• Journal of Gastric Cancer
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• v.6 no.4
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• pp.207-213
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• 2006

Purpose: This study was performed to evaluate the usefulness of computed tomography (CT) gastrography in the surgical management of a gastric gastrointestinal stromal tumor (GIST). Materials and Methods: We retrospectively analyzed the clinicopathologic data of 38 patients who had undergone CT gastrography from among patients who had gastric GISTS surgically resected at the Department of Surgery, Seoul National University Hospital, between January 2001 and February 2006. We compared CT gastrography data, including tumor size and location and distance from the gastroesophageal junction or pylorus with endoscopic, surgical and pathologic findings. Results: The longitudinal tumor locations on CT gastrography and endoscopy were identical to the surgical findings. For tumor sizes on CT gastrography of less than 5 cm, we performed 11 (42.3%) laparoscopic wedge resections from among 26 cases. In the 12 cases with tumor sizes of 5 cm or over, only 1 (8.3%) laparoscopic wedge resection was performed. When the tumor was located in the middle third of the stomach, a laparoscopic wedge resection was performed in 88.9% (8/9) of the cases, but when it was located in the upper or lower third, a laparoscopic wedge resection was performed in only 13.8% (4/29) of the cases. Conclusion: Three-dimensional information from CT gastrography allows the surgeon to perform preoperative planning, including accurate localization.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2006.08a
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• pp.123-123
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• 2006

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.6
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• pp.79-88
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• 1989

In this paper, linear octree is used to reconstruct and to modify the 3-dimensional image from 2-dimensional cross sections provided by computed tomography. Linear octree introduces a considerable data saving of the memory storage required by small computer system. This structure allows the hidden surface removal utilizing the spatial presortedness of hierarchical octree structure and implementation of graphical operations that include viewing transform and shading. An actual human organ is used to illustrate this technique and its implications for theraphy and surgical planning.

• Radiation Oncology Journal
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• v.29 no.4
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• pp.277-282
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• 2011

Purpose: This study was performed to evaluate the change in the lumpectomy cavity volumes before and after whole breast radiation therapy (WBRT) and to identify factors associated with the change of volume. Materials and Methods: From September 2009 to April 2010, the computed tomography (CT) simulation data from 70 patients obtained before and after WBRT was evaluated. The lumpectomy cavity volumes were contoured based on surgical clips, seroma, and postoperative changes. Significant differences in the data from pre-WBRT CT and post-WBRT CT were assessed. Multiple variables were examined for correlation with volume reduction in the lumpectomy cavity. Results: The mean and median volume reduction in the lumpectomy cavity after WBRT were 17.6 $cm^3$ and 16.1 $cm^3$, respectively with the statistical significance (p < 0.001). The volume reduction in the lumpectomy cavity was inversely correlated with time from surgery to radiation therapy (R = 0.390). The presence of seroma was significantly associated with a volumetric change in the lumpectomy cavity after WBRT (p = 0.011). Conclusion: The volume of lumpectomy cavity reduced significantly after WBRT. As the time from surgery to the start ot WBRT increased, the volume reduction in the lumpectomy cavity during WBRT decreased. A strong correlation was observed between the presence of seroma and the reduced volume. To ensure appropriate coverage and to limit normal tissue exposure during boost irradiation in patients who has seroma at the time of starting WBRT, repeating CT simulation at boost planning is suggested.

• Journal of IKEEE
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• v.7 no.1 s.12
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• pp.119-126
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• 2003

This paper presents a methodology for constructing a surgical simulation environment for the replacement of artificial knee join using CT image data. We provide a user interface of preoperative planning system for performing complex 3-D spatial manipulation and reasoning tasks. Simple manipulation of joystick and mouse has been proved to be both intuitive and accurate for the fitness and the wear expect of joint. The proposed methodology are useful for future virtual medical system where all the components of visualization, automated model generation, and surgical simulation are integrated.

• Proceedings of the KSMRM Conference
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• 2002.11a
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• pp.106-106
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• 2002

Purpose： The purposes of our study are (1) to develop a brain phantom which can be used for multimodal image registration, (2) to evaluate the accuracy of image registration with the home-made phantom. Method： A brain phantom which could be used for image registration technique of CT-MR and CT-SPECT images using chamfer matching was developed. The brain phantom was specially designed to obtain imaging dataset of CT, MR, and SPECT. The phantom had an external frame with 4 N-shaped pipes filled with acryl rods for CT, MR imaging and Pb rods for SPECT imaging. 8 acrylic pipes were inserted into the empty space of the brain phantom to be imaged for geometric evaluation of the matching. Accuracy of image fusion was assessed by the comparison between the center points of the section of N-shaped bars in the external frame and the inserted pipes of the phantom. Technique with partially transparent, mixed images using color on gray was used for visual assessment of the image registration process.

