• Investigative Magnetic Resonance Imaging
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• 제17권2호
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• pp.91-100
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• 2013

목적: 요추 MR 영상에 추가된 경흉추 시상T2강조영상(CT SAG T2WI)의 임상적 효용성을 평가하고자 한다. 대상과 방법: 2005년 1월부터 2005년 12월까지 요추 MRI를 시행하였던 2,113명의 환자를 대상으로 하였다. 경흉추 시상T2강조영상을 후향적으로 분석하였고, 의무기록을 후향적으로 검토하여 경추 또는 흉추 병변의 추가적인 평가를 위한 MRI 또는 CT 시행여부와 이러한 병변에 대한 치료 및 경과를 알아보았다. 결과: 2,113명중 139명의 환자에게서 총 142개의 병변이 경흉추 시상T2강조영상에서 관찰되었다. 요추 MRI 촬영시, 환자의 자세변화 없이 2분 이내에 경흉추 시상T2강조영상을 추가적으로 얻었다. 13명의 환자만이 경추 또는 흉추의 병변에 대해 MR영상 또는 CT를 시행하였고, 7명의 환자는 T2강조영상 고신호강도 여부에 상관 없이 척추관협착증 또는 추간판탈출증에 대해 수술적 치료를 받았다. 결론: 요추 MRI촬영 시, 2분 이내로 소요되는 경흉추 시상T2강조영상의 추가촬영은 요추의 증상으로 오인된 경흉추의 병변을 평가하는데 유용하다.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제27권5호
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• pp.488-491
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• 2005

A 3-year-old female, 5kg, Shih-tzu developed an acute onset of depression, disorientation, hypersalivation, nystagmus after falling down 2 meter height place. In plain skull radiography, there was fracture line in the frontal and parietal bones and next day magnetic resonance imaging examination was performed. Magnetic resonance imaging of the brain was performed with 3.0 Tesla unit. Under general anesthesia, the dog was placed in prone with its head positioned in a birdcage coil. Transverse, sagittal and coronal fast spin echo images of the brain were obtained with the following pulse sequences: T1 weighted images (TR = 560 ms and TE = 18.6 ms) and T2 weighted images (TR = 3500 ms and TE = 80 ms). Magnetic resonance imaging showed epidural hematoma in the left frontal area resulting in compression of the adjacent brain parenchyma. Left lateral ventricle was compressed secondarily and the longitudinal fissure shifted to the right, representing mass effect. The lesion was iso-to slightly hyperintense on T1 weighted image and iso-slightly hypointense signal on T2 weighted image. At necropsy, there was a skull fracture and epidural hematoma in the left frontal area. Magnetic resonance imaging of epidural hematoma is reviewed.

• Journal of Korean Neurosurgical Society
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• 제38권1호
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• pp.71-73
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• 2005

A case of intramedullary spinal cord lipoma is presented. A one month-old male infant presented with irritability and weakness on his upper extremities. A magnetic resonance[MR] image of the cervical spine demonstrated a well defined, high signal intensity lesion on both T1 and T2-weighted MR images and suppression on the fat saturation sequence. The tumor mass extended from the foramen magnum to T2 vertebra level. Ventral displacement of the spinal cord with kinking of the cervico-medullary junction was evident on the T2-weighted sagittal image. Partial resection of the tumor mass through laminoplastic laminotomy from C1 to T2 resulted in improved motor weakness on his upper extremities.

• Imaging Science in Dentistry
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• 제52권4호
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• pp.393-398
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• 2022

Purpose: This study proposed a generative adversarial network (GAN) model for T2-weighted image (WI) synthesis from proton density (PD)-WI in a temporomandibular joint(TMJ) magnetic resonance imaging (MRI) protocol. Materials and Methods: From January to November 2019, MRI scans for TMJ were reviewed and 308 imaging sets were collected. For training, 277 pairs of PD- and T2-WI sagittal TMJ images were used. Transfer learning of the pix2pix GAN model was utilized to generate T2-WI from PD-WI. Model performance was evaluated with the structural similarity index map (SSIM) and peak signal-to-noise ratio (PSNR) indices for 31 predicted T2-WI (pT2). The disc position was clinically diagnosed as anterior disc displacement with or without reduction, and joint effusion as present or absent. The true T2-WI-based diagnosis was regarded as the gold standard, to which pT2-based diagnoses were compared using Cohen's ĸ coefficient. Results: The mean SSIM and PSNR values were 0.4781(±0.0522) and 21.30(±1.51) dB, respectively. The pT2 protocol showed almost perfect agreement(ĸ=0.81) with the gold standard for disc position. The number of discordant cases was higher for normal disc position (17%) than for anterior displacement with reduction (2%) or without reduction (10%). The effusion diagnosis also showed almost perfect agreement(ĸ=0.88), with higher concordance for the presence (85%) than for the absence (77%) of effusion. Conclusion: The application of pT2 images for a TMJ MRI protocol useful for diagnosis, although the image quality of pT2 was not fully satisfactory. Further research is expected to enhance pT2 quality.

