• Journal of Korean Neurosurgical Society
• /
• 제44권4호
• /
• pp.265-267
• /
• 2008

Angiolipomas in the lumbar spinal region are extremely rare. The present report describes the identification of such a tumor and its removal, and discusses the tumor characteristics and prognosis. A 74-year-old woman was presented with a 5-month history of lower back pain. Severe radiculopathy was experienced in the left leg for 5 days prior to the presentation, and there were no neurological deficits. Magnetic resonance (MR) images showed an approximately 3.5 cm heterogeneously enhanced and elongated mass at the left L5-S1 level. A portion of the mass appeared with high signal intensity on T2-weighted MR images, with low signal intensity on T1-weighted images, and with high signal intensity on T1 fat suppression enhancement images. Resection of the tumor was approached via an L5 and S1 laminectomy. A fibrous sticky yellowish hypervascular tumor was identified. Histological study revealed the tumor as an angiolipoma. Symptoms were relieved after tumor excision, and there were no neurological sequelae. Although extremely rare, lumbar epidural angiolipoma should be considered in the differential diagnosis of lumbar spinal epidural lesions. The prognosis after surgical management of this lesion is favorable.

• 한국컴퓨터정보학회논문지
• /
• 제17권5호
• /
• pp.29-32
• /
• 2012

본 논문에서는 요부 영상에서 근육을 추출하는 방법을 제안한다. 제안된 방법은 요부 초음파 영상에서 피하지방층과 등뼈 영역을 각각 분류하여 피하지방층의 하단 부분과 등뼈의 상단 부분의 경계선을 개선된 4방향 윤곽선 추적 알고리즘을 적용하여 추출하고 이 두 경계선 내에 있는 영역을 요부의 근육 영역으로 추출한다. 본 연구에서 제안한 방법을 392개의 요부 초음파 영상에 적용하여 근육 영역을 추출한 결과, 제안된 방법은 94% 이상의 추출률을 보였다.

• 대한의용생체공학회:의공학회지
• /
• 제44권2호
• /
• pp.139-146
• /
• 2023

Osteoporosis is a disease in which the risk of bone fractures increases due to a decrease in bone density caused by aging. Osteoporosis is diagnosed by measuring bone density in the total hip, femoral neck, and lumbar spine. To accurately measure bone density in the lumbar spine, the vertebral region must be segmented from the lumbar X-ray image. Deep learning-based automatic spinal segmentation methods can provide fast and precise information about the vertebral region. In this study, we used 695 lumbar spine images as training and test datasets for a deep learning segmentation model. We proposed a lumbar automatic segmentation model, CM-Net, which combines the center point of the spine and the modified U-Net network. As a result, the average Dice Similarity Coefficient(DSC) was 0.974, precision was 0.916, recall was 0.906, accuracy was 0.998, and Area under the Precision-Recall Curve (AUPRC) was 0.912. This study demonstrates a high-performance automatic segmentation model for lumbar X-ray images, which overcomes noise such as spinal fractures and implants. Furthermore, we can perform accurate measurement of bone density on lumbar X-ray images using an automatic segmentation methodology for the spine, which can prevent the risk of compression fractures at an early stage and improve the accuracy and efficiency of osteoporosis diagnosis.

• Korean Journal of Radiology
• /
• 제22권11호
• /
• pp.1850-1857
• /
• 2021

Objective: The purpose of this study was to assess whether a deep learning (DL) algorithm could enable simultaneous noise reduction and edge sharpening in low-dose lumbar spine CT. Materials and Methods: This retrospective study included 52 patients (26 male and 26 female; median age, 60.5 years) who had undergone CT-guided lumbar bone biopsy between October 2015 and April 2020. Initial 100-mAs survey images and 50-mAs intraprocedural images were reconstructed by filtered back projection. Denoising was performed using a vendor-agnostic DL model (ClariCT.AI^TM, ClariPI) for the 50-mAS images, and the 50-mAs, denoised 50-mAs, and 100-mAs CT images were compared. Noise, signal-to-noise ratio (SNR), and edge rise distance (ERD) for image sharpness were measured. The data were summarized as the mean ± standard deviation for these parameters. Two musculoskeletal radiologists assessed the visibility of the normal anatomical structures. Results: Noise was lower in the denoised 50-mAs images (36.38 ± 7.03 Hounsfield unit [HU]) than the 50-mAs (93.33 ± 25.36 HU) and 100-mAs (63.33 ± 16.09 HU) images (p < 0.001). The SNRs for the images in descending order were as follows: denoised 50-mAs (1.46 ± 0.54), 100-mAs (0.99 ± 0.34), and 50-mAs (0.58 ± 0.18) images (p < 0.001). The denoised 50-mAs images had better edge sharpness than the 100-mAs images at the vertebral body (ERD; 0.94 ± 0.2 mm vs. 1.05 ± 0.24 mm, p = 0.036) and the psoas (ERD; 0.42 ± 0.09 mm vs. 0.50 ± 0.12 mm, p = 0.002). The denoised 50-mAs images significantly improved the visualization of the normal anatomical structures (p < 0.001). Conclusion: DL-based reconstruction may enable simultaneous noise reduction and improvement in image quality with the preservation of edge sharpness on low-dose lumbar spine CT. Investigations on further radiation dose reduction and the clinical applicability of this technique are warranted.

