• Korean Journal of Radiology
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• v.23 no.2
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• pp.289-289
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• 2022

• Journal of IKEEE
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• v.23 no.4
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• pp.1408-1414
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• 2019

Deep artificial neural network with transfer learning is applied to compressed sensing cardiovascular MRI. Transfer learning is a method that utilizes structure, filter kernels, and weights of the network used in prior learning for current learning or application. The transfer learning is useful in accelerating learning speed, and in generalization of the neural network when learning data is limited. From a cardiac MRI experiment, with 8 healthy volunteers, the neural network with transfer learning was able to reduce learning time by a factor of more than five compared to that with standalone learning. Using test data set, reconstructed images with transfer learning showed lower normalized mean square error and better image quality compared to those without transfer learning.

• Journal of Biomedical Engineering Research
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• v.24 no.2
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• pp.61-68
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• 2003

This paper presents a quantitative analysis method for fall in sick times of the cerebral infarction patients using three types of magnetic resonance image, which play an important role in deciding method of medical treatment. For this object, image characteristics obtained by three radiographic methods of MRI and their relation were analyzed by means of object centered hierarchical Planning method. This methode presents an approach to the knowledge based processes for image interpretation and analysis. To compare three type of MRI. a multiple warping algorithm and affine transform method performed for image matching. Then each fall in sick times level of cerebral infarction was quantified and pseudo-color mapping performed by comparing gray level value one another according to Previously obtained hand maid data. The result of this study was compared to a medical doctors decision.

• Journal of the Korean Society of Radiology
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• v.83 no.4
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• pp.898-903
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• 2022

The incidence of ductal carcinoma in situ has increased with the rise in screening mammography; currently, ductal carcinoma in situ constitutes 20%-25% of all breast cancers, and up to half of them may become invasive. Its early detection is critical in improving the cure rate. Moreover, MRI has higher sensitivity for its detection than mammography. Herein, we report an unusual case of ductal carcinoma in situ presenting as a continuous, serpentine, linear enhancement with regional distribution on MRI.

• Journal of the Korean Society of Radiology
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• v.82 no.2
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• pp.469-474
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• 2021

Japanese encephalitis (JE) is a common infection caused by the Japanese encephalitis virus in Southeast Asia, which is transmitted to humans through Culex mosquitoes. Magnetic resonance imaging (MRI) is used to diagnose JE, which is often characterized by the presence of bilateral symmetric thalamic involvement. Here, we report a rare case of JE characterized by leptomeningeal enhancement without thalamic involvement. This leptomeningeal enhancement disappeared with the treatment; however, new non-specific multifocal and bilateral high signal intensities in the cerebral white matter were found on follow-up MRI.

• Journal of the Korean Society of Radiology
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• v.82 no.4
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• pp.889-902
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• 2021

Purpose To assess the diagnostic performance of contrast-enhanced ultrasound (CEUS) for additional MR-detected enhancing lesions and to determine whether or not kinetic pattern results comparable to dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) of the breast can be obtained using the quantitative analysis of CEUS. Materials and Methods In this single-center prospective study, a total of 71 additional MR-detected breast lesions were included. CEUS examination was performed, and lesions were categorized according to the Breast Imaging-Reporting and Data System (BI-RADS). The sensitivity, specificity, and diagnostic accuracy of CEUS were calculated by comparing the BI-RADS category to the final pathology results. The degree of agreement between CEUS and DCE-MRI kinetic patterns was evaluated using weighted kappa. Results On CEUS, 46 lesions were assigned as BI-RADS category 4B, 4C, or 5, while 25 lesions category 3 or 4A. The diagnostic performance of CEUS for enhancing lesions on DCE-MRI was excellent, with 84.9% sensitivity, 94.4% specificity, and 97.8% positive predictive value. A total of 57/71 (80%) lesions had correlating kinetic patterns and showed good agreement (weighted kappa = 0.66) between CEUS and DCE-MRI. Benign lesions showed excellent agreement (weighted kappa = 0.84), and invasive ductal carcinoma (IDC) showed good agreement (weighted kappa = 0.69). Conclusion The diagnostic performance of CEUS for additional MR-detected breast lesions was excellent. Accurate kinetic pattern assessment, fairly comparable to DCE-MRI, can be obtained for benign and IDC lesions using CEUS.

