Tumor Margin Infiltration in Soft Tissue Sarcomas: Prediction Using 3T MRI Texture Analysis

Purpose@#To determine the value of 3 Tesla (T) MRI texture analysis for predicting tumor margin infiltration in soft tissue sarcomas. @*Materials and Methods@#Thirty-one patients who underwent 3T MRI and had a pathologically confirmed diagnosis of soft tissue sarcoma were included in this study. Margin infiltration on pathology was used as the gold standard. Texture analysis of soft tissue sarcomas was performed on axial T1-weighted images (WI) and T2WI, fat-suppressed contrast-enhanced (CE) T1WI, diffusion-weighted images (DWI) with b-value of 800 s/mm², and apparent diffusion coefficient (ADC) was mapped. Quantitative parameters were compared between sarcomas with infiltrative margins and those with circumscribed margins. @*Results@#Among the 31 patients with soft tissue sarcomas, 23 showed tumor margin infiltration on pathology. There were significant differences in kurtosis with the spatial scaling factor (SSF) of 0 and 6 on T1WI, kurtosis (SSF, 0) on CE-T1WI, skewness (SSF, 0) on DWI, and skewness (SSF, 2, 4) on ADC between sarcomas with infiltrative margins and those with circumscribed margins (p ≤ 0.046). The area under the receiver operating characteristic curve based on MR texture features for identification of infiltrative tumor margins was 0.951 (p < 0.001). @*Conclusion@#MR texture analysis is reliable and accurate for the prediction of infiltrative margins of soft tissue sarcomas.

Benign versus Malignant Soft-Tissue Tumors: Differentiation with 3T Magnetic Resonance Image Textural Analysis Including Diffusion-Weighted Imaging

Purpose@#To investigate the value of MR textural analysis, including use of diffusionweighted imaging (DWI) to differentiate malignant from benign soft-tissue tumors on 3T MRI. @*Materials and Methods@#We enrolled 69 patients (25 men, 44 women, ages 18 to 84 years) with pathologically confirmed soft-tissue tumors (29 benign, 40 malignant) who underwent pre-treatment 3T-MRI. We calculated MR texture, including mean, standard deviation (SD), skewness, kurtosis, mean of positive pixels (MPP), and entropy, according to different spatial-scale factors (SSF, 0, 2, 4, 6) on axial T1-and T2-weighted images (T1WI, T2WI), contrast-enhanced T1WI (CE-T1WI), high b-value DWI (800 sec/mm2 ), and apparent diffusion coefficient (ADC) map. We used the Mann-Whitney U test, logistic regression, and area under the receiver operating characteristic curve (AUC) for statistical analysis. @*Results@#Malignant soft-tissue tumors had significantly lower mean values of DWI, ADC, T2WI and CE-T1WI, MPP of ADC, and CE-T1WI, but significantly higher kurtosis of DWI, T1WI, and CE-T1WI, and entropy of DWI, ADC, and T2WI than did benign tumors (P < 0.050). In multivariate logistic regression, the mean ADC value (SSF, 6) and kurtosis of CE-T1WI (SSF, 4) were independently associated with malignancy (P ≤ 0.009). A multivariate model of MR features worked well for diagnosis of malignant soft-tissue tumors (AUC, 0.909). @*Conclusion@#Accurate diagnosis could be obtained using MR textural analysis with DWI and CE-T1WI in differentiating benign from malignant soft-tissue tumors.

Benign versus Malignant Soft-Tissue Tumors: Differentiation with 3T Magnetic Resonance Image Textural Analysis Including Diffusion-Weighted Imaging

