• Journal of Digestive Cancer Research
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• v.12 no.1
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• pp.31-37
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• 2024

Pancreatic cancer is a highly fatal malignancy with a 5-year survival rate of < 10%. Endoscopic ultrasound (EUS) is a useful noninvasive tool for differential diagnosis of pancreatic malignancy and treatment decision-making. However, the performance of EUS is suboptimal, and its accuracy for differentiating pancreatic malignancy has increased interest in the application of artificial intelligence (AI). Recent studies have reported that EUS-based AI models can facilitate early and more accurate diagnosis than other preexisting methods. This article provides a review of the literature on EUS-based AI studies of pancreatic malignancies.

• The Journal of the Acoustical Society of Korea
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• v.17 no.7
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• pp.3-11
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• 1998

본 논문에서는 분포정수선로의 간단한 모델을 이용해서, 외부에서 진동을 가했을 때 에 뼈 표면에서 발생하는 굴곡파의 전파속도와 종파의 전파속도를 구할 수 있는 새로운 측 정원리를 제안했다. 이 측정원리를 이용해서, 봉(brass, polymethylmethacrylate)표면에 발생 하는 정재파에 대한 속도의 공간분포를 laser Doppler법으로 측정해서, 각각의 주파수에 대 한 전파속도를 구했다. 이 새로운 측정방법은 in vivo에서 초음파 Doppler법을 이용해서 뼈 의 이상(골다공증, osteoporosis)진단의 가능성을 제시했다.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.17 no.1
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• pp.23-30
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• 2014

Manometry is a noninvasive diagnostic tool for identifying motility dysfunction of the gastrointestinal tract. Despite the great technical advances in monitoring motility, performance of the study in pediatric patients has several limitations that should be considered during the procedure and interpretation of the test results. This article reviews the clinical applications of conventional esophageal and anorectal manometries in children by describing a technique for performing the test. This review will develop the uniformity required for the methods of performance, the parameters for measurement, and interpretation of test results that could be applied in pediatric clinical practice.

• Annals of Clinical Neurophysiology
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• v.23 no.1
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• pp.7-16
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• 2021

Transcranial magnetic stimulation (TMS) is a safe and noninvasive tool for investigating the cortical excitability of the human brain and the neurophysiological functions of GABAergic, glutamatergic, and cholinergic neural circuits. Neurophysiological biomarkers based on TMS parameters can provide information on the pathophysiology of dementia, and be used to diagnose Alzheimer's disease and differentiate different types of dementia. This review introduces the basic principles of TMS, TMS devices and stimulating paradigms, several neurophysiological measurements, and the clinical implications of TMS for Alzheimer's disease.

• The Korean Journal of Cytopathology
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• v.17 no.1
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• pp.18-26
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• 2006

Transitional cell carcinoma of the urinary bladder is common in the genitourinary tract. The gold standard for the diagnosis of bladder cancer has been cystoscopy, along with urine cytology. Cystoscopy is an invasive and relatively expensive technique. By comparison, urine cytology is easy to perform and specific for a diagnosis of bladder cancer, although less sensitive, especially in low-grade tumors. For this reason, there has been a need for superior noninvasive technology to increase our confidence in being able to detect bladder cancer. There are many reports of the various urinary tests that are available to facilitate the diagnosis. In this article, I reviewed the literature on urinary markers and tests that may be clinically useful, including fluorescence in situ hybridization, uCyt+/Immunocyte, the $BTA^{(R)}$ test, the NMP 22TM, the $FDP^{(R)}$ test, the telomerase activity test, the HA and HAse tests, and flow cytometry. Most of these tests have a higher sensitivity and specificity than cytology. However, urine cytology has the highest specificity, especially in individuals with a high-grade tumor. We conclude that no urinary markers or tests can replace the role of cystoscopy along with cytology in the diagnosis of transitional cell carcinoma of the bladder. However, some markers could be used adjunctively to increase the diagnostic accuracy during screening or during the postoperative follow-up examination of patients with bladder cancer.

• Journal of the Optical Society of Korea
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• v.16 no.2
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• pp.133-140
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• 2012

In this study we investigate the use of 2D and 3D scanning optical coherence tomography (OCT) technology for use in apple blotch diagnosis. In order to test the possible application of OCT as a detection tool for apple trees affected by Marssonina coronaria, we conducted several experiments and compared the results from both healthy and infected leaves. Using OCT, we found several distinctive features in the subsurface boundary regions of both the diseased and healthy leaves. Our results indicate that leaves from diseased trees, while still appearing healthy, can be affected by M. coronaria. The A-scan analysis method confirmed that the boundaries found under the subsurface layers can be faint. This shows that M. coronaria can exert its influence on entire apple trees (as opposed to only on leaves with lesions) once it infects healthy trees. Our results indicate that OCT can be used as a noninvasive tool for the diagnosis of fungal disease in apple trees. Microscopic imaging results, performed as a histological study for comparison, correlated well with the OCT results.