• Journal of the Korean Society of Radiology
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• v.82 no.5
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• pp.1281-1286
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• 2021

Brainstem infarction due to vertebrobasilar insufficiency is a rare initial presentation of systemic lupus erythematosus (SLE) patients and small-vessel dissection as the direct cause of infarction has not been reported. We report the case of a 20-year-old female with acute infarction on the right side of the pons due to a small artery (pontine perforator) dissection, identified on digital subtraction angiography and high-resolution vessel wall MRI (vwMRI). She was diagnosed with SLE based on the presence of neurologic disorders and relevant laboratory findings. The pontine perforator-dissecting aneurysm had occluded and the right distal vertebral artery had resolved on subsequent vwMRI. She had a modified Rankin Scale (mRS) score of 1 at discharge with mild symptom improvement, and exhibited no further aggravation of symptoms at 3 or 12 months, maintaining an mRS score of 1.

• The Journal of the Korea Contents Association
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• v.10 no.9
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• pp.302-308
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• 2010

In MRI, the Ferromagnetic artifact is generated by the metalization within in which the before inspection removal is impossible and the distortion of an image is brought. The distortion measure according to the steel for each sequence of T1 image and magnetic field intensity are analyzed and minimized method is looked into. We used SIEMENS 1.5T and 3.0T MRI for experiment equipment. First, it places within the Phantom making a metalization(Ti+Al, Stainless, Nitinol) on 1.5T, 3.0T MRI and the T1 weighted image for each Sequence is acquired. The distortion of an image and about adjacent portion change of the metal material were compared through the obtained image, we analyzed. In all metalizations, a distortion was generated and a distortion was few in particularly, and Titanium-Aluminium alloy. And the extent of a distortion was worse image in the Turbo spin Echo. The use of the Titanium-Aluminium alloy the inserted in an internal material of the metalization is recommend. and, equipment of 1.5T the patient inserting a metal in an internal is used in an inspection than equipment of 3.0T. Also, the sequence is suitable when it obtains the optimum T1 weighted image of an impersonate to use the Turbo spin Echo.

• The Journal of Korean Association of Computer Education
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• v.13 no.6
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• pp.35-42
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• 2010

In this paper, the characteristics of online game addiction have been analyzed using fMRI. The fMRI images are taken from six target subjects who are around 20 years old, right-handed, and undergraduate male students with online game stimulations. The images are processed using SPM5, and statistical analysis showed following characteristics. First, online game stimuli produces an activation in BA18 of brain, and the Pearson correlation coefficient between the activation intensity of BA18 area and the addiction index value is very highly as .94. Second, the Pearson correlation coefficient is .75 between addiction index of subjects and activation index of the mesencephalon. From these observations, we found that the online game stimuli were processed as visual stimuli by subjects' brain, and the subject's brain with bigger addiction index processes more actively from the online game stimuli. Also, the online game stimuli activate the mesolimbic system, and therefore these findings may contribute for comparing the mechanism between general addiction and online game addiction.

• Journal of the Korean Society of Radiology
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• v.14 no.7
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• pp.957-964
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• 2020

T2 FLAIR sequence of MRI in Acute Ischemic Stroke patients is meaningful to those who have the diagnosis of cerebral hemorrhage and neurological deficiency, including the detection of cerebral infarction around Cerebrospinal fluid. However, because of the long acquisition time and mutative motion artifacts caused by movement, It is difficult to take the MRI image acquisition for non-cooperative patients who need to apply a rapid image acquisition. In this study, we applied the EPI-FLAIR sequence, which is one of the fastest pulse sequences in use, which is a combination of EPI sequence and T2 FLAIR sequence, to patients with acute ischemic cerebral infarction. Based on the qualitative and quantitative evaluation results of the EPI-FLAIR and T2 FLAIR image, we will evaluate the diagnostic usefulness of the EPI-FLAIR sequence.