Purpose@#To investigate the value of MR textural analysis, including use of diffusionweighted imaging (DWI) to differentiate malignant from benign soft-tissue tumors on 3T MRI. @*Materials and Methods@#We enrolled 69 patients (25 men, 44 women, ages 18 to 84 years) with pathologically confirmed soft-tissue tumors (29 benign, 40 malignant) who underwent pre-treatment 3T-MRI. We calculated MR texture, including mean, standard deviation (SD), skewness, kurtosis, mean of positive pixels (MPP), and entropy, according to different spatial-scale factors (SSF, 0, 2, 4, 6) on axial T1-and T2-weighted images (T1WI, T2WI), contrast-enhanced T1WI (CE-T1WI), high b-value DWI (800 sec/mm2 ), and apparent diffusion coefficient (ADC) map. We used the Mann-Whitney U test, logistic regression, and area under the receiver operating characteristic curve (AUC) for statistical analysis. @*Results@#Malignant soft-tissue tumors had significantly lower mean values of DWI, ADC, T2WI and CE-T1WI, MPP of ADC, and CE-T1WI, but significantly higher kurtosis of DWI, T1WI, and CE-T1WI, and entropy of DWI, ADC, and T2WI than did benign tumors (P < 0.050). In multivariate logistic regression, the mean ADC value (SSF, 6) and kurtosis of CE-T1WI (SSF, 4) were independently associated with malignancy (P ≤ 0.009). A multivariate model of MR features worked well for diagnosis of malignant soft-tissue tumors (AUC, 0.909). @*Conclusion@#Accurate diagnosis could be obtained using MR textural analysis with DWI and CE-T1WI in differentiating benign from malignant soft-tissue tumors.

Diagnosis of Rotator Cuff Tears with Non-Arthrographic MR Imaging: 3D Fat-Suppressed Isotropic Intermediate-Weighted Turbo Spin-Echo Sequence versus Conventional 2D Sequences at 3T

PURPOSE: To assess the diagnostic performance in detecting rotator cuff tears at 3T of non-arthrographic shoulder magnetic resonance imaging (MRI) using 3D isotropic turbo spin-echo (TSE-SPACE) sequence as compared with 2D sequences. MATERIALS AND METHODS: Seventy-four patients who were arthroscopically confirmed to have underwent non-arthrographic shoulder MRI with 2D sequences and TSE-SPACE were included. Three independent readers retrospectively scored supraspinatus and infraspinatus tendon (SST-IST) and subscapularis tendon (SCT) tears on 2D sequences and TSE-SPACE. RESULTS: The mean sensitivity, specificity, and accuracy of the three readers were 95%, 100%, and 95% on TSE-SPACE and 99%, 93%, and 98% on 2D sequences for detecting SST-IST tears, respectively, whereas those were 87%, 49%, and 68% on TSE-SPACE and 88%, 66%, and 77% on 2D sequences for detecting SCT tears, respectively. There was no statistical difference between the two sequences, except for in the specificity of one reader for detecting SCT tears. The mean AUCs of the three readers on TSE-SPACE and 2D sequences were 0.96 and 0.98 for detecting SST-IST tears, respectively, which were not significantly different, while those were 0.71 and 0.82 for detecting SCT tears, respectively, which were significantly different (P < 0.05). CONCLUSION: TSE-SPACE may have accuracy and reliability comparable to conventional 2D sequences for SST-IST tears at non-arthrographic 3T shoulder MRI, whereas TSE-SPACE was less reliable than conventional 2D sequences for detecting SCT tears.

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.

MR Findings of the Osteofibrous Dysplasia

OBJECTIVE: The aim of this study was to describe MR findings of osteofibrous dysplasia. MATERIALS AND METHODS: MR images of 24 pathologically proven osteofibrous dysplasia cases were retrospectively analyzed for a signal intensity of the lesion, presence of intralesional fat signal, internal hypointense band, multilocular appearance, cortical expansion, intramedullary extension, cystic area, cortical breakage and extraosseous extension, abnormal signal from the adjacent bone marrow and soft tissue and patterns of contrast enhancement. RESULTS: All cases of osteofibrous dysplasia exhibited intermediate signal intensity on T1-weighted images. On T2-weighted images, 20 and 4 cases exhibited heterogeneously intermediate and high signal intensity, respectively. Intralesional fat was identified in 12% of the cases. Internal low-signal bands and multilocular appearance were observed in 91%. Cortical expansion was present in 58%. Intramedullary extension was present in all cases, and an entire intramedullary replacement was observed in 33%. Cortical breakage (n = 3) and extraosseous mass formation (n = 1) were observed in cases with pathologic fractures only. A cystic area was observed in one case. Among 21 cases without a pathologic fracture, abnormal signal intensity in the surrounding bone marrow and adjacent soft tissue was observed in 43% and 48%, respectively. All cases exhibited diffuse contrast enhancement. CONCLUSION: Osteofibrous dysplasia exhibited diverse imaging features ranging from lesions confined to the cortex to more aggressive lesions with complete intramedullary involvement or perilesional marrow edema.

