• Imaging Science in Dentistry
• /
• v.31 no.2
• /
• pp.93-99
• /
• 2001

Purpose: To analyze the possible association between magnetic resonance imaging signal intensity of temporomandibular joint disk and posterior attachment, and the type and extent of disk displacement, disk configuration, effusion and clinical signs in patients with internal derangement. Materials and Methods: Magnetic resonance images of the 132 temporomandibular joints of 66 patients with temporomandibular joint displacement were analyzed. The clinical findings were obtained by retrospective review of the patients' records. The type and extent of disk displacement, disk configuration and effusion were evaluated on the proton density MR images. The signal intensity from the anterior band, posterior band and posterior attachment were measured on MR images. The associations between the type and extent of disk displacement, disk configuration, effusion and clinical signs and the MR signal intensity of disk and posterior attachment were statistically analyzed by student's t-test. Results: Of 132 joints, 87 (65.9%) showed anterior disk displacement with reduction (ADR) and 45 (34.1%) showed anterior disk displacement without reduction (ADnR). The signals from posterior attachments were lower in joints with ADnR than those of ADR (p<0.05). The results showed statistically significant (p<0.05) association between the type and extent of disk displacement and disk configuration, and decreased signal intensity of posterior attachment. There were no statistical associations between pain, noise and limited mouth opening, and signal intensity of disk and posterior attachment. Conclusions: The average signal from posterior attachment was lower in joints with ADnR than that of ADR. The type and extent of disk displacement and disk configuration appeared to be correlated with the signal intensity from posterior attachment.

• Proceedings of the KSMRM Conference
• /
• 2002.11a
• /
• pp.138-138
• /
• 2002

To determine the accuracy of magnetic resonance (MR) imaging for discrimination between intervertebral disk extrusion versus protrusion. MR images of 80 patients who had MR imaging of the spine and confirmed as intervertebral disk extrusion or protrusion were retrospectively reviewed by an experienced musculoskeletal radiologist. A 1.5-T scanner was used. After review of medical records, MR findings of disk extrusion and protrusion were compared using the chi-square test. Intraobserver agreement for differentiation of disk extrusion from protrusion was calculated by using coefficient.

• Journal of the Korean Society for Railway
• /
• v.10 no.3 s.40
• /
• pp.251-256
• /
• 2007

The research analyzed dynamo test results to evaluate compatibility between brake disk made of NCM-CV cast iron and various pads. The dynamo test was executed with one kind of resin pad and three kinds of sintered pads suitable for 200 km/h trains according to a program which refers to UIC 541-3. The thermocouples were established in specific location in order to measure the temperature of disk and pads. In addition, the thermal imaging camera was used for capturing the instantaneous thermal characteristic of disk. The research results may be utilized to use as basis data of pad development for NCM-CV brake disk hereafter.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.28 no.2
• /
• pp.136-142
• /
• 2006

Temporomandibular joint(TMJ) disorders have characteristic clinical findings such as pain, joint sound, and abnormal jaw function. With the rapid progress in TMJ imaging techniques, magnetic resonance imaging(MRI) especially provides the clinician and researcher with the ability to evaluate TMJ disorders(effusion, anterior disk displacement) and the hard and soft tissue of the TMJ. In order to manage the internal derangement of TMJ such as anterior disk displacement, the so-called appliance therapy is commonly used. This technique became the treatment of choice before surgical intervention by many practitioners. The purpose of the present study was to evaluate and determine the efficacy of anterior repositioning splint by means of the change of the position of the disk through pre- and post-treatment MRI. MRI and clinical symptom were carefully recorded in TMJ disorder patients. The relationship between TMJ symptoms such as pain, clicking sound, and disk displacement and effusion in MRI were analyzed. Then, splint therapy was applied for 3 months according to our protocol; at day 1, patients should wear 24 hours, in order to accomodate the splint and then, wearing time is reduced to 12 hours per day for one month. During next 2 months, it is tapered to 8 hours per day according to the evaluation of the clinical symptoms. Post-treatment MRI was obtained after 3 month protocol. This treatment strategy improved the clinical symptoms of TMJ disorder, and effusion and articular disk position showed a significant change. In conclusion, a treatment modality using an anterior repositioning splint therapy is an appropriate method for temporomandibular disorder patients.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.15 no.3
• /
• pp.189-197
• /
• 1993

Tempormandibular Joint pain and dysfunction is a common and important clinical problem. With the recent advances in imaging technology, radiologists have made major contribution to the understanding of TMJ disease. The MRI has several advantages over the conventional imaging methods. It is possible to obtain surprisingly precise images of internal hard and soft tissues with MRI. It is not invasive without ionizing radiation. The abnormal disk position has been thought as the cause of TMJ internal derangement. But there are few methods to relate disk position to TMJ internal derangement quantatively. The object of our study is to determine the amount of anterior displacement fo articular disk in symptomatic patients related each symptoms. Using the method of Dr. Drace, we studied the 38 joints of 22 persons with susceptable TMJ internal derangement. 1. In determining the anterior displacement of TMJ articular disk, the junction between the posterior band and bilaminar zone was useful. 2. The mean anterior displacement of disk in reduction group and without reduction group were $51.0^{\circ}C$ and $81.1^{\circ}C$ respectively. The difference was significant. 3. In the mean anterior displacement of disk, the pain without clicking group showed $84.8^{\circ}C$ and the clicking and pain group $70.8^{\circ}C$, the clicking group respectively.

