• Imaging Science in Dentistry
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• 제48권4호
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• pp.269-275
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• 2018

Purpose: The aim of this study was to evaluate the correlations between measurements made using panoramic radiography and cone-beam computed tomography (CBCT) based on certain anatomical landmarks of the jaws, with the goal of preventing complications due to inaccurate measurements in the pre-surgical planning phase of dental implant placement. Materials and Methods: A total of 56 individuals who underwent panoramic radiography and a CBCT evaluation before dental implant surgery were enrolled in the study. Measurements were performed to identify the shortest vertical distance between the alveolar crest and neighboring anatomical structures, including the maxillary sinus, nasal floor, mandibular canal, and foramen mentale. The differences between the measurements on panoramic radiography and CBCT images were statistically analyzed. Results: Statistically significant differences were observed between the measurements on panoramic radiography and CBCT for all anatomical structures (P<.05). The correlation coefficients (r) between the paired samples obtained from panoramic radiography and CBCT were closely correlated (P<.05), with r values varying from 0.921 and 0.979 for different anatomical regions. Conclusion: The results of this study support the idea that panoramic radiography might provide sufficient information on bone height for preoperative implant planning in routine cases or when CBCT is unavailable. However, an additional CBCT evaluation might be helpful in cases where a safety margin cannot be respected due to insufficient bone height.

• Journal of Radiation Protection and Research
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• 제47권2호
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• pp.93-98
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• 2022

Background: This study aims to derive the characteristics of each work type for industrial radiography based on empirical evidence through expert advice and a survey of radiation workers of various types of industrial radiography. Materials and Methods: According to a Korean report, work types of industrial radiography are classified into indoor tests, underground pipe tests, tests in a shielded room (radiographic testing [RT] room test), outdoor field tests, and outdoor large structure tests. For each work type, exposure geometry and radiation sources were mainly identified through the expert advice and workers' survey as reliable empirical evidence. Results and Discussion: The expert advice and survey results were consistent as the proportion of the work types were high in the order of RT room test, outdoor large structure test, underground pipe test, outdoor field test, and indoor test. The outdoor large structure test is the highest exposure risk work type in the industrial radiography. In most types of industrial radiography, radiation workers generally used ¹⁹²Ir as the main source. In the results of the survey, the portion of sources was high in the order of ¹⁹²Ir, X-ray generator, ⁶⁰Co, and ⁷⁵Se. As the exposure geometry, the antero-posterior geometry is dominant, and the rotational and isotropic geometry should be also considered with the work type. Conclusion: In this study, through expert advice and a survey, the external exposure characteristics for each work type of industrial radiography workers were derived. This information will be used in the reconstruction of organ dose for health effects assessment of Korean radiation workers.

• 한국방사선학회논문지
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• 제5권2호
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• pp.81-92
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• 2011

응급상황에서 방사선 촬영 분포 분석 및 문헌을 토대로 응급상황 대처 및 서비스 효율성을 개선시키기 위하여 연구를 하였다. 2010년 12월, 광주 광역시 한 대학병원에 응급실을 내원한 1270명 응급 외래환자를 분석하여 방사선 촬영 분포 데이터를 분석하였다. 결과는 다음과 같다. 응급 방사선 촬영은 56.6% 일반 방사선 촬영, 2.5% 특수촬영, CT 34.2%, 초음파 6.7%였으며, 일반 방사선 촬영에서 남성은 51.7%, 흉부외과의 촬영률 90.0%, 입원환자 77.9% 및 응급실에서 머무르는 시간이 긴 환자에게서 촬영하였다. 특수 촬영의 비율은, 비뇨기계 28.6%, CT에서는 신경외과 49.2%, 신경과 36.7%의 높은 비율을 나타냈다. 초음파의 경우 여성이 8.8%, 내과가 15.9% 비율을 나타냈다. 방사선 촬영의 분포도를 분석하면, 일반 방사선 촬영에서 흉부촬영 55.3%, 특수 촬영에서는 1.2%의 비뇨기계, CT에서는 두부 검사가 40.0%로 높은 비율을 차지했다. 일반 촬영의 진료과의 분포도에 따르면, 두부가 64.6% 신경외과, 흉부검사는 흉부외과는 90.9%, 복부가 58.0% 일반외과, 척추는 신경외과 40.0%, 골반 및 상하지는 정형외과가 15.9%, 20.5%, 31.8%를 차지하였다. 일반 촬영의 환자 1인당 평균검수는 전체 인원을 고려하여 성별, 연령별, 전원 여부별 모두에서 유의한 차이를 나타냈다(p<0.05). 촬영만을 고려한 경우에는 성별에서 남자가 2.2건 높았으며, 연령대에서는 30대에서 2.7건이, 진단부분에서는 신경외과가 3.4건이 더 높게 차지하였다. 전체 촬영 부위 건수에서는 흉부가 998건으로 가장 많았다. 결과를 고려해보면, 응급실에서 근무하는 방사선사는 응급 촬영에서 노년층을 돌봐야 하며, 촬영동안에 가능한 2차 손상을 특수 촬영인 비뇨기계 계통이 기구와 관련이 되어 있기 때문이다. 줄이기 위한 부상응급 환자를 검사하는 모든 방사선사는 방사선 촬영하는 동안에 긴급 상황에 대처해야 한다. 방지 대처가 필요하다. 왜냐하면, 특히 야간에 CT 촬영하는 두부 손상 환자는 환자 처치가 매우 중요하다. 담당 의사는 언제나 CT실에 상주하여 환자를 지켜봐야 한다. 응급실에서 방사선 촬영은 여러 진료과에서 관여 한다. 일반 방사선 촬영의 높은 비율, 응급 방사선 촬영에 대한 특수 촬영실이 응급실 내에 설치하여만 하고, 능력이 있는 응급 환자 처치를 할 수 있는 방사선사가 필요로 하고 응급환자 증가로 적절한 인원배치가 필요하다.

