• Journal of Biosystems Engineering
• /
• 제30권6호통권113호
• /
• pp.340-346
• /
• 2005

Major quality features of the beef carcass in most countries including Korea are size, marbling state of the lean tissue, color of the fat and lean tissue, and thickness of back fat of the 13th rib. To evaluate the beef quality, extracting loin parts from the sectional image of the 13th beef rib is crucial and is the first step. However, because of the inhomogeneous distribution and fuzzy pattern of the fat and lean tissues on the beef cut, it is difficult to extract automatically the proper contour of the lean tissue. In this paper, a prototype mobile beef quality measurement system, which can be implemented practically at the beef processing site was developed. The developed system was composed of the hand held image acquisition unit and mobile processing unit mounted with touch-pad screen. Algorithms to extract the boundary of the lean tissue and a proper tool to evaluate the marbling status have been developed using color image processing. The boundary extraction algorithm showed successful results for the beef cuts with simple and moderate patterns of the lean tissue and fat. However, it had some difficulty in eliminating complex pattern of the extraneous tissues adhered to the lean tissue in the boundary extraction. The developed algorithms were implemented to the prototype mobile processing unit.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• 제18권2호
• /
• pp.77-105
• /
• 2014

Medical imaging techniques have evolved to expand our ability to visualize new contrast information of electrical, optical, and mechanical properties of tissues in the human body using noninvasive measurement methods. In particular, electrical tissue property imaging techniques have received considerable attention for the last few decades since electrical properties of biological tissues and organs change with their physiological functions and pathological states. We can express the electrical tissue properties as the frequency-dependent admittivity, which can be measured in a macroscopic scale by assessing the relation between the time-harmonic electric field and current density. The main issue is to reconstruct spectroscopic admittivity images from 10 Hz to 1 MHz, for example, with reasonably high spatial and temporal resolutions. It requires a solution of a nonlinear inverse problem involving Maxwell's equations. To solve the inverse problem with practical significance, we need deep knowledge on its mathematical formulation of underlying physical phenomena, implementation of image reconstruction algorithms, and practical limitations associated with the measurement sensitivity, specificity, noise, and data acquisition time. This paper discusses a number of issues in electrical tissue property imaging modalities and their future directions.

• 정보저장시스템학회논문집
• /
• 제9권1호
• /
• pp.17-21
• /
• 2013

Optical coherence tomography (OCT) allows non-invasive, cross-sectional optical imaging of biological tissue with high spatial resolution and acquisition speed. In principle, it is analogous to ultrasound imaging, but uses near-infrared light instead of ultrasound, measuring the time-delay of back-scattered light from within biological tissue. Compared to ultrasound imaging, it exhibits superior spatial resolution (1~10 um) and high sensitivity. Therefore, OCT has been applied to a wide range of applications such as cellular imaging, ophthalmology and cardiology. Here, we describe a novel application of OCT technology in visualizing microneedles embedded in tissue that is developed to deliver drugs into the dermis without the injection mark in the human skin. Detailed three-dimensional structural images of microneedles and biological tissues were obtained. Examining structural modification of microneedles and tissues during insertion process would enable to evaluate performance of various types of microneedles in situ.

• 한국의학물리학회지:의학물리
• /
• 제32권1호
• /
• pp.1-17
• /
• 2021

The evolution of X-ray computed tomography (CT) has been based on the discovery of X-rays, the inception of the Radon transform, and the development of X-ray digital data acquisition systems and computer technology. Unlike conventional X-ray imaging (general radiography), CT reconstructs cross-sectional anatomical images of the internal structures according to X-ray attenuation coefficients (approximate tissue density) for almost every region in the body. This article reviews the essential physical principles and technical aspects of the CT scanner, including several notable evolutions in CT technology that resulted in the emergence of helical, multidetector, cone beam, portable, dual-energy, and phase-contrast CT, in integrated imaging modalities, such as positron-emission-tomography-CT and single-photon-emission-computed-tomography-CT, and in clinical applications, including image acquisition parameters, CT angiography, image adjustment, versatile image visualizations, volumetric/surface rendering on a computer workstation, radiation treatment planning, and target localization in radiotherapy. The understanding of CT characteristics will provide more effective and accurate patient care in the fields of diagnostics and radiotherapy, and can lead to the improvement of image quality and the optimization of exposure doses.

