• Journal of the Korean Society of Radiology
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• v.11 no.6
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• pp.453-458
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• 2017

Computed Tomography (CT) provides information on the Diagnostic Reference Level Computed Tomography Dose Index (CTDI) and Dose Length Product (DLP) for accurate diagnosis of patients. However, it does not provide a dose change according to the table height for the diagnostic reference level provided by the CT equipment. The purpose of this study was to evaluate the image and dose according to the table height change using phantom (PMMA: Polymethyl Methacrylate) in order to find the optimal image and the minimum dose during computed tomography examination. When examining using a 32 cm PMMA phantom with the same thickness as the abdomen of an adult, there was little change in dose with table height. However, the noise evaluation of the image caused a high fluctuation of noise depending on the table height. and in the case of the 16 cm PMMA phantom, the change of the noise was small, but the dose change was about 30%. In conclusion, the location of the patient and the center of the detector are important during computed tomography (CT) examinations. In addition, table height setting is considered to be important for examinations with optimized image and minimum dose.

• The KIPS Transactions:PartB
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• v.12B no.5 s.101
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• pp.553-560
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• 2005

Generally, it is known that the spleen accompanied by liver cirrhosis is hypertrophied or enlarged. We examined the wave pattern of the spleen by using abdominal CT images of a patient with liver cirrhosis, and found that they are different from those of a person with a normal liver In the abdominal CT image of the patient with liver cirrhosis, there is a deep wave part on the left side of the spleen. In the case of the normal liver, there are waves on the left side, but they aren't deep. Therefore, the total area of waving parts of the spleen with liver cirrhosis is found to be greater than that of the spleen with the normal liver. Moreover, when examining circularity by abstracting the waves of the spleen from the image iO liver cirrhosis, we found they are more circular than those of the spleen accompanied by a normal liver. This paper suggests an automatic method to diagnose splenic enlargement by using the wave pattern of the spleen in abdominal CT images on the basis of the two principles. It tells us that we can judge if the abdomen has a focal splenic enlargement automatically, without the manual test of the size of spleen, only with the shape of spleen.

• Journal of the Korean Society of Radiology
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• v.15 no.5
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• pp.575-584
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• 2021

The aim of this study was to achieve optimal portal phase while reducing contrast medium by applying weight-based dose protocol compared to standard fixed dose protocol to performing of pediatric abdominal CT examination. Discovery 750HD (General Electric Medical Systems, Milwaukee, USA) was used, and a total of 167 children consisting of 85 men and 82 women under the age of 18 were studied. The group in which the 300 mgI/ml(Xenetix, Guerbet, France) contrast medium was fixedly injected at twice body weight and the group injected with physiological saline while gradually decreasing the injection amount by 10% while applying the weight-based protocol were distinguished. Also, the CT number and SNR of abdominal organs were compared and evaluated while changing the scan delay time. Subjective image quality of enhancement and beam-hardening artifacts of around the heart was assessed with five-point criterion. The group adapted weight-based protocol with 20% reduction in contrast medium was most similar in contrast enhancement in the group with fixed injection at twice body weight. Furthermore, the group with a delay time of 20% had the highest contrast enhancement effect, and the difference in CT attenuation coefficient from the group scanned immediately after injection of the contrast media. Therefore, the appropriate delay time after injection of the contrast agent increased the contrast enhancement of the parenchymal organ. In addition, the weight-based injection protocol with normal saline reduced artifacts around the heart, and the effect of contrast enhancement could be maintained. In conclusion, it is possible to reduce dosage of contrast media through the application of weight-based injection protocols and appropriate latency, and to characterize optimal portal phase imaging on pediatric abdominal CT.