• 대한물리의학회지
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• 제2권1호
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• pp.93-99
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• 2007

Purpose : The aim of this study is to consider degenerative spine disease theoretically and compare plain radiography which is a basic study for low back pain with MRI in cases of degenerative lumbar spine disease to find out whether the abnormalities agree with each other. Methods : In 4 cases of lumbar degenerative disease, we studied the relation of the abnormalities such as disc space narrowing, spinal space narrowing, loss of lordosis and osteophytes on plain radiography with those on MRI of HIVD, spinal stenosis and spondylolisthesis. Results : Many abnormalities such as disc space narrowing, spinal space narrowing, loss of lordosis, osteophytes and change of cortex & bone marrow on plain radiography suggest HIVD, spinal stenosis, spondylolysis or spondylolisthesis on MRI. Conclusion : For low back pain patients, plain radiography is a basic study in diagnosis of HIVD, spinal stenosis, spondylolysis or spondylolisthesis but MRI or CT scan is necessary to develop(build) a treatment plan like an operation.

• 대한방사선기술학회지:방사선기술과학
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• 제10권1호
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• pp.37-41
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• 1987

Authors could recognize surrounding areas induding target area by the observable film density with spot radiography using Cu mask and also, radiographic images maintained high quality. Spot radiography has been utilized for a long time for the purpose of observing detail image by the control of scattered radiation. But it has been difficult to know body part in general spot radiography. Therefore it is thought that attempt to use Cu mask in spot radiography is very advantageous in a clinical examinations.

• 대한방사선기술학회지:방사선기술과학
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• 제15권2호
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• pp.31-36
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• 1992

Grids can improve the diagnostic quality of chest radiography by trapping the greater part of scattered radiation thus providing more detailed. chest radiographic images. It is most effective mathod of reduce the scatter ratio but must increase the expour factor. The benefit of use of grid is improve the contrast and the loss is increase of patient dose. In chest radiography especially hard quality high voltage radiography it will have to be considered to select the optimum grid with view point of benefit and loss. In this experiment, author got some result of characteristics about 4 different grids with film method. 1. There was no difference the scatter ratio in case of no grid and the scatter ratio was about 60%. 2. 16 : 1 grid was excellent of scatter reduction factor in high voltage chest radiography, next was 10 : 1, CROSS, MICRO FINE grid have low scatter reduction rate compare to 16:1, 10:1 grid. 3. The bucky factor of CROSS grid in accordance of kVp was find out the highest in 4 grids, on the contraly 10 : 1 grid was profitable to the exposure does. 4. With careful consideration in the point of scatter reducion rate and bucky factor, author suggest the 10 : 1 linear grid on the use of chest radiography in $80{\sim}120\;kVp$, 16 : 1 grid in $120{\sim}140\;kVp$.

• 동력기계공학회지
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• 제12권6호
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• pp.70-77
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• 2008

The purpose of this study is to compare the quality of digital radiography image with that of classical film images for welded structure in power plants. The CMOS(Complementary Metal Oxide Semiconductor) flat panel detecter and Agfa D5 film are used to image flaw specimens respectively. In the test, CMOS flat panel detector has been determined to have a better image than that of film image. In the IQI(Image Quality Indicator) transmission test, one or two more line can be seen in digital image than in film image. Digital Radiography Test enabled to successfully detect all defects on the weld specimens fabricated with real reheat stem pipe and boiler tube as well. In the specific comparison test, Digital radiography test detected micro flaws in the size of 0.5 mm in length by 0.5 mm in depth. However, film test has limited it to 1.0 mm in length by 1.0 mm in depth. As a result of this study, digital radiography technology is estimated well enough to perform the inspection in the industry with far more cost effective way, compared to the classical film test.

