• Journal of the Korean Society of Radiology
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• v.5 no.5
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• pp.303-308
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• 2011

Background/Aims : The increasing use of diagnostic and therapeutic interventional radiology calls for greater consideration of radiation exposure risk to radiologist and radiological technician, and emphasizes the proper system of radiation protection. This study was designed to assess the effect of a protective grass shield. Methods : A protective grass was following data depth, 0.8 cm; width, 100 cm; length, 100 cm, lead equivalent, 1.6 mmPb. The protective shield was located between the patient and the radiologist. Thirty patients (13 male and 17 female) undergoing interventional radiology between September 2010 and December 2010 were selected for this study. The dose of radiation exposure was recorded with or without the protective grass shield at the level of the head, chest, and pelvis. The measurement was made at 50 cm and 150 cm from the radiation source. Results : The mean patient age was 69 years. The mean patient height and weight was $159.7{\pm}6.7$ cm and $60.3{\pm}5.9$ kg, respectively. The mean body mass index (BMI) was $20.5{\pm}3.0$ kg/m2. radiologists received $1530.2{\pm}550.0$ mR/hr without the protective lead shield. At the same distance, radiation exposure was significantly reduced to $50.3{\pm}85.2$ mR/hr with the protective lead shield (p-value<0.0001). The radiation exposure to radiologist and radiological technician was significantly reduced by the use of a protective lead shield (p value <0.0001). The amount of radiation exposure during interventional radiology was related to the patient' BMI (r=0.749, p=0.001). Conclusions : This protective shield grass is effective in protecting radiologist and radiological technician from radiation exposure.

• Nuclear Medicine and Molecular Imaging
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• v.42 no.3
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• pp.201-208
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• 2008

Purpose: We aimed to assess the role of positron emission tomography using fluorodeoxyglucose (FDG-PET) in the diagnosis of recurrence or the assessment of therapeutic response in cervical and ovarian cancer patients through making a comparison between FDG-PET, abdominal computed tomography (CT) and serum tumor marker. Materials and methods: We included 103 cases (67 patients) performed FDG-PET and abdominal CT. There were 42 cervical cancers and 61 ovarian cancers. We retrospectively reviewed the interpretations of PET and CT images as well as the level of tumor marker. We calculated their sensitivity, specificity, positive predictive value and negative predictive value for these three modalities. And then we analyzed the differences between these three modalities. Results: Tumor recurrences were diagnosed in 37 cases (11 cervical cancers and 26 ovarian cancers). For PET, CT and tumor marker, in cervical cancer group, sensitivity was 100% (11/11), 54.5% (6/11) and 81.1% (9/11), respectively. And specificity was 93.6% (29/31), 93.6% (29/31) and 100% (31/31). In ovarian cancer group, sensitivity was 96.2% (25/26), 84.6% (22/26) and 80.8% (21/26), and specificity was 94.3% (33/35), 94.3% (33/35), 94.3% (33/35), PET was highly sensitive to detect the intraperitoneal and extraperitoneal metastasis with the help of the CT images to localize the lesions. However, CT had limitations in differentiation of the recurrent tumor from benign fibrotic tissue, identification of viable tumors at the interface of tissues, and detecting extraperitoneal lesions. Conclusion: FDG-PET can be an essential modality to detect the recurrent or residual tumors in gynecologic cancer patients because of its great field of the application and high sensitivity.

• Journal of Gastric Cancer
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• v.9 no.4
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• pp.172-176
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• 2009

Purpose: The rapid urease test is a rapid and reliable method for diagnosing Helicobacter pylori infection. However it requires gastric mucosal biopsies during endoscopy, and the test is not covered by national health insurance for patients with gastric cancer. So, we introduced an alternative method for a rapid urease test using back-table gastric mucosal biopsies from gastrectomy specimen. Materials and Methods: Ninety gastric cancer patients underwent an anti H. pylori IgG ELISA test and gastrectomy. Just after gastrectomy, two gastric mucosal biopsies from the prepyloric antrum and lower body of the gastrectomy specimen were taken from the back table in the operative room, and these were fixed immediately with the rapid urease test kit, and the color change was monitored for up to 24 hours. In this study, H. pylori infection was defined as positive when the serology or rapid urease test showed positive results. Results: The positive rate of the rapid urease test and serology was 91.1% and 77.8%, respectively. The sensitivity, specificity, positive predictive value and negative predictive value of the rapid urease test and serology were 94.3 and 80.5%, 100 and 100%, 100 and 100%, and 37.5 and 15%, respectively. The accuracy of the rapid urease test was higher than that of serology (94.4 vs. 81.1%, respectively). The rapid urease test showed a higher rate of detecting H. pylori infection than that of serology (McNemar's test, P=0.019). Conclusion: The result of the rapid urease test using back-table gastric mucosal biopsies from a gastrectomy specimen is comparable to the reference data of the conventional rapid urease test using gastric mucosal endoscopic biopsies. Therefore, it can be an alternative diagnostic method for H. pylori infection.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.2
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• pp.35-43
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• 2012