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.

Role of MRI and Plain Radiograph to Diagnose Fibrous Dysplasia Mimicking Metastasis on PET/CT in a Patient with Breast Cancer / 대한골관절종양학회지

Fibrous dysplasia is a common benign disorder of bone in which normal bone marrow is replaced with fibro-osseous tissue. As PET/CT is increasingly used for the staging of different malignant disease, incidentally found fibrous dysplasia with increased FDG uptake may mimic metastasis. We report on a 46-year-old woman with fibrous dysplasia who underwent PET/CT because of suspected recurrence of breast cancer and was misdiagnosed as a bony metastasis with a focal FDG uptake on left proximal femur. This lesion was interpreted as fibrous dysplasia based on MRI in addition to the plain radiographs. We conclude that MRI in addition to radiography may help to differentiate fibrous dysplasia mimicking metastasis on PET/CT in the patients with malignancy.

MR Imaging of Ankylosing Spondylitis / 대한류마티스학회지

Magnetic resonance imaging (MRI) is a highly reliable tool for diagnosing ankylosing spondylitis. MRI can identify cartilage abnormalities, subcortical erosions, bone marrow edema with inflammation, and synovial enhancement. Subchondral sclerosis and juxta-articular fat deposition are noted in the chronic stage of ankylosing spondylitis. Spinal changes associated with spondyloarthropathy are florid anterior spondylitis (or Romanus lesion), florid diskitis (Anderson lesion), ankylosis, and arthritis of the apophyseal and costovertebral joints. A MRI grading system for inflammation in sacroiliac joints and the spine could help clinicians evaluate the anti-inflammatory efficacy of therapeutics. Newer technologies based on MRI are aimed at broadening the diagnostic scope and facilitating the quantification of active inflammation but still require extensive validation.

Ultrasound and MR Findings of Aleukemic Leukemia Cutis in a Patient with Complete Remission of Acute Lymphoblastic Leukemia: A Case Report

Aleukemic leukemia cutis is an extremely rare condition characterized by the infiltration of leukemic cells in skin without blasts in the peripheral blood. Leukemia cutis is considered a grave prognostic sign, thus early diagnosis is important. Leukemia cutis usually occurs in patients with myeloid leukemia. To the best of our knowledge, there has been no report regarding the radiological findings of aleukemic leukemia cutis, which is probably due to the presence of the skin changes in most patients. We report the ultrasound and MR findings of aleukemic leukemia cutis, even without the skin manifestation in patients with a history of complete remission of the acute lymphoblastic leukemia following an allogeneic peripheral blood stem cell transplantation.

Thoracic Intramedullary Schwannoma Aggravated on Follow-up MRI: Case Report and Review of the Literature

Schwannoma is a rare intramedullary tumor. There has been no reported case about interval aggravation on follow-up MR imaging. We report initial and follow-up MR findings of a thoracic intramedullary schwannoma with syringomyelia and edema in a patient without neurofibromatosis. Intramedullary schwannoma should be included for differential diagnosis of intramedullary tumor even though followup MR imaging shows interval increase in size of the tumor and extent of associated edema to mimic malignancy.

Granulocytic Sarcoma in the Leg Mimicking Hemorrhagic Abscess

Granulocytic sarcoma is a rare extramedullary tumor composed of immature granulocytic precursors. Usually, granulocytic sarcoma is seen in association with acute myeloid leukemia, or other myeloproliferative disorders. Rarely, it may manifest as a primary presentation before the onset of systemic disease in acute myeloid leukemia. The clinical suspicion of granulocytic sarcoma based on imaging findings is important for the management of the patient especially when systemic disease of acute myeloid leukemia is not confirmed as in our case. We report the MR findings of a granulocytic sarcoma in the left leg mimicking hemorrhagic abscess in a patient with acute myeloid leukemia. We believe that MRI can be a helpful diagnostic method of making a differential diagnosis of granulocytic sarcoma in a patient with leukemia, and this can be done by analyzing the signal intensity and the enhancement pattern.