• Korean Journal of Radiology
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• v.24 no.6
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• pp.529-540
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• 2023

Objective: To compare the diagnostic performance and clinical outcomes of 2-mSv computed tomography (CT) and conventional-dose CT (CDCT), following radiology residents' interpretation of CT examinations for suspected appendicitis. Materials and Methods: Altogether, 3074 patients with suspected appendicitis aged 15-44 years (28 ± 9 years, 1672 females) from 20 hospitals were randomly assigned to the 2-mSv CT (n = 1535) or CDCT (n = 1539) groups in a pragmatic trial from December 2013 and August 2016. Overall, 107 radiology residents participated in the trial as readers in the form of daily practice after online training for 2-mSv CT. They made preliminary CT reports, which were later finalized by attending radiologists via addendum reports, for 640 and 657 patients in the 2-mSv CT and CDCT groups, respectively. We compared the diagnostic performance of the residents, discrepancies between preliminary and addendum reports, and clinical outcomes between the two groups. Results: Patient characteristics were similar between the 640 and 657 patients. Residents' diagnostic performance was not significantly different between the 2-mSv CT and CDCT groups, with a sensitivity of 96.0% and 97.1%, respectively (difference [95% confidence interval {CI}], -1.1% [-4.9%, 2.6%]; P = 0.69) and specificity of 93.2% and 93.1%, respectively (0.1% [-3.6%, 3.7%]; P > 0.99). The 2-mSv CT and CDCT groups did not significantly differ in discrepancies between the preliminary and addendum reports regarding the presence of appendicitis (3.3% vs. 5.2%; -1.9% [-4.2%, 0.4%]; P = 0.12) and alternative diagnosis (5.5% vs. 6.4%; -0.9% [-3.6%, 1.8%]; P = 0.56). The rates of perforated appendicitis (12.0% vs. 12.6%; -0.6% [-4.3%, 3.1%]; P = 0.81) and negative appendectomies (1.9% vs. 1.1%; 0.8% [-0.7%, 2.3%]; P = 0.33) were not significantly different between the two groups. Conclusion: Diagnostic performance and clinical outcomes were not significantly different between the 2-mSv CT and CDCT groups following radiology residents' CT readings for suspected appendicitis.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.7 no.1
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• pp.108-111
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• 2004

Tuberculosis is not a common cause of liver abscess and it is rarely considered in the differential diagnosis of a patient with hepatic mass. We report a case of tuberculous abscess of liver and spleen in a 15-year-old boy who presented with abdominal pain, fever and weight loss. The ultrasonographic and computed tomographic scan of the abdomen revealed multiple cystic lesions in the liver and spleen. Mycobacterium tuberculosis was cultured from the ascitic fluid and biopsy specimen of lymph node. Follow up CT scan of the abdomen after anti-tuberculosis medication for eighteen months showed complete resolution of the cystic lesions with calcified nodules.

• Investigative Magnetic Resonance Imaging
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• v.18 no.3
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• pp.253-257
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• 2014

Wandering spleen is a rare clinical condition caused by lax splenic suspensory ligaments. The laxity of ligaments causes torsion of splenic vascular pedicle. CT scan of a 7-year-old girl with abdominal pain showed a non-enhancing lobular mass in lower abdomen. Small bowel loops were located at the right-sided abdomen and colonic loops at the left-sided abdomen. MRI scan showed non-enhancing heterogeneous mass with twisted vascular pedicle. To our knowledge, only a few cases have been reported about wandering spleen diagnosed on MRI.

• Journal of the Korean Society of Radiology
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• v.79 no.5
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• pp.286-289
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• 2018

Toxocariasis, a parasitic infection, causes hyper eosinophilia resulting in radiological presentation of eosinophilic infiltrations in the involved organs. In the abdomen, toxocariasis has been reported to manifest as infiltrations in the liver or in the gastrointestinal tract, but it is known to be uncommon to manifest as multiple lymphadenopathy. There have been two case reports of toxocariasis presenting as generalized lymphadenopathy in the chest, neck and inguinal regions. To the best of our knowledge, generalized conglomerated lymphadenopathy occurring mostly in the abdomen from toxocariasis has not been published in the English literature. Herein, we report a rare case of toxocariasis presenting as multiple conglomerated lymphadenopathy mimicking lymphoma on CT.

