• Proceedings of the IEEK Conference
• /
• 2003.11b
• /
• pp.153-156
• /
• 2003

In this paper, we propose a new scheme for automatic segmentation of the liver in CT images. The proposed scheme is carried out on region of interest(ROI) blocks that include regions of the liver with high probabilities. The ROI approach saves unnecessary computational loss in finding the accurate boundary of the liver. The proposed method utilizes the composition of multi-size morphological filters with a prior knowledge, such as the general location or the approximate intensity of the liver to detect the initial boundary of the liver. Then, we make the gradient image with the weight of the initial liver boundary and segment the liver legion by using an immersion-based waters hed algorithm in the gradient image. finally, the refining process is carried out to acquire a more accurate liver region.

• Journal of radiological science and technology
• /
• v.40 no.2
• /
• pp.229-235
• /
• 2017

In abdominal Ultrasonography, the fatty liver is diagnosed through hepatic parenchymal echo increased parenchymal density and unclear blood vessel boundary, and according to many studies, abdominal Ultrasonography has 60~90% of sensitivity and 84~95% of specificity in diagnosis of fatty liver, but the result of Ultrasonography is dependent on operators, so there can be difference among operators, and quantitative measurement of fatty infiltration is impossible. Among examinees who same day received abdominal Ultrasonography and chest computed tomography (CT), patients who were diagnosed with a fatty liver in the Ultrasonography were measured with liver Hounsfield Units (HU) of chest CT imaging to analyze the accuracy of the fatty liver diagnosis. Among 720 subject examinees, those who were diagnosed with a fatty liver through abdominal Ultrasonography by family physicians were 448, which is 62.2%. The result of Liver HU measurement in the chest CT imaging of those who were diagnosed with a fatty liver showed that 175 out of 720 had the measured value of less than 40 HU, which is 24.3%, and 173 were included to the 175 among 448 who were diagnosed through Ultrasonography, so 98.9% corresponded. This indicates that the operators' subjective ability has a great impact on diagnosis of lesion in Ultrasonography diagnosis of a fatty liver, and that in check up chest CT, under 40 HU in the measurement of Liver HU can be used for reference materials in diagnosis of a fatty liver.

• Nuclear Medicine and Molecular Imaging
• /
• v.40 no.3
• /
• pp.188-189
• /
• 2006

A 53-year -old man underwent $^{18}F$-FDG whole body PET/CT because of the detected liver mass on abdominal CT. The PET/CT showed a huge liver mass ($9{\times}9cm$, SUV: 12.12 ) in the right lobe and a focally hypermetabolic lesion in the right lower quadrant of abdomen (SUV: 9.12). At first, we suspected that the focal hypermetabolic lesion in RLQ was the physiologic uptake of ureter or a metastatic lesion of small bowel. We repeated the abdominal PET/CT next day. The focally hypermetabolic lesion was identified as the appendiceal mass. He underwent right hemicolectomy and right lobectomy of the liver. It was confirmed that the lesion was appendiceal adenocarcinoma with liver metastasis. Cancer of the appendix is an uncommon disease that is rarely suspected before surgery. But, we suggest that PET/CT is useful to identify the small lesion like appendiceal malignant mass.

• Korean Journal of Radiology
• /
• v.1 no.2
• /
• pp.98-103
• /
• 2000

Objective: The purpose of this study was to describe the CT findings of hepatic hypereosinophilic syndrome in which hepatic lobes or segments were involved. Materials and Methods: Seven patients with hypereosinophilic syndrome with hepatic lobar or segmental involvement were included in our study. In all seven, diagnosis was based on liver biopsy and the results of corticosteroid treatment. CT findings were retrospectively reviewed by three radiologists, who reached a consensus. Biopsy specimens were examined, with special reference to portal and periportal inflammation. Results: CT demonstrated well-defined, homogeneous or heterogeneous low attenuation with a straight margin limited to a hepatic lobe (n = 2), segments (n = 3), or subsegments (n = 2), particularly during the portal phase. Where there was subsegmental involvement, lesions were multiple, ovoid or wedge-shaped, and showed low attenuation. In two patients with lobar or segmental involvement, segmental portal vein narrowing was observed. Histopathologic examination disclosed eosinophilic infiltration in the periportal area, sinusoids and central veins, as well as portal phlebitis. Conclusion: Hypereosinophilic syndrome may involve the presence of hepatic lobar, segmental, or subsegmental low-attenuated lesions, as seen on CT images. Their presence may be related to damage of the liver parenchyma and to portal phlebitis.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.28 no.1
• /
• pp.23-29
• /
• 2024

Purpose: 99mTc-mebrofenin hepatobiliary scintigraphy (HBS) is an important and clinically useful diagnostic imaging study for detecting complications after liver transplantation. CT contrast agents due to their high atomic numbers, lead to a decrease in gamma ray count rates. This study investigated the impact of CT contrast agents on the uptake of 99mTc-mebrofenin in the liver. Materials and Methods: The quantitative HBS was performed on sixty-two liver transplantation patients (male:female=36:26), with a mean age of 59.4±6.4 years. Statistical comparison of hepatic uptake reduction ratio (HURR%) before and after the injection of CT contrast agents was performed using a paired t-test. Results: Hepatic uptake of the reduction ratio was 94.47±3.65% for the pre-CT contrast agents and 92.17±4.00% for the post-CT contrast agents. HURR% after CT contrast agent injection showed a statistically significant difference compared to before the injection (t=11.09, P<0.001). Conclusion: It will be necessary to pay attention when examining the HBS of patients with liver transplantation after the injection of CT contrast medium. It is advisable to schedule the examination on a different day to prevent residual contrast medium in the body from interfering with the quantitative evaluation of the nuclear medicine examination.

