• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.27 no.1
• /
• pp.179-188
• /
• 1997

This study was intended to compare the diagnostic ability between Waters' radiograph and CT in the diagnosis of midfacial fracture. The study group included 44 patients(male:32, female :12, age range :16-74 years old) with facial injury who underwent surgery. Waters' radiograph and both axial and coronal scanning were performed before surgery. Three oral radiologists and three non-oral radiologist interpreted 44 Waters' radiographs and 88 CT in three ways; 1) interpretation using Waters' radiograph only, 2) interpretation using CT only, 3) interpretation using Waters' radiograph and CT. The interpretation sites were confined to the walls of maxillary sinus; anterior, posterior, medial, lateral and superior wall. ROC curves were made with the findings during surgery as a gold standard except the posterior wall, where the joint evaluation of Waters' radiograph and CT by other three oral radiologists was used. ROC areas were compared according to the interpreting methods, the interpretation sites, and groups (R group ; oral radiologist group, N group ; non-oral radiologist group). The obtained results were as followed : 1. The diagnostic ability of CT only and Waters' radiograph and CT was higher than Waters' radiograph only in both groups(P<0.05). But there was no difference between CT only and Waters' radiograph and CT. 2. Generally, the diagnostic ability for the lateral antral wall was the highest and that for the posterior antral wall was the lowest in both groups(P<0.05). 3. In R group, for the anterior antral wall the diagnostic ability using CT only was increased but for the medial, lateral and superior antral walls the diagnostic ability was increased in only using Waters' radiograph and CT. 4. In N group, for the anterior and medial walls the diagnostic ability using CT only was increased. But for the posterior, lateral and superior antral walls there were no difference among three interpreting methods. 5. The diagnostic ability of R group was higher than N group in all interpreting methods.

• Imaging Science in Dentistry
• /
• v.36 no.4
• /
• pp.177-182
• /
• 2006

Purpose: To evaluate the diagnostic ability in differentiating between ameloblastoma and odontogenic keratocyst according to the imaging modalities and observers. Materials and Methods: We evaluated thirty-six cases of ameloblastomas and forty-seven cases of odontogenic keratocysts all histologically confirmed. Six oral and maxillofacial radiologists diagnosed the lesions by 3 methods: using panoramic radiograph, using computed tomograph (CT), and using panoramic radiograph and CT. The observers were classified by 3 groups: group 1 had experienced over 10 years in oral and maxillofacial radiologic field, group 2 had experienced for 3-4 years, and group 3 was in the process of residentship. After over 2 weeks, the observers diagnosed them by the same methods. Results: The ROC curve areas except for group 3 were the highest with interpretation using panoramic radiograph and CT, followed by interpretation using CT only, and the lowest with interpretation using panoramic radiograph only. The overall difference was not found in diagnostic ability among groups in using panoramic radiograph only, but there was difference in diagnostic ability of group 1 and 2 vs 3 in using CT only, and combination panoramic radiograph and CT. Conclusions: To differentiate between ameloblastoma and odontogenic keratocyst more accurately, the experienced oral and maxillofacial radiologist should diagnose with combination of panoramic radiograph and CT.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.33 no.5
• /
• pp.504-510
• /
• 2007

Purpose: The purpose of this study was to determine the incidence of antral septa and the accuracy of panoramic radiograph in identifying maxillary sinus septa. In addition, when panoramic radiograph led to a false diagnosis of more than majority, we analyzed findings of the panoramic radiograph. Patients and methods: This study included 180 patients who were radiographically examined before the surgery was done using both panoramic and computerized tomographic radiographs(CT scan), Samsung Medical Center from April 2003 to March 2006, and examined the incidence of antral septa, the false diagnosis rate of panoramic radiograph, and radiographic characters in case of false diagnosis. Only those bone lamellae were considered as septa that showed a height of at least 3.0mm. It was thus possible to exclude the alveolar recess. One oral and maxillofacial surgeon(OMFS) determined the presence or absence of sinus septa in CT scan, and five OMFS determined the presence or absence of sinus septa in panoramic radiograph. Results: The septa were observed in 81 of 360 sinuses(22.5%). All septa were oriented in a buccopalatal plane. More or less greater prevalence was observed in the second molar region(38.2%) but no predominant location was found. Panoramic radiograph led to false diagnosed septa in 361 of 1800 cases(20.1%). In case of false diagnosis of more than majority, superimposed image on zygomatic process was 44.1%, faint image in the region not related to sinus lifting 26.5%, faint image in the region related to sinus lifting 17.6%, and misconception for superimposed image 11.8% Conclusion: In this study we could get clinico-anatomical information of septum in the maxillary sinus. Compared to CT scan, panoramic radiograph can not clearly differentiate the sinus septa, but we consider that panoramic radiograph may improve its usefulness if we take additional modified panoramic radiograph and clinical exam.