• Journal of Radiation Protection and Research
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• v.36 no.2
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• pp.79-85
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• 2011

OThe purpose of this article was to measure and compare the value of the metal artifact reduction (MAR) algorithm by Dual energy(kVp switching) CT (Computed Tomography) for non using MAR and we introduced new variable Dual energy CT applications through a clinical scan. The used equipment was GE Discovery 750HD with Dual-Energy system(kVp switching). CT scan was performed on the neck and abdomen area subject for patients. Studies were from Dec 20 2010 to Feb 10 2011 and included 25 subject patients with prosthesis. We were measured the HU (Hounsfield Unit) and noise value at metal artifact appear(focal loss of signal and white streak artifact area) according to the using MAR algorithm. Statistical analyses were performed using the paired sample t-test. In patient subject case, the statistical difference of showing HU was p=0.01 and p=0.04 respectively. At maximum black hole artifact area and white streak artifact area according to the using MAR algorithm. However noise was p=0.05 and p=0.04 respectively; and not the affected black hole and white streak artifact area. Dual Energy CT with the MAR algorithm technique is useful reduce metal artifacts and could improve the diagnostic value in the diagnostic image evaluation of metallic implants area.

• Journal of the Korean Society of Radiology
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• v.83 no.1
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• pp.138-148
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• 2022

Purpose This study evaluated the rates and annual trends of pediatric CT scans in South Korea using a nationwide population-based database. Materials and Methods Data regarding pediatric CT scan usage between 2012 and 2017 were retrieved from the health insurance review and assessment service. Data on the age, sex, diagnosis, and the anatomical area of involved patients were also extracted. Results A total of 576376 CT examinations were performed among 58527528 children aged below 18 years (9.8 scans/1000 children), and the number of CT examinations per 1000 children was noted to have increased by 23.2% from 9.0 in 2012 to 11.0 in 2017. Specifically, the number of CT examinations increased by 32.9% for the 6-12 years of age group (7.4/1000 to 9.8/1000) and by 34.0% for the 13-18 years of age group (11.4/1000 to 15.3/1000). Moreover, majority of the CT scans were limited to the head (39.1%), followed by the extremities (32.5%) and the abdomen (13.7%). Notably, the number of extremity CT scans increased by 83.6% (2.3/1000 to 4.2/1000), and its proportion as compared to other scans increased from 25.3% to 37.7%. Conclusion CT scans in the pediatric population increased continuously from 2012 to 2017 at an annual rate of 4.4%. Therefore, physicians should balance the benefits of CT with its potential harms from associated radiation exposure in pediatric patients.

• YAKHAK HOEJI
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• v.51 no.6
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• pp.455-462
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• 2007

The participants were recruited 77 healthy adult persons aged between 20 and 50 who have BMI above $25kg/m^2$ in this study. All subjects were randomly assigned to the Gentro $F^{(R)}$ drinking group and non-drinking group. We were investigated about abdomen fat decreasing effect of Gentro $F^{(R)}$, distillate of pepper. Total fat area (TFA), subcutaeneous fat area (SFA) and visceral fat area (VFA) and subcutaneous fat area/visceral fat area ratio (SVR) has been assessed by obesity index (BMI, body fat percent, waist circumference), CT scan taken on the $L4{\sim}5$ position, umbilicus level and blood analysis evaluated during 3 month. The obesity indexes were a little decreased in two groups. However, the waist circumference (WC) was decreased about 5% in drinking group after 3 month and there was significant difference in the change 2 and 3 between two group. TFA and VFA were significantly decreased in the drinking group compare to the non-drinking group (p<0.05) and in umbilicus and $L4{\sim}5$ position, were $370.33{\pm}92.30,\;380.35{\pm}97.64\;and\;114.90{\pm}44.91,\;101.99{\pm}41.24$, respectively. These result means that Gentro $F^{(R)}$ is effective on abdomen fat decreasing. Total cholesterol were decreased without difference in both groups. Lipid factors (TG, HDL- and LDL-cholesterol) were decreased without significance. The mea surement of SVR taken on the $L4{\sim}5$ position were more significantly correlated with obesity index that BMI was 0.787, body fat percentage was 0.754 than on the umbilicus level. The TFA and VSA was correlated with ALP, ASP, Albumin, Insulin and the SVR was correlated with the indexes of liver function and lipid factor found in the blood. Therefore, it is conclude that Gentro $F^{(R)}$ drinking leads to a decrease in abdominal obesity by reducing waist circumference and visceral fat area.