• The Journal of the Korea Contents Association
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• v.6 no.5
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• pp.145-152
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• 2006

Radiographic contrast medium may cause tissue injury by extravasation during intravenous automated injection during CT examination. A large - volume extravasation (140 mL) occurred in an adult during contrast-enhanced CT The patient had a swelling and injury on the dorsum right hand of intravenous catheter region. The extravasation injury site was determined by CT scanning. The extavasation compartment syndrome case was examined using four separate display techniques. These 3D MDCT findings might help to determine the best course of treatment for patient with contrast extravasation. 3D image reconstructions provide accurate views of high-resolution and soft-tissue imaging. This paper introduces extravasation with the radiography and 3D MDCT findings.

• Investigative Magnetic Resonance Imaging
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• v.1 no.1
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• pp.148-153
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• 1997

Purpose: To evaluate the diagnostic role of a three-dimensional MR cholangiopancreatography (MRCP) over endoscopic retrograde cholangio-pancreatography (ERCP) in various extrah-epatic biliary disease. Materials and Methods: MRCP and ERCP were performed in 45 consecutive patients with suspected extrahepatic biliary diseases. MRCP was obtained using a reverse fast imaging with a steady-state free precession (reverse FISP: PSIF) sequence, and then images were reconstructed by standard MIP algorithm. The predictability of biliary dilatation and level of obstruction of MRCP was evaluated using ERCP as a gold standard. The accuracy distinguishing malignant from benign lesions, and overall diagnostic accuracy were compared between MRCP and ERCP. Results: The sensitivity, specificity and accuracy of MRCP in predicting biliary dilatation were 94.6%, 75.0% and 91.1%, respectively. The level of obstruction was accurate in 87.0% with MRCP. The sensitivity, specificity and accuracy of MRCP and ERCP in distinguishing malignant from benign lesions were 76.2%, 87.5% and 82.2% and 71.4%, 83.3% and 77.8%, respectively. The overall diagnostic accuracy was 60.0% with MRCP and 55.6% with ERCP. Conclusion: 3D MRCP shows a good diagnostic value compared to that of ERCP, and can replace a ERCP.

• Journal of the Korean Society of Radiology
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• v.14 no.1
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• pp.61-68
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• 2020

The purpose of this study is to investigate the correlation of blooming artifacts according to dilution ratio of contrast agent on CT angiography images. A total of 10 sets were prepared by differently setting the ratio of contrast media and saline in a ball phantom made by a 3D printer. CT scan images were obtained and reconstructed by MIP and MPR techniques to obtain axial, sagittal and coronal images, respectively. After, the diameter of the ball phantom of the image obtained after the test was measured each 30 times, a total 1800 times. As a result, the dilution of 20:80 in the coronal plane was the smallest (p<0.05). Similarly, when dilute to 20:80 in the sagittal plane of MIP, it was the smallest as 20.39 ± 0.08 mm (p<0.05). Correlation analysis between dilution ratio and measurement size confirmed strong negative correlations in all reconstructed images (p<0.05). In conclusion, the higher the dilution ratio of the contrast agent, the more difficult it is to measure actual blood vessel measurement. Therefore, this study may provide basic data in future studies on actual measurement.

• 대한방사선치료학회:학술대회논문집
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• 2005.06a
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• pp.13-17
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• 2005

Introduction : For stereotactic radiosurgery (SRS) of a tumor in the region whose movement due to respiration is significant, like Lung lower lobe, the gated therapy, which delivers radiation dose to the selected respiratory phases when tumor motion is small, was peformed using the Respiratory gating system and its clinical effectiveness was evaluated. Methode and Materials : For two SRS patients with a tumor in Lung lower lobe, a marker block (infrared reflector) was attached on the abdomen. While patient' respiratory cycle was monitored with Real-time Position Management (RPM, Varian, USA), 4D CT was performed (10 phases per a cycle). Phases in which tumor motion did not change rapidly were decided as treatment phases. The treatment volume was contoured on the CT images for selected treatment phases using maximum intensity projection (MIP) method. In order to verify setup reproducibility and positional variation, 4D CT was repeated. Result : Gross tumor volume (GTV) showed maximum movement in superior-inferior direction. For patient $\#$1, motion of GTV was reduced to 2.6 mm in treatment phases ($30\%\~60\%$), while that was 9.4 mm in full phases ($0\%\~90\%$) and for patient $\#$2, it was reduced to 2.3 mm in treatment phases ($30\%\~70\%$), while it was 11.7 mm in full phases ($0\%\~90\%$). When comparing two sets of CT images, setup errors in all the directions were within 3 mm. Conclusion : Since tumor motion was reduced less than 5 mm, the Respiratory gating system for SRS of Lung lower lobe is useful.

