Joon-Yong Jung

Meniscal Tear Configurations: Categorization With 3D Isotropic Turbo Spin-Echo MRI Compared With Conventional MRI at 3 T

OBJECTIVE The purpose of our study was to compare the accuracy of 3D fat-suppressed isotropic turbo spin-echo (TSE) sequences using sampling perfection with application-optimized contrasts using different flip angle evolution (SPACE) with 2D conventional MRI at 3 T in determining meniscal tear types. MATERIALS AND METHODS Sixty-nine patients with arthroscopically confirmed meniscal tears underwent MRI with 2D sequences and 3D TSE SPACE. Images were retrospectively analyzed by two reviewers and correlated with arthroscopic findings. Meniscal tears were classified into one of eight types: horizontal, longitudinal, radial, root, flap, oblique, complex, and bucket-handle. For every type of tear, sensitivity, specificity, and interobserver agreement were calculated. RESULTS Mean sensitivities and specificities on 3D TSE SPACE versus 2D sequences were as follows: for radial tears, 77% and 93% versus 68% and 90%; for flap tears, 73% and 96% versus 54% and 85%; for horizontal tears, 85% and 91% versus 78% versus 87%; for longitudinal tears, 50% and 97% versus 72% and 96%; and for root tears, 88% and 99% versus 81% and 99%. The specificity for flap tears was statistically higher on 3D TSE SPACE than 2D sequences. Interobserver agreements were higher on 3D TSE SPACE than 2D sequences for radial, flap, and longitudinal tears. CONCLUSION In categorizing meniscal tears, 3D TSE SPACE has higher specificity for flap tears than 2D conventional sequences. However, there is no significant difference between 2D conventional sequences and 3D TSE SPACE except for flap tears.

Differentiation of Acute Osteoporotic and Malignant Compression Fractures of the Spine: Use of Additive Qualitative and Quantitative Axial Diffusion-weighted MR Imaging to Conventional MR Imaging at 3.0 T

PURPOSE To retrospectively determine the value of adding qualitative and quantitative axial diffusion-weighted (DW) imaging to standard spine magnetic resonance (MR) imaging to differentiate between acute osteoporotic and malignant compression fractures at 3.0 T. MATERIALS AND METHODS The institutional ethics committee approved this retrospective study and waived the requirement to obtain informed consent. The authors retrospectively analyzed 3.0-T MR images, including DW images (b values: 0, 800, and 1400 sec/mm(2)), in 62 patients with acute compression fractures. Three radiologists independently interpreted MR images for the presence of malignancy by using conventional MR images alone and in combination with axial DW images with qualitative and quantitative analysis. Apparent diffusion coefficients (ADCs) were measured within solid portion with careful use of a small region of interest (ROI). The Mann-Whitney U test was performed. RESULTS There were 30 malignant and 32 acute osteoporotic compression fractures. At qualitative analysis, hyperintensity relative to spinal cord was more frequent in malignant compression fractures than in acute osteoporotic compression fractures (87% vs 22%, respectively; P < .001). Median ADCs of malignant fractures were significantly lower than those of benign fractures (P < .001). With conventional MR imaging alone, sensitivity, specificity, and accuracy were 100%, 94%, and 97%, respectively, for reader 1; 97%, 78%, and 87% for reader 2; and 100%, 84%, and 92% for reader 3. With conventional and DW MR imaging combined, sensitivity, specificity, and accuracy were 100%, 97%, and 98% for all three readers. The addition of DW imaging led to correct changes in diagnosis: Reader 1 improved by 1.6% (one of 62 fractures), reader 2 improved by 11% (seven of 62 fractures), and reader 3 improved by 6.5% (four of 62 fractures). CONCLUSION The addition of axial DW imaging to a conventional MR imaging protocol improved diagnostic accuracy in the differentiation of acute osteoporotic from malignant compression fractures by measuring ADCs in the solid portion with careful use of a small ROI.

Magnetic resonance arthrography including aber view in diagnosing partial-thickness tears of the rotator cuff: Accuracy, and inter- and intra-observer agreements