• Imaging Science in Dentistry
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• 제50권2호
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• pp.93-98
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• 2020

Purpose: Little is known regarding the accuracy of clinical magnetic resonance imaging (MRI) protocols with acceptable scan times in sinus graft assessment. The aim of this study was to evaluate the correlations between MRI and cone-beam computed tomographic (CBCT) measurements of maxillary sinus grafts using 2 different clinical MRI imaging protocols. Materials and Methods: A total of 15 patients who underwent unilateral sinus lift surgery with biphasic calcium phosphate were included in this study. CBCT, T1-weighted MRI, and T2-weighted MRI scans were taken 6 months after sinus lift surgery. Linear measurements of the maximum height and buccolingual width in coronal images, as well as the maximum anteroposterior depth in sagittal images, were performed by 2 trained observers using CBCT and MRI Digital Imaging and Communication in Medicine files. Micro-computed tomography (micro-CT) was also performed to confirm the presence of bone tissue in the grafted area. Correlations between MRI and CBCT measurements were assessed with the Pearson test. Results: Significant correlations between CBCT and MRI were found for sinus graft height (T1-weighted, r=0.711 and P<0.05; T2-weighted, r=0.713 and P<0.05), buccolingual width (T1-weighted, r=0.892 and P<0.05; T2-weighted, r=0.956 and P<0.05), and anteroposterior depth (T1-weighted, r=0.731 and P<0.05; T2-weighted, r=0.873 and P<0.05). The presence of bone tissue in the grafted areas was confirmed via micro-CT. Conclusion: Both MRI pulse sequences tested can be used for sinus graft measurements, as strong correlations with CBCT were found. However, correlations between T2-weighted MRI and CBCT were slightly higher than those between T1-weighted MRI and CBCT.

• Imaging Science in Dentistry
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• 제43권4호
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• pp.245-251
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• 2013

Purpose: This study was performed to evaluate the relationship between anterior disc displacement and effusion in temporomandibular disorder (TMD) patients using magnetic resonance imaging (MRI). Materials and Methods: The study subjects included 253 TMD patients. MRI examinations were performed using a 1.5 T MRI scanner. T1- and T2-weighted images with para-sagittal and para-coronal images were obtained. According to the MRI findings, temporomandibular joint (TMJ) disc positions were divided into 3 subgroups: normal, anterior disc displacement with reduction (DWR), and anterior disc displacement without reduction (DWOR). The cases of effusion were divided into 4 groups: normal, mild (E1), moderate (E2), and marked effusion (E3). Statistical analysis was made by the Fisher's exact test using SPSS (version 12.0, SPSS Inc., Chicago, IL, USA). Results: The subjects consisted of 62 males and 191 females with a mean age of 28.5 years. Of the 253 patients, T1- and T2-weighted images revealed 34 (13.4%) normal, DWR in 103 (40.7%), and DWOR in 116 (45.9%) on the right side and 37 (14.6%) normal, DWR in 94 (37.2%), and DWOR in 122 (48.2%) joints on the left side. Also, T2-images revealed 82 (32.4%) normal, 78 (30.8%) E1, 51 (20.2%) E2, and 42 (16.6%) E3 joints on the right side and 79 (31.2%) normal, 85 (33.6%) E1, 57 (22.5%) E2, and 32 (12.7%) E3 on the left side. There was no difference between the right and left side. Conclusion: Anterior disc displacement was not related to the MRI findings of effusion in TMD patients (P>0.05).

• Korean Journal of Radiology
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• 제2권2호
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• pp.63-67
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• 2001