• Journal of Magnetics
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• v.17 no.2
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• pp.138-144
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• 2012

3-dimensional magnetic resonance cholangiopancreatography (MRCP) images reconstructed using the maximum intensity projection technique were analyzed qualitatively in patients diagnosed with pancreatobiliary diseases to determine their diagnostic utility. Single shot fast spin echo (SSFSE), fast spin echo (FSE) and 3-dimensional reconstructive images were acquired from 20 patients diagnosed histologically with pancreatobiliary diseases using a 3.0T MR scanner. According to qualitative analysis, the fast spin echo images and 3-dimensional reconstructed images of the hepatic duct, gall bladder and common bile duct had a higher signal to noise ratio (SNR) than the single shot fast spin echo images. Fast spin echo images and 3-dimensional reconstructed images did not show any differences. The contrast to noise ratio of the hepatic duct, gallbladder and common bile duct on the fast spin echo images and 3-dimensional reconstructed images was higher than that of the single shot fast spin echo images. The fast spin echo images and 3-dimensional reconstructed images showed similar quality.

• Journal of radiological science and technology
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• v.26 no.1
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• pp.63-70
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• 2003

SMAS(Superior Mesenteric Artery Syndrome) is a disease caused by a chronic obstruction of the duodenum(transverse portion), which is hardly detectable. However, it is known that when the superior mesenteric artery and abdominal aorta form a narrow angle, that the transverse portion of the duodenum is pressed down between the superior mesenteric artery and the abdominal aorta, and that this can lead to obstruction of the duodenum. Measuring this angle is a complicated job using conventional angiography, and results often turns out to be inaccurate. In addition, no attempt has been made to determine the value of this angle in Koreans. In this study, we conducted abdominal CT angiography using MIP(maximum intensity projection) on patients with no clinical evidence of SMAS in order to determine the angle at which the superior mesenteric artery branches from the abdominal aorta by using PC based software(Rapidia ver. 1.2) for the image reconstruction. Accordingly, we found that the mean angle between the abdominal aorta and the superior mesenteric artery was $50.05{\pm}15.87^{\circ}$ on average, and that the angle in men($53.64{\pm}16.57^{\circ}$) is higher than in women($46.46{\pm}14.98^{\circ}$). We hope that the angles determined by our study will serve as an important indicator for detecting SMAS.

• Investigative Magnetic Resonance Imaging
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• v.5 no.1
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• pp.49-56
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• 2001

Purpose : To evaluate value of superparamagnetic iron oxide (SPIO) as a negative oral contrast agent in MR cholangiopancreatography (MRCP). Materials and methods : Forty-eight patients with suspected biliary tract or pancreatic diseases and six healthy volunteers were enrolled in this study. All MR images were obtained using a 1.5 T MR unit. MR-CP using fat-suppressed half-Fourier acquisition single-shot turbo spin echo (HASTE) and turbo spin echo (TSE) techniques were performed and reconstructed with maximal intensity projection (MIP). To determine the most optimal concentration of SPIO to obliterate the high signal intensity of water, a phantom experiment was conducted with various concentrations of SPIO-water mixture. Two radiologists evaluated pre- and postcontrast MRCPS. The contrast enhancement was assessed on the basis of loss of signal intensity in the stomach and duodenum. Results : In the phantom experiment, a significant increase of percentage of signal intensity loss (PSIL) occurred in concentration of 22.4 ugFe/ml (Feridex1 ml diluted with water 500 ml). Postcontrast MRCP showed an improved image quality compared with precontrast images. The rate of improvement in the diagnosis of diseases of the common bile duct and pancreatic duct was 25% (12/48). Conclusion : In patients with suspected biliary tract and pancreatic diseases, the SPIO is useful as a negative oral contrast agent for MRCP and provides an improvement of image quality.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.2
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• pp.38-40
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• 2010

Purpose: This study was performed to find the current problems of PET/CT data from other hospitals. Materials and Methods: The subjects were acquired from 64 hospitals referred to our department for image interpretation. The formats and contents of PET/CT data were reviewed and the phone questionnaire survey about these were performed. Results: PET/CT data from 39 of 64 hospitals (61%) included all transaxial CT and PET images with DICOM (Digital Imaging Communications in Medicine) standard format which were required for authentic interpretation. PET/CT data from the others included only secondary capture images or fusion PET/CT images. Conclusion: The majority of hospitals provided limited PET/CT data which could be inadequate for accurate interpretation and clinical decision making. It is necessary to standardize the format of PET/CT data to transfer including all transaxial CT and PET images with DICOM standard format.

