• The Korean Journal of Nuclear Medicine
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• v.30 no.4
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• pp.524-531
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• 1996

Purpose : To evaluate the pattern- of skeletal metastases and to classify the pattern of renal uptakes on bone scans in renal cell carcinoma. Materials and Methods : We reviewed the bone scans of 158 patients with RCC established pathologically. In order to identify individual scan lesion as a bone metastasis, we reviewed all available correlative radiological studies, follow-up bone scans, and biopsies for each lesion. The metastatic bone lesions were divided into seven anatomic regions; skull, spine, shoulder girdle, sternum, ribs, pelvis, and long bones of extremities. The individual scan lesions were divided into two groups as the pattern of uptakes, hot and cold lesion. In addition, the contours and uptakes of kidneys with RCC were classified into 6 groups ; normal uptake, photon-deficient lesion, faint up-take with enlargement, uneven uptake with enlargement, lateralization with crescentic shape, and increased uptake. Results : Twenty out of 158(12.7%) patients with RCC at varying stages showed 71 metastatic bone lesions at presentation and on follow- up bone scans. Nearly 80% of all metastatic lesions were in the axial skeleton with predominantly increased uptake of the radioactivity However a considerable number(22.5%) showed cold lesions on bone scan. A half of bone scans revealed abnormal uptake of involved kidney and much more(82.4%) in case of bone metastases. Two common patterns of abnormal renal uptake were photon-deficient lesion (50%) and faint uptake with enlargement(24.3%). In four patients with bone pain or pathologic fracture, bone scans were useful for the serendipitious localization of previously unrecognized primary lesion of RCC as well as for the detection of bone metastases from RCC. Conclusion : The understanding of the pat-terns of skeletal metastases and renal uptakes on bone scans in RCC is important for the useful information about primary lesion(RCC) as well as detection of bone metastases.

• Progress in Medical Physics
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• v.24 no.4
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• pp.243-252
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• 2013

The aim of this study was to clarify the impacts of acquisition parameters on artifacts in four-dimensional computed tomography (4D CT) images, such as the partial volume effect (PVE), partial projection effect (PPE), and mis-matching of initial motion phases between adjacent beds (MMimph) in cine mode scanning. A thoracic phantom and two cylindrical phantoms (2 cm diameter and heights of 0.5 cm for No.1 and 10 cm for No.2) were scanned using 4D CT. For the thoracic phantom, acquisition was started automatically in the first scan with 5 sec and 8 sec of gantry rotation, thereby allowing a different phase at the initial projection of each bed. In the second scan, the initial projection at each bed was manually synchronized with the inhalation phase to minimize the MMimph. The third scan was intentionally un-synchronized with the inhalation phase. In the cylindrical phantom scan, one bed (2 cm) and three beds (6 cm) were used for 2 and 6 sec motion periods. Measured target volume to true volume ratios (MsTrueV) were computed. The relationships among MMimph, MsTrueV, and velocity were investigated. In the thoracic phantom, shorter gantry rotation provided more precise volume and was highly correlated with velocity when MMimph was minimal. MMimph reduced the correlation. For moving cylinder No. 1, MsTrueV was correlated with velocity, but the larger MMimph for 2 sec of motion removed the correlation. The volume of No. 2 was similar to the static volume due to the small PVE, PPE, and MMimph. Smaller target velocity and faster gantry rotation resulted in a more accurate volume description. The MMimph was the main parameter weakening the correlation between MsTrueV and velocity. Without reducing the MMimph, controlling target velocity and gantry rotation will not guarantee accurate image presentation given current 4D CT technology.

• Investigative Magnetic Resonance Imaging
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• v.5 no.1
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• pp.18-23
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• 2001

Purpose : To describe the MRI findings in the bronchial anthracofibrosis mimicking lung cancer on CT examination. Materials and methods : Ten patients, who showed CT findings mimicking lung cancer, were selected among fifty patients of bronchial anthracofibrosis proven by bronchoscopic biopsy, consisting of two men and eight women, ranging in age from 58 to 79 years old faverage age, 68 years old). CT scan and MRI were performed in all patients (n=10). Percutaneous lung biopsy on mass was performed in one patient. MRI findings were analyzed with the emphasis on the signal intensity of the mass (n=4), collapsed lung (n=4) and Iymph node (n=10) on axial T1 and T2-weighted images by two radiologists in consensus. No contrast enhancement was used in all cases. Results : CT scan revealed mass (n=4), atelectasis with obstructive pneumonia(n=4) and bronchial wall thickening(n=2). All patients showed enlarged medistinal Iymph nodes(n=10). The mass showed low signal intensity on T1WI and T2WI (n =4). The collapsed lung in patients with atelectasis indicated intermediate signal intensity on T1WI and low signal intensity on T2WI (n= 4). Nine patients showed low sisnal intensity of Iymph node on T1WI and T2WI, except one patient who showed central high signal intensity with peripheral rim of low signal intensity in right lower paratracheal llmph node on T2WI. Conclusion : Low signal intensity of a mass, collapsed lung, and lymph nodes on T2WI in anthracofibrosis patients may be helpful in differentiation of the lesion from lung cancer.

