• Investigative Magnetic Resonance Imaging
• /
• v.23 no.2
• /
• pp.167-171
• /
• 2019

$M\ddot{o}bius$ syndrome is a rare congenital condition, characterized by abducens and facial nerve palsy, resulting in limitation of lateral gaze movement and facial diplegia. However, to our knowledge, there have been few studies on evaluation of cranial nerves, on MR imaging in $M\ddot{o}bius$ syndrome. Herein, we describe a rare case of $M\ddot{o}bius$ syndrome representing limitation of lateral gaze, and weakness of facial expression, since the neonatal period. In this case, high-resolution MR imaging played a key role in diagnosing $M\ddot{o}bius$ syndrome, by direct visualization of corresponding cranial nerves abnormalities.

• Korean Journal of Radiology
• /
• v.21 no.10
• /
• pp.1115-1125
• /
• 2020

Combined hepatocellular-cholangiocarcinoma (cHCC-CCA) is a primary liver cancer (PLC) with both hepatocytic and cholangiocytic phenotypes. Recently, the World Health Organization (WHO) updated its histological classification system for cHCC-CCA. Compared to the previous WHO histological classification system, the new version no longer recognizes subtypes of cHCC-CCA with stem cell features. Furthermore, some of these cHCC-CCA subtypes with stem cell features have been recategorized as either hepatocellular carcinomas (HCCs) or intrahepatic cholangiocarcinomas (ICCs). Additionally, distinctive diagnostic terms for intermediate cell carcinomas and cholangiolocarcinomas (previous cholangiolocellular carcinoma subtype) are now recommended. It is important for radiologists to understand these changes because of its potential impact on the imaging-based diagnosis of HCC, particularly because cHCC-CCAs frequently manifest as HCC mimickers, ICC mimickers, or as indeterminate on imaging studies. Therefore, in this review, we introduce the 2019 WHO classification system for cHCC-CCA, illustrate important imaging features characteristic of its subtypes, discuss the impact on imaging-based diagnosis of HCC, and address other important considerations.

• Journal of the Korean Society of Radiology
• /
• v.82 no.2
• /
• pp.298-314
• /
• 2021

Owing to the anatomic complexity of the hepatic hilum, it has been considered difficult to diagnose and treat peri-hilar cholangiocarcinoma. Currently, imaging studies, including contrast-enhanced CT and MRI, play a crucial role in the detection, characterization, staging, and resectability assessment of peri-hilar cholangiocarcinoma. In this review, the classification of perihilar cholangiocarcinoma and proposed imaging protocol for the evaluation will be discussed. The typical imaging finding of peri-hilar cholangiocarcinoma, evaluation of longitudinal tumor extent, adjacent vascular invasion, and distant metastasis will also be mentioned. Finally, traditional concepts and recent updates for the resectability assessment of peri-hilar cholangiocarcinoma will be introduced.

• Clinical Endoscopy
• /
• v.56 no.5
• /
• pp.553-562
• /
• 2023

Colonoscopy plays an important role in reducing the incidence and mortality of colorectal cancer by detecting adenomas and other precancerous lesions. Image-enhanced endoscopy (IEE) increases lesion visibility by enhancing the microstructure, blood vessels, and mucosal surface color, resulting in the detection of colorectal lesions. In recent years, various IEE techniques have been used in clinical practice, each with its unique characteristics. Numerous studies have reported the effectiveness of IEE in the detection of colorectal lesions. IEEs can be divided into two broad categories according to the nature of the image: images constructed using narrow-band wavelength light, such as narrow-band imaging and blue laser imaging/blue light imaging, or color images based on white light, such as linked color imaging, texture and color enhancement imaging, and i-scan. Conversely, artificial intelligence (AI) systems, such as computer-aided diagnosis systems, have recently been developed to assist endoscopists in detecting colorectal lesions during colonoscopy. To gain a better understanding of the features of each IEE, this review presents the effectiveness of each type of IEE and their combination with AI for colorectal lesion detection by referencing the latest research data.

• Korean Journal of Digital Imaging in Medicine
• /
• v.5 no.1
• /
• pp.78-84
• /
• 2002

To evaluate the relative time required to perform a CT(computed tomography) examination in a filmless versus a film-based system and helical versus nonhelical studies. Time and Motion studies were performed in 175 consecutive CT examinations. Images from 85 examinations were electronically transferred to a PACS, and 90 were printed to film. The time required to obtain and electronically transfer the images or print the images to film and make the current and previous studies available to the radiologists for interpretation was recorded. The time required for a radiological technologist to complete a CT examination was reduced by 43% with the PACS compared with the film-based system and nonhelical was reduced 10-20% with helical studies. This reduction was due to the elimination of a transfer and printing, such as the printing at window or level settings. The use of PACS can result in the elimination of time tasks for the radiological technologist, resulting in marked reduction in examination time. This reduction can result in decreased cost and increased productivity in PACS operation.

• Proceedings of the Korean Society of Medical Physics Conference
• /
• 2006.08a
• /
• pp.47-47
• /
• 2006

• Nuclear Medicine and Molecular Imaging
• /
• v.42 no.sup1
• /
• pp.149-152
• /
• 2008

Nonmelanomatous skin cancer includes basal cell carcinoma, squamous cell carcinoma, merkel cell carcinoma and dermatofibrosarcoma protuberance. So far, there have been a few reports that $^{18}F-FDG$ PET was useful in the evaluation of metastasis and therapeutic response in nonmelanomatous skin cancer, however, those are very weak evidences. Therefore, further studies on the usefulness of $^{18}F-FDG$ PET in nonmelanomatous skin cancer are required.

• Proceedings of the KSMRM Conference
• /
• 2003.10a
• /
• pp.109-111
• /
• 2003

Compared to the present clinical field strengths, MR at 47 and above promises to improve anatomic imaging quality by factors, and to bring metabolic and functional imaging to the forefront of research and diagnostic modalities. While human bore sized magnets as high as 9.4T are now installed, realization of the potential benefit of these magnets will require more of the MR system than a simple field, frequency or power scaling from technologies used at lower fields. New constraints on the high field MR studies, both physical and physiological, will require new technical developments to be considered for the highest field systems.

• Proceedings of the KSMRM Conference
• /
• 2002.11a
• /
• pp.117-122
• /
• 2002

Contrast-enhanced MR angiography has become a widely used method useful for clinical diagnosis. Early studies identified a number of technical issues, and many of these have been addressed with various MRI physics innovations over the last several years. The quality of the results is high enough that CE MRA is replacing conventional x-ray angiography methods at many institutions. Ongoing research is expected to provide further improvements in performance, most notably in additional reductions in examination time, in time-resolved 3D imaging, and in improved imaging of the peripheral vasculature with extended fields of view.

• Proceedings of the KSEEG Conference
• /
• 2003.04a
• /
• pp.150-153
• /
• 2003

High-resolution imaging of electrical conductivity has been the subject of many studies in crosshole tomography using electromagnetic (EM) fields (Zhou et al., 1993; Wilt et al., 1995; Alumbaugh and Morrison, 1995; Newman, 1995; Alumbaugh and Newman, 1997). Although the theoretical understanding and associated field practices for crosshole EM methods are relatively mature, fast and stable imaging of crosshole EM data is still a challenging problem. (omitted)