• Journal of Veterinary Clinics
• /
• v.32 no.4
• /
• pp.313-318
• /
• 2015

The lung opacity on radiography is influenced by various factors. The physical density of the lung and the attenuation ensured on computed tomography (CT) scans is determined by three components : lung tissue, blood, and air. Temporary right lateral recumbency may responsible for the increase of opacity on ventrodorsal projection view. Thus, our aim is to demonstrate that the effect of right lateral recumbency posture on right lung opacity using radiograph and CT scan. In this study, 62 dogs without clinical or radiologic signs of cardiopulmonary disease are selected. Thorax radiographs per 30 seconds for 2 minutes (30s, 60s, 90s, 120s) were performed for 62 dogs. After discussion of the radiographic findings of lung field by two radiologists and a student at Chungbuk national university veterinary medical center a consensus opinion was recorded. Computed tomography per a minute (1 min, 2 min) for 2 minutes were performed for 2 dogs. Mean x-ray attenuation of lung was measured quantitatively using software at two levels (aortic arch and basal level). Among 62 dogs with radiograph comparison, 9.3% of dogs showed influence by postural effect. However, all 2 dogs with computed tomography comparison, showed influence by postural effect. In conclusion, position dependent changes of lung density in CT exam are not consistent with thoracic radiograph.

• The Journal of the Korea Contents Association
• /
• v.12 no.10
• /
• pp.340-348
• /
• 2012

To evaluate the usefulness of tomosynthesis in the chest area, simple radiograph, low-dose CT, and tomosynthesis examinations were performed, and their absorbed doses were compared, and finally the images were evaluated. The absorbed dose recorded with the simple Radiograph examination was $0.33{\pm}0.27$ mGy, that of low-dose CT $1.26{\pm}0.56$ mGy, and that of tomosynthesis $0.55{\pm}0.02$ mGy, which indicate significance differences in absorbed doses among the examinations(p<0.001). Based on the evaluations of the images, The simple radiograph scores were $1.66{\pm}0.72$, $1.61{\pm}0.63$, and $1.57{\pm}0.73$, respectively; low-dose CT scores were $2.92{\pm}0.26$, $2.91{\pm}0.29$, and $2.88{\pm}0.32$, respectively; and tomosynthesis scores were $2.69{\pm}0.51$, $2.76{\pm}0.43$, and $2.66{\pm}0.61$, respectively. That is, there were statistically significant differences among the examinations(p<0.001), although there was no significant difference between low-dose CT and tomosynthesis examinations. Therefore, tomosynthesis is judged to be a useful examination that can minimize radiation doses to patients during chest examinations and enhance diagnostic efficacy.

• Tuberculosis and Respiratory Diseases
• /
• v.57 no.2
• /
• pp.118-124
• /
• 2004

Lung cancer is the leading cause of cancer death for men and women in the industrialized world. It is desirable to detect disease at a stage when it is not causing symptoms and when control or cure is possible. If the screening test detects patients with the disease at an early stage, they can be examined to confirm the diagnosis and intervention can alter the natural history of the disease. The results of screening programs designed to detect early lung cancer using either conventional chest radiograph or sputum cytology are disappointing for a diagnostic screening test. Because of advances in helical CT imaging techniques, screening for lung cancer has been suggested as a possible method of improving outcome. Findings in recent publications suggest that substantial dose reduction is possible in chest CT. The advantages of low-dose CT are more sensitive than chest radiograph for detecting small pulmonary nodules that may be lung cancers, shorter scanning time than conventional chest CT scan without intravenous contrast injection, cheaper cost than standard CT, low radiation dose. However, the true clinical significance of the small tumors found by screening is still unknown, and their effect on mortality awaits future investigation. Furthermore, in addition to detecting an increased number of lung cancers, low-dose CT found at least one indeterminate nodule in many of all screened patients. The majority should be benign but evaluation of all these indeterminate nodules is not a trivial problem in routine practice. In conclusion, lung cancer screening with low-dose CT is a complex subject. The true effectiveness of lung cancer screening (a reduction in mortality from lung cancer) with low-dose CT can be determined through well-designed randomized control trials with enrolment of appropriate subjects.

