Publications (29)60.5 Total impact
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Article: Preliminary experience using dynamic MRI at 3.0 tesla for evaluation of soft tissue tumors.
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ABSTRACT: 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. 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. 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. 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.Korean journal of radiology: official journal of the Korean Radiological Society 01/2013; 14(1):102-9. · 1.32 Impact Factor -
Article: MR differentiation of low-grade chondrosarcoma from enchondroma.
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ABSTRACT: PURPOSE: To evaluate magnetic resonance (MR) imaging for the discrimination between low-grade chondrosarcoma and enchondroma. MATERIALS AND METHODS: MR images of 34 patients who were confirmed with low-grade chondrosarcoma or enchondroma were retrospectively reviewed. After review of medical records, MR findings in 18 patients with low-grade chondrosarcoma and 16 patients with enchondroma were compared. MR images were retrospectively reviewed for the lesion location (central or eccentric; epiphysis, metaphysic, or diaphysis), margin, contour, mineralized matrix, endosteal scalloping, cortical expansion, cortical destruction, soft tissue mass formation, and periosteal reaction. Signal intensity, the patterns of contrast enhancement (unilocular or multilobular), soft tissue mass, and adjacent abnormal bone marrow and soft tissue signal were also reviewed. Statistical analysis was performed with chi-square test. RESULTS: The patients with low-grade chondrosarcoma had a significantly higher incidence of MR findings (P<.05): predominantly intermediate signal on T1-weighted images [72% (13/18) in low-grade chondrosarcoma vs. 25% (4/16) in enchondroma], multilocular appearance on contrast-enhanced T1-weighted images [83% (15/18) vs. 44% (7/16)], cortical destruction [33% (6/18) vs. 0% (0/16)], a soft tissue mass [28% (5/18) vs. 0% (0/16)], adjacent bone marrow and soft tissue abnormal signal [22% (4/18) vs. 0% (0/16)], and an involvement of the epiphysis or flat bone [56% (10/18) vs. 19% (3/16)]. CONCLUSION: MR imaging shows helpful features for differentiating low-grade chondrosarcoma from enchondroma.Clinical imaging 10/2012; · 0.73 Impact Factor -
Article: Extracranial skeletal Langerhans cell histiocytosis: MR imaging features according to the radiologic evolutional phases.
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ABSTRACT: The purpose was to describe the magnetic resonance (MR) findings of extracranial skeletal Langerhans cell histiocytosis according to the radiologic evolutional phases. Twenty-two patients with pathologically confirmed extracranial skeletal Langerhans cell histiocytosis were included. The lesions were classified as early, mid, and late phases according to the radiologic evolutional phases. MR images were retrospectively analyzed regarding signal intensity, internal hypointense band, fluid levels, periosteal reaction, adjacent bone marrow and soft tissue abnormal signal, and patterns of contrast enhancement in each phase. According to the radiologic evolutional phases, there were 4 patients with early phase, 16 with mid phase, and 2 with late phase. All cases showed hypointense to intermediate signal intensity on T1-weighted images. On T2-weighted images, 12 (55%) of the 22 lesions were hyperintense, and 10 (45%) showed intermediate signal. All lesions showed diffusely heterogeneous signal on T2-weighted images. Internal low-signal bands of the lesions were observed in 13 cases (59%). There were two cases with fluid levels in mid phase. Periosteal reaction was observed in 13 (59%) cases. Adjacent bone marrow or soft tissue abnormal signal was observed in 20 cases (91%), respectively. According to early, mid, and late phases, bone marrow and soft tissue abnormal signals were observed in 100%, 100%, and 0% cases, respectively. Soft tissue mass was seen in eight cases (36%). Ten (46%) lesions showed cortical destruction, including one patient with a pathologic fracture. Among 21 patients with contrast infusion, diffuse enhancement was observed in 19 patients (90%), and marginal and septal enhancement was seen in 2 patients (10%). MR imaging was helpful in the diagnosis of extracranial skeletal Langerhans cell histiocytosis, particularly in early and mid phases.Clinical imaging 09/2012; 36(5):466-71. · 0.73 Impact Factor -
Article: SLAP tears: diagnosis using 3-T shoulder MR arthrography with the 3D isotropic turbo spin-echo space sequence versus conventional 2D sequences.
