• The Journal of the Acoustical Society of Korea
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• v.35 no.3
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• pp.175-182
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• 2016

For application to several MHz photoacoustic imaging systems, a needle hydrophone was designed and fabricated by using PMN-PZT piezoelectric single crystal, and its characteristics were evaluated through comparison with a commercial PVDF(Polybinylidene Fluoride) hydrophone of which receiving sensitivity is known. The simulation using the KLM model results show that the peak receiving impulse response for $50{\Omega}$ terminating impedance of the fabricated hydrophone is -261.6 dB re $1V/{\mu}Pa$ and the frequency response is relatively flat over 2 ~ 12 MHz with fluctuation less than 5 dB. The measurement results using tone burst signals also show that it has higher (ave. 10.9 dB) sensitivity than the commercial hydrophone in 2 ~ 8 MHz, and the receiving sensitivity of $-255.8{\pm}2.8$ dB re $1V/{\mu}Pa$ was measured for the fabricated hydrophone. In addition, it is known that the photoacoustic signals and the image of a hair obtained by a mechanical scanned photoacoustic imaging system with the fabricated hydrophone were bigger and better than those obtained with the commercial hydrophone.

• The Journal of Korean Medicine
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• v.35 no.3
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• pp.70-92
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• 2014

Objectives: Due to advance of science and IT technology, high tech imaging equipment like ultrasonography, CT, MRI and PET scan is constantly being developed and progressed; use of these techniques is needed for Korean medicine. Methods: Historical study was undertaken on the evidence of using ultrasonography. Normal organs and various sorts of diseases were also observed by ultrasonography. Results: Korean medicine judges disease of internal organs and condition of health by symptoms of functional disease and organic disease based on anatomical theory. Ultrasonography based on anatomical theory is non-invasive and free from radiation exposure and can be performed directly from clinical practice in real-time. Ultrasonography can be a big help for securing the stability of the internal organs in inserting needles in the thorax and abdomen as well as diagnosing functional and organic diseases based on anatomical theory. Conclusion: We look forward to a great development of scientification and objectification of Korean medicine by using and researching imaging equipment based on anatomical theory as well as ultrasonography.

• Journal of Yeungnam Medical Science
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• v.18 no.2
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• pp.170-186
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• 2001

Musculoskeletal ultrasound (MSUS) has newly evolved by the mechanical improvement of the machine over past several years, becoming a part of imaging techniques for the evaluation of variable diseases in the musculoskeletal system. MSUS has proven diagnostic superiority in pathologies including rotator cuff disease of the shoulder, lateral epicondylitis of the elbow, diseases of the peripheral nerve, detection of intra-articular loose bodies and soft tissue foreign bodies, and in evaluating small superficial soft tissue tumors such as ganglion, epidermoid cyst, and glomus tumor. Besides, MSUS is very useful for obtaining tissue or fluid via percutaneous fine needle aspiration and/or biopsy for the histopathologic diagnosis. Combining MSUS with MR would play a great role in the field of the diagnostic imaging of the musculoskeletal system. The MSUS examiner should have the knowledge of cross-sectional anatomy, and of the mechanical and physical properties of ultrasound in order to interpret the ultrasound findings accurately and properly, and to avoid diagnostic errors due to variable artifacts subsequently. The goal of this article is to introduce the capabilities of MSUS in certain kinds of clinical situation and to familiarize the reader with MSUS. For the purpose, author intends to describe this article according not to the disease-, or organ-based, but to the clinical problem-based format.

• Journal of Oral Medicine and Pain
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• v.44 no.3
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• pp.127-132
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• 2019

Septic arthritis of the temporomandibular joint (TMJ) is an uncommon disease caused by microbial pathogens through hematogenous infection, local spread, or iatrogenic infection. As the symptoms have an insidious onset, the early stage of septic arthritis is often confused with other diseases. A 49-year-old man was referred for increasing preauricular pain, swelling, and restricted mouth opening. He had been initially diagnosed as having a conventional temporomandibular joint disorder and trigeminal neuralgia and had been treated for the same. Imaging studies including panoramic view, lateral tomography, computed tomography with contrast enhancement, and magnetic resonance imaging were performed. Erosive bone change with displacement of the involved condyle, diffuse swelling of adjacent soft tissue, and fluid collection in the joint space were noted. Needle aspiration of the joint space and bacterial culture confirmed the diagnosis of septic arthritis of the TMJ and he was treated with antibiotic therapy and surgical drainage. Clinicians should always consider the diagnosis of septic arthritis of the TMJ in patients with preauricular pain or swelling.

• Journal of the Korean Society of Radiology
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• v.83 no.1
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• pp.218-223
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• 2022

Although the typical CT findings of Pneumocystis jiroveci pneumonia (PJP) include diffuse or multifocal areas of ground-glass opacities in both lungs, it can also rarely manifest as multiple pulmonary nodules. We report a rare case of atypical PJP in an immunocompromised patient with multiple myeloma, presenting as widespread ground-glass opacities and multiple necrotic subpleural nodules in both lungs on CT, which proved to be granulomatous PJP on percutaneous transthoracic needle biopsy.

• Journal of the Korean Society of Radiology
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• v.84 no.1
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• pp.304-310
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• 2023

Solitary fibrous tumors (SFTs) commonly arise from the pleura and are mostly benign. However, they may develop anywhere in the body, and 10%-30% are malignant. Classically, SFTs appear as solitary enhancing masses, and bilateral presentation is extremely rare. In this case, an 88-year-old male presented with back pain and a history of chronic tuberculous empyema. Imaging studies revealed bilateral paravertebral masses with aggressive radiologic features, which were speculatively presumed as thoracic malignancies in association with chronic empyema. Herein, we report a unique case of bilateral paravertebral malignant SFTs that were accurately diagnosed with a CT-guided coaxial needle biopsy.

