• Progress in Medical Physics
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• v.24 no.3
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• pp.162-170
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• 2013

Dedicated single-photon emission computed tomography (SPECT) systems based on pixelated semiconductors are being developed for studying small animal models of human disease. To clarify the possibility of using a SPECT system with CdTe for a high resolution low-dose small animal imaging, we compared the quality of reconstructed images from pixelated CdTe detector to those from a small SPECT system with NaI(Tl). The CdTe detector was $44.8{\times}44.8$ mm and the pixels were $0.35{\times}0.35{\times}5$ mm. The intrinsic resolution of the detector was 0.35 mm, which is equal to the pixel size. GATE simulations were performed to assess the image quality of both SPECT systems. The spatial resolutions and sensitivities for both systems were evaluated using a 10 MBq $^{99m}Tc$ point source. The quantitative comparison with different injected dose was performed using a voxelized MOBY phantom, and the absorbed doses for each organ were evaluated. The spatial resolution of the SPECT with NaI(Tl) was about 1.54 mm FWHM, while that of the SPECT with a CdTe detector was about 1.32 mm FWHM at 30 mm. The sensitivity of NaI(Tl) based SPECT was 83 cps/MBq, while that of the CdTe detector based SPECT was 116 cps/MBq at 30 mm. The image statistics were evaluated by calculating the CNR of the image from both systems. When the injected activity for the striatum in the mouse brain was 160 Bq/voxel, the CNR of CdTe based SPECT was 2.30 while that of NaI(Tl) based SPECT was 1.85. The CNR of SPECT with CdTe was overall higher than that of the NaI(Tl) based SPECT. In addition, the absorbed dose was higher from SPECT with CdTe than those from NaI(Tl) based SPECT to acquire the same quantitative values. Our simulation results indicated that the SPECT with CdTe detector showed overall high performance compared to the SPECT with NaI(Tl). Even though the validation study is needed, the SPECT system with CdTe detector appeared to be feasible for high resolution low-dose small animal imaging.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.1 no.1
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• pp.27-39
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• 1990

The neural mechanisms involved in attention deficit hyperactivity disorder are largely unknown. In order to investigate the neuroanatomical lesions of attention deficit hyperactivity disorders and their relationships with psychopathology, Single Photon Emission Computed Tomography(SPECT) using HMPAO was performed in 46 ADHDS and Yale Children's Inventory(YCI), Conners Parent Questionaire and DSM-III-R Questionaire for Disruptive Behavior Disorder were used to assess the psychopathology of ADHDS The results are summarized as follows; 1) 30.4% (14/46) of this series revealed decreased perfusion In SPECT. 2) Regions of hypoperfusion were seen in cerebral cortex(17.4%, 8/46), thalamus(13.0%, 6/46), deep gray matter(8.7%, 4/46), basal ganglia(6.5%, 3/46) and cerebellum(2.2%, 1/ 46). 3) The mean scores of the total YCI revealed significant difference between the two groups(SPECT abnormal versus normal group), and among the subscales, hyperactivity, language and fine-motor subscales showed significant differences between the two groups. Although the relationship between the abnormal findings and specific symptom clusters of ADHDS remains unclear, we can suggest that these abnormal findings could be associated with ADHD, and based on these findings, the ADHDS can be subclassified into two groups. This study can be said to reinforce the current conception of heterogeneity of ADHD.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.4 no.1
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• pp.68-78
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• 1993