Purpose : PET/CT performed CT-based attenuation correction generates the beam hardening artifact by metallic implant. The attenuation correction causes over or underestimate of the area adjacent to metallic hip prosthetic material and change of $^{18}F$-FDG uptake. Also, the image quality and the diagnosability on genitourinary disease are reduced. Therefore, this study will evaluate the usefulness of MAR (Metal Artifact Reduction) algorithm method to improve the image quality on PET/CT. Materials and Methods : PET/CT was performed by fixing hip prosthesis in SPECT/PET phantom. In PET images with and Without MAR algorithm, the Bright streak, Dark streak, Metal region and Background area that appeared on CT were confirmed, and the change of each SUV (standardized uptake value) was analyzed. Also, in 15 patients who underwent total hip arthroplasty, each MAR algorithm and Without MAR algorithm and non attenuation correction was evaluated. Results : In PET image Without MAR algorithm, SUV of Bright streak region was $0.98{\pm}0.48$ g/ml; Dark streak region was $0.88{\pm}0.02$ g/ml; Metal region was $0.24{\pm}0.16$ g/ml, Background area was $0.91{\pm}0.18$ g/ml. In SUV of PET image with MAR algorithm, Bright streak region was $0.88{\pm}0.49$ g/ml, Dark streak region was $0.63{\pm}0.21$ g/ml, Metal region was $0.06{\pm}0.07$ g/ml, Background was $0.90{\pm}0.02$ g/ml. SUV generally decreased when applying MAR algorithm. In PET image Without MAR algorithm, SUVs of Bright region were higher than those measured in the Background, and it was false positive uptake. But, in PET image with MAR algorithm, SUVs of Bright region were similar to the Background, and false positive uptake disappeared. Conclusion : MAR algorithm could reduce an increase of $^{18}F$-FDG uptake due to attenuation correction in the hip surrounding tissue. However, decrease of SUV in Dark streak region should be considered in the future. Therefore, this study propose that the diagnostic accuracy can be improved in genitourinary diseases adjacent to metallic hip prosthesis, if provided PET images with and Without MAR algorithm, and non attenuation correction images at the same time.

• Tuberculosis and Respiratory Diseases
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• v.41 no.2
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• pp.135-143
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• 1994

Background: The cell mediated immunity has an important role in the pathogenesis of tuberculosis. sIL-2R has been known as a sensitive marker of T lymphocyte activation Elevated serum levels of sIL-2R have been found in patients with lymphoproliferative disorders, organ transplantation, autoimmune diseases, and various granulomatous diseases. Elevated levels of sIL-2R have been also found in the serum and pleural fluid of the patients with tuberculosis. To evaluate the diagnostic value of sIL-2R in the differentiation of tuberculous pleurisy and nontuberculous pleurisy. We measured the level of sIL-2R in the sera and pleural fluids of 12 patients with tuberculous pleurisy and 32 patients with nontuberculous pleurisy. Method: Samples of pleural fluid and serum were centrifuged at 2500 rpm for 10 min to remove cell pellets. Soluble IL-2R was measured with a sandwitch enzyme immunoassay using the Cellfree(r) Interleukin-2 Receptor Test kit(T-cell science,Inc. Cambridge, MA). Results: The results obtained were as follows: 1) The sIL-2R level in pleural fluid of the patients with tuberculous pleurisy was higher than that of patients with nontuberculous pleurisy(P<0.005). 2) When the sIL-2R level above 5,000 u/ml in pleural fluid was used as the cut-off value to diagnose tuberculous pleurisy, it had a sensitivity of 84.6% and a specificity of 90.9%. 3) The sIL-2R level in the sera of the patients with tuberculous pleurisy was higher than that of patients with bacterial pleural effusions and normal control group(P<0.05) and there was no difference of levels compared with malignant pleural effusions and transudative pleural effusions(P>0.05). 4) In patients with tuberculous pleurisy, the mean concentration of sIL-2R in pleural fluid was higher than that in serum(P<0.005). Conclusion: These findings suggest that the measurement of elevated levels of pleural fluid sIL-2R in tuberculous pleurisy may be useful in the differential diagnosis between patients with tuberculous pleurisy and nontuberculous pleurisy.