• Imaging Science in Dentistry
• /
• v.33 no.2
• /
• pp.63-70
• /
• 2003

Purpose: To describe the MRI findings of the retrodiskal tissue in patients presenting with TMJ internal derangement and to correlate these findings with clinical and other MRI manifestations. Materials and Methods: One hundred eighteen joints of 63 patients with TMJ internal derangement were examined by MRI. Tl-weighted sagittal MR images taken in both closed- and open-mouth were evaluated for the presence of demarcation between disk and retrodiskal tissue, the presence of low signal intensity, and the depiction of the temporal part of the posterior attachment. The results were correlated with the duration of TMJ internal derangement, the presence of pain, and other MRI findings, including the type of internal derangement, the extent of disk displacement, the degree of disc deformation, and the presence of osteoarthrosis. Results: A significant relationship between the presence of low signal intensity in the retrodiskal tissue and other MRI findings was determined. Low signal intensity on the open-mouth view was observed more frequently in patients with disc displacement without reduction, severe disc displacement and deformation, and osteoarthrosis (p<0.05). The demarcation between disk and retrodiskal tissue, and the depiction of the temporal part of the posterior attachment(TPA) were correlated neither with clinical, nor with other MRI findings. Conclusion: This study suggests that low signal intensity in the retrodiskal tissue on open-mouth MR image can be indicative of advanced stages of disk displacement.

• Journal of The Korean Astronomical Society
• /
• v.44 no.1
• /
• pp.23-32
• /
• 2011

We present a deep CCD imaging in B and V bands which allows us to analyze the vertical structure of NGC 4631. We derive the scale heights of the thin and thick disks at a variety of positions along the major axis of the disk. The scale heights of the thin disk are nearly constant while those of the thick disk tend to increase with increasing galactocentric distance. The mean scale heights of the thin disk derived from B and V images are similar to each other (~ 450 pc). Instead, those of the thick disk show a strong east-west asymmetry which is caused by the diffuse stellar emission that is most prominent in the north west regions above the disk plane. The ratio of scale heights ($z_{thick}/z_{thin}$) is about 2.5 in the east side of the disk. However, this ratio is greater than 4 for the thick disk above the disk plane in the west side of the galaxy.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.19 no.6
• /
• pp.15-20
• /
• 2019

Fundamental processes in digital forensic investigation - such as disk imaging - were developed when digital investigation was relatively young. As digital forensic processes and procedures matured, these fundamental tools, that are the pillars of the reset of the data processing and analysis phases of an investigation, largely stayed the same. This work is a study of modern digital forensic imaging software tools. Specifically, we will examine the feature sets of modern digital forensic imaging tools, as well as their development and release cycles to understand patterns of fundamental tool development. Based on this survey, we show the weakness in current digital investigation fundamental software development and maintenance over time. We also provide recommendations on how to improve fundamental tools.

• Journal of Veterinary Science
• /
• v.22 no.1
• /
• pp.3.1-3.13
• /
• 2021

Background: Multifidus muscle stiffness decreases in patients with lumbar intervertebral disk herniation; however, age-related changes in humans have not been reported. Objectives: The reliability of ultrasound shear wave elastography in dogs, and changes in the shear elastic modulus of the thoracolumbar multifidus muscle with aging in dogs, were investigated. Methods: Twelve beagle dogs were divided into 2 groups based on the age of onset of intervertebral disk herniation: young (aged not exceeding 2 years; 1.3 ± 0.6 years old, n = 5) and adult (4.9 ± 1.2 years old, n = 7). The shear elastic modulus of the multifidus muscle, from the thirteenth thoracic spine to the fourth lumbar spine, was measured using ultrasound shear wave elastography. The length, cross-sectional area and muscle to fat ratio of the multifidus muscle, and the grade of intervertebral disk degeneration, were assessed using radiographic and magnetic resonance imaging examinations. Results: The length and cross-sectional area of the multifidus muscle increased caudally. In the young group, the shear elastic modulus of the multifidus muscle of the thirteenth thoracic spine was less than that of the third lumbar spine. In the adult group, the shear elastic modulus of the multifidus muscle of first and third lumbar spine was lower than that of the same site in the young group. Conclusions: Ultrasound can be used to measure shear wave elastography of the thoracolumbar multifidus in dogs. If the multifidus muscle stiffness decreases, we should consider age-related change.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.16 no.3
• /
• pp.273-280
• /
• 1994

The Magnetic Resonance Imaging has been used widely to evaluate the disk position without any interruption of the TMJ structures, and the Dynamic MRI presenting computed serial imaging or the video-recorded simulation images is thought to be very effective to evaluate the disk position under function. This is to study the correlation between the clinical diagnosis and the findings of Dynamic MRI for the diagnosis of internal derangement of the temporomandibular joints. 30 joints(15 patients) were examined clinically, and the movement of TMJ meniscus was reviewed in the dynamic MRI. The comparative results are as follows : 1. All internal derangements of TMJ disk displacement without reduction were consistent with MRI findings. 2. 5 joints (50%) of disk displacements with reduction could not be confirmed by MRI findings. 3. The disk displacements in MRI were found in 55% of painful joints, 50% of clicking joints, and 70% of the joints with restricted movement. 4. The reliability of MRI for the diagnosis of TMD was evaluated as 77% ; 24 of 30 joints who presented with clinical diagnosis of TMD. 5. MRI is very reliable to diagnose the disk displacement without reduction, but it is rather not so effective to diagnose the early derangement or muscle disorders.