Necrotizing Fasciitis versus Pyomyositis: Discrimination with Using MR Imaging

OBJECTIVE: We wanted to evaluate the MR findings for differentiating between necrotizing fasciitis (NF) and pyomyositis (PM). MATERIALS AND METHODS: The MR images of 19 patients with surgically confirmed NF (n = 11) and pathologically confirmed PM (n = 8) were retrospectively reviewed with regard to the presence or absence of any MRI finding criteria that could differentiate between them. RESULTS: The patients with NF had a significantly greater prevalence of the following MR findings (p < 0.05): a peripheral band-like hyperintense signal in muscles on fat-suppressed T2-weighted images (73% of the patients with NF vs. 0% of the patients with PM), peripheral band-like contrast enhancement (CE) of muscles (82% vs. 0%, respectively) and thin smooth enhancement of the deep fascia (82% vs. 13%, respectively). The patients with PM had a significantly greater prevalence of the following MRI findings (p < 0.05): a diffuse hyperintense signal in muscles on fat-suppressed T2-weighted images (27% of the patients with NF vs. 100% in the patients with PM), diffuse CE of muscles (18% vs. 100%, respectively), thick irregular enhancement of the deep fascia (0% vs. 75%, respectively) and intramuscular abscess (0% vs. 88%, respectively). For all patients with NF and PM, the superficial fascia and muscle showed hyperintense signals on T2-weighted images and CE was seen on fat-suppressed CE T1-weighted images. The subcutaneous tissue and deep fascia showed hyperintense signals on T2-weighted images and CE was seen in all the patients with NF and in seven (88%) of the eight patients with PM, respectively. CONCLUSION: MR imaging is helpful for differentiating between NF and PM.

Initial Plain Radiographs versus MR Imaging: Comparison of Prognostic Efficacy in Legg-Calve-Perthes Disease

PURPOSE: To evaluate if at the time of diagnosis of Legg-Calve-Perthes disease, MR imaging is superior to radiographs for identifying patients with a favorable long term prognosis as determined by maintenance of a spherical configuration of the femoral head epiphysis on follow-up radiographs. MATERIALS AND METHODS: We retrospectively analyzed plain radiographs and MR images of 48 femoral heads in 41 patients with Legg-Calve-Perthes disease at time of diagnosis. Femoral head involvement was estimated on initial plain radiographs and MR images using the Catterall classification. Prognosis as determined by maximum femoral head deformity was determined on follow-up radiographs evaluated according to Stulberg classification. RESULTS: Catterall classification of greater than 1 at MR imaging had 100% sensitivity (14/14) for detecting patients with a poor prognosis as indicated by deformity of the femoral head on follow-up radiographs (Stulberg class > 2). Initial radiographs had a lower sensitivity of 57% (8/14) for detecting patients with poor prognosis. Specificity for MR imaging was 21% (7/34) which was not significantly different from 32% (11/34) specificity for initial radiographs. CONCLUSION: Catterall group 1 at initial MR imaging indicates favorable prognosis for Legg-Calve-Perthes disease. Patients with more extensive involvement of the femoral head can have a good outcome, however they are at risk for loss of spherical configuration of the femoral head and subsequent osteoarthritis in adulthood. MR imaging may be superior to radiographs for identifying a subgroup of patients with favorable prognosis.

Aspergillus Spondylitis involving the Cervico-Thoraco-Lumbar Spine in an Immunocompromised Patient: a Case Report

Aspergillosis is a rare cause of spondylitis. Moreover, early diagnosis by MR imaging and adequate treatment can prevent the serious complications of fungal infection. To our knowledge, the MR findings of multilevel aspergillus spondylitis in the cervico-thoraco-lumbar spine have not been previously described. Here, we report the MR findings of aspergillus spondylitis involving the cervical, thoracic, and lumbar spine in a liver transplant recipient.

Fracture of Ossification of the Yellow Ligament Causing Thoracic Myelopathy: A Case Report / 대한척추외과학회지

Ossification of the yellow ligament (OYL) is a rare disease that causes myeloradiculopathy at the thoracic spine. The advances in radiographic imaging techniques have made a diagnosis of this pathological entity relatively simple. Surgical decompression and excision of the OYL is the treatment of choice if there are neurological complications from the OYL. We describe a 50-yearold male with thoracic myelopathy caused by a fractured OYL at T10-11, and suggest possible mechanism of the fracture of the OYL at the thoracolumbar spine.