• Tuberculosis and Respiratory Diseases
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• v.57 no.6
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• pp.528-534
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• 2004

Background : Microscopic examination of sputum smears for acid-fast bacilli (AFB) is the most important and rapid diagnostic test for pulmonary tuberculosis. However, the AFB observed on the smear may represent either M. tuberculosis or nontuberculous mycobacteria (NTM). This study examined the clinical usefulness of a polymerase chain reaction test for M. tuberculosis (TB-PCR) for the differentiation of pulmonary tuberculosis and NTM lung disease in patients with smear-positive sputums in a tertiary hospital in Korea. Material and Methods : From January, 2003 to December, 2003, 826 AFB smear-positive and culture-positive sputum specimens were collected from 299 patients. Results : NTM were recovered from 26.6% (220/826) of the smear-positive sputum specimens and 23.4% (70/299) of the patients with smear-positive sputum. All the patients with isolated NTM had clinically significant NTM lung disease; 38 patients (54.3%) had M. avium and 26 patients (37.1%). had M. abscessus. In the patients with pulmonary tuberculosis, 78.7% of the patients (74/94) showed TB-PCR positivity, and all the patients with NTM lung disease showed negative results on the TB-PCR test (p<0.001). A positive result of the TB-PCR test on the sputum or bronchial washing fluid specimens was able to predict pulmonary tuberculosis with 88.4% sensitivity, 100% specificity, a 100% positive predictive value and a 79.7% negative predictive value for the patients with smear-positive sputum. Conclusion : The TB-PCR test for sputum specimens or bronchial washing fluid specimens could be useful for differentiating pulmonary tuberculosis and NTM lung disease for the patients with smear-positive sputum in Korea.

• Progress in Medical Physics
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• v.17 no.2
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• pp.61-66
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• 2006

To evaluate the T1, T2 magnetic relaxation properties of water molecule according to molecular weight of paramagnetic complex. 4-aminomethyicyclohexane carboxylic acid (0.63 g, 4 mmol) was mixed with the suspension solution of DMF (15 ml) and DTPA-bis-anhydride (0.71 g, 2 mmol) to synthesize the ligand. The ligand was then mixed with $Gd_2O_3$ (0.18 g, 0.5 mmol) to synthesize Gd-chelate. For the measurement of magnetic relaxivity of paramagnetic compounds, the compounds were diluted to 1 mM and then the relaxation times were measured at 1.57 (64 MHz). Inversion-recovery pulse sequence was employed for T1 relaxation measurement and CPMG (Carr-Purcell-Meiboon-Gill) pulse sequence was employed for T2 relaxation measurement. In case of inversion recovery sequence, total 35 images with different inversion time(T1)s ranging from 50 msec to 1,750 msec. To estimate the relaxation times, the signal intensity of each sample was measured using region of Interest (ROI) and then fitted by non-linear least square method to yield T1, T2 relaxation times and also R1 and R2. Compared to T1=($205.1{\pm}2.57$) msec and T2=($209.4{\pm}4.28$) msec of Omniscan (Gadodiamide), which is commercially available paramagnetic MR agent, T1 and T2 values of new paramagnetic complexes were reduced along with their molecular weight. That is, T1 value was ranged from $(96.35{\pm}2.04)\;to\;(79.38{\pm}1.55)$ msec and T2 value was ranged from $(91.02{\pm}2.08)\;to\;(76.66{\pm}1.84)$ msec. Among new paramagnetic complexes, there is a tendency that the R1 and R2 increase as the molecular weight is increases. As molecular weight of paramagnetic complex increases, T1 and T2 relaxation times reduce and thus the increase of relaxivity (R1 and R2) Is proportional to molecular weight.