• Tuberculosis and Respiratory Diseases
• /
• 제75권5호
• /
• pp.181-187
• /
• 2013

The emergence of new therapeutic agents for non-small cell lung cancer (NSCLC) implies that histologic subtyping and molecular predictive testing are now essential for therapeutic decisions. Histologic subtype predicts the efficacy and toxicity of some treatment agents, as do genetic alterations, which can be important predictive factors in treatment selection. Molecular markers, such as epidermal growth factor receptor (EGFR) mutation and anaplastic lymphoma kinase (ALK) rearrangement, are the best predictors of response to specific tyrosine kinase inhibitor treatment agents. As the majority of patients with NSCLC present with unresectable disease, it is therefore crucial to optimize the use of tissue samples for diagnostic and predictive examinations, particularly for small biopsy and cytology specimens. Therefore, each institution needs to develop a diagnostic approach requiring close communication between the pulmonologist, radiologist, pathologist, and oncologist in order to preserve sufficient biopsy materials for molecular analysis as well as to ensure rapid diagnosis. Currently, personalized medicine in NSCLC is based on the histologic subtype and molecular status. This review summarizes strategies for tissue acquisition, histologic subtyping and molecular analysis for predictive testing in NSCLC.

• 대한디지털의료영상학회논문지
• /
• 제9권2호
• /
• pp.23-30
• /
• 2007

This study attempts to propose an appropriate method of using digital medical imaging equipments, by studying the effects of automatic exposure control(AEC), grid ratio and the change of radiography distance on the patient dose and detertor acquisition dose during the procedure of acquiring image through a digital medical imaging detector. The change of dose following the change of grid ratio's exposure and radiography distance was measured, by using an abdominal phantom organized with tissue equivalent materials in an amorphous silicon thin film transistor detecter installed with AWC. The case to use grid ratio 12 : 1, focal distance 180cm to radiography distance 110cm in AEC, the patient dose increased rather when we used grid ration 10 : 1, focal distance 110cm. When AEC was not used,the dose necessary for image acquisition decreased as the grid ratio became higher and the distance became further. but detector acquisition dose was not reduced when in applied AEC. When purchasing digiral medical imaging equipments, optional items such as AEC and grid shall be accurately selected to satisfy the use of the equipments. Radiography error made by radiation technologist and unnenessary patient dose can be reduced by selecting equipments with a radiography distance marker equipment when it did not apply AEC. These equipments can also be helpful in maintaining high imaging quality, one of the merits of digital detectors.

• 한국의학물리학회:학술대회논문집
• /
• 한국의학물리학회 2002년도 Proceedings
• /
• pp.429-431
• /
• 2002

Metabolic analysis of biological tissues, the interventional radiology in MRT (Magnetic Resonance Treatment) and for clinical diagnoses, representation of 4-Dimensional (4D) structural information (x,y,z,t) of biological tissues is required. This paper discusses image representation techniques for those 4D MR Images. We have proposed an image reconstruction method for ultra-fast 3D MRI. It is based on image interpolation and prediction of un-acquired pictorial data in both of the real and the k-space (the acquisition domain in MRI). A 4D MR image is reconstructed from only two 3D MR images and acquired a few echo signals that are optimized by prediction of the tissue motion. This prediction can be done by the phase of acquired echo signal is proportioned to the tissue motion. On the other hand, reconstructed 4D MR images are represented as a 3D-movie by using computer graphics techniques. Rendered tissue surfaces and/or ROIs are displayed on a CRT monitor. It is represented in an arbitrary plane and/or rendered surface with their motion. As examples of the proposed representation techniques, the finger and the lung motion of healthy volunteers are demonstrated.

