[en] The device that controls dynamic motions in a washing machine is called as MICOM. This device includes an IPM that controls the rotation of a tub. Also, the overheating of IPM gives cause for lowering the service life of an applied chip and is directly linked with its faults. A heat sink that is larger than the volume of the applied chip more than 50 times is installed to prevent such overheating. In the operation of the IPM, the temperature specification of the heat sink can be determined as 80 .deg. C under the air temperature of 25 .deg. C. However, the heat sink used at the present time cannot satisfy this condition, so it is necessary to redesign such a heat sink to satisfy this condition. This study proposes an STM that is able to precisely calculate the temperature applied to IPM in a system level prior to redesigning the heat sink. The STM can be considered as a model that complements a JEDEC analysis model. This model implements a parameter analysis to perform the optimization of a heat sink and verifies the priority of parameters to reduce material costs. Furthermore, it investigates a counterproposal that replaces the conventional cooling methods in which it seeks a counterproposal that performs heat dissipation in a device according to the SoC of chips and is able to suppress EMI

[en] We performed this study to compare Tl-201 and Tc-99m MIBI scans for the differentiation of malignant from benign breast mass. Thirty-eight female patients underwent Tl-201 breast scan and thirty-two of them also underwent Tc-99m MIBI scan of the breast. After intravenous injection of 74-111 MBq of Tl-201, early (10 minutes) and delayed (3 hours) images were obtained. Then, 555-740 MBq of Tc-99m MIBI was injected and images after 30 minutes were obtained. We compared Tl-201 and Tc-99m MIBI scans with pathologic results. Twenty-three patients were confirmed to have infiltrating duct carcinoma and fifteen patients to have benign breast mass by excisonal biopsy. The sensitivity of early and delayed Tl-201 scan and Tc-99m MIBI scan in the detection of malignant breast lesion were 100% (23/23), 82% (18/22), and 90% (18/20), respectively. The sensitivity of early Tl-201 scan was significantly higher than that of delayed Tl-201 scan, (p<0.05). The specificity of early and delayed Tl-201 scan and Tc-99m MIBI scan were 73% (11/15), 73% (11/15) and 83% (10/12), respectively (p: not significant). Three patients out of nine with fibroadenoma and one patient with atypical duct hyperplasia were false positive in both early and delayed Tl-201 scans. The size of fibroadenoma with false positive in early and delayed Tl-201 scan (4 cases) was larger than that of 11 fibroadenoma with true negative scan (p<0.01). Metastatic axillary lymph node involvement was present in fifteen patients. The sensitivity to detect metastatic nodes was 38% (5/13) for early Tl-201 images, 15% (2/13) for delayed Tl-201 images, 58% (7/12) for Tc-99m MIBI planar images and 67% (4/6) for Tc-99m MIBI SPECT. The sensitivity of Tc-99m MIBI planar or SPECT was significantly higher than that of delayed Tl-201 images (p<0.05). Early Tl-201 and Tc-99m MIBI scan are useful noninvasive methods to differentiate malignant from benign mass of breast. Tc-99m MIBI scan was sensitive in detecting axillary lymph node metastasis in patients with breast cancer

[en] It is crucial to select the candidate with stage II (increased CBV/CVF and OEF) for revascularization surgery. Eighteen patients with unilateral occlusive disease of the internal carotid artery or the trunk of the middle cerebral artery (MCA) were compared by acetazolamide N-isopropyl-p-[123I]-iodoamphetamine brain SPECT and O-15 labeled gas inhalation steady state PET to differentiate stages of hemodynamic failure. Acetazolamide reactivity was expressed as the asymmetry index (AI). Which was the percentage of the activity rate of the ischemic, to the contralateral area after acetazolamide challenge. Forty eight rectangular regions of interests (ROIs) were placed in the anterior cerebral artery cortex, the anterior watershed, the MCA cortex, posterior watershed and in cerebella hemispheres. Four hundred and sixty ROIs of the ischemic hemisphere were classified as normal (n=107), stage I (CBV/CBF> 0.093 l/min and OEF<0.52; n=117) and stage II (CBV/CBF>0.093 l/min and OEF>0.52; n=140). The AI values in normal, stage I and stage II ROIs -6.2 ±7.8%, -10.1±10.2% and -13.5±10.6%, respectively. The AI significantly differed between normal and stage I (P<0.05) and between stage I and stage II ROIs (P<0.05). The AI correlated with ipsilateral CBF (r=-0.20; P <0.01), OEF (r=0.28; P<0.01), and CBV/CBF (r=-0.28; P<0.01). We concluded that I-123 IMP brain SPECT with acetazolamide challenge could determine the severity of hemodynamic failure and provide a reliable indicator for selection of revascularization surgery