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ABSTRACT: OBJECTIVES: The aim of this study was to determine the accuracy and reliability of shoulder magnetic resonance (MR) arthrography with three-dimensional (3D) isotropic intermediate-weighted turbo spin-echo (TSE) sampling perfection with application-optimised contrasts using different flip angle evolution (SPACE) in the diagnosis of superior labrum anterior-to-posterior (SLAP) lesions compared with two-dimensional (2D) TSE at 3.0 T. METHODS: MR arthrograms, including 2D TSE and 3D TSE-SPACE, in 87 patients who underwent arthroscopy were retrospectively analysed by two reviewers for the presence and type of SLAP lesions. Sensitivity and specificity were compared using McNemar's test, and inter-observer agreement was calculated using Cohen's kappa. Receiver operating characteristic (ROC) curve analyses were performed. RESULTS: The mean sensitivity, specificity and accuracy were 90%, 85% and 86% for 2D TSE, and 81%, 86% and 85% for 3D TSE-SPACE respectively, with no statistically significant differences. Inter-observer agreements were substantial in 2D TSE (κ = 0.76) and 3D TSE-SPACE (κ = 0.68). The areas under the ROC curves were 0.92 for 2D TSE and 0.90 for 3D TSE-SPACE, which were not significantly different. CONCLUSIONS: MR arthrography with 3D TSE-SPACE showed comparable accuracy and substantial inter-observer agreement for the diagnosis of SLAP lesions KEY POINTS : • MR arthrography is regarded as the definitive method of shoulder imaging • Different MR sequences are evolving for SLAP lesions • 3D TSE-SPACE demonstrated comparable overall accuracy to 2D TSE for SLAP lesions • But more false-negative interpretations occurred using 3D TSE-SPACE • Further technical improvement is necessary before 3D TSE-SPACE replaces 2D TSE sequences.European Radiology 08/2012; · 3.22 Impact Factor -
Article: Experimental study of artificially induced intramuscular gossypiboma in rabbits: correlation of sequential MRI findings with pathologic findings.
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ABSTRACT: The purpose of this study was to evaluate the sequential MRI findings of intramuscular gossypiboma and to correlate them with the pathologic findings in rabbits. Sterile gauze was packed in the hamstring muscles of 12 rabbits, and sequential MR images were obtained 1, 2, and 4 weeks and 2, 6, and 12 months after gauze insertion. Two rabbits were sacrificed at each time point. Their pathologic findings were compared with the MRI findings on each date. At the acute stage, the gossypibomas appeared as areas of heterogeneous low signal intensity on T2-weighted MR images with inflammatory change around the gossypiboma. In the subacute stage, the gossypibomas appeared as areas of peripheral low and central high signal intensity with wavy stripes of low signal intensity on T2-weighted images. On contrast-enhanced fat-suppressed T1-weighted images, the peripheral enhancement of the masses advanced toward the center of the mass as the fibrocollagenization between the gauze bundles progressed centrally. In the chronic stage, on contrast-enhanced fat-suppressed T1-weighted images, central advancement of the peripheral enhancement occurred according to the maturation of the fibrocollagenization. Calcifications around individual gauze fibers were observed 6-12 months after gauze insertion. On sequential contrast-enhanced fat-suppressed T1-weighted images of rabbits, intramuscular gossypiboma exhibited a chronologic centripetal enhancement pattern for 1 year mainly owing to concentric progression of fibrocollagenization between gauze bundles toward the center of the mass.American Journal of Roentgenology 07/2012; 199(1):W114-22. · 2.78 Impact Factor -
Article: Kimura’s disease involving a long bone
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ABSTRACT: Kimura’s disease is a rare, benign lymphoproliferative disorder of unknown etiology. It occurs most often in Asian men, usually in the second or third decade of life. Most lesions occur in the head and neck followed by the axilla, groin, popliteal region, and arm. The lesions are commonly found in soft tissues. To the best of our knowledge, there has been only one case report of bone involvement in Kimura’s disease presented on plain radiography. We report a case of Kimura’s disease that involved the proximal meta-diaphysis of the humerus and adjacent soft tissue shown on radiography and MR imaging. KeywordsKimura’s disease-Long bone-Radiography-MRISkeletal Radiology 04/2012; 39(5):495-500. · 1.54 Impact Factor -
Article: MR imaging manifestations of skin tumors
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ABSTRACT: In this study, we evaluated MR imaging findings of skin tumors and categorized them into four types: (1) discrete mass lesions of the dermis and epidermis, (2) mass lesions of the subcutis with or without abutment to the skin, (3) diffuse or localized skin thickening without a true mass, and (4) a skin mass with bone destruction. The categorization of MR images may be useful in the differential diagnosis of skin tumors.European Radiology 04/2012; 18(11):2652-2661. · 3.22 Impact Factor -
Article: Supraspinatus tendon tears at 3.0 T shoulder MR arthrography: diagnosis with 3D isotropic turbo spin-echo SPACE sequence versus 2D conventional sequences.
