치아회분과 석고혼합제제 매식후 Digital Subtraction Radiography에 의한 골량 변화의 평가

김재덕,김광원,조영곤,김동기,최의환,Kim Jae-Duk,Kim Kwang-Won,Cho Yaung-Gon,Kim Dong-Kie,Choi Eui-Hwan 대한영상치의학회 1999 Imaging Science in Dentistry Vol.29 No.2

Purpose : To assess the methods for the clinical evaluation of the longitudinal bone changes after implantation of tooth ash-plaster mixture into the defect area of human jaws. Materials and methods : Tooth ash-plaster mixtures were implanted into the defects of 8 human jaws. 48 intraoral radiograms taken with copper step wedge as reference at soon, 1st, 2nd, 4th, and 6th week after implantation of mixture were used. X-ray taking was standardized by using Rinn XCP device customized directly to the individual dentition with resin bite block. The images inputted by Quick scanner were digitized and analyzed by NIH image program. Cu­equivalent values were measured at the implanted sites from the periodic digital images. Analysis was performed by the bidirectional subtraction with color enhancement and the surface plot of resliced contiguous image. The obtained results by the two methods were compared with Cu­equivalent value changes. Results : The average determination coefficient of Cu-equivalent equations was 0.9988 and the coefficient of variation of measured Cu values ranged from 0.08~0.10. The coefficient of variation of Cu-equivalent values measured at the areas of the mixture and the bone by the conversion equation ranged from 0.06 ~0.09. The analyzed results by the bidirectional subtraction with color enhancement were coincident with the changes of Cu-equivalent values. The surface plot of the resliced contiguous image showed the three dimensional view of the longitudinal bone changes on one image and also coincident with Cu-equivalent value changes after implantation. Conclusion : The bidirectional subtraction with color enhancement and the surface plot of the resliced contiguous image was very effective and reasonable to analyze clinically and qualitatively the longitudinal bone change. These methods are expected to be applicable to the non-destructive test in other fields.

골판톰을 이용한 골밀도측정 참조체의 결정

김재덕,Kim Jae-Duk 대한영상치의학회 2002 Imaging Science in Dentistry Vol.32 No.3

Purpose: To determine the proper reference step wedge for digital Cu-Equivalent Image analyzing systems for measurement of bone density. Meterials and Methods : Radiograms of lumbar vertebrae phantom (1g/㎠) with 3 test copper step wedges of 0.03, 0.05 and, 0.1 mm thickness unit were taken and analyzed using NIH image software on a Macintosh personal computer. Measured densities of the lumbar areas in the Cu-Equivalent images made by utilizing 3 different copper stepwedges were compared with a known bone density. Results: The values of r2 for all copper equivalent images were over 0.99. The mean Cu-Eq value of lumbar in copper equivalent image made by a 0.1 mm copper stepwedge was 0.22 ± 0.06 mm and converted to hydroxyapatite density of 1.03 g/㎠. The stepwedges of 0.03 and 0.05 mm produced results having higher values than the actual known bone density. They did not show the blue and green color level that appeared in lumbar on color enhanced image. Conclusion : A copper stepwedge of adequate thickness and range of steps which can express the range of density of bone being measured should be used.

한국인의 디지털파노라마 방사선영상에서 하악관에 관한 연구

김재덕,김진수,Kim, Jae-Duk,Kim, Jin-Soo 대한영상치의학회 2007 Imaging Science in Dentistry Vol.37 No.1

Purpose : To determine the more valuable information to detect the mandibular canal and the mental foramen in panoramic radiographs of a selected Korean population for the implant. Materials and Methods : This study analysed 288 panoramic radiographic images of patients taken at the Dental hospital of Chosun University retrospectively. Indirect digital panoramic X-ray machine (ProlineXC, PLANMECA, Finland) with processing by using Directview $CR950^@$ (Kodak, U.S.A.) and Direct digital panoramic X-ray machine (Promax, PLANMECA, Finland) were used for all exposures. All images were converted into Dicom format. Results : The common position of the mental foramen was in line with the longitudinal axis of the second premolar (68.1%). The mental foramen was symmetrical in 81.8% of cases. The mandibular canal was not identified at anterior portion and discontinued with the mental foramen in 27.8% of all cases, in 42.4% identified with lower border line continued with the mental foramen, in 14.6% with both upper and lower border lines, and in 15.3% unilaterally identified with lower border line. Conclusion : Clinicians can estimate the upper border line of the mandibular canal from the confirmation of the mental foramen and the lower border line of the mandibular canal symmetrically on the panoramic radiography taken in adjusted midsaggital plane of patient's head.