• Journal of Chest Surgery
• /
• v.42 no.2
• /
• pp.226-232
• /
• 2009

Background: Blunt chest trauma accounts for 90% of all chest traumas in Europe and the United States and this causes 20% of all trauma-related deaths. The major cause of morbidity and mortality after blunt chest trauma is undetected injuries. For this reason, chest computerized tomography has gained popularity for the evaluation of trauma, but it is expensive and it exposes patients to radiation. This study identified the clinical features associated with the diagnosic information obtained on a CT chest scan, as compared with a standard chest X-ray, for patients who sustained blunt trauma to the chest. This study also evaluated the role of a routine computed tomographic (CT) scan for these patients. The patients who had chest computed tomography done after the initial chest x-ray were analyzed separately for the presence of occult injuries. Material and Method: We studied 100 consecutive patients from November 2006 to July 2007: 74 patients after motor vehicle crashes and 26 patients after a fall from a height >2m. Simultaneous with the initial clinical evaluation, an anteroposterior chest radiograph and a helical chest CT scan were obtained for all the patients. The data extracted from the medical record included the vital signs, the interventions and the type and severity of injury (RTS). Result: Among the 100 cases, 79 patients showed at least more than one pathologic sign on their chest radiograph, and 21 patients had a normal chest radiograph. For 17 of the patients who had a normal chest X ray, the CT scan showed multiple injuries, which were pneumothorax, hemothorax, lung contusion, sternal fracture etc. This represents that a CT scan is statistically superior to a chest radiograph to diagnose the pathologic signs. But on the other hand, as for treatment, only 31 patients were diagnosed by CT scan and they were treated with chest tube insertion ect. 42 patients needed ony conservative management without invasive thoracosurgical treatment such as chest tube insertion or open thoracotomy. 27 patients were treated based on the diagnosis made by the chest radiograph and physical examination. Conclusion: Chest computerized tomography was significantly more effective than routine chest X-ray for detecting lung contusion, pneumothorax and mediastinal hematoma, as well as fractured ribs, scapula and, sternum. Although the occult findings increased, the number of patients who needed treatment was small. Therefore, we suggest making selective use of a CT scan to avoid its overuse in ERs.

• Nuclear Medicine and Molecular Imaging
• /
• v.41 no.3
• /
• pp.252-254
• /
• 2007

Image fusion is fast catching attention as Wagner pointed out in his 2006 version of the recent progress and development presented at the annual meeting of Society of Nuclear Medicine. Prototypical fusion of bone scan and radiograph was already attempted at in 1961 when Fleming et al. published an article on strontium-85 bone scan. They simply superimposed dot scan on radiograph enabling simultaneous assessment of altered bone metabolism and local bone anatomy. Indeed the parallel reading of images of bone scan and radiography, CT, MRI or ultrasonography has been practiced in nuclear medicine long since. It is fortunate that recent development of computer science and technology along with the availability of refined CT and SPECT machines has permitted us to open a new avenue to digitally produce precise fusion image so that they can readily be read, exchanged and disseminated using internet. Ten years ago fusion was performed using Bresstrahlung SPECT/CT and it is now achievable by PET/CT and SPECT/CT software and SPECT/CT hardware. The merit of image fusion is its feasibility of reliable assessment of morphological and metabolic change. It is now applicable not only to stationary organs such as brain and skeleton but also to moving organs such as the heart, lung and stomach. Recently, we could create useful fusion image of cardiac SPECT and 64-channel CT angiograph. The former provided myocardial metabolic profile and the latter vascular narrowing in two patients with coronary artery stenosis and myocardial ischemia. Arterial stenosis was severe in Case 1 and mild in Case 2.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.36 no.6
• /
• pp.285-291
• /
• 2014

Osteopathia striata with cranial sclerosis (OS-CS) is characterized by linear bone dysplasia at the long bone radiographically and sclerotic change at the cranium. The purpose of this case report is to study the symptoms and treatments of osteomyelitis in a patient with OS-CS. A 41-year-old patient had pus discharge from a fistula at the mental region and increase in radiolucencies with sequestra in panoramic radiograph images. Computed tomography (CT) as well as radiograph images for the whole skeleton were taken. The patient was diagnosed with OS-CS. Sequestrectomy and fistulectomy were performed. The patient recovered and no relapse occurred within six months after surgery. For diagnosis of OS-CS, CT and additional radiograph images for the whole skeleton are required. Because of the increased bone density, this patient is prone to relapse after sequestrectomy. Therefore, the surgeon must minimize trauma with the least incision and exfoliation, and preoperative antibiotics.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.25 no.3
• /
• pp.545-548
• /
• 1998

Sialolithiasis is the formation of calcareous concretions within ductal system of a major or minor salivary gland. They are formed by deposition of calcium salts around a central nidus which may consist of desquamated epithelial cells, bacteria, foreign bodies, or products of bacterial decomposition. An 11-year-old boy complained of pain during meals and intermittent mild swelling in the right submandibular region. Although it was not detected in true occlusal radiograph, panoramic radiograph showed a round radiopaque mass 3mm in diameter. Computed tomography(CT) was taken for locating the stone and 3-dimensional reconstruction was performed. Under general anesthesia, sialoadenectomy was done through extraoral approach. Diagnosis of submandibular sialolithiasis using high-resolution CT with reconstructions was helpful for surgical decisions, namely radical removal of the submandibular gland and its duct.