• Journal of the Korean Society of Radiology
• /
• v.9 no.1
• /
• pp.17-21
• /
• 2015

Recently, As people's interest in the health of teeth is increased in the medical field changed into aging society, the number of times for the radiological diagnosis is increased. It can be said that the radiation exposure dose of Korean population is increased. It is also growing concern about radiation exposure. Therefore, the basic data for the dental panoramic X-ray system, its investigation and measuring the radiation dose is needed. In this study, we used ALOKA PDM-117 dosimeter and estimated a two-dimensional dose distribution of the dental panoramic X-ray system (VATEC Pax-400). Dose evaluation about the distribution is confirmed from the point of radiation exposure of a patient. Dose distribution of the dental panoramic X-ray system irradiated chin and the facial region to high dose as well as the parts of teeth. It was founded that the eye lens which are sensitive to radiation are exposed to unnecessary radiation, considering the effect of scattered radiation. The results of this study will be used more accurate dose assessment in a variety of object size and location of measuring dose.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.26 no.3
• /
• pp.301-304
• /
• 2000

Hemangiopericytoma is uncommon vascular neoplasm that arises from pericytes arround the capillary walls. It was first described as a distinct vascular neoplasm by Stout and Murray in 1942 The anatomic distribution is widespread throughout the body, with approximately one third occur in the head and neck. No sex predilection has been found. Although middle age appears to be the most prevalent time of onset, this neoplasm has been found in all age groups. The differentiation between benign and malignant hemangiopericytoma can be difficult. Although the majority of these tumors are benign, there are malignant variants that can metastasize. Metastasis of seemingly benign tumors may appear year of decade later, so long term close follow-up is needed. The treatment of choice is complete surgical excision of the tumor. Despite their vascular origin, these tumors are relatively radioresistant. Radiation therapy is reserved for inoperable metastases or treatment of postoperative surgical fields. Here we present a case of hemangiopericytoma occuring on the Lt. buccal mucosa.

• Proceedings of the Korean Society of Medical Physics Conference
• /
• 2002.09a
• /
• pp.138-140
• /
• 2002

The spinal cord dose is the one of the limiting factor for the radiation treatment of the head & neck (H&N) or the thorax region. Due to the fact that the cord is the elongated shaped structure, it is not an easy task to maintain the cord dose within the clinically acceptable dose range. To overcome this problem, the spinal cord partial block technique (PBT) with the dynamic Multi-Leaf Collimator (dMLC) has been developed. Three dimension (3D) conformal beam directions, which minimize the coverage of the normal organs such as the lung and the parotid gland, were chosen. The PBT field shape for each field was designed to shield the spinal cord with the dMLC. The transmission factors were determined by the forward calculation method. The plan comparisons between the conventional 3D conformal therapy plan and the PTB plan were performed to evaluate the validity of this technique. The conformity index (CI) and the dose volume histogram (DVH) were used as the plan comparison indices. A series of quality assurance (QA) was performed to guarantee the reliable treatment. The QA consisted of the film dosimetry for the verification of the dose distribution and the point measurements. The PBT plan always generated better results than the conventional 3D conformal plan. The PBT was proved to be useful for the H&N and thorax region.

• Investigative Magnetic Resonance Imaging
• /
• v.18 no.1
• /
• pp.70-74
• /
• 2014

Actinomycosis is caused by filamentous Gram positive anaerobic bacteria from the Actinomycetaceae family, and known as a rare cause of the infection at the eyeball. We report magnetic resonance findings of a 60-year-old Korean man with cervicofacial actinomycosis, including cellulitis in the eye and central nervous system actinomycosis. On orbital magnetic resonance imaging, gadolinium-enhanced T1-weight images showed multiple abnormal enhancing lesions in head and neck including right eye, and some include low signal intensities which considered as abscesses. The lesions was diagnosed as actinomycosis by incisional biopsy, and since then was cured by using antibiotics of penicillin family.

• Pediatric Infection and Vaccine
• /
• v.27 no.1
• /
• pp.62-68
• /
• 2020

Acute bacterial sinusitis is one of the most common diseases in children, and 5-13% of patients with viral upper respiratory infection experience secondary bacterial sinusitis as a complication. Isolated sphenoid sinusitis is rarer than frontal, maxillary, and ethmoid sinusitis. However, it presents potentially devastating complications, such as cranial nerve involvement, brain abscess, and meningitis, owing to its anatomical location. Nontypeable Haemophilus influenzae (NTHi) commonly causes acute bacterial sinusitis but rarely causes bacteremia, particularly in immunocompetent patients. We present a rare case of a 14-year-old boy with bacteremia due to isolated sphenoid sinusitis caused by NTHi.

