Jiyeon Ha - Academia.edu (original) (raw)
Papers by Jiyeon Ha
Archives of Dermatology, 1963
On the basis of a direct clinical and histologic investigation of two patients and five tumors, t... more On the basis of a direct clinical and histologic investigation of two patients and five tumors, the so-called clear cell hidradenoma is described as a benign and sometimes malignant neoplasm originating in the epithelial matrix of the ductal and poral segment of the eccrine sweat gland.
BACKGROUND Despite the dramatic increase in the use of medical imaging in various therapeutic fie... more BACKGROUND Despite the dramatic increase in the use of medical imaging in various therapeutic fields of clinical trials, image quality check is still performed manually by image analysts, which requires a lot of manpower and time. OBJECTIVE This study aimed to develop a deep learning model that simultaneously identifies anatomical locations and contrast enhancement on medical images, with accuracy and clinical effectiveness validation, to support an automated image quality check. METHODS In this retrospective study, 1,669 computed tomography (CT) images with five specific anatomical locations were collected from Asan Medical Center and Kangdong Sacred Heart Hospital. To generate the ground truth, two radiologists reviewed the anatomical locations and presence of contrast enhancement using the collected data. A deep learning framework called ImageQC-net (Image Quality Check-network) with transfer learning was developed using an InceptioResNetV2 model. To evaluate their clinical effec...
Korean Journal of Radiology
Objective: Computed tomography enterography (CTE) and magnetic resonance enterography (MRE) are c... more Objective: Computed tomography enterography (CTE) and magnetic resonance enterography (MRE) are considered substitutes for each other for evaluating Crohn's disease (CD). However, the adequacy of mixing them for routine periodic follow-up for CD has not been established. This study aimed to compare MRE alone with the mixed use of CTE and MRE for the periodic follow-up of small bowel inflammation in patients with CD. Materials and Methods: We retrospectively compared two non-randomized groups, each comprising 96 patients with CD. One group underwent CTE and MRE (MRE followed by CTE or vice versa) for the follow-up of CD (interval, 13-27 months [median, 22 months]), and the other group underwent MRE alone (interval, 15-26 months [median, 21 months]). However, these two groups were similar in clinical characteristics. Three independent readers from three different institutions determined whether inflammation had decreased, remained unchanged, or increased within the entire small bowel and the terminal ileum based on sequential enterography of the patients after appropriate blinding. We compared the two groups for inter-reader agreement and accuracy (terminal ileum only) using endoscopy as the reference standard for enterographic interpretation. Results: The inter-reader agreement was greater in the MRE alone group for the entire small bowel (intraclass correlation coefficient [ICC]: 0.683 vs. 0.473; p = 0.005) and the terminal ileum (ICC: 0.656 vs. 0.490; p = 0.030). The interpretation accuracy was higher in the MRE alone group without statistical significance (70.9%-74.5% vs. 57.9%-64.9% in individual readers; adjusted odds ratio = 3.21; p = 0.077). Conclusion: The mixed use of CTE and MRE was inferior to MRE alone in terms of inter-reader reliability and could probably be less accurate than MRE alone for routine monitoring of small bowel inflammation in patients with CD. Therefore, the consistent use of MRE is favored for this purpose.
Korean Journal of Radiology
Objective: To evaluate the reliability of CT measurements of muscle quantity and quality using va... more Objective: To evaluate the reliability of CT measurements of muscle quantity and quality using variable CT parameters. Materials and Methods: A phantom, simulating the L2-4 vertebral levels, was used for this study. CT images were repeatedly acquired with modulation of tube voltage, tube current, slice thickness, and the image reconstruction algorithm. Reference standard muscle compartments were obtained from the reference maps of the phantom. Cross-sectional area based on the Hounsfield unit (HU) thresholds of muscle and its components, and the mean density of the reference standard muscle compartment, were used to measure the muscle quantity and quality using different CT protocols. Signal-to-noise ratios (SNRs) were calculated in the images acquired with different settings. Results: The skeletal muscle area (threshold,-29 to 150 HU) was constant, regardless of the protocol, occupying at least 91.7% of the reference standard muscle compartment. Conversely, normal attenuation muscle area (30-150 HU) was not constant in the different protocols, varying between 59.7% and 81.7% of the reference standard muscle compartment. The mean density was lower than the target density stated by the manufacturer (45 HU) in all cases (range, 39.0-44.9 HU). The SNR decreased with low tube voltage, low tube current, and in sections with thin slices, whereas it increased when the iterative reconstruction algorithm was used. Conclusion: Measurement of muscle quantity using HU threshold was reliable, regardless of the CT protocol used. Conversely, the measurement of muscle quality using the mean density and narrow HU thresholds were inconsistent and inaccurate across different CT protocols. Therefore, further studies are warranted in future to determine the optimal CT protocols for reliable measurements of muscle quality.
