• The Korean Journal of Nuclear Medicine
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• v.30 no.1
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• pp.56-64
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• 1996

The purpose of this study was to evaluate the characteristic perfusion changes in patients with Sturge-Weber syndrome by comparison of the findings of brain MR images and perfusion SPECT images. $^{99m}Tc$-HMPAO or $^{99m}Tc$-ECD interictal brain SPECTs were performed on 5 pediatric patients with Sturge-Weber syndrome within 2 weeks after MR imaging. Brain SPECTs of three patients without calcification showed diminished perfusion in the affected area on MR image. A 3 month-old patient without brain atrophy or calcification demonstrated paradoxical hyperperfusion in the affected hemisphere, and follow-up perfusion SPECT revealed decreased perfusion in the same area. The other patient with advanced calcified lesion and atrophy on MR image showed diffusely decreased perfusion in the affected hemisphere, but a focal area of increased perfusion was also noted in the ipsilateral temporal lobe on SPECT. In conclusion, brain perfusion of the affected area of Sturge-Weber syndrome patients was usually diminished, but early or advanced patients may show paradoxical diffuse or focal hyperperfusion in the affected hemisphere. Further studies are needed for better understanding of these perfusion changes and pathophysiology of Sturge-Weber syndrome.

• Clinical and Experimental Pediatrics
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• v.50 no.11
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• pp.1116-1124
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• 2007

Purpose : Juvenile dermatomyositis (JDM) is the most common of the idiopathic inflammatory myopathies in children. The purpose of this study is to observe demographic, initial presentations, duration of time between disease onset and diagnosis, clinical manifestations and laboratory findings at diagnosis of patients with JDM. Methods : Forty seven patients identified at Seoul National University Children's Hospital from January 1986 to May 2007. Medical records were reviewed retrospectively focusing on initial presentations, clinical manifestations and laboratory findings at the time of diagnosis of patients with JDM. Results : Male and female patients were 25 and 22, respectively and sex ratio was 1.14:1. The average age at the time of diagnosis was 6.51 years. Skin rash (94%) was the most common symptom, followed by the proximal muscle weakness (89%). The disease activity score was 10.8. The duration between the onset of the skin rash and the muscle weakness and diagnosis was 7.18 and 4.70 months, respectively. The serum muscle enzymes, LDH, AST, CK and aldolase, were elevated in the patient with JDM. Autoimmune antibodies, antinuclear antibody, anti SSA antibody and anti SSB antibody, were negative findings. Electromyography findings were consistent with JDM in 88% of the patients, the muscle biopsy was in 91% and all MRI findings were compatible with those of patients with JDM. The most common symptom besides musculocutaneous lesions was the calcinosis (62.5%). The most common site of calcinosis was the pelvic area and buttocks. Conclusion : This study shows that the major symptoms are proximal muscle weakness and cutaneous lesion, and they are important to diagnose JDM.

• The Korean Journal of Nuclear Medicine
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• v.35 no.1
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• pp.23-32
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• 2001

Purpose: Cortical dysplasia (CD) designates a diverse group of malformations resulting from one or more abnormalities in the development of the cerebral cortex. We investigated the findings of interictal SPECT and the diagnostic usefulness of interical and ictal SFECT according to pathological grading (PG) in comparison with MRI. Materials and Methods: This study included 16 patients (M:F=9:7, age: $19.9{\pm}11.8$ yrs) with pathologically proven CD. Tc-99m ECD SPECT was performed in all patients: interictal 11, interictal and ictal 3, ictal 2. MRI were obtained in all patients and image analysis was done blindly as to the result of SPECT. Pathologic findings of CD were classified into grade 1 G1, dyslamination), grade 2 (G2, dysplastic neurons) and grade 3 (G3, balloon cells). We compared SFECT with MRI in lesions-to-lesions and analyzed the result according to PG. Results: In SFECT and MRI. 38 and 27 lesions were visually recognized. In 14 interictal SPECT, variable findings in 35 lesions were demonstrated: 25 were hypoperfusion, 7 hyperperfusion, 2 heterotopic perfusion in the white matter. By comparison between two studios, missed lesions were founded: SPECT were 1 lesion, MRI 12. Review of missed 12 lesions of MRI were followed according to PG: G1 patients were 16.7% (4/19), G2 40.0% (6/15), and G3 50% (2/4). Conclusion: Interictal SFECT in CD showed variable findings such as hypoperfusion, hyperperfusion or heterotopic perfusion. However, for detection of missed CD on MRI, SFECT may help to detect a functional abnormality of the lesion with high PG.