The pathophysiology and neural mechanism involved in Tourette's and chronic motor tic disorder are highly controversial. In order to investigate the functional abnormalities of brain. In Tourette's and chronic motor tic disorder, 42 children with Tourette's and chronic motor disorder underwent single photon emission computed tomography(SPECT) using Tc-99m-HM-PAO. The results are summarized as follows : 1) 31.0% (13/42) of this series revealed perfusion defect in cerebral cortex. 2) 4.8% (2/42) revealed perfusion defect in basal ganglia. 3) 4.8(2/42) revealed perfusion defect in thalamus. 4) 16.7%(7/42) showed perfusion defect in cerebellum. 5) The frequency of abnormal perfusion showed no significant difference between tic with and without attention deficit hyperactivity disorder. 6) The frequency of abnormal perfusion showed no significant difference between Tourette's and chronic motor tic disorder. These findings support the hypothesis of a possible involvement of brain dysfunction in the production of Tourette's and chronic motor tic disorder, and quantification of blood flow and co-registration with magnetic resonance imaging will increase the validity of this study.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.24 no.1
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• pp.21-27
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• 2013

Objectives : Dysregulation of the central noradrenergic system may be involved in the pathophysiology of attention-deficit hyperactivity disorder (ADHD). The aim of this study was to examine the differences in pre- and post-treatment cerebral perfusion according to the MspI polymorphisms of the alpha-2A-adrenergic receptor gene (ADRA2A) in children with ADHD. Methods : Thirty seven drug-naive ADHD children (8.9+1.8 years old, M=32, F=5) were genotyped. Baseline single-photon emission computed tomography (SPECT) and clinical assessments were performed for ADHD children. After treatment with methylphenidate for eight weeks, SPECT and clinical assessment were repeated. Results : No differences in baseline clinical assessments or cerebral perfusion were observed according to the MspI genotype. However, after treatment, ADHD children with the G/G genotype at the MspI polymorphism showed hyperperfusion in the right cerebellar declive (p=.001, uncorrected) and hypoperfusion in the left lentiform nucleus and left cingulate gyrus (p<.001 and p=.001, uncorrected), compared to children without the G/G genotype. Conclusion : Although the results of this study should be interpreted cautiously, they suggest a possible role of the MspI polymorphisms of the ADRA2A gene in methylphenidate-induced changes in cerebral perfusion.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.2
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• pp.1061-1065
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• 2013

Objective: To investigate the treatment effect of additional information obtained by single photon emission computed tomography (SPECT) lung perfusion imaging (LPI) in the radiotherapy planning process for patients with stage III non-small cell lung cancer (NSCLC). Methods: 39 patients with stage III NSCLC were enrolled. Gross tumor volume (GTV) was outlined by SPECT/CT images, SPECT-LPIs being used to define functional lung (FL) and non-functional lung (NFL) regions. Two sets of IMRT plans were designed to deliver 64Gy to PTV. One was a regular IMRT plan using CT images only (Plan 1), and the other was a corresponding IMRT plan using co-registered images (Plan 2). $FL_{Vx}$ (the % volume of functional lung receiving ${\geq}$x Gy) and $WL_{Vx}$ (% volume of whole lung to receive ${\geq}$x Gy) were compared by paired Student's t test. Kendalls correlation was used to analyze the factor (s) related with the FLV20 decrease. Results: Compared with plan 1, both $WL_{Vx}$ and $FL_{Vx}$ were decreased in plan 2. $WL_{V10}$, $WL_{V15}$, $WL_{V20}$, $WL_{V25}$, $WL_{V30}$ and $WL_{V35}$ decreased 9.7%, 13.8%, 17.2%, 12.9%, 9.8% and 9.8%, and $FL_{V10}$, $FL_{V15}$, $FL_{V20}$, $FL_{V25}$, $FL_{V30}$ and $FL_{V35}$ decreased 10.8%, 14.6%, 17.3%, 14.5%, 14.5% and 10.5%. $FL_{Vx}$ decreased significantly compared with $WL_{Vx}$. There were significant differences in $WL_{V10}$, $WL_{V15}$, $WL_{V20}$, $WL_{V25}$, $WL_{V3}$ and $FL_{V10}$, $FL_{V15}$, $FL_{V20}$, $FL_{V25}$, $FL_{V30}$ between plan 1 and plan 2 (P=0.002, 0.000, 0.000, 0.005, 0.027 and 0.002, 0.000, 0.000, 0.006, 0.010). According to Kendall correlation analysis, NFL had a negative relation with the percentage FLV20 decrease (r=-0.559, P<0.01), while the distance of PTV and NFL center had a significantly positive relation with the percentage of FLV20 decrease (r=0.768, P<0.01). Conclusion: Routine use of SPECT-LPI for patients undergoing radiotherapy planning for stage III NSCLC appears warranted.