BACKGROUND Muscle quality is associated with fatty degeneration or infiltration of the muscle, wh... more BACKGROUND Muscle quality is associated with fatty degeneration or infiltration of the muscle, which may be associated with decreased muscle function and increased disability. OBJECTIVE The aim of this study is to evaluate the feasibility of automated quantitative measurements of the skeletal muscle on computed tomography (CT) images to assess normal-attenuation muscle and myosteatosis. METHODS We developed a web-based toolkit to generate a muscle quality map by categorizing muscle components. First, automatic segmentation of the total abdominal muscle area (TAMA), visceral fat area, and subcutaneous fat area was performed using a predeveloped deep learning model on a single axial CT image at the L3 vertebral level. Second, the Hounsfield unit of each pixel in the TAMA was measured and categorized into 3 components: normal-attenuation muscle area (NAMA), low-attenuation muscle area (LAMA), and inter/intramuscular adipose tissue (IMAT) area. The myosteatosis area was derived by addin...
Journal of the Korean Society of Radiology
Ansa pancreatic is a rare variation of pancreas duct. Ansa pancreatica is characterized by focal ... more Ansa pancreatic is a rare variation of pancreas duct. Ansa pancreatica is characterized by focal accessory duct atrophy and an additional curved duct linking main and accessory ducts replacing atrophied duct. Ansa pancreatica is considered as a predisposing factor of recurrent pancreatitis. Pancreatitis can be localized in pancreas head and uncinate process, because pancreas head and uncinate process might be drained through the additional hooked duct of ansa pancreatica. We reports three cases of localized chronic or recurrent pancreatitis cases with underlying ansa pancreatica type anatomic variation.
Emergency Medicine Australasia
Archives of Dermatology, 1963
On the basis of a direct clinical and histologic investigation of two patients and five tumors, t... more On the basis of a direct clinical and histologic investigation of two patients and five tumors, the so-called clear cell hidradenoma is described as a benign and sometimes malignant neoplasm originating in the epithelial matrix of the ductal and poral segment of the eccrine sweat gland.
BACKGROUND Despite the dramatic increase in the use of medical imaging in various therapeutic fie... more BACKGROUND Despite the dramatic increase in the use of medical imaging in various therapeutic fields of clinical trials, image quality check is still performed manually by image analysts, which requires a lot of manpower and time. OBJECTIVE This study aimed to develop a deep learning model that simultaneously identifies anatomical locations and contrast enhancement on medical images, with accuracy and clinical effectiveness validation, to support an automated image quality check. METHODS In this retrospective study, 1,669 computed tomography (CT) images with five specific anatomical locations were collected from Asan Medical Center and Kangdong Sacred Heart Hospital. To generate the ground truth, two radiologists reviewed the anatomical locations and presence of contrast enhancement using the collected data. A deep learning framework called ImageQC-net (Image Quality Check-network) with transfer learning was developed using an InceptioResNetV2 model. To evaluate their clinical effec...