Digora$\textregistered$에서 정량영상의 특성에 대한 평가

김재덕,Kim Jae-Duk 대한영상치의학회 1999 Imaging Science in Dentistry Vol.29 No.2

Purpose: To clarify the usefulness and the limitation of Digora system/sup (R)/ by evaluating the physical characteristics as the quantitative image on Image Plate(Ip). Materials and Methods: Radiograms were taken by Heliodent MD(Siemens Co.. Germany) with the image plate for adult. Cu-step wedge as reference material. and three pieces of dry mandibular bone. Image analysis was performed by single color enhancement. density measurement with histogram. The relationship between the exposure conditions and the distribution of the pixel values of the image. the variation of pixel values of each step of Cu-step wedge at two different area and Cu-equivalent value of three pieces of dry mandibular bone measure by the conversion equation. Results: There was no linear relationship between the exposure condition and the average pixel value of the image. of which the distribution was not even. The pixel value differences between the center portion and the periphery were ranged from 60 to 70 in vertical plane and from 15 to 26 in horizontal plane. Two plot profile formed at two different areas of the Cu-step wedge were different. The measured Cu-equivalent values showed the discrepancy among the times of measurement. Conclusion: As above results. Image Plate(Ip) of Digora system/sup (R)/ showed the limitation as the quantitative image. The physical property of IP was expected to need to be compensated for the quantitative evaluation of the bone or others

파노라마방사선사진에서 골형태 계측과 구내표준필름에서 구리당량치의 상관관계

김재덕,Kim Jae-Duk 대한영상치의학회 2003 Imaging Science in Dentistry Vol.33 No.3

Purpose: To determine whether the mandibular radiomorphometric indices in panoramic radiography are correlated with the bone mineral density of Cu-equivalent images in intraoral film. Materials and Methods: The bone mineral density (BMD) of the mandibular premolar area was measured in the Cu-equivalent image of intraoral film. The Panoramic Mandibular Index (PMI) and Mandibular Cortical Width (MCW) were measured in panoramic radiographs of six dry mandibles, and the Pearson correlation between PMI, MCW, and BMD were tested. Results: There were no significant correlations between PMI and BMD (r = 0.280), nor between MCW and BMD (r =0.237). Conclusion: The results show that PMI and MCW were poor diagnostic indicators of mandibular BMD in the six dry mandibles used in this study. The correlationship between the mandibular radiomorphometric indices (PMI and MCW) and mandibular BMD needs to be researched further using large in vivo patient samples.

파노라마촬영장치의 협설선형단층상에 의한 상악동과 치조골 평가

김재덕,Kim Jae-Duk 대한영상치의학회 2003 Imaging Science in Dentistry Vol.33 No.3

Purpose: To evaluate the precision of measurements taken of dental implants in bucco-lingually sectioned views of the maxilla by linear tomograms of the panorama and to assess the visibility of the inferior wall of the maxillary sinus. Materials and Methods : Eighty sites prepared with implants of gutta percha cone in the sockets of the upper premolars and molars of 10 dry skulls were radiographically examined using linear tomograms of panorama, and scanned coronally and axially by computed tomography. The differences in mm between the measurements in bucco-lingually sectioned images of maxillary alveolar bone and the true length and width of the implanted gutta percha cones were compared as mean values (mean) and standard deviations (SD) for each radiographic technique. Linear tomography of panorama was compared with computed tomography for visualization of the relationship between the inferior wall of maxillary sinus and the end of each implant. Results: The deviations between the actual implant length and the measured values taken from the linear tomograms (0.44±0.39 mm) was significantly less than the measured values from the multiplanar reconstructed images of the axially scanned computed tomogram (1.21 ± 0.90 mm). There was statistically significant difference (p < 0.05) between two techniques in the differences between the measurements and true implant length. The relationship of the inferior border of maxillary sinus with end of implant was worse identified with the linear tomogram of panorama (68%) than the multiplanar reconstructed image of axially scanned computed tomogram (99%). Conclusion: We could not find any differences in the accuracy of length measurement between the linear tomogram of panorama and computed tomogram, but computed tomogram allowed for a better visualization of the inferior wall of the maxillary sinus than the linear tomogram.

