• Archives of Hand and Microsurgery
• /
• v.23 no.4
• /
• pp.281-289
• /
• 2018

Purpose: Preoperative surgical planning utilizing computed tomography angiography (CTA) has now become a routine in many practices. We analyzed the course of the deep inferior epigastric artery (DIEA) and its perforators (DIEP) that would either facilitate or hinder flap dissection based on CTA to aid surgical planning. Methods: The 115 consecutive patients who underwent abdominally based free flap breast reconstruction were enrolled in this prospective study. DIEA/P courses were categorized mainly according to their intramuscular courses and their incidences were investigated. Results: A total of 425 perforators were identified preoperatively on the CTA, with an average number of 3.7 distinctly visualized in the entire flap territory. Eighty-nine perforators (20.9%) had a favorable (less than 1 cm intramuscular course) pattern, namely long submuscular (34.8% of the patients), long subfascial (15.6%), and total circummuscular (13.9%). Overall 56.5% of the patients had at least one favorable DIEA/P. On the other hand, absence of DIEA and absence of adequate (>1 mm) DIEP was reported in 3 and 8 hemiabdomen. Conclusion: Preoperative CTA evaluation of DIEA/P can be used to identify favorable as well as unfavorable courses for dissection to aid surgical planning.

• KIPS Transactions on Software and Data Engineering
• /
• v.1 no.2
• /
• pp.109-114
• /
• 2012

Honeycombs are dense structures that small cysts, which generally have about 2~10 mm in diameter, are surrounded by the wall of fibrosis. When honeycomb is found in the patients, the incidence of acute exacerbation is generally very high. Thus, the observation and quantitative measurement of honeycomb are considered as a significant marker for clinical diagnosis. In this point of view, we propose an automatic segmentation method using morphological image processing and assessment of the degree of clustering techniques. Firstly, image noises were removed by the Gaussian filtering and then a morphological dilation method was applied to segment lung regions. Secondly, honeycomb cyst candidates were detected through the 8-neighborhood pixel exploration, and then non-cyst regions were removed using the region growing method and wall pattern testing. Lastly, final honeycomb regions were segmented through the extraction of dense regions which are consisted of two or more cysts using cluster analysis. The proposed method applied to 80 High resolution computed tomography (HRCT) images and achieved a sensitivity of 89.4% and PPV (Positive Predictive Value) of 72.2%.

• Journal of the Korea Computer Graphics Society
• /
• v.22 no.4
• /
• pp.11-19
• /
• 2016

In this paper, we propose an automatic segmentation method of renal parenchyma on abdominal CT image using graph-cuts with shape constraint based on multi-probabilistic atlas. The proposed method consists of following three steps. First, to use the various shape information of renal parenchyma, multi-probabilistic atlas is generated by cortex-based similarity registration. Second, initial seeds for graph-cuts are extracted by maximum a posteriori (MAP) estimation and renal parenchyma is segmented by graph-cuts with shape constraint. Third, to reduce alignment error of probabilistic atlas and increase segmentation accuracy, registration and segmentation are iteratively performed. To evaluate the performance of proposed method, qualitative and quantitative evaluation are performed. Experimental results show that the proposed method avoids a leakage into neighbor regions with similar intensity of renal parenchyma and shows improved segmentation accuracy.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.43 no.5 s.311
• /
• pp.68-79
• /
• 2006

Electrical capacitance tomography (ECT) is a non-invasive imaging reconstruction technique that aims at visualization of cross sectional permittivity distribution of dielectric object based on the measured capacitance. There are lots of iterative image reconstruction methods to accelerate convergence rate and enhance quality of reconstructed image, Among them iterative Landweber method is one of the widely used reconstruction algorithm in En. In this paper, modified generalized Landweber method is proposed to accelerate convergence rate. In doing so, acceleration term is considered to the generalized Landweber method with shaping matrix and an optimal step length is determined analytically. Extensive computer simulations are provided to illustrate the reconstruction performance of the proposed algorithm.