Korean Journal of Radiology
Objective: Computed tomography enterography (CTE) and magnetic resonance enterography (MRE) are c... more Objective: Computed tomography enterography (CTE) and magnetic resonance enterography (MRE) are considered substitutes for each other for evaluating Crohn's disease (CD). However, the adequacy of mixing them for routine periodic follow-up for CD has not been established. This study aimed to compare MRE alone with the mixed use of CTE and MRE for the periodic follow-up of small bowel inflammation in patients with CD. Materials and Methods: We retrospectively compared two non-randomized groups, each comprising 96 patients with CD. One group underwent CTE and MRE (MRE followed by CTE or vice versa) for the follow-up of CD (interval, 13-27 months [median, 22 months]), and the other group underwent MRE alone (interval, 15-26 months [median, 21 months]). However, these two groups were similar in clinical characteristics. Three independent readers from three different institutions determined whether inflammation had decreased, remained unchanged, or increased within the entire small bowel and the terminal ileum based on sequential enterography of the patients after appropriate blinding. We compared the two groups for inter-reader agreement and accuracy (terminal ileum only) using endoscopy as the reference standard for enterographic interpretation. Results: The inter-reader agreement was greater in the MRE alone group for the entire small bowel (intraclass correlation coefficient [ICC]: 0.683 vs. 0.473; p = 0.005) and the terminal ileum (ICC: 0.656 vs. 0.490; p = 0.030). The interpretation accuracy was higher in the MRE alone group without statistical significance (70.9%-74.5% vs. 57.9%-64.9% in individual readers; adjusted odds ratio = 3.21; p = 0.077). Conclusion: The mixed use of CTE and MRE was inferior to MRE alone in terms of inter-reader reliability and could probably be less accurate than MRE alone for routine monitoring of small bowel inflammation in patients with CD. Therefore, the consistent use of MRE is favored for this purpose.
Korean Journal of Radiology
Objective: To evaluate the reliability of CT measurements of muscle quantity and quality using va... more Objective: To evaluate the reliability of CT measurements of muscle quantity and quality using variable CT parameters. Materials and Methods: A phantom, simulating the L2-4 vertebral levels, was used for this study. CT images were repeatedly acquired with modulation of tube voltage, tube current, slice thickness, and the image reconstruction algorithm. Reference standard muscle compartments were obtained from the reference maps of the phantom. Cross-sectional area based on the Hounsfield unit (HU) thresholds of muscle and its components, and the mean density of the reference standard muscle compartment, were used to measure the muscle quantity and quality using different CT protocols. Signal-to-noise ratios (SNRs) were calculated in the images acquired with different settings. Results: The skeletal muscle area (threshold,-29 to 150 HU) was constant, regardless of the protocol, occupying at least 91.7% of the reference standard muscle compartment. Conversely, normal attenuation muscle area (30-150 HU) was not constant in the different protocols, varying between 59.7% and 81.7% of the reference standard muscle compartment. The mean density was lower than the target density stated by the manufacturer (45 HU) in all cases (range, 39.0-44.9 HU). The SNR decreased with low tube voltage, low tube current, and in sections with thin slices, whereas it increased when the iterative reconstruction algorithm was used. Conclusion: Measurement of muscle quantity using HU threshold was reliable, regardless of the CT protocol used. Conversely, the measurement of muscle quality using the mean density and narrow HU thresholds were inconsistent and inaccurate across different CT protocols. Therefore, further studies are warranted in future to determine the optimal CT protocols for reliable measurements of muscle quality.
BACKGROUND Muscle quality is associated with fatty degeneration or infiltration of the muscle, wh... more BACKGROUND Muscle quality is associated with fatty degeneration or infiltration of the muscle, which may be associated with decreased muscle function and increased disability. OBJECTIVE The aim of this study is to evaluate the feasibility of automated quantitative measurements of the skeletal muscle on computed tomography (CT) images to assess normal-attenuation muscle and myosteatosis. METHODS We developed a web-based toolkit to generate a muscle quality map by categorizing muscle components. First, automatic segmentation of the total abdominal muscle area (TAMA), visceral fat area, and subcutaneous fat area was performed using a predeveloped deep learning model on a single axial CT image at the L3 vertebral level. Second, the Hounsfield unit of each pixel in the TAMA was measured and categorized into 3 components: normal-attenuation muscle area (NAMA), low-attenuation muscle area (LAMA), and inter/intramuscular adipose tissue (IMAT) area. The myosteatosis area was derived by addin...
Journal of the Korean Society of Radiology
Ansa pancreatic is a rare variation of pancreas duct. Ansa pancreatica is characterized by focal ... more Ansa pancreatic is a rare variation of pancreas duct. Ansa pancreatica is characterized by focal accessory duct atrophy and an additional curved duct linking main and accessory ducts replacing atrophied duct. Ansa pancreatica is considered as a predisposing factor of recurrent pancreatitis. Pancreatitis can be localized in pancreas head and uncinate process, because pancreas head and uncinate process might be drained through the additional hooked duct of ansa pancreatica. We reports three cases of localized chronic or recurrent pancreatitis cases with underlying ansa pancreatica type anatomic variation.
Emergency Medicine Australasia