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ABSTRACT: To assess the diagnostic performance of shoulder MR arthrography with 3D isotropic fat-suppressed (FS) turbo spin-echo sequence (TSE-SPACE) for supraspinatus tendon tears in comparison with 2D conventional sequences at 3.0 T. The study was HIPAA-compliant and approved by the institutional review board with a waiver of informed consent. Eighty-seven arthroscopically confirmed patients who underwent 3.0 T shoulder MR arthrography with 2D sequences and 3D TSE-SPACE were included in a consecutive fashion from March 2009 to February 2010. Two reviewers independently analyzed 2D sequences and 3D TSE-SPACE. Sensitivity, specificity, accuracy, and interobserver agreement (κ) were compared between 2D sequences and 3D TSE-SPACE for full-thickness and partial-thickness supraspinatus tendon tears together and for partial-thickness supraspinatus tendon tears alone. There were 33 full-thickness tears and 28 partial-thickness tears of supraspinatus tendons. For full-thickness and partial-thickness supraspinatus tendon tears together, the mean sensitivity, specificity, and accuracy of both readers were 96, 92, and 94% on 2D sequences and 91, 84, and 89% on 3D TSE-SPACE. For partial-thickness supraspinatus tendon tears alone, the mean sensitivity, specificity, and accuracy were 95, 92, and 94% on 2D sequences and 84, 85, and 84% on 3D TSE-SPACE. There was no statistical difference between 2D sequences and 3D TSE-SPACE. Interobserver agreements were almost perfect on 2D conventional sequences and substantial on 3D TSE-SPACE. Compared with 2D conventional sequences, MR arthrography using 3D TSE-SPACE was comparable for diagnosing supraspinatus tendon tears despite limitations in detecting small partial-thickness tears and in discriminating between full-thickness and deep partial-thickness tears.Skeletal Radiology 02/2012; 41(11):1401-10. · 1.54 Impact Factor -
Article: Meniscal tear configurations: categorization with 3D isotropic turbo spin-echo MRI compared with conventional MRI at 3 T.
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ABSTRACT: 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. 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. 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. 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.American Journal of Roentgenology 02/2012; 198(2):W173-80. · 2.78 Impact Factor -
Article: MRI of chondromyxoid fibroma.