Digital Subtraction Radiography를 이용한 근관치료 후 골회복의 정량적평가에 관한 연구

김재덕,Kim Jae-Duk 대한영상치의학회 1997 Imaging Science in Dentistry Vol.27 No.2

This study was performed to prepare the quantitative method of judging the sensitive prognosis of chronic apical periodontitis as early as possible. The subjects were 25 cases with periapical radiolucencies of which were treated with endodontic treatment. Serial radiographs were taken by standardized method longitudinally. The density slice function of digital radiographic system were employed for quantitative and longitudinal assessment of the radiolucent area and the condensing osteitis simultaneously. Obtained results were as follows: 1. The amount of bone repair after endodontic treatment could be detected quantitatively by the density slice function of digital radiographic system. 2. Within the 6-week period after root canal filling, the prognosis could be evaluated by assessment both radiolucent area and condensing osteitis on digital radiographic system. 3. The pattern of bone repair showed peripheral type in most cases from the 6th week after root canal filling. 4. In longitudinal change, bone repair showed two patterns; the succeeding reduction of radiolucent area showing the increase of condensing osteitis in size till 6th week and following by static state or reduction tendency and the reduction following the initial increase of both areas. 5. Cases with pulpitis by trauma showed initial increase of condensing osteitis at 2nd week, marked reduction of radiolucent area and condensing osteitis at 6th week, and approximately normal bone state at 8th week after root canal filling.

ROC(receiver operating characteristics) 해석

김재덕,Kim Jae-Duk 대한영상치의학회 2000 Imaging Science in Dentistry Vol.30 No.3

1. 일반방사선사진과 칼라화한 방사선사진의 비교에서 각각 필름에서 진단을 시행할 때 ROC해석법에서는 true positive fraction (TPF), false positive fraction (FPF)를 매개변수로 하고 있으므로 우선 두가지 필름형태에 대해 각각 따로 다음과 같이 평가한다. 2. 판정기준 병변없다 A, 거의 없다 B, 모르겠다 C, 거의 있다 D, 있다 E 먼저 일반방사선사진에서 실제로 병소가 총있는 것이 50, 총없는 것이 50인데 위 판정기준 각각에 대해(equation omitted) 3. 곡선만들기 a.횡축은 FPF 종축은 TPF로 한 그래프를 plot를 한다. sensitivity 17/50 specificity 26/50 accuracy 43/100 b. 곡선만들기 프로그램을 이용하여 곡선을 만들시에는 TPF를 a에 입력하고 PFP를 b에 입력한다. 이 plot을 그릴 수 있는 프로그램은 http://www.members.tripod.co.kr/jdakim 또는 http://www.chosun.ac.kr/∼jdakim의 홈페이지내 공개자료실에서 다운 받으실 수 있습니다. (equation omitted) 이 프로그램에서 입력할 a, b의 값은 (equation omitted) 위와같이 입력하여 얻어진 일반방사선사진에서의 판독 결과 얻어진 곡선이 그래프에서 곡선이 된다. 이와 같은 커브를 컬러화한 사진 판독에서 똑같이 시행하여 ROC곡선(윗곡선)을 만든 다음 두 곡선을 비교하여 아래면적이 더 큰 쪽이 병소 판독에 우수하다고 결론짓는다. The purpose of this paper is to explain the making procedure and the usage of receiver operating characteristic (ROC) curve for interpretation of radiographic images. The conventional radiograms obtained after the creation of the lesions in the acrylic plates and were enhanced in color. The observer were informed of which tooth to examine, the 'a priori' probability of a lesion present and the approximate diameter of the lesions. The two groups of films were interpreted separately by the same observer using the same rating scale. The following rating scale was used: A; definitely no lesion, B; probably no lesion, C; not sure, D; probably a lesion, and E; definitely a lesion. In analysis, for each observer the diagnostic results in terms of true positive (TP) and false positive (FP) decisions were plotted on a graph. The lowest point on the graph represents the TP and FP when only decisions designated as E according to the rating scale are included. The next point shows the TP and FP values when diagnoses designated as D are added and so forth. By connecting such plot points, a receiver operating characteristic (ROC) curves is obtained. The area under the curve represents the diagnostic accuracy resulting from a diagnostic performance at pure chance level and a value of 1.0 at perfect performance. This method has been known as an useful method to detect the minute difference for each radiographic technic, each observer and for the different lesion depths.