• Investigative Magnetic Resonance Imaging
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• v.1 no.1
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• pp.94-102
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• 1997

Purpose: There have been some efforts to diagnose intracranial aneurysm through a non-invasive method using MRA, although the process may be difficult when the lesion is less than 3mm. The present study prospectively compares the results of high resolution, fast speed slice interpolation MRA and DSA thereby examing the potentiality of primary non-invasive screening test. Materials and Methods: A total of 26 cerebral aneurysm lesions from 14 patients with subarachnoid hemorrhage from ruptured aneurysm (RA) and 5 patients with unruptured aneurysm(UA). In all subjects, MRA was taken to confirm the vessel of origin, definition of aneurysm neck and the relationship of the aneurysm to nearby small vessels, and the results were compared with the results of DSA. The images were obtained with 1.5T superconductive machine (Vision, Siemens, Erlangen, Germany) on 4 slabs of MRA using slice interpolation. The settings include TR/TE/FA=30/6.4/25, matrix $160{\times}512$, FOV $150{\times}200$, 7minutes 42 seconds of scan time, effective thickness of 0.7 mm and an entire thickness of 102. 2mm. The images included structures from foramen magnum to A3 portion of anterior cerebral artery. MIP was used for the image analysis, and multiplanar reconstruction (MPR) technique was used in cases of intracranial aneurysm. Results: A total of 26 intracranial aneurysm lesions from 19 patients with 2 patients having 3 lesion, 3 patients having 2 lesions and the rest of 14 patients having 1 lesion each were examined. Among those, 14 were RA and 12 were UA. Eight lesions were less than 2mm in size, 9 lesions were 3-5mm, 7 were 6-9mm and 2 were larger than IOmm. On initial exams, 25 out of 26 aneurysm lesions were detected in either MRA or DSA showing 96% sensitivity. Specificity cannot be estimated since there was no true negative of false positive findings. When MRA and MPR were used concurrently for the confirmation of size and shape, the results were equivalent to those of DSA, while in the confirmation of aneurysm neck and parent vessels, the concurrent use of MRA and MPR was far superior to the sole use of either MRA or DSA. Conclusion: High resolution MRA using slice interpolation technique showed equal results as those of DSA for the detection of intracranial aneurysm, and may be used as a primary non-invasive screening test in the future.

• The Journal of Korean Society for Radiation Therapy
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• v.17 no.2
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• pp.125-131
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• 2005

Purpose : For stereotactic radiosurgery (SRS) of a tumor in the region whose movement due to respiration is significant, like Lung lower lobe, the gated therapy, which delivers radiation dose to the selected respiratory phases when tumor motion is small, was performed using the Respiratory gating system and its clinical effectiveness was evaluated. Materials and Methods : For two SRS patients with a tumor in Lung lower lobe, a marker block (infrared reflector) was attached on the abdomen. While patient' respiratory cycle was monitored with Real-time Position Management (RPM, Varian, USA), 4D CT was performed (10 phases per a cycle). Phases in which tumor motion did not change rapidly were decided as treatment phases. The treatment volume was contoured on the CT images for selected treatment phases using maximum intensity projection (MIP) method. In order to verify setup reproducibility and positional variation, 4D CT was repeated. Results : Gross tumor volume (GTV) showed maximum movement in superior-inferior direction. For patient #1, motion of GTV was reduced to 2.6 mm in treatment phases ($30{\sim}60%$), while that was 9.4 mm in full phases ($0{\sim}90%$) and for patient #2, it was reduced to 2.3 mm in treatment phases ($30{\sim}70%$), while it was 11.7 mm in full phases ($0{\sim}90%$). When comparing two sets of CT images, setup errors in all the directions were within 3 mm. Conclusion : Since tumor motion was reduced less than 5 mm, the Respiratory gating system for SRS of Lung lower lobe is useful.