• The Korean Journal of Pain
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• v.24 no.2
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• pp.81-86
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• 2011

Background: Facet joint disease plays a major role in axial low-back pain. Few diagnostic tests and imaging methods for identifying this condition exist. Single photon emission computed tomography (SPECT) is reported that it has a high sensitivity and specificity in diagnosing facet disease. We prospectively evaluated the use of bone scintigraphy with SPECT for the identification of patients with low back pain who would benefit from medial branch block. Methods: SPECT was performed on 33 patients clinically suspected of facet joint disease. After SPECT, an ultrasound guided medial branch block was performed on all patients. On 28 SPECT-positive patients, medial branch block was performed based on the SPECT findings. On 5 negative patients, medial branch block was performed based on clinical findings. For one month, we evaluated the patients using the visual analogue scale (VAS) and Oswestry disability index. SigmaStat and paired t-tests were used to analyze patient data and compare results. Results: Of the 33 patients, the ones who showed more than 50% reduction in VAS score were assigned 'responders'. SPECT positive patients showed a better response to medial branch blocks than negative patients, but no changes in the Oswestry disability index were seen. Conclusions: SPECT is a sensitive tool for the identification of facet joint disease and predicting the response to medial branch block.

• Childhood Kidney Diseases
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• v.17 no.2
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• pp.86-91
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• 2013

Purpose: The aim of this study was to verify renal inflammation following Kawasaki disease (KD) using single photon emission computed tomography along with Technetium-99m dimercaptosuccinic acid scintigraphy (DMSA renal SPECT). Methods: From March 2011 to October 2011, 15 patients diagnosed with KD at the National Health Insurance System Ilsan Hospital were enrolled in the study. All patients underwent DMSA renal SPECT to evaluate renal involvement during the acute phase of KD. Urine ${\beta}2$-microglobulin (${\beta}2$-MG), a marker of renal proximal tubular dysfunction, was also measured to assess renal damage. Results: All 15 patients had normal renal function test results. However, microscopic hematuria and pyuria were observed in 13% and 33% of the patients, respectively. Moreover, urine ${\beta}2$-MG was elevated in 46% of the patients. In addition, patients were divided into two groups based on ${\beta}2$-MG level: those with an increased ${\beta}2$-MG level, and those with a normal ${\beta}2$-MG level. No significant differences were found between these two groups in clinical characteristics, laboratory, sonography, and echocardiography findings. All patients' DMSA renal SPECT scans were normal. Conclusion: Our study showed that mild abnormalities in the urinalysis and elevated urine ${\beta}2$-MG were the only findings of renal involvement in KD. However, no aggressive renal manifestations were detected on DMSA renal SPECT.

• The Korean Journal of Nuclear Medicine
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• v.29 no.1
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• pp.118-124
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• 1995

단일광자방출전산화 단층촬영술을 이용한 영상정보를 효과적으로 얻기 위하여 고려되어야 할 사항으로는 1) 조준기(collimator)의 선택, 2) 기질(matrix)의 크기, 3) 회전각의 수 (number of angles), 4) 360도 또는 180도 획득(acquisition), 5) continuous 또는 step& shoot, 6) 원형 또는 비원형회전 등이 있다. 저자들은 비원형회전으로 검체와 검출기 사이의 거리를 단축시킴으로써 직선성, 균일성, 대조도, 해상력에 미치는 영향을 알아보기 위하여 원형회전 방법과 비교하여 다음과 같은 결과를 얻었다. (1) 비원형회전을 하여도 균일성(uniformity)과 직선성(linearlity)을 유지한다. (2) 균일성, 대조도(contrast), 해상력(resolution)들이 비원형 회전을 한 경우에 보다 더 개선되었다. (3) 영상 획득시간은 비원형회전인 경우에 더 소요되었다. (매스캔 당 10분) 따라서 검사자는 영상 화질의 개선효과와 상반되는 보정(calibration)과 설치(set-up)에 소요되는 시간(매스캔당 10분이상)을 비교하여 자료획득(data acquisition) 회전방법을 선택하여야한다.