Objective: Atrophy and a high T2 signal of the hippocampus are known to be the principal MR imaging findings of hippocampal sclerosis. The purpose of this study was to determine whether or not individual MRI findings correlate with surgical outcome in patients with this condition. Materials and Methods: Preoperative MR imaging findings in 57 consecutive patients with pathologically-proven hippocampal sclerosis who underwent anterior temporal lobectomy and were followed-up for 24 months or more were retrospectively reviewed, and the results were compared with the postsurgical outcome (Engel classification). The MR images included routine sagittal T1-weighted and axial T2-weighted spin-echo images, and oblique coronal T1-weighted 3D gradient-echo and T2-weighted 2D fast spin-echo images obtained on either a 1.5 T or 1.0 T unit. The images were visually evaluated by two neuroradiologists blinded to the outcome; their focus was the presence or absence of atrophy and a high T2 hippocampal signal. Results: Hippocampal atrophy was seen in 96% of cases (55/57) [100% (53/53) of the good outcome group (Engel class I and II), and 50% (2/4) of the poor outcome group (class III and IV)]. A high T2 hippocampal signal was seen in 61% of cases (35/57) [62% (33/53) of the good outcome group and 50% (2/4) of the poor outcome group]. All 35 patients with a high T2 signal had hippocampal atrophy. 'Normal' hippocampus, as revealed by MR imaging, occurred in 4% of patients (2/57), both of whom showed a poor outcome (Engel class III). The presence or absence of hippocampal atrophy correlated well with surgical outcome (p<0.01). High T2 signal intensity did not, however, significantly correlate with surgical outcome (p>0.05). Conclusion: Compared with a high T2 hippocampal signal, hippocampal atrophy is more common and correlates better with surgical outcome. For the prediction of this, it thus appears to be the more useful indicator.

• 대한방사선기술학회지:방사선기술과학
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• 제33권1호
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• pp.45-50
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• 2010

본 연구는 T2고속스핀에코 3.0T 자기공명영상에서 지방조직 소거기법인 SPAIR와 STIR기법의 임상적 유용성에 관한 비교연구를 시행하였다. SPAIR와 STIR 프로토콜을 사용하여 뇌의 축방향 영상(20개), 요추의 시상단면영상(20개), 고관절의 관상단면영상(17개), 무릎관절의 축방향 영상(25개)을 획득하였다. 검사부위별로 지방억제기법의 지방소거능력과 화질을 파악하기위해 지방조직의 신호강도와 불균일성을 측정하였다. 지방조직에서 불균일치는 측정된 지방 신호의 평균치(mean)에 대한 표준편차(SD)로서 그 산출은 SD/mean으로 계산하였다. 수집된 자료는 SPSS(Statistical Package for the Social Science) WIN 13.0 프로그램을 이용하여 분석한 결과 다음과 같은 결론을 얻었다. 첫째, 뇌 검사는 SPAIR가 STIR보다 지방억제능력과 화질면에서 우수한 결과를 나타냈으며, 둘째, 요추, 고관절, 무릎관절 검사는 지방의 신호억제능력은 STIR가 우수하고, 화질면에서는 SPAIR가 우수한 결과를 나타냈다.

• 디지털콘텐츠학회 논문지
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• 제11권4호
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• pp.425-431
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• 2010

본 연구에서는 돌발성 난청을 보이는 환자를 대상으로 임상에서 자주 사용 하는 기법인 3D FSE과 새로운 기법인 3D FIESTA-C 을 정량적으로 비교 분석하여 3D FIESTA 기법의 효과와 유용성을 고찰해보고자 한다. 감각신경성 난청으로 진단받은 40명의 환자를 대상으로 3.0T MR scanner를 이용하여 3D FSE 영상과 3D FIESTA 영상인 축상면 T2 영상을 획득하였다. 획득한 3D FSE 영상과 3D FIESTA 영상은 신경의 주행방향에 수직으로 재구성을 시행하여 내이도의 오른쪽, 왼쪽의 시상면 영상을 획득 하였다. 분석 결과 3D FSE 기법을 이용한 그룹과 3D FIESTA기법을 이용한 두 그룹에서의 신호대 잡음비는 3D FIESTA 기법을 이용한 그룹에서 높은 신호대 잡음비를 보였으며 두 그룹에서의 대조도대 잡음비는 3D FIESTA 기법을 이용한 그룹에서 높은 대조도대 잡음비를 보였다.

• 한국임상수의학회지
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• 제23권3호
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• pp.366-370
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• 2006

Arachnoid cysts are intra-arachnoid collections of cerebrospinal fluid. They may cause neurological deficit through expansion that can compress normal neural tissue and obstruct cerebrospinal fluid flow. Intracranial arachnoid cysts were found in 4 patients aged 10 months to 20 months(mean age 15 months). The presenting symptoms included circling(dog 2,3), seizure(dog 1), progressive weakness(dog 1,2,3), increasing scoliosis(dog 3), worsening spasticity(dog 3), and salivation(dog 3). One patient showed no symptoms from the intracranial arachnoid cyst. There were no significant findings in complete blood count and serum chemistry. Computed tomography(CT) with/without magnetic resonance imaging(MRI) scans were performed in these cases. Hypodense intracranial arachnoid cyst was observed on CT images in dog 4. Sagittal T1-weighted(T1W) and T2-weighted(T2W) images and transverse T1W and T2W images revealed a intracranial arachnoid cysts with syringohydromyelia(dog 3) and hydrocephalus(dog 3,4) in the brain. Clinical signs of three cases were improved by medication.