[en] Hot uptake and cold defect in infarct of Tc-99m HMPAO brain SPECT in patients with a subacute stroke were compared with cerebral blood flow (CBF), cerebral blood volume (CBV), oxygen extraction fraction (OEF), cerebral metabolic rate of oxygen consumption (CMRO₂) and hypefixation rate to determine the cause of hot uptake in infarct area. Twelve patients with stroke were studied by positron emission tomography (PET), Tc-99m HMPAO brain SPECT and magnetic resonance (MR) imaging from 5 to 49 days after onset. Four patient showed a hot uptake in the infarct and eight patient showed a cold defect in infarct. Regions of interest (ROIs) were drawn in cold defect and hot uptake of the infarct in both SPECT and PET. CBF and CBV values of the hot uptake group were significantly higher than those of the group with cold defects (P<0.05). CMRO₂ and OEF were not significantly different between the cold defect and the hot uptake groups (ns). The infarct to contralateral ratio in CBF in the hot uptake group was significantly higher than that in the group with cold defects (P<0.05), whereas CMRO₂ ratio was not. The hyperfixation rate (the surplus rate compared with CBF by PET) of the hot uptake and cold defect groups were 0.33±0.21 and 0.05±0.12, respectively (P<0.05), Hyperfixation rate of the hot uptake group was correlated with CBV (r=0.80; P<0.01). We concluded that the hot uptake in the infarct with Tc-99m HMPAO brain SPECT in subacute stroke indicated the relative luxury perfusion. Hyperfixation might be caused by vasodilatation

[en] Cerebral blood flow (CBF) reactivity to acetazolamide (ACZ) is useful to select patients with hemodynamic failure. However, it is still a matter of speculation that varying degree of regional CBF increases after ACZ administration represent the severity or stage of regional hemodynamic failure as assessed by positron emission tomography (PET). We studies to elucidate whether ACZ challenge ¹²³I-IMP brain single photon emission tomography (SPECT) can accurately grade the severity of regional hemodynamic failure. Eighteen patients (M: 16, F: 2, average age: 61 years) with unilateral occlusive disease of the internal carotid artery or the trunk of the middle cerebral artery (MCA). Patients underwent ¹²³I-IMP brain SPECT study with acetazolamide challenge and PET study was carried out within 2 weeks before and after SPECT study. Five healthy volunteers with a mean age of 48 years (range: 28-73yr, M: 3, F: 2) underwent PET studies to determine normal values. In SPECT study, an asymmetry index (Al)-the percentage of radioactivity of region of interest (ROI) in the occlusive cerebrovascular lesion to the contralateral homologous ROI-was used for numerical evaluation of relative ¹²³I-IMP distribution. In PET study, regional CBF, oxygen extraction fraction (OEF), cerebral metabolic rate of oxygen (CMRO₂) and cerebral blood volume (CBV) values were measured with ¹⁵O-labeled gas inhalation method and the values were used for comparison with Al (Al during acetazolamide challenge-Al of basal study) on the SPECT study. ROIs were classified by severity into three groups (normal, stage I and stage II). Mean values of Al in areas with normal, stage I and stage II hemodynamic failure were 6.25±7.77% (n=107), -10.38±10.41% (n=117) and 13.30±10.51% (n=140), respectively. Al significantly differed with each groups (p<0.05) Correlation between Al and CBF, OEF and CBV/CBF in hemisphere with occlusive cerebrovascular lesion was 0.20 (p<0.01), -0.28 (p<0.01), -0.28 (p<0.01), respectively. We concluded that ¹²³I-IMP brain SPECT with acetazolamide challenge could determine the severity and stage of regional hemodynamic failure as assessed by PET

[en] A 69-year old male with cholangiocellular carcinoma (CCC) was assigned to our department for whole body PET/CT scan. ¹⁸F- FDG PET/CT images showed an intense hypermetabolic lobulating mass(SUVmax= 8.7 / size : 11.4 mm) in the right hepatic lobe with multiple metastatic lung nodules. We made three dimensional volume rendering fusion images by using advantage workstation 4.3 (GE health care) which provide quick anatomic overview and improve the planning process significantly