• The Journal of the Korean bone and joint tumor society
• /
• v.13 no.2
• /
• pp.130-134
• /
• 2007

Paragangliomas arise from a multicentric system of paraganglion cells derived from the neuroectoderm. Although these tumors are the most common in the head and neck region, they may occur in diverse locations including mediastinum, retroperitoneum and visceral organs. Spinal paragangliomas arising in the intradural space of the thoracolumbar spine have been reported rarely, with the majority located in the cauda equina. Only few cases of thoracic paraganglioma have been previously reported. We present an additional case of thoracolumbar paraganglioma and review the clinical MRI and histopathological features of this unusual tumor.

• Archives of Craniofacial Surgery
• /
• v.13 no.1
• /
• pp.41-45
• /
• 2012

Purpose: Fibular osteocutaneous free flap is the procedure of choice for mandibular reconstruction. However, the anatomic consistency and the reliability of the skin paddle have been considered to be questionable and the utilization of the fibular osteocutaneous free flap can be challenging for the inexperienced surgeon. Preoperative computed tomography (CT) angiography can support revolutionary help with the operator design of the fibular osteocutaneous flap. The purpose of this article is to share the valuable experience of support with preoperative CT angiography. Methods: Three consecutive patients, who needed mandibular reconstruction, were treated with fibular osteocutaneous free flap. Each of the patients had undergone lower extremity CT angiography before the surgery. The CT angiographies were scrupulously investigated to calculate the locations and the tracts of the peroneal artery perforators. We compared the findings of the CT angiography with those of the real operation. Results: The information about the perforators was sufficiently matched with the findings of the operation. With the use of preoperative CT angiography, we were able to achieve confident performance during operation, shortening of operation time, and fine outcomes with a no flap failure. Conclusion: The CT angiography of lower extremity can provide reliable information of the perforators of the fibular osteocutaneous free flap.

• Proceedings of the KOR-BRONCHOESO Conference
• /
• 1993.05a
• /
• pp.92-92
• /
• 1993

It is generally agreed that cellular immune functions are damaged by radiation therapy(RT). However, the exact effects of RT on peripheral lymphocytes are not yet clear. Authors previously reported the radiation effects on lymphocytes subpopulations, but these results merely showed the alteration of proportion of lymphocytes subpopulations after RT. So we try to evaluate the number of lymphocytes in each subpopulations as well as the proportion of subpopulations, and the recovery patterns of these alterations by time duraion after RT. The result shows that the proportion of subpopulations and number of lymphocytes in each subpopulations are decreased after RT except natural killer cells(NK cells), which proportion is increased but number is not changed, and these changes are stationary continued for post RT 6 months and then gradually recovered. However, the radiation effects on peripheral lymphocytes still remain after one year.

• Journal of Oral Medicine and Pain
• /
• v.41 no.1
• /
• pp.30-33
• /
• 2016

Malignant tumors located in the head and neck areas intermittently show symptoms similar to a temporomandibular disorder (TMD). In our case, a patient who first visited us complaining of TMD-like symptoms, such as trismus and temporomandibular joint (TMJ) pain on the left side, was identified as a sufferer of adenoid cystic carcinoma (ACC) that arose from the left maxillary sinus. The patient may have a TMD symptom, but we are skeptical because the patient also complained of a spontaneously developed numbness on the same side of his upper lip. We observed the panoramic radiograph closely and found the blurred maxillary sinus inferior wall. Dental cone-beam computed tomography confirmed the tentative diagnosis of malignancy on the maxillary sinus. After he had been referred to the Department of Otolaryngology, the diagnosis of the ACC was confirmed. Adequate diagnosis is vital for a quick treatment of the malignancy. There are some keys for differential diagnosis of TMD-like symptoms.

• Imaging Science in Dentistry
• /
• v.46 no.1
• /
• pp.63-68
• /
• 2016

Panoramic radiographs are a relatively simple technique that is commonly used in all dental specialties. In panoramic radiographs, in addition to the formation of real images of metal objects, ghost images may also form, and these ghost images can hinder an accurate diagnosis and interfere with the accuracy of radiology reports. Dentists must understand the formation of these images in order to avoid making incorrect radiographic diagnoses. Therefore, the present study sought to present a study of the formation of panoramic radiograph ghost images caused by metal objects in the head and neck region of a dry skull, as well as to report a clinical case in order to warn dentists about ghost images and to raise awareness thereof. An understanding of the principles of the formation of ghost images in panoramic radiographs helps prevent incorrect diagnoses.