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조기표,정경복 한국물리학회 2021 New Physics: Sae Mulli Vol.71 No.7
Pr3+-doped Y2O3 powders were synthesized using high-energy ball milling. Their structural and photoluminescence properties were investigated as functions of the concentration of the praseodymium and the annealing temperatures. The X-ray diffraction peaks of the Y2O3:Pr3+ powders matched the standard X-ray diffraction(XRD) peaks of the cubic Y2O3 phase without impurities well. The intensity of the XRD peak increased with increasing annealing temperature, as did the photoluminescence emission intensity. These results indicate that the crystallinity of the powder improved with increasng annealing temperature. The highest PL emission intensity was observed at an annealing temperature of 1200 ◦C and Pr3+ concentration of 0.1 mol%. The PL spectra showed characteristic peaks at 618 (3P0 ! 3H6), 630 (2D1 ! 3H4), 644 (3P0 ! 3F2), and 509 nm (3P0 ! 3H5) at an excitation wavelength of 285 nm.
박지선,이아영,정경표,최수정,이석모,배상균 대한핵의학회 2013 핵의학 분자영상 Vol.47 No.1
Purpose The aim of this study was to investigate the usefulness of breast-specific gamma imaging (BSGI) with dualphase imaging for increasing diagnostic performance and interpreter confidence. Methods We studied 76 consecutive patients (mean age:49.3 years, range: 33–61 years) who received 925 MBq (25 mCi) 99mTc-sestamibi intravenously. Craniocaudal and mediolateral oblique planar images were acquired for all patients. Delayed images were obtained from all patients 1 h after tracer injection, except for patients with no definite abnormal uptake. All images were classified into four categories: group 1 (definite negative) 0 no definite abnormal uptake; group 2 (possible negative) 0 symmetrically diffuse and amorphous uptake; group 3 (possible positive) 0 asymmetrically mild and nodular uptake;group 4 (definite positive) 0 asymmetrically intense and nodular uptake. To evaluate diagnostic performance, the BSGI studies were classified as positive (group 3 or 4) or negative (group 1 or 2) for malignancy according to a visual analysis. The final diagnoses were derived from histopathological confirmation and/or imaging follow-up after at least 6 months (range: 6–14 months) by both ultrasonography and mammography. Results The patients’ ages ranged from 33 to 61 years, with an average of 49.3 years. Thirteen patients were diagnosed with malignancy, and 63 patients were diagnosed as negative for malignancy. Using early images, 43 patients were classified as group 1, 12 as group 2, 10 as group 3 and 11 as group 4. Based on early images, the sensitivity, specificity,positive predictive value (PPV), negative predictive value (NPV) and accuracy of BSGI were 77 %, 83 %, 48 %, 95 %and 82 %, respectively. Dual-phase BSGI had a sensitivity,specificity, PPV, NPV and accuracy of 69 %, 95 %, 75 %,94 % and 91 %, respectively. The BSGI specificity was significantly higher with dual-phase imaging than with single-phase imaging (p00.0078), but the sensitivity did not differ significantly (p01.0). Based on dual-phase imaging,the sensitivity, specificity, positive predictive value,negative predictive value and accuracy of BSGI for the evaluation of US BI-RADS 4 lesions were 60 %, 86 %,67 %, 83 % and 78 %, respectively. Conclusion Dual-phase imaging in BSGI showed good diagnostic performance and would be useful for increasing interpreter diagnostic confidence, with higher specificity,positive predictive value and accuracy for breast cancer screening as well as the differential diagnosis of breast disease compared with single-phase imaging.
이아영,최수정,정경표,박지선,이석모,배상균 대한핵의학회 2014 핵의학 분자영상 Vol.48 No.1
Purpose The aim of this study was to evaluate the characteristicsof PETand CT features of mediastinalmetastatic lymph nodeson F-18 FDG PET/CTand to determine the diagnostic criteriain nodal staging of non-small cell lung cancer. Methods One hundred four non-small cell lung cancerpatients who had preoperative F-18 FDG PET/CT wereincluded. For quantitative analysis, the maximum SUV ofthe primary tumor, maximum SUV of the lymph nodes(SUVmax), size of the lymph nodes, and average Hounsfieldunits (aHUs) and maximum Hounsfield units (mHUs) of thelymph nodes were measured. The SUVmax, SUV ratio of thelymph node to blood pool (LN SUV/blood pool SUV), SUVratio of the lymph node to primary tumor (LN SUV/primarytumor SUV), size, aHU, and mHU were compared betweenthe benign and malignant lymph nodes. Results Among 372 dissected lymph node stations that werepathologically diagnosed after surgery, 49 node stations weremalignant and 323 node stations benign. SUVmax, LN SUV/blood pool SUV, and size were significantly different betweenthe malignant and benign lymph node stations (P <0.0001). However, there was no significant difference in LN SUV/primary tumor SUV (P =0.18), mHU (P =0.42), and aHU(P =0.98). Using receiver-operating characteristic curveanalyses, there was no significant difference among thesethree variables (SUVmax, LN SUV/blood pool SUV, andsize). The optimal cutoff values were 2.9 for SUVmax, 1.4for LN SUV/blood pool SUV, and 5 mm for size. When thecutoff value of SUVmax≥2.9 and size≥5 mm were used incombination, the positive predictive value was 44.2%, and thenegative predictive value was 90.9 %. When we evaluated theresults based on the histology of the primary tumor, thenegative predictive value was 92.3 % in adenocarcinoma(cutoff values of SUVmax≥2.3 and size≥5 mm) and 97.2 %in squamous cell carcinoma (cutoff values of SUVmax≥3.6and size≥8 mm), separately. Conclusions In the lymph node staging of non-small cell lungcancer, SUVmax, LN SUV/blood pool SUV, and size showstatistically significant differences between malignant andbenign lymph nodes. These variables can be used to differentiatemalignant from benign lymph nodes. The combination of theSUVmax and size of lymph node might have a good negativepredictive value.