[en] A 53-year-old man underwent ¹⁸F-FDG whole body PET/CT because of the detected liver mass on abdominal CT. The PET/CT showed a huge liver mass (9x9cm, SUV: 12.12 ) in the right lobe and a focally hypermetabolic lesion in RLQ was the physiologic uptake of ureter or a metastatic lesion of small bowel. We repeated the abdominal PET/CT next day. The focally hypermetabolic lesion was identified as the appendiceal mass. He underwent right hemicolectomy and right lobectomy of the liver. It was confirmed that the lesion was appendiceal adenocarcinoma with liver metastasis. Cancer of the appendix is an uncommon disease that is rarely suspected before surgery. But, we suggest that PET/CT is useful to identify the small lesion like appendiceal malignant mass

[en] A 71-year-old woman was assigned to our department for Tc-99m myocardial perfusion SPECT(MPS) and coronary CT angiography. She admitted for substernal pain, via the ER, 2 days ago. The heart was scanned after intravenous injection of 925 MBq of ^99mTc-sestamibi adenosine-induced stress SPECT using dual head gamma camera (Hawkeye, GE healthcare. USA). The MPS shows decreased tracer uptake in the apical and mid area of anterior and lateral wall and mid and basal inferior wall. Coronary CT angiography was obtained using Discovery VCT (GE healthcare). 3D angiography portrayed significant stenosis of ramus intermedius(RI) and posterolateral branch of right coronary artery(PLB) with fibrocalcified plaque. Two images were fused using Cardiac IQ fusion software package (Advantage workstation 4.4, GE healthcare) The fusion images explain the perfusion defect of anterior, lateral and inferior wall is due to stenosis of the RI and PLB. And 3 days later, coronary angiography was done and revealed the marked stenosis of RI and PLB. Then balloon angioplasty and stent was instituted in RI. Cardiac SPECT/CT fusion imaging provides additional information about hemodynamic relevance and facilitates lesion interpretation by allowing exact allocation of perfusion defects to its subtending coronary artery

[en] Positron emission tomography (PET) using F-18 fluorodeoxyglucose (FDG) is frequently used to characterize malignant mediastinal lymphadenopathy suspected of being malignant. However, increased FDG activity in benign mediastinal lymphadenopathy is not uncommon and can be seen with active granulomatous disease (tuberculosis, fungal infections, and sarcoidosis) producing false-positive FDG results. An 58-year-old man presented to our PET Center for FDG positron emission tomography (PET) evaluation of a multiple mediastinal lymphadenopathy found on computed tomography (HRCT). The multiple lymphadenopathy was moderate FDG-avid, raising the possibility of malignancy. In addition, FDG-avid skin lesion and lymphadenopathy in left parotid gland was noted. A mediastinoscopic biopsy was performed and the lymphadenopathy was found to be sarcoidosis. This case emphasizes the limitations of specificity of FDG PET in mediastinal lymphadenopathy and the importance of confirming suspected malignancy with histology before potentially curative treatment is undertaken

[en] Conventional chest X-ray and pulmonary function test cannot sensitively detect inhalation injury. Bronchoscopy is known to be the gold standard but it is invasive method. We evaluated whether lung inhalation/perfusion scans can sensitively detect inhalation injury of fire victims. Nineteen patients (male 9, female 10, mean age 31.6 yr) of fire victims were enrolled in this study. Inhalation lung scan was performed 2 days later after inhalation injury with ^99mTc-technegas. Perfusion lung scan was performed 4 days later with ^99mTc-MAA (macaroaggregated albumin). Follow up lung scans were performed 16 and 18 days later for each. Chest X-ray was performed in all patients and bronchoscopy was performed in 17 of 19 patients at the same period. Pulmonary function test was performed in 9 patients. Four of 19 patients showed inhalation and perfusion defects and one showed inhalation defect but, normal perfusion scan findings. These five patients with abnormal scan findings showed abnormal bronchoscopic findings and severe respiratory symptoms. On chest X-ray, 2 of them had pulmonary tuberculosis and one of them showed pulmonary congestion. FEV1/FVC was abnormal in 3 patients. On the follow up scan, all patients with abnormal initial scan findings showed improved findings and they had improved clinical state. Inhalation/perfusion lung scan can detect inhalation burn injury noninvasively in early stage and may be useful in therapeutic decision making and follow up of patients