• Journal of the Korean Society of Radiology
• /
• v.84 no.1
• /
• pp.15-33
• /
• 2023

The liver imaging reporting and data system (LI-RADS) has been developed with the support of the American College of Radiology to standardize the diagnosis and evaluation of treatment response of hepatocellular carcinoma (HCC). The CT/MRI LI-RADS version 2018 has been incorporated in the American Association for the Study of Liver Diseases guidance. This review examines the effect of CT/MRI LI-RADS on the standardized reporting of liver imaging, and the evidence in diagnosing HCC and evaluating treatment response after locoregional treatment using CT/MRI LI-RADS. The results are compared with other HCC diagnosis guidelines, and future directions are described.

• Journal of Korea Multimedia Society
• /
• v.9 no.12
• /
• pp.1588-1595
• /
• 2006

In this paper, we proposed a liver extracting procedure for computer aided liver diagnosis system. Extraction of liver region in an abdominal CT image is difficult due to interferences of other organs. For this reason, liver region is extracted in a region of interest(ROI). ROI is selected by the window which can measure the distribution of Hounsfield Unit(HU) value of liver region in an abdominal CT image. The distribution is measured by an existential probability of HU value of lever region in the window. If the probability of any window is over 50%, the center point of the window would be assigned to ROI. Actually, liver region is not clearly discerned from the adjacent organs like muscle, spleen, and pancreas in an abdominal CT image. Liver region is extracted by the watershed segmentation algorithm which is effective in this situation. Because it is very sensitive to the slight valiance of contrast, it generally produces over segmentation regions. Therefore these regions are required to merge into the significant regions for optimal segmentation. Finally, a liver region can be selected and extracted by prier information based on anatomic information.

• Nuclear Medicine and Molecular Imaging
• /
• v.42 no.3
• /
• pp.253-255
• /
• 2008

A 61-year-old man had a F-18 FDG PET/CT scan for evaluation of a common bile duct cancer identified on CT. The PET/CT image showed a hypermetabolic mass in the common bile duct, and a focal area of increased F-18 FDG uptake in segment IV of the liver, which corresponded to a hypoattenuated lesion on non-enhanced CT, and was consistent with hepatic metastasis. The patient underwent choledochojejunostomy with hepatic resection, and pathologic findings were compatible with an eosinophilic abscess in the liver. This case demonstrates that F-18 FDG uptake by an eosinophilic abscess can mimic hepatic metastasis in a patient with a malignancy.

• Korean Journal of Radiology
• /
• v.1 no.3
• /
• pp.165-168
• /
• 2000

We present two cases of solitary necrotic nodules of the liver which on radiologic images mimicked hepatic metastasis. Solitary necrotic nodule of the liver is a rare but benign entity which histopathologically consists of an outer fibrotic capsule with inflammatory cells and a central core of amorphous necrotic material. The lesion was seen on contrast-enhanced CT as an ovoid-shaped hypoattenuating nodule; on CT during hepatic arteriography as enhancing nodule; on intraoperative US as a target-appearing hypoechoic nodule; on T2WI as a hyperintensity nodule, and on dynamic MR as a subtle peripheral enhancing nodule. Although the radiologic features are not specific, solitary necrotic nodule of the liver should be included in the differential diagnosis of hepatic metastasis.

• Journal of Trauma and Injury
• /
• v.23 no.2
• /
• pp.151-156
• /
• 2010

Purpose: The liver is the second most common organ injured by blunt abdominal trauma. The purpose of this study was to determine the utility of liver transaminase in screening blunt abdominal trauma patients for traumatic liver injury. Methods: We retrospectively reviewed the medical records of 231 patients who sustained blunt trauma and were at risk for traumatic liver injury between June 2009 and August 2010. All of them underwent a focused assessment with sonography for trauma (FAST) and abdominal computed tomography (CT). Based on the diagnosis of abdominal CT, patients were divided into two groups: group I with liver injury and group II without liver injury. We compared the two groups and calculated the sensitivity, the specificity and the predictive values of serum aspartate aminotransferase (AST) and serum alanine aminotransferase (ALT) by using multiple cutoff values. Results: Of 231 patients with no abdominal free fluid in the FAST, 33 had traumatic liver injury on abdominal CT. The mean AST and ALT levels in group I (311.6 IU/L and 228.1 IU/L, respectively) were significantly higher than the values in group II (48.4 IU/L and 35.6 IU/L, respectively). The cutoff to distinguish liver injury is 60 IU/L for AST and 58 IU/L for ALT, with 93.8% sensitivity and 79.8% specificity for AST, and 90.6% sensitivity and 87.4% specificity for ALT. Conclusion: We recommend that all patient with suspected blunt abdominal trauma be evaluated using serum liver transaminase as a screening test for liver injury even though no abdominal free fluid is shown on the FAST. If AST > 60 IU/L and/or ALT > 58 IU/L, abdominal CT was useful to confirm liver injury in this study.