accord with hemodynamic abnormalities that have been already reported. Therefore, these findings are compatible with the recently suggested "theory of mind" hypothesis and the disturbances in attention shifting that have been observed in autistic children.

• The Korean Journal of Nuclear Medicine
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• v.32 no.1
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• pp.20-31
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• 1998

A robust algorithm to disclose and display the difference of ictal and interictal perfusion may facilitate the detection of ictal hyperfusion foci. Diagnostic performance of localizing epileptogenic zones with subtracted SPECT images was compared with the visual diagnosis using ictal and interictal SPECT, MR, or PET. Ietal and interictal Tc-99m-HMPAO cerebral perfusion SPECT images of 48 patients(pts) were processed to get parametric subtracted images. Epileptogenic foci of all pts were diagnosed by seizure free state after resection of epileptogenic zones. In subtraction SPECT, we used normalized difference ratio of pixel counts(ictal-interictal)/interictal ${\times}100%$) after correcting coordinates of ictal and interictal SPECT in semi-automatized 3-dimensional fashion. We found epileptogenic zones in subtraction SPECT and compared the performance with visual diagnosis of ictal and interictal SPECT, MR and PET using post-surgical diagnosis as gold standard. The concordance of subtraction SPECT and ictal-interictal SPECT was moderately good(kappa=0.49). The sensitivity of ictal-interictal SPECT was 73% and that of subtraction SPECT 58%. Positive predictive value of ictal-interictal SPECT was 76% and that of subtraction SPECT was 64%. There was no statistical difference between sensitivity or positive predictive values of subtraction SPECT and ictal-interictal SPECT, MR or PET. Such was also the case when we divided patients into temporal lobe epilepsy and neocortical epilepsy. We conclude that subtraction SPECT we produced had equivalent diagnostic performance compared with ictal-interictal SPECT in localizing epileptogenic zones. Additional value of these subtraction SPECT in clinical interpretation of ictal and interictal SPECT should be further evaluated.