• The Korean Journal of Pain
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• v.34 no.4
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• pp.447-453
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• 2021

Background: Provocative discography (PD) is a test that is useful in diagnosing discogenic pain (DP). In this study, to diagnose DP, we used a posterolateral approach of needle placement and followed pressure criteria laid down by the Spine Intervention Society. The aim was to identify the correlation between magnetic resonance imaging (MRI) findings (desiccation, high intensity zone and change in shape and size of the disc) and the results of PD. Methods: Records of 50 patients who underwent PD for DP were analyzed. A total of 109 PDs were performed, with 54 suspect and 55 control discs. Alternate pain generators were ruled out. Results: A total of 35 suspect discs were positive on PD. The mean disc pressure in the suspect disc was 31.9 ± 7.9 psi (range, 15-44). Of the 50 patients who underwent PD, 35 had positive MRI findings. A significant positive correlation was found only between disc desiccation and discography result (r = 0.6, P < 0.001). Logistic regression analysis revealed that only desiccation successfully predicted the result of discography (OR = 26.5, P < 0.001); a high intensity zone and a disc protrusion/extrusion had an OR 2.3 and 1.24, respectively. Disc desiccation of Pfirmann grade 3 or more had a sensitivity and specificity of 0.93 and 0.64 respectively in identifying painful discs; the positive likelihood ratio was 2.58 while the negative likelihood ratio was 0.11. Conclusions: In patients with DP, disc desiccation is the most useful MRI feature that predicts a painful disc on PD.

• Journal of the Korean Society of Radiology
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• v.81 no.3
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• pp.530-548
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• 2020

Thyroid radiology practice is a medical practice in which thyroid diseases are diagnosed using imaging modality and treated by imaging-based interventional techniques, and the primary care target is thyroid nodular disease. Diagnosis of thyroid nodules is primarily done by ultrasound imaging and biopsy; thyroid nodules can be treated by non-surgical interventional treatment and thyroidectomy. Ethanol ablation is the first-line treatment for cystic benign nodules, and radiofrequency ablation is used for the treatment of benign solid nodules and recurrent thyroid cancers. Thyroid radiology practice has an essential clinical role in diagnosis and nonsurgical treatment of thyroid nodular diseases, and treatment should be performed based on standard care guidelines for proper patient care. In order to provide the best care to patients with thyroid nodular disease, it is desirable to treat patients in the radiology outpatient clinic. Thyroid radiology practice centered on outpatient clinic practice needs to be expanded.

• Korean Journal of Radiology
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• v.25 no.2
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• pp.157-165
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• 2024

Objective: We aimed to evaluate the clinical and imaging factors associated with hemorrhagic complications and patient discomfort following ultrasound (US)-guided breast biopsy. Materials and Methods: We prospectively enrolled 94 patients who were referred to our hospital between June 2022 and December 2022 for US-guided breast biopsy. After obtaining informed consent, two breast radiologists independently performed US-guided breast biopsy and evaluated the imaging findings. A hemorrhagic complication was defined as the presence of bleeding or hematoma on US. The patients rated symptoms of pain, febrile sensation, swelling at the biopsy site, and dyspnea immediately, 20 minutes, and 2 weeks after the procedure on a visual analog scale, with 0 for none and 10 for the most severe symptoms. Additional details recorded included those of nausea, vomiting, bleeding, bruising, and overall satisfaction score. We compared the clinical symptoms, imaging characteristics, and procedural features between patients with and those without hemorrhagic complications. Results: Of 94 patients, 7 (7%) developed hemorrhagic complications, while 87 (93%) did not. The complication resolved with 20 minutes of manual compression, and no further intervention was required. Vascularity on Doppler examination (P = 0.008), needle type (P = 0.043), and lesion location (P < 0.001) were significantly different between the groups. Patients with hemorrhagic complications reported more frequent nausea or vomiting than those without hemorrhagic complications (29% [2/7] vs. 2% [2/87], respectively; P = 0.027). The overall satisfaction scores did not differ between the two groups (P = 0.396). After 2 weeks, all symptoms subsided, except bruising (50% 2/4 in the complication group and 25% [16/65] in the no-complication group). Conclusion: US-guided breast biopsy is a safe procedure with a low complication rate. Radiologists should be aware of hemorrhagic complications, patient discomfort, and overall satisfaction related to this procedure.

• The Korean Journal of Pain
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• v.12 no.2
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• pp.258-262
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• 1999

Sacral meningeal cyst is usually asymtomatic, but may be responsible for sciatic pain syndromes and other clinical symptoms. Sacral meningeal cyst might be suspected when definite explanation for the clinical symptom, such as herniation of the intervertebral disc or spinal stenosis is not found. Plain films and CT may suggest the presence of sacral meningeal cyst, but MR is the current imaging study of choice. Evaluation of the correlation between the symptom and the cyst is as important as detection of it. We have experienced a case of sacral meningeal cyst detected during caudal epidural block. The patient complained of low back pain radiating to thigh. Plain films and lumbar spine CT showed no remarkable finding except disc bulging. During caudal epidural needle insertion, there was leakage of clear CSF, and intrasacral cystic shadow was visualized by dye injection. MR confirmed sacral meningeal cyst.