Background: Partial-thickness tear of the rotator cuff is a common cause of shoulder pain. Magnetic resonance (MR) arthrography has been described as a useful measure to diagnose rotator cuff abnormalities. Purpose: To determine the reliability and accuracy of MR arthrography with abduction and external rotation (ABER) view for the diagnosis of partial-thickness tears of the rotator cuff. Material and Methods: Among patients who underwent MR arthrographies, 22 patients (12 men, 10 women; mean age 45 years) who had either partial-thickness tear or normal tendon on arthroscopy were included. MR images were independently scored by two observers for partial-thickness tears of the rotator cuff. Interobserver and intraobserver agreements for detection of partial-thickness tears of the rotator cuff were calculated by using κ coefficients. The differences in areas under the receiver operating characteristic (ROC) curves were assessed with a univariate Z-score test. Differences in sensitivity and specificity for interpretations based on different imaging series were tested for significance using the McNemar statistic. Results: Sensitivity, specificity, and accuracy of each reader on MR imaging without ABER view were 83%, 90%, and 86%, and 83%, 80%, and 82%, respectively, whereas on overall interpretation including ABER view, the sensitivity, specificity, and accuracy of each reader were 92%, 70%, and 82%, and 92%, 80%, and 86%, respectively. Including ABER view, interobserver agreement for partial-thickness tear increased from κ=0.55 to κ=0.68. Likewise, intraobserver agreements increased from κ=0.79 and 0.53 to κ=0.81 and 0.70 for each reader, respectively. The areas under the ROC curves for each reader were 0.96 and 0.90, which were not significantly different. Conclusion: Including ABER view in routine sequences of MR arthrography increases the sensitivity, and inter- and intraobserver agreements for detecting partial-thickness tear of rotator cuff tendon.

MRI of the lumbar spine: comparison of 3D isotropic turbo spin-echo SPACE sequence versus conventional 2D sequences at 3.0 T

Background Three-dimensional (3D) fast spin-echo sequence with variable flip-angle refocusing pulse allows retrospective alignments of magnetic resonance imaging (MRI) in any desired plane. Purpose To compare isotropic 3D T2-weighted (T2W) turbo spin-echo sequence (TSE-SPACE) with standard two-dimensional (2D) T2W TSE imaging for evaluating lumbar spine pathology at 3.0 T MRI. Material and Methods Forty-two patients who had spine surgery for disk herniation and had 3.0 T spine MRI were included in this study. In addition to standard 2D T2W TSE imaging, sagittal 3D T2W TSE-SPACE was obtained to produce multiplanar (MPR) images. Each set of MR images from 3D T2W TSE and 2D TSE-SPACE were independently scored for the degree of lumbar neural foraminal stenosis, central spinal stenosis, and nerve compression by two reviewers. These scores were compared with operative findings and the sensitivities were evaluated by McNemar test. Inter-observer agreements and the correlation with symptoms laterality were assessed with kappa statistics. Results The 3D T2W TSE and 2D TSE-SPACE had similar sensitivity in detecting foraminal stenosis (78.9% versus 78.9% in 32 foramen levels), spinal stenosis (100% versus 100% in 42 spinal levels), and nerve compression (92.9% versus 81.8% in 59 spinal nerves). The inter-observer agreements (κ = 0.849 vs. 0.451 for foraminal stenosis, κ = 0.809 vs. 0.503 for spinal stenosis, and κ = 0.681 vs. 0.429 for nerve compression) and symptoms correlation (κ = 0.449 vs. κ = 0.242) were better in 3D TSE-SPACE compared to 2D TSE. 3D TSE-SPACE with oblique coronal MPR images demonstrated better inter-observer agreements compared to 3D TSE-SPACE without oblique coronal MPR images (κ = 0.930 vs. κ = 0.681). Conclusion Isotropic 3D T2W TSE-SPACE at 3.0 T was comparable to 2D T2W TSE for detecting foraminal stenosis, central spinal stenosis, and nerve compression with better inter-observer agreements and symptom correlation.

Preliminary Experience Using Dynamic MRI at 3.0 Tesla for Evaluation of Soft Tissue Tumors

Objective We aimed to evaluate the use of dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) at 3.0 T for differentiating the benign from malignant soft tissue tumors. Also we aimed to assess whether the shorter length of DCE-MRI protocols are adequate, and to evaluate the effect of temporal resolution. Materials and Methods Dynamic contrast-enhanced magnetic resonance imaging, at 3.0 T with a 1 second temporal resolution in 13 patients with pathologically confirmed soft tissue tumors, was analyzed. Visual assessment of time-signal curves, subtraction images, maximal relative enhancement at the first (maximal peak enhancement [Emax]/1) and second (Emax/2) minutes, Emax, steepest slope calculated by using various time intervals (5, 30, 60 seconds), and the start of dynamic enhancement were analyzed. Results The 13 tumors were comprised of seven benign and six malignant soft tissue neoplasms. Washout on time-signal curves was seen on three (50%) malignant tumors and one (14%) benign one. The most discriminating DCE-MRI parameter was the steepest slope calculated, by using at 5-second intervals, followed by Emax/1 and Emax/2. All of the steepest slope values occurred within 2 minutes of the dynamic study. Start of dynamic enhancement did not show a significant difference, but no malignant tumor rendered a value greater than 14 seconds. Conclusion The steepest slope and early relative enhancement have the potential for differentiating benign from malignant soft tissue tumors. Short-length rather than long-length DCE-MRI protocol may be adequate for our purpose. The steepest slope parameters require a short temporal resolution, while maximal peak enhancement parameter may be more optimal for a longer temporal resolution.

