• Journal of Periodontal and Implant Science
• /
• 제48권4호
• /
• pp.202-212
• /
• 2018

Purpose: Bone-to-implant contact (BIC) is difficult to measure on micro-computed tomography (CT) because of artifacts that hinder accurate differentiation of the bone and implant. This study presents an advanced algorithm for measuring BIC in micro-CT acquisitions using a spiral scanning technique, with improved differentiation of bone and implant materials. Methods: Five sandblasted, large-grit, acid-etched implants were used. Three implants were subjected to surface analysis, and 2 were inserted into a New Zealand white rabbit, with each tibia receiving 1 implant. The rabbit was sacrificed after 28 days. The en bloc specimens were subjected to spiral (SkyScan 1275, Bruker) and round (SkyScan 1172, SkyScan 1275) micro-CT scanning to evaluate differences in the images resulting from the different scanning techniques. The partial volume effect (PVE) was optimized as much as possible. BIC was measured with both round and spiral scanning on the SkyScan 1275, and the results were compared. Results: Compared with the round micro-CT scanning, the spiral scanning showed much clearer images. In addition, the PVE was optimized, which allowed accurate BIC measurements to be made. Round scanning on the SkyScan 1275 resulted in higher BIC measurements than spiral scanning on the same machine; however, the higher measurements on round scanning were confirmed to be false, and were found to be the result of artifacts in the void, rather than bone. Conclusions: The results of this study indicate that spiral scanning can reduce metal artifacts, thereby allowing clear differentiation of bone and implant. Moreover, the PVE, which is a factor that inevitably hinders accurate BIC measurements, was optimized through an advanced algorithm.

• 대한핵의학회:학술대회논문집
• /
• 대한핵의학회 1972년도 제11차 학술대회
• /
• pp.67.2-67.2
• /
• 1972

• 대한핵의학회:학술대회논문집
• /
• 대한핵의학회 1973년도 제12차 학술대회
• /
• pp.57.4-58
• /
• 1973

• 비파괴검사학회지
• /
• 제22권4호
• /
• pp.386-392
• /
• 2002

골다공골증은 해면골의 골소주 두께 감소 및 파단에 기인한 전체적인 골질이 저하되는 질병이다. 골다공증의 진단은 X-ray 및 초음파를 이용하는 방법이 있다. 그러나 X-ray 방법은 인체에 해로우며 단지 골밀도만을 평가한다. 대부분 골다공증 진단 초음파 시스템은 heel뼈를 통과하는 초음파 속도 및 감쇠 파라미터를 측정하고 있다. 한편, 기존의 초음파 시스템들은 heel뼈의 한 점에서만 측정을 실행하므로 측정 위치에 따른 오차로 인하여 골다공증의 진단 예측성이 매우 낮다. 본 연구에서는 두 개의 초음파 탐촉자를 이용하여 선형 스캐닝 방식에 의한 heel뼈 전체 영역에 대한 초음파 파라미터 값들은 2차원 영상처리기법을 통하여 골다공증을 진단하는 기법을 수행하였다.

• 대한핵의학회지
• /
• 제30권1호
• /
• pp.1-14
• /
• 1996

Since the publication of the first bone scintiscans in 1962 three decades have elapsed. The bone scan has made great strides during this period, becoming one of the most commonly used nuclear imaging tests. In spite of the progress, however, the specificity of bone scan has remained relatively low. As the result it is a common practice to seek additional information from radiograph, CT scan and MR image, which is euphemistically termed as "image fusion or co-location." The basic reason is the inapplicability of the classical piecemeal analysis to interpreting planar and SPECT bone scans. Such analysis has its base on the observation of elemental features of morphology, which include the size, shape, contour, location, topography and internal architecture. The physiochemical profile may well also be included. Understandably, however, the miniatured images of the planar bone scan cannot provide these features in acceptable detail and the same holds true even with SPECT Images which are but sliced views of the reconstructed planar scans. Fortunately pinhole scanning has the capacity to portray both the morphological and chemical profiles of bone and joint diseases in greater detail through true magnification. The magnitude of pinhole scan resolution is practically comparable to that of radiography as far as gross anatomy is concerned. Thus, we feel strongly that pinhole scanning is a potential breakthrough of the long-lamented low specificity of bone scan. This presentation will discuss the fun-damentals, advantages and disadvantages and the most recent advances of pinhole scanning. It high-lights the actual clinical applications of pinhole scanning in relation to the diagnosis of infective and inflammatory diseases of bone and joint.