• Clinical and Experimental Pediatrics
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• v.53 no.4
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• pp.519-524
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• 2010

Purpose : To determine the efficacy of the N-terminal fragment of B-type natriuretic peptide (NT-proBNP) as a useful diagnostic method in children with incomplete Kawasaki disease (KD). Methods : Ninety-six patients who were diagnosed as having KD between January 2008 and June 2009 were enrolled in the study. American Heart Association recommendations for diagnosis were used, and patients were divided into the complete KD and incomplete KD groups. Blood tests including NT-proBNP were performed on admission day. Nineteen patients who had other febrile diseases other than KD were enrolled as control. Results : Thirty-three patients (34%) had incomplete KD. Change in the lips and oral cavity and conjunctivitis were the most common clinical features, but their frequency was lower than complete KD (76% vs 98%, 76% vs 90%). Patients with incomplete KD exhibited significantly higher NT-proBNP level than that of control ($1,407.7{\pm}1633.5pg/mL$ vs $126.2{\pm}135.5pg/mL$, $P$<0.001). An NT-proBNP cutoff value of 158 pg/mL provided a sensitivity of 81% and a specificity of 74% for diagnosis of incomplete KD. Conclusion : NT-proBNP assay can be clinically useful for the diagnosis of incomplete KD, if the patient has persistent fever, change in the lips and oral cavity, and conjunctivitis, and if the patient with those symptoms is suspected to have incomplete KD.

• Journal of radiological science and technology
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• v.32 no.3
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• pp.271-276
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• 2009

The aim of this study was to evaluate the effect of Bone Mineral Density(BMD) at mandible. So, we studied how to measure the BMD at mandible using DEXA(Dual energy X-ray absorptiometry, DEXA) by Horner er al (1996) and knew reproducibility of the measurements. Thirty-five patients (13 men, 22 women, mean age : 25.4 years) were examined using the GE Lunar Prodigy Advance(LUNAR Corporation, madison, USA). They were examined in Semiprone position of their body and true lateral position of their mandible selected the Lumbar lateral mode. We used the custom mode in analysis when ROI (area $30{\times}2.5\;mm^2$). Three ROIs ($30{\times}2.5\;mm^2$, $50{\times}2.5\;mm^2$, $20{\times}2.5\;mm^2$) were located each at the two different sites of the mandible (angle of mandible and mental symphysis) and BMD was measured. Differences in BMD measurement was statistically compared according to the size and location of ROI. BMD was $1.320{\pm}0.358g/cm^3$ in men and was $1.152{\pm}0.340g/cm^3$ in women. BMD at the angle of mandible was $1.201{\pm}0.361g/cm^3$ in men and was $1.025{\pm}0.377g/cm^3$ in women. BMD of men at the mental symphysis was $1.434{\pm}0.341g/cm^3$ and that of women was $1.19{\pm}0.358g/cm^3$. With the ROI of $20{\times}2.5\;mm^2$, BMD was $1.262{\pm}0.384g/cm^3$ in men and was $1.113{\pm}0.357g/cm^3$ in women. With the ROI of $50{\times}2.5\;mm^2$, BMD of men was $1.320{\pm}0.358g/cm^3$ and that of women was $1.129{\pm}0.340g/cm^3$. There was a statistically significant difference of BMD according to the size and location of ROI. When measuring mandible BMD, there are good for increasing ROI and locate between ramus and mental symphysis. Especially following exam, refer to same size and location with fore exam. According to study which measure mandible BMD, It's correct to measure better a portion of mandible then whole of BMD. Using DEXA protocol is studied good for the additional study to compare the BMD at mandible. Later date, It will be good for measurement value in implant and bone graft quantitatively. Using DEXA method gain BMD threshold value in korean.

• Radiation Oncology Journal
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• v.17 no.3
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• pp.261-267
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• 1999

Purpose : In FSRT (Fractionated stereotactic radiotherapy) planning, we studied the usefulness between multiple arc FSRT and conformal FSRT by comparing tumor shape and DVH (dose volume histogram). Materials and Methods In Chungnam Univ. hospital, we had treated the sixteen patients with FSRT from Aug. 1997 to Dec. 1998. In choosing multiple arc FSRT or conformal FSRT, we had considered If (irregular factor) after calculating tumor volume and surface area. We had considered multiple arc FSRT if tumor shape was similar to sphere or the value of If was less than 1.25, conformal FSRT if tumor shape was very irregular or If was more than 1.3. For evaluation of treatment planning, we had considered the appropriate DVH for tumor volume and for critical organs. Results : The errors between reference point and the coordinates point on AP, Lat radiography were less than 1 mm before treatment. We had planned $3\~$5 arcs for multiple arc FSRT, $5\~6$ports for conformal FSRT. The mean dose distribution of tumor volume of cumulative DVH between multiple arc FSRT and conformal FSRT was 90.6, 85%, respectively. The dose of critical organs irradiated was less than $5\%$ maximum dose of cumulative DVH. Conclusion : We had obtained the similar value between multiple arc FSRT and conformal FSRT, so that we had appropriate treatment planning of FSRT for multiple arc FSRT and conformal FSRT according to tumor shape and size.