• Archives of Plastic Surgery
• /
• 제33권2호
• /
• pp.175-180
• /
• 2006

Preoperative angiography is frequently used in the planning of microsurgical reconstruction for identification of vascular abnormality that influence the planning of operation. But, recently 3D CT angiography is considered as new technique that can provide detailed information about vascular anatomy as well as soft and bony tissue without the risks of invasive angiography. 3D CT angiograms were performed in 19 patients before microsurgical reconstruction for the lower extremity and hand between May of 2003 and Oct of 2004. Sixteen of the studies were of the donor site and all of 19 studies were of the recipient site. No complications were found from the 3D CT angiograms. In one case of the bone exposed open wound, the injury of anterior tibial artery was identified and the zone of injury was adequately demonstrated. With the improvement in quality of CT imaging, 3D CT angiograms may provide a favorable alternative to invasive angiography. It is capable of providing high-resolution, three dimensional vascular imaging without the need for arterial puncture and prolonged post-procedure observation. The relation among blood vessels, bones, and soft tissue is well demonstrated in 3D CT angiogram. Also The acquisition time and examination cost were considerably lower in comparison with invasive angiography. In conclusion, this study demonstrates that 3D CT angiography may provide accurate, safe, and cost-effective preoperative imaging. The 3D CT angiography with relatively low morbidity, low cost, ease of image acquisition can have an broader role in microsurgical reconstructive surgery.

• Clinical Endoscopy
• /
• 제56권4호
• /
• pp.510-520
• /
• 2023

Background/Aims: We aimed to investigate (1) promising clinical findings for the recognition of focal type autoimmune pancreatitis (FAIP) and (2) the impact of endoscopic ultrasound (EUS)-guided tissue acquisition (EUS-TA) on the diagnosis of FAIP. Methods: Twenty-three patients with FAIP were involved in this study, and 44 patients with resected pancreatic ductal adenocarcinoma (PDAC) were included in the control group. Results: (1) Multivariate analysis revealed that homogeneous delayed enhancement on contrast-enhanced computed tomography was a significant factor indicative of FAIP compared to PDAC (90% vs. 7%, p=0.015). (2) For 13 of 17 FAIP patients (76.5%) who underwent EUS-TA, EUS-TA aided the diagnostic confirmation of AIPs, and only one patient (5.9%) was found to have AIP after surgery. On the other hand, of the six patients who did not undergo EUS-TA, three (50.0%) underwent surgery for pancreatic lesions. Conclusions: Homogeneous delayed enhancement on contrast-enhanced computed tomography was the most useful clinical factor for discriminating FAIPs from PDACs. EUS-TA is mandatory for diagnostic confirmation of FAIP lesions and can contribute to a reduction in the rate of unnecessary surgery for patients with FAIP.

• Clinical Endoscopy
• /
• 제56권2호
• /
• pp.221-228
• /
• 2023

Background/Aims: Endoscopic ultrasound-guided tissue acquisition (EUS-TA) is essential for the diagnosis of pancreatic cancer. The feasibility of comprehensive genomic profiling (CGP) using samples obtained by EUS-TA has been under recent discussion. This study aimed to evaluate the utility of EUS-TA for CGP in a clinical setting. Methods: CGP was attempted in 178 samples obtained from 151 consecutive patients with pancreatic cancer at the Aichi Cancer Center between October 2019 and September 2021. We evaluated the adequacy of the samples for CGP and determined the factors associated with the adequacy of the samples obtained by EUS-TA retrospectively. Results: The overall adequacy for CGP was 65.2% (116/178), which was significantly different among the four sampling methods (EUS-TA vs. surgical specimen vs. percutaneous biopsy vs. duodenal biopsy, 56.0% [61/109] vs. 80.4% [41/51] vs. 76.5% [13/17] vs. 100.0% [1/1], respectively; p=0.022). In a univariate analysis, needle gauge/type was associated with adequacy (22 G fine-needle aspiration vs. 22 G fine-needle biopsy [FNB] vs. 19 G-FNB, 33.3% (5/15) vs. 53.5% (23/43) vs. 72.5% (29/40); p=0.022). The sample adequacy of 19 G-FNB for CGP was 72.5% (29/40), and there was no significant difference between 19 G-FNB and surgical specimens (p=0.375). Conclusions: To obtain adequate samples for CGP with EUS-TA, 19 G-FNB was shown to be the best in clinical practice. However, 19 G-FNB was not still sufficient, so further efforts are required to improve adequacy for CGP.