Panorama 촬영술에 의한 정상 성인 이하선 조영상에 관한 연구

김재덕,Kim Jae-Duk 대한영상치의학회 1996 Imaging Science in Dentistry Vol.26 No.2

This study was performed to determine the postitional relationships of two lobes of parenchyma and to analysis the anatomical feature and its variations of duct on the panoramic views of the normal parotid glands in adults. Materials included 66 panoramic views and anterioposterior views of sialograms of selected persons and the radiograms of the gland experimentally reproduced on dry skull with lead foil and the reference images of computed tomograms of normal persons. Results were as follows : 1. On panoramic view of sialogram, the superficial lobe was revealed with totally being superimposed with the mandibular ramus and condyle and its tail portion superimposed with mandibular angle area, the deep lobe was revealed between the posterior border of the ramus and the mastoid process, and the isthmus was begin from the marked furcation off main duct and superimposed partially with the medial part of the deep lobe. 2, The mean length and the lateral extension of parenchyma was 63.18±8.05mm and 21.78±4.87mm respectively on panoramic view and showed no statistical relationship between them. 3. The main duct was generally perpendicular to the posterior border of ramus at middle portion and its configurations revealed 57,58% of curvilinear type, 21.21% sigmoid type, 15.15% reverse sigmoid type. 4, The interlobular ducts of the deep lobe showed relatively well defined features between the mandibular ramus and the mastoid process.

Morpho-anatomical Characteristics on Spikelet Filling of Different Tiller Orders in Rcie

김재덕,비 에스 벨가라,Kim, Jae-Duk,Vergara, B.S. The Korean Society of Crop Science 1991 Korean journal of crop science Vol.36 No.6

분얼력이 서로 다른 일본형, 인도형, 통일형, Java형, Hybrid등 8개 품종 분얼경의 해부생태학적 특성과 수량 및 수량구성요소를 비교검토하기 위해 국제미작연구소에서 실험을 실시하였다. 1. 1차 분얼의 시작은 일본형 벼는 이앙후 12-14일, 인도형 벼는 9-ll일, 기타품종은 8-l0일 경에 시작되었으며 2차 분얼은 1차 분얼후 7일 (Hybrid)-14일 (SR14453)로 품종간 특성은 1차 분얼과 비슷한 경향이었다. 또한 분얼경수는 1차 분얼경은 4(SR14453)-8개(IR30), 2 차는 3 (SR14453) -20개 (IR30) 이었다. 2. 분얼기간은 21일 (IR14453)-65B (IR30)이 소요되었고 출수는 단기간(6-32일)내에 끝나 생육기간이 다양하였으며 주간의 출수는 밀양 83 호와 운봉벼에서만 가장 먼저 출수하였다. 3. 이삭목의 대유관속수는 품종에 따라 다양하였으며 IR30, 밀양 8003, Rewa, Hybrid 벼는 대유관속수가 소유관속수보다 많았으나 IR47705, Silewah, 운봉벼, SR14453은 반대 의 경향이었다. 4. 이삭목의 대유관속수의 감소율은 주간과 1차 분얼경간에 0(SR14453)-3.0개(Hybrid)로 품종간 차이가 현저하였으며 일반적으로 출현이 빠른 분얼경은 늦은 것보다 유관속수가 많았으나 품종에 따라 차이가 없는 것도 있었다. 5. 분얼경간 수량특성은 임실율이나 천립중은 분얼순서와 큰 차가 없었으나 수당입수의 차가 크기 때문에 수량은 주간에 가장 많았고 1차 분얼경, 2차 분얼경 순으로 감소하는 경향이었으며 주간과 1차 분얼경은 2차 분얼경에 비해 초장, 수장, 엽면적이 크고 유관속의 수가 많았다 . 6. 이삭목의 유관속수는 수당입수 및 수량과 고도의 정의 상관을 보였으나 임실률과 천립중과는 유의성이 없었으며 수당입수는 분얼시기에 따라 부의 상관이 있었으나 출수시기와는 품종간 차이가 인정되었다. Greenhouse experiments were conducted at the International Rice Research Institute during the 1989 dry season to investigate varietal differences in morpho-anatomical characters affecting spikelet filling in different tiller orders. There were varietal differences in tiller initiation and heading dates, and tiller duration. The main culm bad competitive advantage over the other tillers. The maximum contribution to filled spikelet weight was made by primary tillers in low tillering cultivars and by secondary tillers in high tillering cultivars. The reduction in inner vascular bundle (IVB) by tiller orders and the namber of IVB and outer vascular bundles (OVB) varied amop.g cultivars. The number of IVB in the peduncle of IR30, Rewa and Hybrid was more than OVB but in IR47705, Silewah, Unbongbyeo and SR14453, OVB was more than IVB. Early formed tillers produced more IVB than the late formed tillers. The number of IVB was positively correlated with number of spikelet and filled spikelet weight, however percent of filled spikelet did not show significant differences as well as 1000 spikelet weight in all types of cultivars.