• Investigative Magnetic Resonance Imaging
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• v.6 no.2
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• pp.129-136
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• 2002

Purpose : To evaluate the usefulness of MRCP in the diagnosis of the variable causes of common bile duct(CBD) dilatation, except stone or tumor Materials and methods : Twenty-six patients(M:F=15:11, mean age; 62 years) with both MRCP and ERCP were included in this study. Dynamic MRCP(n=12) and contrast-enhanced MRI(n=10) of abdomen were also added. Dilatation of CBD, intrahepatic ducts and pancreatic duct was evaluated, including coexistence of intrahepatic ductal stone, pancreatic pseudocyst, and papillary or papillary edema. The criteria of CBD dilatation was over than 7mm(n= 21, without cholecystectomy) or 10 mm(n=5, with cholecystecto-my) in diameter on T2-weighted coronal image. Results : The mean diameter of CBD was 12.7mm without cholecystectomy(9-19 mm) and 13.0 mm with cholecystectomy(10-15mm), respectively(p 〉0.05). Cholangitis(n=11, 42.3%), chronic pancreatitis(n=8, 30.8%), stenosis of distal CBD(n= 6, 23.1%), periampullary diverticulum(n=3, 11.5%), stenosis of ampulla of Vater(n=2, 7.7%), dysfunction of sphincter of Oddi(n=2, 7.7%), acute focal pancreatitis in the pancreatic head(n=2, 7.7%), papillitis(n=1, 3.8%), pseudocyst in the pancre atic head(n = 1, 3.8%), and ascaris in CBD(n=1, 3.8%) were noted. Pancreatic duct dilatation(n=10, 38.5%) and duodenal diverticulum(n=3, 11.5%) were also seen on MRC P. On dynamic MRCP(12 patients), distal CBD was visualized in 2 patients(16.7%), which was not shown on routine MRCP. Only 1 patient(10.0%) showed papillitis with slightly enhancing papilla on contrast-enhanced MRI (10 patients). Conclusion : MRCP was thought to be helpful in the evaluation of the causes of CBD dilatation, not caused by stone or tumor, especially in the cases of stenosis of distal CBD and chronic pancreatitis, dysfunction of sphincter of Oddi on dynamic MRCP and cholangitis and pericholangitic abnormality on contrast-enhanced MRI.

• Neonatal Medicine
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• v.17 no.1
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• pp.64-74
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• 2010

Purpose : The aim of this study was to determine the risk factors, clinical characteristics and prognosis for the development of periventricular leukomalacia (PVL) in preterm infants according to the extent and site of the PVL. Methods : The medical records of infants (under 36 weeks of gestational age) delivered from January 1999 to December 2008 were reviewed. Twenty-five preterm infants with were PVL were diagnosed by brain magnetic resonance imaging (MRI) and an addition 50preterm infants with no brain lesions were enrolled in this study. The perinatal and neonatal risk factors for the development of PVL was determine in these infants. Mental and Psychomotor Developmental Indices (MDI, PDI) were assessed by a clinical psychologist using the Bayley Scales of Infant Development II. We compared the differences of the clinical characteristics and prognosis according to brain MRI findings. Results : Maternal fever, young maternal age, extended oxygen use, hypotension within the first week of birth, use of inotropics within the first week of birth, and respiratory distress syndrome were the risk factors associated with PVL (P <0.05). In the multivariate analysis, maternal fever and extended oxygen use were statistically significant independent risk factors (P <0.05). The mean MDI and PDI scores of the PVL group (74.4$\pm$ 27.8 and 58.0$\pm$17.7) were significantly lower than those of the control group (103.5$\pm$8.9 and 101.7$\pm$16.1, P <0.05). Conclusion : Maternal fever and extended oxygen use were independent risk factors for PVL. We should pay attention to infants who had the risk factors and follow them up closely by brain imaging study and Bayley Scales of Infant Development II.