• 대한수의학회지
• /
• 제62권1호
• /
• pp.8.1-8.6
• /
• 2022

The aim of this prospective study was to investigate the effects of focal spot size of X-ray tube on sharpness of clinical radiographic images of dogs and cats. Radiographic images of 24 stifle joints, 15 carpi, 18 lumbar spines, 61 thoraxes, and 47 abdomens of 102 dogs and 4 cats were obtained in the present study, using 2 X-ray tubes with nominal focal spots of 2.0 mm and 0.6 mm, respectively. The sharpness of specific anatomical structures in all the images of 5 projections was assessed. The radiographic sharpness of various anatomical structures of lumbar spine and cortex of stifle with fine focal spot was increased significantly compared with broad focal spot images. In addition, the blurred motion was significantly higher in the fine focal spot images of thorax. In conclusion, our study suggests that a selective use of fine foci for imaging of lumbar spine or cortex of stifle enhanced radiographic sharpness.

• Imaging Science in Dentistry
• /
• 제32권3호
• /
• pp.135-139
• /
• 2002

Purpose: To determine the proper reference step wedge for digital Cu-Equivalent Image analyzing systems for measurement of bone density. Meterials and Methods : Radiograms of lumbar vertebrae phantom (1g/㎠) with 3 test copper step wedges of 0.03, 0.05 and, 0.1 mm thickness unit were taken and analyzed using NIH image software on a Macintosh personal computer. Measured densities of the lumbar areas in the Cu-Equivalent images made by utilizing 3 different copper stepwedges were compared with a known bone density. Results: The values of r2 for all copper equivalent images were over 0.99. The mean Cu-Eq value of lumbar in copper equivalent image made by a 0.1 mm copper stepwedge was 0.22 ± 0.06 mm and converted to hydroxyapatite density of 1.03 g/㎠. The stepwedges of 0.03 and 0.05 mm produced results having higher values than the actual known bone density. They did not show the blue and green color level that appeared in lumbar on color enhanced image. Conclusion : A copper stepwedge of adequate thickness and range of steps which can express the range of density of bone being measured should be used.

• Journal of Korean Neurosurgical Society
• /
• 제29권5호
• /
• pp.623-627
• /
• 2000

Objective : Spontaneous lumbar epidural hematoma is a rare entity, although the precipitating factors such as anticoagulation therapy frequently precede it. The authors report four cases of surgically confirmed spontaneous epidural hematoma mimicking lumbar disc herniation. Methods : Between 1995 and 1998, four patients with spontaneous lumbar epidural hematoma were diagnosed. The clinical findings which are identical to that of acute disc herniation are included in this study. The operative findings and radiological characteristics are also included. Results : The magnetic resonance(MR) image findings demonstrated epidural lesions of intermediate to low signal intensity equivalent to those of normal discs on $T_1$-weighted images, and epidural lesions of high signal intensity higher than these normal discs on a $T_2$-weighted image. The image findings also showed rim enhanced pattern of the gadolinium-enhanced $T_1$-weighted MR images. All of the hematomas was associated with a small concomitant disc herniation or underlying annular tear. Conclusion : The authors speculate that spontaneous lumbar epidural hematoma results from tearing of the fragile penetrating vein caused by underlying disc or annulus disruption between Batson' plexus and vertebral body.