• Imaging Science in Dentistry
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• 제44권1호
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• pp.1-6
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• 2014

Professionals performing radiographic examinations are responsible for maintaining optimal image quality for accurate diagnoses. These professionals must competently execute techniques such as film manipulation and processing to minimize patient exposure to radiation. Improper performance by the professional and/or patient may result in a radiographic image of unsatisfactory quality that can also lead to a misdiagnosis and the development of an inadequate treatment plan. Currently, the most commonly performed extraoral examination is panoramic radiography. The invention of panoramic radiography has resulted in improvements in image quality with decreased exposure to radiation and at a low cost. However, this technique requires careful, accurate positioning of the patient's teeth and surrounding maxillofacial bone structure within the focal trough. Therefore, we reviewed the literature for the most common types of positioning errors in panoramic radiography to suggest the correct techniques. We would also discuss how to determine if the most common positioning errors occurred in panoramic radiography, such as in the positioning of the patient's head, tongue, chin, or body.

• Imaging Science in Dentistry
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• 제51권4호
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• pp.407-412
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• 2021

Purpose: The purpose of this study was to evaluate the accuracy of virtual 3-dimensional (3D) cephalograms constructed using the principle of biplanar radiography by comparing them with cone-beam computed tomography (CBCT) images. Materials and Methods: Thirty orthodontic patients were enrolled in this study. Frontal and lateral cephalograms were obtained with the use of a head posture aligner and reconstructed into 3D cephalograms using biplanar radiography software. Thirty-four measurements representing the height, width, depth, and oblique distance were computed in 3 dimensions, and compared with the measurements from the 3D images obtained by CBCT, using the paired t-test and Bland-Altman analysis. Results: Comparison of height, width, depth, and oblique measurements showed no statistically significant differences between the measurements obtained from 3D cephalograms and those from CBCT images (P>0.05). Bland-Altman plots also showed high agreement between the 3D cephalograms and CBCT images. Conclusion: Accurate 3D cephalograms can be constructed using the principle of biplanar radiography if frontal and lateral cephalograms can be obtained with a head posture aligner. Three-dimensional cephalograms generated using biplanar radiography can replace CBCT images taken for diagnostic purposes.

• Journal of Periodontal and Implant Science
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• 제26권4호
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• pp.933-948
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• 1996

The purpose of this study was to examine the anatomic structures of the mandible-inferior alveolar canal, mental foramen, mental canal-with panoramic radiography and conventional tomography and to compare both radiographic techniques in conjunction with endosseous implants. In this study 14 adult dentulous mandibles -27 cases of right and left side of mandibles- were examined and the results were as follows. 1. The distance between superior border of the inferior alveolar canal and the alveolar ridge crest showed a decreasing tendency from the mental foramen to 4cm posterior to the mental foramen. 2. The mean diameter of the inferior alveolar canal was $4.11{\pm}0.50mm$ with panoramic radiography and $3.29{\pm}0.59mm$ with conventional tomography. 3. The inferior border of the inferior alveolar canal and inferior border of the mandible was closest at 2cm posterior to the mental foramen but it was not statistically significant. the mean distance was $1l.64{\pm}2.95mm$ in panoramic radiography and $1l.68{\pm} 2.91mm$ in conventional tomography. 4. The inferior alveolar canal located lingually in bucco-lingual direction 16%(mental foramen), 54%(lcm posterior to the mental foramen), 68%(2cm posterior to the mental foramen), 50%(3cm posterior to mental foramen), 55%(4cm posterior to the mental foramen). 5. Mean length of the anterior loop of the mental canal was 2.73mm, and the loop below 2mm was 35% and 15% of mental canal was invisible in panoramic radiography. 6. The minimum interforaminal distance was 56.7mm, the maximum distance was 73.2mm and the mean distance was 66.42mm in panoramic radiography. 7. The mean distance between midpoint of the mental canal and alveolar ridge crest was 16.24mm and the mean buccolingual angulation of the mental canal was $52.98^{\circ}$ in conventional tomography. 8. In comparison of panoramic radiography and conventional tomography, inferior alveolar canal is better visualized with conventional tomography than panoramic radiography from the mental foramen to the 2cm posterior to the mental foramen, while visiblity of conventional tomography prominently decreased in 4cm posterior to the mental foramen and alveolar ridge crest is better visualized with panoramic radiography than conventional radiography at the mental foramen and at 4cm posterior to the mental foramen. In radiologic examination of anatomic structures of the mandible for endosseous implants, panoramic radiography and conventional tomography can be effectively used when it is used to overcome the anatomic limitations.