• Journal of radiological science and technology
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• v.29 no.3
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• pp.167-175
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• 2006

With the recent prevalence of helical CT and multi-slice CT, which deliver higher radiation dose than conventional CT due to overbeaming effect in X-ray exposure and interpolation technique in image reconstruction. Although multi-detector and helical CT scanner provide a variety of opportunities for patient dose reduction, the potential risk for high radiation levels in CT examination can't be overemphasized in spite of acquiring more diagnostic information. So much more concerns is necessary about dose characteristics of CT scanner, especially dose efficient design as well as dose modulation software, because dose efficiency built into the scanner's design is probably the most important aspect of successful low dose clinical performance. This study was conducted to evaluate z-axis geometric dose efficiency in single detector CT and each level multi-detector CT, as well as to compare z-axis dose efficiency with change of technical scan parameters such as focal spot size of tube, beam collimation, detector combination, scan mode, pitch size, slice width and interval. The results obtained were as follows ; 1. SDCT was most highest and 4 MDCT was most lowest in z-axis geometric dose efficiency among SDCT, 4, 8, 16, 64 slice MDCT made by GE manufacture. 2. Small focal spot was 0.67-13.62% higher than large focal spot in z-axis geometric dose efficiency at MDCT. 3. Large beam collimation was 3.13-51.52% higher than small beam collimation in z-axis geometric dose efficiency at MDCT. 4. Z-axis geometric dose efficiency was same at 4 slice MDCT in all condition and 8 slice MDCT of large beam collimation with change of detector combination, but was changed irregularly at 8 slice MDCT of small beam collimation and 16 slice MDCT in all condition with change of detector combination. 5. There was no significant difference for z-axis geometric dose efficiency between conventional scan and helical scan, and with change of pitch factor, as well as change of slice width or interval for image reconstruction. As a conclusion, for reduction of patient radiation dose delivered from CT examination we are particularly concerned with dose efficiency of equipment and have to select proper scanning parameters which increase z-axis geometric dose efficiency within the range of preserving optimum clinical information in MDCT examination.

• Neonatal Medicine
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• v.17 no.2
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• pp.224-231
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• 2010

Purpose: Hospital readmissions have recently increased due to early hospital discharge and increased trends in breast-feeding. Neonatal hyperbilirubinemia can lead to fatal permanent neurological sequelae without appropriate management. Early detection and intervention are critical. We evaluated the clinical features, risk factors, and brain MRI findings of Korean newborns with idiopathic nonhemolytic hyperbilirubinemia to determine the optimal management policy. Methods: A retrospective review of the medical records of 79 newborns with idiopathic nonhemolytic hyperbilirubinemia was performed at the NICU of the Kyungpook National University Hospital from January 2006 to September 2009. All patients were 35 or more weeks of gestation, and their peak level of serum total bilirubin was more than 20 mg/dL. Results: The mean gestational age was $38^{+3}{\pm}1^{+4}$ weeks, and the mean age on admission was 8.8$\pm$4.0 days. The mean body weight (3,105$\pm$479 g) was decreased by 2.8$\pm$6.4 percent compared to the mean birth weight (3,174$\pm$406 g). There were no statistically significant differences for the peak serum bilirubin level or the duration and effects of phototherapy between the patients with and without risk factors, which included: breastfeeding, cephalohematoma, subdural hemorrhage, and/or ABO incompatibility. Patients were grouped according to change of body weight. Group I consisted of patients that gained weight compared to birth weight, and group II of patients that lost weight compared to birth weight. There were significant differences in the peak serum total bilirubin level between the two groups. Thirty nine patients had brain MRI evaluation; 21 patients had bilateral symmetric signal intensity increases in the globus pallidus compared to adjacent corticospinal tract and putamen on T1-weighted images. Conclusion: Bilirubin encephalopathy is preventable with early screening and proper management. Parents require instruction on feeding practices and follow-up to prevent complications from idiopathic nonhemolytic hyperbilirubinemia.