• Clinics in Shoulder and Elbow
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• v.15 no.2
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• pp.109-116
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• 2012

Purpose: The aim of this study was to evaluate preoperative ultrasonographic findings and usefulness in ulnar neuropathy around elbow. Materials and Methods: Twenty-two patients with ulnar neuropathy were performed preoperative ultrasonogram. The route, location, thickness of the ulnar nerve and space occupying lesion through longitudinal scan were evaluated. Cross-sectional areas of the ulnar nerve were measured at the level of medial epicondyle and 3 cm proximal and distal to the medial epicondyle through axial scan. Correlations between swelling ratio of ulnar nerve and eletrophysiologic study and preoperative Dellon's assessment were checked. Results: In 21 cases (95.6%) of total 22 cases, diffuse swelling of the ulnar nerve around elbow were identified. 4 cases had space occupying lesions including 3 ganglionic cysts and 1 heterotopic ossification. Cross sectional areas at the level of medial epicondyle were significantly larger than at the level of 3 cm proximal and distal to the medial epicondyle (p<0.05). There were no statistically significant correlations between swelling ratio of ulnar nerve and eletrophysiologic study and preoperative clinical assessment (p>0.05). Conclusion: This study showed that ultrasonography was helpful to detect etiology of ulnar neuropathy around elbow such as space occupying lesion, morphological change or dislocation of ulnar nerve. It could be useful tool for diagnosis and treatment in patients with ulnar neuropathy at elbow.

• Clinics in Shoulder and Elbow
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• v.21 no.3
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• pp.151-157
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• 2018

Background: Nonunion of lateral humeral condyle fracture causes cubitus valgus deformity. Although corrective osteotomy or osteosynthesis can be considered, there are controversies regarding its treatment. To evaluate elbow joint biomechanics in non-united lateral humeral condyle fractures, we analyzed the motion of elbow joint and pseudo-joint via in vivo three-dimensional (3D) kinematics, using 3D images obtained by computed tomography (CT) scan. Methods: Eight non-united lateral humeral condyle fractures with cubitus valgus and 8 normal elbows were evaluated in this study. CT scan was performed at 3 different elbow positions (full flexion, $90^{\circ}$ flexion and full extension). With bone surface model, 3D elbow motion was reconstructed. We calculated the axis of rotation in both the normal and non-united joints, as well as the rotational movement of the ulno-humeral joint and pseudo-joint of non-united lateral condyle in 3D space from full extension to full flexion. Results: Ulno-humeral joint moved to the varus on the coronal plane during flexion, $25.45^{\circ}$ in the non-united cubitus valgus group and $-2.03^{\circ}$ in normal group, with statistically significant difference. Moreover, it moved to rotate externally on the axial plane $-26.75^{\circ}$ in the non-united cubitus valgus group and $-3.09^{\circ}$ in the normal group, with statistical significance. Movement of the pseudo-joint of fragment of lateral condyle showed irregular pattern. Conclusions: The non-united cubitus valgus group moved to the varus with external rotation during elbow flexion. The pseudo-joint showed a diverse and irregular motion. In vivo 3D motion analysis for the non-united cubitus valgus could be helpful to evaluate its kinematics.

• Journal of Technologic Dentistry
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• v.41 no.2
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• pp.63-69
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• 2019

Purpose: The purpose of this study is to evaluate the effect of CAD/CAM system milling tool wear on the marginal and internal fit of PMMA implant interim prosthesis three-dimensional manner. Methods: A total of 20 crowns were fabricated with CAD/CAM method. Their designs were unified to first molar of the left maxilla. The Customized abutments were prepared and scanned with on optical model scanner. Five crowns were milled by the newly replaced tool (1st milling), and 15 crowns were milled by 2nd, 3rd, 4th milling tool. The marginal and internal fit of 20 interim crowns were measured using the triple-scan protocol. Results: Statistically significant difference was found between the $1^{st}$ milling group ($51.8{\pm}14.6{\mu}m$) and the $3^{rd}$, $4^{th}$ milling group ($128.6{\pm}43.8{\mu}m$, $146.2{\pm}38.1{\mu}m$, respectively) at the distal margins. In the mesial margins, There was a statistically significant difference between the $1^{st}$ milling group ($63.6{\pm}25.9{\mu}m$) and the $3^{rd}$, $4^{th}$ milling group ($137.2{\pm}25.9{\mu}m$, $186.8{\pm}70.6{\mu}m$, respectively). In the distal line angle, significant difference was found between the $1^{st}$, $2^{nd}$, $3^{rd}$ milling groups and the $4^{th}$ milling group. In the mesial axial wall, significant difference was found between the $1^{st}$ milling group ($52.2{\pm}20.3{\mu}m$) and the $3^{rd}$, $4^{th}$ milling groups ($22.8{\pm}8.8{\mu}m$, $7.8{\pm}5.7{\mu}m$). Conclusion: As a result of the experiment, decrease of the marginal and internal fit was statistically significant as the number of machining cycles increased. In order to produce clinically excellent restorations, it is recommandable to consider the condition of the milling tool wear, when designing the restoration with CAD program.

• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.3
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• pp.157-166
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• 2018

Purpose: This study was aimed to compare the consistency between the custom abutment design and the output in two CAD software programs. Materials and Methods: Customized abutments were designed by using 3Shape Dental System CAD software and Delta9 CAD software on a plaster model with implants (CRM STL file). After milling of the designed abutments, the abutments were scanned with a contact method scanner (Test STL file). We overlaid the Test STL file with each CRM STL file by using inspection software, and then compared the milling reproducibility by measuring the output error of the specimens from each CAD software program. Results: The Delta9 showed better milling reproducibility than 3Shape when comparing the milling errors obtained with a full scan of all specimens (P < .05) and also when comparing the axial wall region specifically according to the axial angle. With 0.9 mm marginal radius, the Delta9 showed better consistency between the design and the output than 3Shape (P < .05). While, anti-rotation form had no significant difference in error between the two systems. When cumulative errors were compared, the Delta9 showed better milling reproducibility in almost cases (P < .05). Conclusion: Delta9 showed a significantly smaller error for most of the abutment design options. This means that it is possible to facilitate generation of printouts with reliable reproducibility and high precision with respect to the planned design.

• Imaging Science in Dentistry
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• v.33 no.3
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• pp.187-193
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• 2003

Purpose: To compare the measurements of the mandible and the detectability of the mandibular canal on reformatted images using a newly developed 3-dimensional implant simulation program with traditionally used CT multiplanar reconstruction program and true measurements. Materials and Methods: Ten dry dog mandibles were used in this study. Occlusal templates for CT examination were fabricated and marked with gutta perch a at ten sites. Axial CT scans were taken and reconstructed using DentaScan (D group) and Vimplant program (V group), and each mandible was sectioned at the previously marked sites (R group). Maximum vertical height (H) and maximum width (W) of the mandible, the distances from buccal border of the mandibular canal to the most buccal aspect of the mandible (X), and the distance from the superior border of the mandibular canal to the alveolar crest (Y) were measured, and the mandibular measurements in each group were compared. Detectability of mandibular canal was evaluated using a 3-point scale in both V and D groups by three oral radiologists and compared. Results: H in the V group was slightly greater than that in the D group, and Wand X in the V group was slightly less than those in the D group. H in the V group was less than that in the R group, and Wand X in the V group was larger than those in the R group. The detectability of the mandibular canal did not show statistically significant differences between V and D groups. Conclusion: The results of the experiment show that the newly developed, inexpensive Vimplant/TM/ simulation program can be used as an alternative to the traditionally used, and more expensive CT multiplanar reconstruction program.

• The Journal of the Korean bone and joint tumor society
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• v.14 no.1
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• pp.68-72
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• 2008

Parachordoma is an extremely rare tumor that histologically resembles chordoma of axial skeleton but occurs in a peripheral site. It is considered an indolent neoplasm with potential for local recurrence. We present a case of soft tissue parachordoma at inguinal subcutaneous tissue which recurred 2 months after primary simple excision under local anesthesia and was performed revisional wide excision. Bone scan showed no other metastatic lesion. Immunohistochemical findings revealed tumor cells to be reactive to EMA, S-100 protein, vimentin and cytokeratin.

• Journal of Korean Neurosurgical Society
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• v.56 no.2
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• pp.108-113
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• 2014

Objective : Ankylosing spondylitis is an inflammatory rheumatic disease mainly affecting the axial skeleton. The rigid spine may secondarily develop osteoporosis, further increasing the risk of spinal fracture. In this study, we reviewed fractures in patients with ankylosing spondylitis that had been clinically diagnosed to better define the mechanism of injury, associated neurological deficit, predisposing factors, and management strategies. Methods : Between January 2003 and December 2013, 12 patients with 13 fractures with neurological complications were treated. Neuroimaging evaluation was obtained in all patients by using plain radiography, CT scan, and MR imaging. The ASIA Impairment Scale was used in order to evaluate the neurologic status of the patients. Management was based on the presence or absence of spinal instability. Results : A total of 9 cervical and 4 thoracolumbar fractures were identified in a review of patients in whom ankylosing spondylitis had been diagnosed. Of these, 7 fractures were associated with a hyperextension mechanism. 10 cases resulted in a fracture by minor trauma. Posttraumatic neurological deficits were demonstrated in 11 cases and neurological improvement after surgery was observed in 5 of these cases. Conclusions : Patients with ankylosing spondylitis are highly susceptible to spinal fracture and spinal cord injury even after only mild trauma. Initial CT or MR imaging of the whole spine is recommended even if the patient's symptoms are mild. The patient should also have early surgical stabilization to correct spinal deformity and avoid worsening of the patient's neurological status.