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ABSTRACT: Chondromyxoid fibroma is a rare benign primary bone tumor of cartilage. Despite a characteristic radiographic appearance, chondromyxoid fibroma with atypical radiographic findings may mimic more common tumors. To describe the MR findings of chondromyxoid fibroma. MR images of 19 histopathologically confirmed chondromyxoid fibromas were retrospectively analyzed for signal intensity, periosteal reaction, adjacent abnormal bone marrow and soft tissue signal, and patterns of contrast enhancement. All cases of chondromyxoid fibroma showed hypointense to intermediate signal intensity and internal hyperintense foci were observed in seven (37%) cases on T1-weighted images. On T2-weighted images, all lesions were hyperintense: peripheral intermediate signal band with central hyperintense signal in 11 (58%) of 19 lesions, whereas diffusely hyperintense with heterogeneous pattern in eight (42%). Periosteal reaction was observed in 11 (58%) of 19 cases. Adjacent abnormal bone marrow or soft tissue signal was observed in 12 (63%) or 14 (74%) of 19 cases, respectively. On contrast-enhanced T1-weighted images, peripheral nodular enhancement was observed in 69% (11/16) and diffuse contrast enhancement was observed in 31% (5/16) with homogeneous (n = 3) or heterogeneous (n = 2) patterns. Among the cases with peripheral nodular enhancement, the peripheral nodular enhancing portion generally corresponded to the peripheral intermediate signal band on T2-weighted images, although the peripheral enhancement was not as wide as a band of intermediate signal intensity. On the other hand, the central non-enhancing portion generally corresponded to the central hyperintense signal intensity on T2-weighted images. The helpful features of chondromyxoid fibroma are the peripheral intermediate signal band and central hyperintense signal on T2-weighted images, generally corresponding to the peripheral nodular enhancement and central non-enhancing portion on contrast-enhanced T1-weighted images, respectively.Acta Radiologica 08/2011; 52(8):875-80. · 1.37 Impact Factor -
Article: Proton density-weighted MR imaging of the knee: fat suppression versus without fat suppression.
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ABSTRACT: To prospectively evaluate the diagnostic accuracy of proton density-weighted imaging with and without fat suppression for detecting meniscal tears. The study involved 48 patients who underwent arthroscopy less than 3 months after proton density-weighted imaging with and without fat suppression. Sagittal images were independently reviewed by two radiologists for the presence of meniscal tears. Medial and lateral menisci were separately analyzed in terms of anterior horn, body, and posterior horn. Interobserver agreement was assessed using κ coefficients. The McNemar test was used to determine any differences between the two methods in terms of sensitivity and specificity. Arthroscopy findings were used as the diagnostic reference standard. Arthroscopy revealed 71 tears involving 85 meniscal segments: 34 medial meniscal segments and 51 lateral meniscal segments. The sensitivity, specificity, and accuracy of each radiologist were 95% (81/85), 92% (186/203), and 93% (267/288), and 93% (79/85), 93% (189/203), and 93% (268/288) when using fat-suppressed proton density-weighted imaging, and 91% (77/85), 93% (189/203), and 92% (266/288), and 91% (77/85), 93% (188/203), and 92% (265/288) when using proton density-weighted imaging without fat suppression, respectively. Interobserver agreement for meniscal tears was very high with proton-weighted imaging with (κ = 0.87) or without (κ = 0.86) fat suppression. There were no significant differences for detection of medial meniscal tears when using proton density-weighted imaging with or without fat suppression for both readers (p > 0.05). Fat-suppressed proton density-weighted imaging can replace proton density-weighted imaging without fat suppression for the detection of meniscal tears.Skeletal Radiology 02/2011; 40(2):189-95. · 1.54 Impact Factor -
Article: MRI features of skeletal muscle lymphoma.
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ABSTRACT: The purpose of this study was to assess the MRI findings of skeletal muscle lymphoma. MR images of pathologically proven lymphoma of skeletal muscle in 20 patients were retrospectively reviewed for the presence or absence of individual imaging findings. Nine patients had primary muscle lymphoma, and 11 patients had muscle metastasis from systemic lymphoma. The initial manifestation of skeletal muscle lymphoma was a muscle mass in 15 patients (75%) and abnormal muscle signal intensity in five patients (25%). Muscle enlargement was found in all cases. Long segmental involvement with orientation of the tumor along muscle fascicles was found in 15 patients (75%). Seventeen patients (85%) had traversing vessels within involved muscles. All of the tumors had equal to slightly increased signal intensity compared with normal muscle on T1-weighted images and intermediate signal intensity compared with fat on T2-weighted images. Among the 19 patients who underwent contrast-enhanced imaging, skeletal muscle lymphoma exhibited diffuse homogeneous enhancement in 13 patients (68%), predominantly peripheral thick bandlike enhancement in four patients (21%), and marginal septal enhancement in two patients (11%). Thick irregular enhancement of both deep and superficial fascia was found in 16 patients (84%), and one patient (5%) had deep enhancement only. Subcutaneous stranding was found in 16 patients (80%) and skin thickening in four patients (20%). Skeletal muscle lymphoma has distinctive MRI features that help differentiate it from other soft-tissue tumors and tumorlike lesions.American Journal of Roentgenology 12/2010; 195(6):1355-60. · 2.78 Impact Factor -
Article: Kimura's disease involving a long bone.