• 치과방사선
• /
• 제29권1호
• /
• pp.43-53
• /
• 1999

Purpose: The aim of this study was to analyze radiologically the location and course of the mandibular canal and to observe the alveolar and basal bone changes during the remodeling procedures of atrophic mandible. Materials and Methods: CT scanning was performed on dry 30 edentulous or partially dentulous mandibles. In 48 edentulous lower halves, measuring areas were determined by three points in the length of the mandibular canal. The distance from the mandibular canal towards cranial and caudal edges, buccal and lingual external borders of the body of the mandible were measured. A statistical comparison between the mean values of different classes of mandibular body was carried out in the selected areas. Results: The distance between the mandibular canal and caudal borders of the body of the mandible and lingual borders dose not change in the atrophic process of mandible. The mandibular canal within the mandible courses downwards from mandibular foramen towards mesial and subsequently it gets to the mental foramen. The distance between the mandibular canal and buccal external border of basal bone changes similar to the change of cranial borders of alveolar bone in the atrophic process of mandible. Conclusion: CT scanning was very effective and practicable to analyze the location and course of the mandibular canal and to observe the alveolar and basal bone changes of atrophic mandible. Also more detailed investigation of basal bone changes observed during the remodeling procedures of atrophic mandibles seems reasonable to rely on the massive anthropologic collections of atrophic mandibles combined with CT scanning.

• Journal of Korean Dental Science
• /
• 제5권2호
• /
• pp.77-87
• /
• 2012

Purpose: This study examined the scanning electron microscopic feature, protein marker expression and osteoinductive activity of demineralized dentin matrix (DDM) from human for nude mice. Materials and Methods: Twenty healthy nude mice, weighing about 20 g were used for study. DDM from Human was prepared and implanted into the dorsal portion of nude mouse. Before implantation, DDM was examined by scanning electron microscopy (SEM). Nude mice were sacrificed at 2 weeks, 4 weeks and 8 weeks after DDM grafting and evaluated histologically by H-E, MT staining. And also immunohistochemistry analysis (ostecalcin, osteopontin) was performed. Result: Dentinal tubules and collagen fibers were observed by SEM of dentin surface of DDM. The DDM induced bone and cartilage independently in soft tissues. And, the histological findings showed bone forming cells like osteoblasts, fibroblasts at 2, 4 and 8 weeks. On immunohistochemistry analysis, osteocalcin and osteopontin positive bone forming cells were observed. Conclusion: This results showed that the DDM from human has osteoinductive ability and is a good alternative to autogenous bone graft materials.

• Journal of Korean Neurosurgical Society
• /
• 제50권5호
• /
• pp.409-414
• /
• 2011

Objective : The aim of this study was to evaluate the impact of sodium hyaluronate-sodium carboxymethyl cellulose (HA-CMC), an anti-adhesive material for spinal surgery, on bone fusion by applying it to rat spinal models after lumbar posterolateral fusion. Methods : Lumbar posterolateral fusion was performed at L4-5 using bone graft substitutes in 30 rats. HA-CMC was injected in 15 rats at a dose of 0.2 cc (HA-CMC group) and a saline solution of 0.2 cc in the other 15 rats (control group). Simple radiographs were taken until postoperative 9 weeks with an interval of one week. At postoperative 4 and 9 weeks, three dimensional computed tomography (3D CT) scanning was performed to observe the process of bone fusion. At 9 weeks, bone fusion was confirmed by gross examination and manual palpation. Results : There were no statistically significant differences in bone fusion between the two groups. 3D CT scanning did not reveal significant differences between the groups. The gross examination and manual palpation after autopsy performed at 9 weeks confirmed bone union in 93.3% of both groups. Conclusion : The anti-adhesive material used for spinal surgery did not have adverse effects on spinal fusion in rats.

• 대한핵의학회지
• /
• 제17권2호
• /
• pp.63-69
• /
• 1983

In order to establish criteria for distinguishing between occult fracture and metastases, we have reviewed 52 records of cancer patients and 24 of rib fracture patients referred for bone scanning. In 52 patients with biopsy-proven malignancy, multiple linear increased uptake of the ribs was found in 32 cases (61.5%), and was the most common finding. In 24 patients with rib fracture, all but 1 had fecal increased uptake of the ribs, and lesions almost always aligned in a row. By analyzing the appearance of rib lesions in total 76 patients, it was concluded that there is a high probability that rib lesions detected by bone scanning are bony metastases if 1) they are multiple linear as opposed to fecal, ad 2) they are not aligned in the same location.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
• /
• pp.111-111
• /
• 2011

Arrangement of individual atoms and molecules with atomic precision and understanding the resulting properties at the molecular level are ultimate goals of chemistry, biology, and materials science. For the past three decades, scanning probe microscopy has made strides towards these goals through the direct observation of individual atoms and molecules, enabling the discovery of new and unexpected phenomena. This talk will discuss the origin of forces governing motion of small organic molecules and their extended self-assembly into two-dimensional surface structures by direct observation of individual molecules using scanning tunneling microscopy (STM). In addition, atomic force microscopy (AFM) is utilized for the investigation of fundamental mechanisms of bone mineral dissolution by examining atomically well characterized simulated bone minerals under aqueous solution environments.