• The KIPS Transactions:PartB
• /
• v.17B no.4
• /
• pp.303-308
• /
• 2010

In this paper, we propose a medical image registration technique combining the gradient vector flow and modified conditional entropy. The registration is conducted by the use of a measure based on the entropy of conditional probabilities. To achieve the registration, we first define a modified conditional entropy (MCE) computed from the joint histograms for the area intensities of two given images. In order to combine the spatial information into a traditional registration measure, we use the gradient vector flow field. Then the MCE is computed from the gradient vector flow intensity (GVFI) combining the gradient information and their intensity values of original images. To evaluate the performance of the proposed registration method, we conduct experiments with our method as well as existing method based on the mutual information (MI) criteria. We evaluate the precision of MI- and MCE-based measurements by comparing the registration obtained from MR images and transformed CT images. The experimental results show that the proposed method is faster and more accurate than other optimization methods.

• Journal of the Korean Society of Radiology
• /
• v.82 no.3
• /
• pp.688-692
• /
• 2021

Cervicovaginal venous malformations are extremely rare. Sclerotherapy is proven to be effective for superficial venous malformations but not for venous malformations in the lower genital tract of female. A 52-year-old female presented with intermittent vaginal bleeding. The amount of vaginal bleeding gradually increased over 3 months. Contrast-enhanced pelvis CT showed several phleboliths and dilated vessels, but pelvic angiography showed no early draining veins, nidus, or feeding artery. We performed transvaginal direct puncture and ethanol sclerotherapy rather than surgical treatment because she wanted to preserve the uterus. After four sessions of sclerotherapy, she had significantly decreased vaginal bleeding without complications. Here, we report the first case of cervicovaginal venous malformations successfully treated with transvaginal direct puncture and ethanol sclerotherapy.

• Journal of the Korean Society of Radiology
• /
• v.82 no.3
• /
• pp.749-755
• /
• 2021

Congenital defects of the pericardium, which are generally asymptomatic, are rare disorders characterized by complete or partial absence of the pericardium. Here, we report a rare case of a 19-year-old male who was incidentally diagnosed with congenital absence of the left pericardium during examination for symptoms of pneumothorax. Chest radiography and CT revealed a collapsed left lung without any evidence of trauma, no unusual findings of free air spaces along the right side of the ascending aorta, heart shifted toward the left side of the thorax, and a shallow chest. Subsequent thoracoscopy confirmed the absence of the left pericardium and displacement of the heart toward the left thoracic cavity. We further discuss the correlation between radiologic images and surgical findings of a congenital pericardial defect associated with spontaneous pneumothorax.

• Journal of the Korean Society of Radiology
• /
• v.82 no.2
• /
• pp.462-468
• /
• 2021

Parosteal lipoma is a rare type of lipoma, the incidence being approximately 0.3% of all lipomas. Moreover, parosteal lipoma coexisting with osteochondroma is extremely rare. A few cases with coexistence of osteochondroma and parosteal lipoma have been reported and they were thought to be reactive changes of adjacent bone by parosteal lipoma. However, temporal relationship of these tumors could not be explained. Here, we report a case of parosteal lipoma associated with osteochondroma of the right ilium developed over 6 years, with follow-up radiographs.

• Journal of the Korean Society of Radiology
• /
• v.81 no.6
• /
• pp.1497-1503
• /
• 2020

Inflammatory myofibroblastic tumors (IMTs) are rare. They are characterized by myofibroblastic spindle cell proliferation with a varying degree of inflammatory cell infiltration. IMT can occur in any anatomic location but has been reported in the lung, mesentery, and omentum, mainly in children or young adults. It rarely occurs in the pancreas and is often difficult to distinguish from other tumors, including some malignant ones. Therefore, it can be challenging to make a radiological diagnosis of IMT. Here, we present a case of IMT that occurred in the pancreas head of a middle-aged female. The patient's ultrasonography, computed tomography, and magnetic resonance imaging findings are presented along with a review of the literature.

• Journal of the Korean Society of Radiology
• /
• v.84 no.6
• /
• pp.1373-1377
• /
• 2023

Immunoglobulin G4 (IgG4)-related lung disease can have various clinical courses. To our knowledge, reports of IgG4-related lung disease with waxing and waning pulmonary infiltrates only are very rare. A few lung nodules and ground glass opacities were incidentally found in a pre-operative evaluation in a 36-year-old female. The lung lesions showed waxing and waning in the follow-up chest CT. She underwent a surgical biopsy, and IgG4-related lung disease was confirmed.