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ABSTRACT: Kimura's disease is a rare, benign lymphoproliferative disorder of unknown etiology. It occurs most often in Asian men, usually in the second or third decade of life. Most lesions occur in the head and neck followed by the axilla, groin, popliteal region, and arm. The lesions are commonly found in soft tissues. To the best of our knowledge, there has been only one case report of bone involvement in Kimura's disease presented on plain radiography. We report a case of Kimura's disease that involved the proximal meta-diaphysis of the humerus and adjacent soft tissue shown on radiography and MR imaging.Skeletal Radiology 05/2010; 39(5):495-500. · 1.54 Impact Factor -
Article: Differentiation between grade 3 and grade 4 articular cartilage defects of the knee: fat-suppressed proton density-weighted versus fat-suppressed three-dimensional gradient-echo MRI.
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ABSTRACT: Fat-suppressed (FS) proton density (PD)-weighted magnetic resonance imaging (MRI) and FS three-dimensional (3D) gradient-echo imaging such as spoiled gradient-recalled (SPGR) sequence have been established as accurate methods for detecting articular cartilage defects. Purpose: To retrospectively compare the diagnostic efficacy between FS PD-weighted and FS 3D gradient-echo MRI for differentiating between grade 3 and grade 4 cartilage defects of the knee with arthroscopy as the standard of reference. Twenty-one patients who had grade 3 or 4 cartilage defects in medial femoral condyle at arthroscopy and knee MRI were included in this study: grade 3, >50% cartilage defects; grade 4, full thickness cartilage defects exposed to the bone. Sagittal FS PD-weighted MR images and FS 3D gradient-echo images with 1.5 T MR images were independently graded for the cartilage abnormalities of medial femoral condyle by two musculoskeletal radiologists. Statistical analysis was performed by Fisher's exact test. Inter-observer agreement in grading of cartilage was assessed using kappa coefficients. Arthroscopy revealed grade 3 defects in 17 patients and grade 4 defects in 4 patients in medial femoral condyles. For FS 3D gradient-echo images grade 3 defects were graded as grade 3 (n=15) and grade 4 (n=2), and all grade 4 defects (n=4) were correctly graded. However, for FS PD-weighted MR images all grade 3 defects were misinterpreted as grade 1 (n=1) and grade 4 (n=16), whereas all grade 4 defects (n=4) were correctly graded. FS 3D gradient-echo MRI could differentiate grade 3 from grade 4 defects (P=0.003), whereas FS PD-weighted imaging could not (P=1.0). Inter-observer agreement was substantial (kappa=0.70) for grading of cartilage using FS PD-weighted imaging, whereas it was moderate (kappa=0.46) using FS 3D gradient-echo imaging. FS 3D gradient-echo MRI is more helpful for differentiating between grade 3 and grade 4 cartilage defects than is FS PD-weighted imaging.Acta Radiologica 03/2010; 51(4):455-61. · 1.37 Impact Factor -
Article: Magnetic resonance arthrography including ABER view in diagnosing partial-thickness tears of the rotator cuff: accuracy, and inter- and intra-observer agreements.
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ABSTRACT: 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. 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. 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 kappa 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. 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 kappa=0.55 to kappa=0.68. Likewise, intraobserver agreements increased from kappa=0.79 and 0.53 to kappa=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. 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.Acta Radiologica 12/2009; 51(2):194-201. · 1.37 Impact Factor -
Article: Validity of the sonographic longitudinal sagittal image for assessment of the cartilage thickness in the knee osteoarthritis.