• Journal of Chest Surgery
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• v.20 no.2
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• pp.223-229
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• 1987

Doppler echocardiography provides valuable information regarding prosthetic heart valve function rather than structure. There are three methods of expressing the severity of mitral valve obstruction: the transvalvular pressure gradient, effective valve area, and pressure half-time. Of these, the transvalvular pressure gradient [~p] can be determined by the measurement of maximum transvalvular blood flow velocity [V] according to the modified Bernoulli`s equation [gp=4V*]. Eleven patients, who underwent mitral valve replacement with Duromedics mechanical prostheses, and 17 normal persons were investigated. There were significantly higher calculated pressure gradients in prosthetic than normal mitral valves [9.*10*2.22mmHg-vs-3.26*0.99mmHg:p<0,01], and there was a inverse relationship between pressure gradient and prosthetic valve size [11.17*0.%mmHg in size 27mm and 29mm -v- 7.38*1.12mmHg in size 31mm and 33mm; r=0.85, p<0.01] The noninvasive Doppler technique should be useful in the diagnosis of prosthetic valve obstruction.

• Journal of the Institute of Convergence Signal Processing
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• v.14 no.1
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• pp.1-5
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• 2013

The two major problems related to the blood flow in replaced prosthetic heart valve are thrombus formation and hemolysis. Reliability of prosthetic valve is very important because its failure means the death of patient. There are many factors affecting the valvular failures and their representatives are mechanical failure and thrombosis, so early noninvasive detection is essentially required. The purpose of this study is to detect the various thromboses formation by using acoustic signal acquisition and its spectral analysis on the frequency domain. We made the thrombosis models using Polydimethylsiloxane (PDMS) and they are thrombosis model on the disc, around the sewing ring and fibrous tissue growth across the orifice of valve. Using microphone and amplifier, we measured the acoustic signal from the prosthetic valve, which is attached to the pulsatile mock circulation system. A/D converter sampled the acoustic signal and the spectral analysis is the main algorithm for obtaining spectrum. Then the spectrum of normal and 5 different kinds of abnormal valve were obtained. Each spectrum waveform shows a primary and secondary peak. The secondary peak changes according to the thrombus model. To quantitatively distinguish the frequency peak of the normal valve from that of the thrombosed valves, analysis using a neural network was employed. Acoustic measurement has been used as a noninvasive diagnostic tool and is thought to be a good method for detecting possible mechanical failure or thrombus.

• Journal of Digestive Cancer Research
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• v.11 no.2
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• pp.85-92
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• 2023

Colorectal cancer (CRC) is one of the most prevalent cancers and is the leading cause of cancer-related mortality worldwide. Based on the current screening guidelines by the American Cancer Society and Korean multi-society expert committee, CRC screening is recommended in asymptomatic adults starting at the age of 45 years. Fecal immunochemical test-based screening programs reduce the development of CRC and related mortality in the general population. However, this most popular CRC screening strategy demonstrates a crucial limitation due to modest diagnostic accuracy. Colonoscopy may be considered as an alternative primary method for CRC screening; however, its implementation can still be challenging due to concerns regarding invasiveness, low adherence, cost-effectiveness, and quality assurance. To overcome the limitations of current screening tests, innovative noninvasive tests for CRC screening have been developed with advances in molecular biology, genetics, epigenetics, and microbiomics for detecting CRC, which may enhance the approach to CRC screening and diagnosis in clinical practice in the near future. This review explores the emerging screening methods and discusses their potential for integration into current practice.

• Journal of Genetic Medicine
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• v.12 no.2
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• pp.118-122
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• 2015

Noninvasive prenatal test (NIPT) is a novel screening method for the diagnosis of fetal chromosomal aneuploidies. NIPT is based on technology that detects cell-free fetal DNA in maternal plasma and analyzes it with massively parallel sequencing technology to determine whether the fetus is at risk of trisomy 21, trisomy 18, trisomy 13 or sex chromosome abnormalities (SCAs). NIPT has been reported to have sensitivity of 99% and a false positive rate of less than 1% for detecting trisomy 21 and trisomy 18. Although extension of the application of NIPT to other SCAs has been attempted, there are concerns in extending NIPT to SCAs because of maternal or fetal mosaicism, undetected maternal SCAs, and multiple pregnancies. Recently, we assessed a pregnancy with the rare Turner syndrome mosaicism 45, X/47, XXX, which was reported as 45, X with NIPT. We present the case here and briefly review the current literatures on NIPT in testing for fetal monosomy X. To the best of our knowledge, this is the first report of the 45, X/47, XXX mosaicism in Korea to be reported as 45, X by NIPT with whole genome sequencing. This case report will provide valuable information for counseling women who want to undergo NIPT.