• Journal of Korean Neurosurgical Society
• /
• 제60권4호
• /
• pp.465-470
• /
• 2017

Objective : Magnetic resonance imaging (MRI) grading systems using sagittal images are useful for evaluation of lumbar foraminal stenosis. We evaluated whether such a grading system is useful as a diagnostic tool for surgery. Methods : Between July 2014 and June 2015, 99 consecutive patients underwent unilateral lumbar foraminotomy for lumbar foraminal stenosis. Surgically confirmed foraminal stenosis and the contralateral, asymptomatic neuroforamen were assessed based on a 4-point MRI grading system. Two experienced researchers independently evaluated the MR sagittal images. Interobserver agreement and intraobserver agreement were analyzed using ${\kappa}$ statistics. Results : The mean age of patients (54 women, 45 men) was 62.5 years. A total of 101 levels (202 neuroforamens) were evaluated. MRI grades for operated neuroforamens were as follows : Grade 0 in 0.99%, Grade 1 in 5.28%, Grade 2 in 14.85%, and Grade 3 in 78.88%. Interobserver agreement was moderate for operated neuroforamens (${\kappa}=0.511$) and good for asymptomatic neuroforamens (${\kappa}=0.696$). Intraobserver agreement by reader 1 for operated neuroforamens was good (${\kappa}=0.776$) and that for asymptomatic neuroforamens was very good (${\kappa}=0.831$). In terms of lumbar level, interobserver agreement for L5-S1 (${\kappa}=0.313$, fair) was relatively lower than the other level (${\kappa}=0.804$, very good). Conclusion : MRI grading system for lumbar foraminal stenosis is thought to be useful as a diagnostic tool for surgery in the lumbar spine; however, it is less reliable for symptomatic L5-S1 foraminal stenosis than for other levels. Thus, various clinical factors as well as the MRI grading system are required for surgical decision-making.

• 한국방사선학회논문지
• /
• 제15권6호
• /
• pp.927-933
• /
• 2021

본 연구에서는 mDixon 기법과 T2 TSE, T2 SPIR 기법을 비교하여 3번 허리뼈 체부, 등 지방, 척수, 뇌척수액 위치에서 검사 시간, 신호대잡음비, 대조도대잡음비의 차이를 알아보고자 하였다. 성인 30명을 대상으로 신호대잡음비에 영향 인자를 고정하고 요추 시상면을 mDixon검사와 T2 TSE, T2 SPIR 검사를 한 후 비교하였다. mDixon의 검사 시간은 115초, T2 TSE는 60초, T2 SPIR는 60초였다. mDixon T2영상은 T2 TSE 영상보다 3번 허리뼈 체부에서 신호대잡음비가 높았고, 등 지방과 뇌척수액에서는 SNR이 낮았으며(p<0.05), 척수에서는 비슷한 신호대잡음비을 가졌다(p>0.05). 3번 허리뼈 체부와 등 지방의 대조도대잡음비는 mDixon T2영상이 높았으며, 뇌척수액과 척수의 대조도대잡음비는 T2 TSE가 높았다(p<0.05). mDixon T2 FS영상은 T2 SPIR영상보다 3번 허리뼈 체부, 등 지방에서 낮았고, 척수, 뇌척수액에서는 높았다(p<0.05). 3번 허리뼈 체부와 등 지방의 대조도대잡음비는 mDixon T2 FS영상이 높았으며(p<0.05), 뇌척수액과 척수의 대조도 대잡음비는 두 영상이 차이가 없었다(p>0.05). mDixon 기법이 기존의 T2 TSE, T2 SPIR 기법에 비해 검사 시간, 각 부위의 신호대잡음비, 대조도대잡음비에서 보다 우수한 영상이라 하기 어려웠다. 하지만 본 연구는 단순 요추통증환자를 대상으로 제한하였다는 한계로, 기존의 연구에서 보고된 금속물 삽입, 척추 종양, 골절 환자 등 특정 환자군의 설정을 통한 추가 연구들이 필요할 것으로 사료된다.

• Investigative Magnetic Resonance Imaging
• /
• 제21권1호
• /
• pp.28-33
• /
• 2017

Purpose: To investigate and compensate the effects of respiration-induced B0 variations on fat quantification of the bone marrow in the lumbar spine. Materials and Methods: Multi-echo gradient echo images with navigator echoes were obtained from eight healthy volunteers at 3T clinical scanner. Using navigator echo data, respiration-induced B0 variations were measured and compensated. Fat fraction maps were estimated using $T2^*$-IDEAL algorithm from the uncompensated and compensated images. For manually drawn bone marrow regions, the estimated B0 variations and the calculated fat fractions (before and after compensations) were analyzed. Results: An increase of temporal B0 variations from inferior level to superior levels was observed for all subjects. After compensation using navigator echo data, the effects of the B0 variations were reduced in gradient echo images. The calculated fat fractions show significant differences (P < 0.05) in L1 and L3 between the uncompensated and the compensated. Conclusion: The results of this study raise the need for considering respiration-induced B0 variations for accurate fat quantification using gradient echo images in the lumbar spine. The use of navigator echo data can be an effective way for the reduction of the effects of respiratory motion on the quantification.