Post-traumatic extra-articular osteoid osteoma of the calcaneus following military training

Abstract Osteoid osteoma is a benign bone tumor that causes localized pain that typically increases during the night and is relieved by NSAIDs [1]. It most commonly occurs in the femur and tibia. Only 8% of osteoid osteoma is found in the foot [2]. For that reason, if osteoid osteoma develops in the foot, there may be a delay in diagnosis as it often mimics other, more frequent pathologies. Moreover, if the patient has a history of injury, the initial diagnosis of osteoid ostoema is even more difficult to make [3] as it is natural for the physician to attribute the symptoms to the trauma.

Development of Ontology for the Diseases of Spine

KISTI is carrying out an e-Spine project for spinal diseases to prepare for the aged society, so called NAP.

Differentiation of focal indeterminate marrow abnormalities with multiparametric MRI.

To explore magnetic resonance imaging (MRI) parameters from intravoxel incoherent motion diffusion‐weighted imaging (IVIM‐DWI), multiecho Dixon imaging (ME‐Dixon), and dynamic contrast‐enhanced imaging (DCE) for differentiating focal indeterminate marrow abnormalities

Severe bone marrow edema on sacroiliac joint MRI increases the risk of low BMD in patients with axial spondyloarthritis

To determine the association between inflammatory and structural lesions on sacroiliac joint (SIJ) MRI and BMD and to identify risk factors for low BMD in patients with axial spondyloarthritis (axSpA). Seventy-six patients who fulfilled the ASAS axSpA criteria were enrolled. All underwent SIJ MRI and BMD measurement at the lumbar spine, femoral neck, and total hip. Inflammatory and structural lesions on SIJ MRI were scored. Laboratory tests and assessment of radiographic and disease activity were performed at the time of MRI. The association between SIJ MRI findings and BMD was evaluated. Among the 76 patients, 14 (18%) had low BMD. Patients with low BMD showed significantly higher bone marrow edema (BME) and deep BME scores on MRI than those with normal BMD (p < 0.047 and 0.007, respectively). Inflammatory lesions on SIJ MRI correlated with BMD at the femoral neck and total hip. Multivariate analysis identified the presence of deep BME on SIJ MRI, increased CRP, and sacroiliitis on X-ray as risk factors for low BMD (OR = 5.6, 14.6, and 2.5, respectively). The presence of deep BME on SIJ MRI, increased CRP levels, and severity of sacroiliitis on X-ray were independent risk factors for low BMD.

Diagnosis of Nerve Root Compromise of the Lumbar Spine: Evaluation of the Performance of Three-dimensional Isotropic T2-weighted Turbo Spin-Echo SPACE Sequence at 3T

Objective To explore the performance of three-dimensional (3D) isotropic T2-weighted turbo spin-echo (TSE) sampling perfection with application optimized contrasts using different flip angle evolution (SPACE) sequence on a 3T system, for the evaluation of nerve root compromise by disc herniation or stenosis from central to extraforaminal location of the lumbar spine, when used alone or in combination with conventional two-dimensional (2D) TSE sequence. Materials and Methods Thirty-seven patients who had undergone 3T spine MRI including 2D and 3D sequences, and had subsequent spine surgery for nerve root compromise at a total of 39 nerve levels, were analyzed. A total of 78 nerve roots (48 symptomatic and 30 asymptomatic sites) were graded (0 to 3) using different MRI sets of 2D, 3D (axial plus sagittal), 3D (all planes), and combination of 2D and 3D sequences, with respect to the nerve root compromise caused by posterior disc herniations, lateral recess stenoses, neural foraminal stenoses, or extraforaminal disc herniations; grading was done independently by two readers. Diagnostic performance was compared between different imaging sets using the receiver operating characteristics (ROC) curve analysis. Results There were no statistically significant differences (p = 0.203 to > 0.999) in the ROC curve area between the imaging sets for both readers 1 and 2, except for combined 2D and 3D (0.843) vs. 2D (0.802) for reader 1 (p = 0.035), and combined 2D and 3D (0.820) vs. 3D including all planes (0.765) for reader 2 (p = 0.049). Conclusion The performance of 3D isotropic T2-weighted TSE sequence of the lumbar spine, whether axial plus sagittal images, or all planes of images, was not significantly different from that of 2D TSE sequences, for the evaluation of nerve root compromise of the lumbar spine. Combining 2D and 3D might possibly improve the diagnostic accuracy compared with either one.