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ABSTRACT: We compared the validity of the sonographic longitudinal sagittal image with the suprapatellar transverse axial image for assessment of thickness of femoral cartilage in osteoarthritis (OA) patients. Fifty-one patients with knee OA were enrolled in this study. Cartilage thicknesses of medial and lateral femoral condyles were measured with longitudinal sagittal and suprapatellar transverse axial image using sonography. Fat-suppressed 3D spoiled gradient-echo magnetic resonance imaging (MRI) was also used to get the reference value. The joint space width (JSW) and Kellgren and Lawrence (K-L) grade were measured in weight-bearing anteroposterior knee radiograph. The kappa and intraclass correlation coefficient (ICC) were used to determine inter- and intra-observer agreement of the ultrasound sonography (US) measurements. In medial femoral condyle, the opportunity to obtain cartilage thickness was increased significantly using the longitudinal US scan as compared with tansverse scan (48 cases vs. 36 cases, p < 0.05). There was a good correlation between longitudinal US scan and MRI in the maximum and minimum cartilage thicknesses of medial condyle (r = 0.568; r = 0.844, respectively, p < 0.01). However, there was no correlation between suprapatellar transverse US scan and MRI in medial condyle. In lateral condyle, both US scans showed good correlations with MRI. In Bland-Altman analysis, longitudinal US scan showed good agreement with MRI except in the minimal cartilage thickness of lateral condyle. There was high overall intra- and inter-observer agreement in US scan. US scan in the longitudinal plane is a more feasible method than suprapatellar transverse scan for measuring cartilage thickness of medial femoral condyle in knee OA patient.Clinical Rheumatology 08/2008; 27(12):1507-16. · 2.00 Impact Factor -
Article: Radial tear of the medial meniscal root: reliability and accuracy of MRI for diagnosis.
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ABSTRACT: The purpose of this study was to determine the reliability and accuracy of MRI in the diagnosis of radial tears of the medial meniscal root. The MR images of 192 patients who underwent arthroscopy and MRI of the knee from July 2003 through March 2006 were retrospectively reviewed. MR images were independently scored by two observers for the presence of radial tear of the medial meniscal root. Interobserver agreement in detection of these tears was assessed with kappa values. The differences in areas under the receiver operating characteristic curves were assessed with a univariate z-score test. Arthroscopy revealed that 29 patients had radial tears of the medial meniscal root. The sensitivity, specificity, and accuracy of MRI for one reader were 90% (26/29), 94% (154/163), and 94% (180/192) and for the other reader were 86% (25/29), 95% (155/163), and 94% (180/192). Interobserver agreement for radial tears of the medial meniscal root was very high (kappa = 0.93). The areas under the receiver operating characteristic curves for each reader were 0.97 and 0.96, which were not significantly different. There was no significant difference in detection of medial meniscal root tears on T2-weighted coronal images compared with the overall interpretation for both readers. Other image sequences had significantly different sensitivity or specificity for one or both readers (McNemar statistic). MRI of the knee is reliable and accurate for detection of radial tears of the medial meniscal root. Coronal T2-weighted imaging is the most useful MRI sequence.American Journal of Roentgenology 08/2008; 191(1):81-5. · 2.78 Impact Factor -
Article: Degenerative changes of discs and facet joints in lumbar total disc replacement using ProDisc II: minimum two-year follow-up.