• Journal of Korean Neurosurgical Society
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• v.53 no.4
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• pp.235-240
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• 2013

Fusiform aneurysms on the basilar artery (BA) trunk are rare. The microsurgical management of these aneurysms is difficult because of their deep location, dense collection of vital cranial nerves, and perforating arteries to the brain stem. Endovascular treatment is relatively easier and safer compared with microsurgical treatment. Selective occlusion of the aneurysmal sac with preservation of the parent artery is the endovascular treatment of choice. But, some cases, particularly giant or fusiform aneurysms, are unsuitable for selective sac occlusion. Therefore, endovascular coiling of the aneurysm with parent vessel occlusion is an alternative treatment option. In this situation, it is important to determine whether a patient can tolerate parent vessel occlusion without developing neurological deficits. We report a rare case of fusiform aneurysms in the BA trunk. An 18-year-old female suffered a headache for 2 weeks. Computed tomography and magnetic resonance image revealed a fusiform aneurysm of the lower basilar artery trunk. Digital subtraction angiography revealed a $7.1{\times}11.0$ mm-sized fusiform aneurysm located between vertebrovasilar junction and the anterior inferior cerebellar arteries. We had good clinical result using endovascular coiling of unruptured fusiform aneurysm on the lower BA trunk with parent vessel occlusion after confirming the tolerance of the patient by balloon test occlusion with induced hypotension and accompanied by neurophysiologic monitoring, transcranial Doppler and single photon emission computed tomography. In this study, we discuss the importance of preoperative meticulous studies for avoidance of delayed neurological deficit in the patient with fusiform aneurysm on lower basilar trunk.

• Journal of Korean Foot and Ankle Society
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• v.15 no.4
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• pp.212-216
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• 2011

Purpose: This study was designed to analyze the usefulness of Single Photon Emission Computed Tomography/Computed Tomography (SPECT/CT) in diagnosing symptomatic accessory tarsal bones. Materials and Methods: Twenty four feet (16 patients) with symptomatic accessory navicular and/or os trigonum, who agreed to take SPECT/CT, were included in this study. Fifteen feet had accessory navicular, five had os trigonum, and four had both. According to the uptake in the SPECT/CT, 11 feet were classified into high and 13 into low uptake groups. The low uptake group was treated non-operatively, while the high uptake group received operations when initial conservative management failed. A modified Kidner procedure was performed for accessory navicular and arthroscopic excision was done for os trigonum. After a mean follow-up of 6.8 (range, 3~13) months, the American Orthopaedic Foot and Ankle Society (AOFAS) score and the Visual Analogue Scale (VAS) for pain were compared. Results: Patients in the high uptake group had a higher initial mean VAS score ($7.0{\pm}0.8$ vs $2.2{\pm}0.9$, p<0.05) and a lower initial mean AOFAS score ($45.9{\pm}9.2$ vs $83.9{\pm}4.2$, p<0.05) compared to the low uptake group. All patients in the low uptake group improved after non-operative treatment. Seven patients underwent operations and had a decreased VAS ($1.6{\pm}0.5$) and an increased AOFAS score ($88.3{\pm}1.8$) at the last follow-up. Four patients in the high uptake group demonstrated erratic symptoms. Conclusion: SPECT/CT can be a useful diagnostic tool and helpful in designing treatment plans for symptomatic accessory navicular and os trigonum.