Fat-suppressed 3D SPGR MR Imaging of Articular Cartilage Lesion of Medial Femoral Condyle in Osteoarthritic Knee / 대한정형외과학회잡지

PURPOSE: To evaluate the efficacy of sagittal fat-suppressed 3D SPGR MR imaging of the osteoarthritic medial femoral condyle in terms of extent and degree of a focal articular cartilage defect of the knee. MATERIALS AND METHODS: The MRI findings (Disler scale) of normal and osteoarthritic medial femoral condyles from 112 knees were prospectively compared with the arthroscopic findings (Jackson staging). The arthroscopic findings were normal in 10 cases, stage I in 26 cases, stage II in 36 cases, stage III in 21 cases and stage IV in 19 cases on arthroscopy. RESULTS: All 10 cases arthroscopy findings were grade 0 in MRI. Among the 26 knees in arthroscopic stage I, only 11 knees (42.3%) showed surface irregularities on MRI that were consistent with grade 1, otherwise grade 2. All cases of arthroscopic stage II showed grade 2 or grade 3. Stage III was grade 3 in all cases on MRI. Among the 19 knees in arthroscopic stage IV, 16 knees (84.2%) with a large defect showed grade 4 on MRI. The sensitivity, specificity and accuracy of the MRI compared with the arthroscopic findings was 97%, 100% and 97.3%, respectively. The weighted kappa index was 0.7194 and the SE (standard error) was 0.053, suggesting significant consistency. CONCLUSION: The sagittal fat-suppressed 3D SPGR MR imaging is valuable for determining the extent and degree of the articular cartilage lesion of the medial femoral condyle in an osteoarthritic knee.

Angioleiomyoma Presenting as Painless Prepatellar Mass / 대한류마티스학회지

No abstract available.

The Usefulness of MRI in Evaluating the Shoulder Injury / 대한정형외과학회잡지

PURPOSE: The purpose of this study was to evaluate the accuracy and the usefulness of MRI in patients with shoulder injuries. MATERIALS AND METHODS: The sensitivity and the accuracy of MRI in the diagnosis of various lesion were evaluated in 20 patients with shoulder injuries. RESULTS: MRI enabled Bankart lesions and SLAP lesions to be accurately predicted with 100% sensitivity and 90% accuracy in both. However, for types of SLAP lesions, the sensitivity and the accuracy were 60% and 70%, respectively, and for full-thickness or partial-thickness tear of rotator cuff, the sensitivity and the accuracy were 75% in both. MRI was also effective at predicting rotator cuff tear with 100% sensitivity and 95% accuracy. Sensitivity and accuracy for the diagnosis of Hill-Sachs lesion were 91.7% and 90%, respectively. For all lesions except Hill-Sachs lesion, the negative prediction value was higher than the positive prediction value, which means MRI overestimated the lesions. CONCLUSION: MRI was accurate and useful in the prediction of prediction of rotator cuff tear, labral tear and Hill-Sachs lesions. However, for the identification of full-thickness or partial-thickness tear of rotator cuff, and types of SLAP lesions, it was less accurate and less useful.

Correlation between Tenderness &MR Findings in Patellofemoral Joint / 대한정형외과학회잡지

PURPOSE: To investigate the relationship between tenderness and the MR findings of patellofemoral articular cartilage abnormalities. MATERIALS AND METHODS: We investigated 64 patients, 70 knee joints, who had symptoms of knee pain. We evaluated the correlation between the tenderness and the MR grades at each tender point of the patellar and calculated the sensitivity, specificity and accuracy of the tenderness on the basis of MR imaging. RESULTS: The sensitivity, specificity and accuracy of the tenderness were 49.0% (99/202), 83.8% (279/333), 70.6% (378/535), respectively. The tenderness and the MR grades were moderately correlated in the patellofemoral joint as a whole (r=0.41, p<0.01), and tenderness was substantially correlated with MR grade in the femoral trochlear articular surface (r=0.33, p<0.01) and moderately correlated in the patellar articular surface (r=0.47, p<0.01) with MR grades. CONCLUSION: That of tenderness represents the condition of the articular cartilage of the patellar better than that of the femoral trochlear.