• Journal of International Society for Simulation Surgery
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• v.1 no.2
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• pp.87-89
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• 2014

An aberrant left hepatic artery is one of the most common variants of hepatic arteries, and its prevalence has been reported 6.5-30%. During D2 lymph node dissection for gastric cancer, an aberrant left hepatic artery arising from left gastric artery is ligated which may lead to hepatic damage. In this case report, a 66-year-old male patient underwent total gastrectomy with D2 lymph node dissection during which the aberrant left hepatic artery was ligated. Post-operative liver function tests revealed elevated liver enzymes, and ischemic changes in the left lateral hepatic section was seen on the CT scan. On retrospective review of preoperative CT images, a replaced left hepatic artery from left gastric artery could have been identified. The information on the presence of aberrant LHA and its supplying area is clinically important when planning curative gastrectomy for gastric cancer, because extended lymph node dissection requires division of the left gastric artery and this may lead to severe liver damage. By using preoperative CT scan, detection of aberrant left hepatic artery could be done.

• Journal of Veterinary Clinics
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• v.24 no.3
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• pp.461-466
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• 2007

Two dogs were admitted with a history of anorexia, ataxia, shivering, lethargy, hypersalivation and seizure. Patients were suspected for portosystemic shunts on the basis of clinical signs, increased hepatic serum profiles on the blood test, microhepatica on plain abdominal radiographs, and an abnormally dilated and tortuous vessel on abdominal ultrasonographs. To diagnose PSS and to further evaluate type, shape, and location of shunt and hepatic vasculatures, the computed tomography (CT) angiography for portal and systemic circulation was performed. The shape, location and pathway of extrahepatic single shunt were confirmed in two dogs. Dual phases (the arterial phase and the venous phase) CT angiography and reformatted and three-dimensional images offered good understanding of PSS and planning surgical treatment.

• Progress in Medical Physics
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• v.17 no.4
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• pp.192-200
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• 2006

We evaluated the positional accuracy of the delivered beams to the target in a phantom by simulating the whole process of the radiation treatments Including CT scanning, planning and beam exposures with MLCs. For this purpose, a phantom was made to calibrate the alignment between the CT and the attached laser system. A new, convenient method was also devised to align the setup lasers in the treatment room. Film was used for the Identification of the delivered beam and analyzed with a homemade computer program. The positional differences between the target and the beam centers varied with the couch rotations. The accelerator we used showed a maximum discrepancy of 2.0 mm at the table angle of $295^{\circ}$. The same measurements based on the new isocenter from the Winston-Lutz test resulted in the maximum of 1.35 mm for all rotation angles. The evaluation of the differences between the target and the beam centers is useful for the treatment planning.

• Progress in Medical Physics
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• v.13 no.4
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• pp.202-208
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• 2002

The purpose of this study is to evaluate the monitor unit obtained from various methods for the treatment of superficial cancers using electron beams. Thirty-three breast cancer patients who were treated in our institution with 6, 9, and 12 MeV electron beams, were selected for this study. For each patient, irregularly shaped treatment blocks were drawn on simulation film and constructed. Using the irregular blocks, monitor units to deliver 100 cGy to the dose maximum (dmax) were calculated from measurement and three-dimensional radiation treatment planning (3D RTP) system (PINNACLE 6.0, ADAC Laboratories, Milpitas CA) Measurements were made in solid water phantom with plane parallel (PP) chamber (Roos, OTW Germany) at 100 cm source-to surface distances. CT data was used to investigate the effect of heterogeneity. Monitor units were calculated by overriding CT values with 1 g/㎤ and in the presence of heterogeneity. The monitor unit values obtained by the above methods were compared. The dose, obtained from measurement in solid water phantom was higher than that of RTP values for irregularly shaped blocks. The maximum differences between monitor unit calculated in flat water phantom at gantry zero position were 4% for 6 MeV and 2% for 9 and 12 MeV electrons. When CT data was used at a various gantry angle the agreement between the TPS data with and without density correction was within 3% for all energies. These results indicate that there are no significant difference in terms of monitor unit when density is corrected for the treatment of breast cancer patients with electrons.