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ABSTRACT: A retrospective clinical and radiologic data analysis. To determine the radiologic changes in the discs at the adjacent levels and facets at the index and adjacent levels after total disc replacement (TDR) using ProDisc II in a minimum 2-year follow-up. The main purposes of TDR are to preserve the physiologic segmental motion at index level, and to prevent accelerated degeneration at the index and adjacent segments. However, there are few reports dealing with the effects of TDR on the degenerative changes in a long-term follow-up. After TDR using ProDisc II, the degree of disc and facets degeneration at the index and adjacent levels was assessed by observing lumbar magnetic resonance imaging (MRI) and computed tomography (CT) images before surgery and at minimum 26 months after operations. The degenerative changes of the discs and facets were determined in relation to the clinical outcome, various perioperative factors, and prosthesis factors. Thirty-two patients with 41 TDR included in this investigation. The progression of facets degeneration (PFA) was observed in 12 of 41 TDR levels. Among 47 adjacent segments, the progression of disc degeneration and PFA were observed in 2 levels (4.3%), and 3 levels (6.4%), respectively. All cases of PFA occurred only in those with preoperative degeneration of grade 1. PFA at the index segments was positively related with female in gender (P = 0.008), the malposition of prosthesis on frontal plane (P = 0.025), and 2-level TDR in the number of TDR level (P = 0.008). After TDR using ProDisc II, the degenerative changes in the discs and facets at the adjacent segments appeared to be minimal. However, in 29.3% of the TDR segments, the facet joints presented PFA, which was more common in female, malposition of prosthesis on frontal plane, and 2-level TDR in a minimum 2-year follow-up.Spine 08/2008; 33(16):1755-61. · 2.08 Impact Factor -
Article: Adhesive capsulitis of the shoulder: evaluation with MR arthrography.
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ABSTRACT: The purpose of this study was to determine the usefulness of magnetic resonance (MR) arthrography for diagnosing adhesive capsulitis. Shoulder MR images of 28 patients with (n=14) and without (n=14) adhesive capsulitis were retrospectively analyzed. MR images were assessed for capsule and synovium thickness as well as the width of the axillary recess on oblique coronal fat-suppressed T1-weighted images and T2-weighted images, respectively. On oblique sagittal fat-suppressed T1-weighted images, the width of the rotator interval and the presence of abnormal tissue in the interval were evaluated. Significant differences were found between the two groups in capsule and synovium thickness on both sides of the recess on oblique coronal T2-weighted images (P=0.000), whereas thickness on the humeral aspect showed no significant difference on oblique coronal fat-suppressed T1-weighted images (P=0.109). On oblique coronal T2-weighted images, a cut-off value of 3-mm thickness gave the highest diagnostic accuracy for adhesive capsulitis with sensitivity, specificity, and accuracy of 79% (11/14), 100% (14/14), and 89% (25/28) at the humeral side and 93% (13/14), 86% (12/14), and 89% (25/28) at the glenoid side, respectively. There were significant differences in rotator interval width, presence of abnormal tissue in the rotator interval, and axillary recess width between the two groups (P<0.05). Thickness of capsule and synovium of the axillary recess greater than 3 mm is a practical MR criterion for diagnosing adhesive capsulitis when measured on oblique coronal T2-weighted MR arthrography images without fat suppression. The presence of abnormal tissue in the rotator interval showed high sensitivity but rather low specificity.European Radiology 05/2006; 16(4):791-6. · 3.22 Impact Factor -
Article: Discogenic lumbar pain: association with MR imaging and CT discography.
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ABSTRACT: To correlate MR and CT discography findings with pain response at provocative discography in patients with discogenic back pain. Forty-seven patients aged 25-54 years who underwent MR imaging and subsequent CT discography (97 discs) were included in this study. MR images were retrospectively evaluated regarding disc degeneration, endplate abnormalities, facet joint osteoarthritis, and high intensity zone. During discography concordant pain was regarded as positive, whereas discordant pain and no pain were regarded as negative. MR and CT discographic findings were analyzed on the base of concordant pain using the Chi-square test. : Concordant pain was significantly common in the following (P < 0.05): grade 4 or 5 disc degeneration [88% (30/34) in concordant pain versus 48% (30/63) in discordant pain and no pain], high intensity zone [56% (19/34) versus 30% (19/63)], combination of above two findings [53% (18/34) versus 25% (16/63)], fissured and ruptured disc at discogram [94% (32/34) versus 57% (36/63)], and contrast beyond inner annulus at CT discogram [97% (33/34) versus 57% (36/63)]. Typical MR findings with concordant pain at discography include grade 4 or 5 disc degeneration and presence of a high intensity zone. Typical CT discography findings with concordant pain were fissured/ruptured discs and contrast extending into/beyond the outer annulus on CT.European Journal of Radiology 06/2005; 54(3):431-7. · 2.61 Impact Factor
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2003–2012
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Catholic University of Korea
- Department of Radiology
Seoul, Seoul, South Korea
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