So-Yeon Lee

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.

A practical MRI grading system for osteoarthritis of the knee: Association with Kellgren–Lawrence radiographic scores

PURPOSE To propose a reproducible and constant MR grading system for osteoarthritis of the knee joint that provides high interobserver and intraoberver agreement and that does not require complicated calculation procedures. MATERIALS AND METHODS This retrospective study sample included 44 men and 65 women who underwent both MRI and plain radiography of the knee at our institution. All patients were older than 50 years of age (mean 57.7) and had clinically suspected osteoarthritis of the knee. The standard of 4 grades on the MR grade scale was based mainly on cartilage injury and additional findings. Kellgren-Lawrence grades were assessed for the same patient group. The relationship between the results was determined. Statistical analyses were performed including kappa statistics, categorical regression analysis and nonparametric correlation analysis. RESULTS The interobserver and intraoberver agreements between the two readers in the grading of osteoarthritis were found to be almost perfect. Interobserver and intraobserver agreements were slightly lower for the MR grading system than for the Kellgren-Lawrence grading scale. The correlation between the MR grade and Kellgren-Lawrence grade was very high and did not differ with patient age. The MR grades were highly correlated with the Kellgren-Lawrence grades and showed excellent interobserver and intraobserver agreements. CONCLUSION This new MR grading system for osteoarthritis of the knee joint is reproducible and may be helpful for the grading of osteoarthritis of the knee without requiring reference to plain radiography.

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.

Accuracy of MR findings in characterizing peroneal tendons disorders in comparison with surgery

Background Previous studies have shown that magnetic resonance imaging (MRI) has a high sensitivity for peroneal tendon pathology but more studies with surgery as a reference standard are needed. Purpose To evaluate the accuracy of MRI compared to surgery for characterizing chronic peroneal tendon pathology. Material and Methods Ninety-seven patients (57 men, 40 women; mean age, 39 years; range, 15–64 years) with chronic lateral ankle instability underwent MRI followed by surgery, with a mean MR to surgery interval of 30 days. Sagittal, coronal, and axial T1-weighted spin-echo and fat-suppressed T2-weighted fast spin-echo images were obtained for all patients. Two blinded observers evaluated the MR images without clinical information, and the results were compared to surgical findings. The following peroneal injuries were observed: tendon split, interstitial tear, swelling of the tendon, fluid collection, superior peroneal retinaculum injury, and tendon dislocation. Results Swelling of the peroneus longus tendon was the most common finding on MR imaging, followed by fluid collection and a split of the peroneus brevis tendon. Surgical findings showed that nine cases (9%) of interstitial tears were in the peroneus brevis and two cases (2%) were in the peroneus longus, with eight cases (8%) of splits in the peroneus brevis tendon. The sensitivity and specificity for detecting interstitial tears in the peroneus brevis were 44% and 99%, respectively. The sensitivity and specificity for detecting swelling in the peroneus brevis were 50% and 99%, respectively. The sensitivity and specificity for detecting interstitial tears for peroneus longus injuries were 50% and 96%, respectively. The sensitivity and specificity for detecting swelling in these injuries were and 100% and 96%, respectively. Conclusion MRI findings of chronic peroneal tendon pathology are diagnostically specific but not sensitive. MRI showed high sensitivity for diagnosing tendon swelling in the peroneus longus, but not in the peroneus brevis. MRI is sensitive but not specific for detecting negative findings.

Ultrasound elastography in the early diagnosis of plantar fasciitis

BACKGROUND The purpose of this study was to investigate whether ultrasound (US) elastography is useful for the early diagnosis of plantar fasciitis. MATERIAL AND METHODS We retrospectively reviewed US elastography findings of 18 feet with a clinical history and physical examination highly suggestive of plantar fasciitis but with normal findings on conventional US imaging as well as 18 asymptomatic feet. RESULT Softening of the plantar fascia was significantly greater in the patient than in the control group [Reviewers 1 and 2: 89% (16/18) vs. 50% (9/18), P=.027, respectively]. CONCLUSION US elastography is useful for the early diagnosis of plantar fasciitis.

The usefulness of the oblique coronal plane in knee MRI on the evaluation of the posterior cruciate ligament.

Background Imaging findings of posterior cruciate ligament (PCL) injury may be equivocal, particularly when the patient has suffered a partial ligament tear. Some PCLs are positioned more horizontally, making it difficult to diagnose injury based on routine imaging planes alone due to partial volume artifact. Purpose To evaluate the diagnostic accuracy of combining oblique coronal imaging (PCL view) with traditional orthogonal views for PCL evaluation. Material and Methods This retrospective study included 20 patients with PCL injury and 43 patients with intact PCL who underwent PCL view imaging. Anatomic identification of PCL pathology on the orthogonal magnetic resonance imaging (MRI) sequences and PCL views was evaluated. Subjective scoring of the PCL was performed by two radiologists who assessed the possibility of a PCL tear based on an entire length view, an entire width view, and margin sharpness according to a 4-point scale. Diagnostic accuracy using these two views was evaluated by calculating the sensitivity, specificity, and accuracy. Arthroscopic and clinical findings were used as the reference standard. Results Total scores for the PCL view were higher than those of orthogonal views (P < 0.001). Both readers found that anatomic identification using the full width view and sharp margin to be superior using the PCL view compared with the orthogonal views (P < 0.001). The specificities and accuracies were higher in cases where an additional PCL view was provided, but did not show statistical significance. Conclusion PCL view provides better anatomic evaluation of the PCL and mild improvement in the specificity and accuracy.

Value of adding sonoelastography to conventional ultrasound in patients with congenital muscular torticollis

BackgroundSonoelastography has been utilized to evaluate various myopathies. However, the benefits of adding sonoelastography to conventional ultrasound (US) in patients with congenital muscular torticollis are unclear.ObjectiveTo evaluate the value of adding sonoelastography to conventional US in patients with congenital muscular torticollis.Materials and methodsThis study included 27 infants clinically diagnosed with congenital muscular torticollis and 17 healthy infants who underwent conventional US and sonoelastography. The echogenicity of the sternocleidomastoid muscle was assessed as isoechoic, heterogeneous, hyperechoic or hypoechoic compared with normal muscle. The thickness of the involved and contralateral sternocleidomastoid muscles was measured. Elastographic findings were scored from 1 (soft) to 3 (hard) by two independent radiologists.ResultsThe sternocleidomastoid muscle thickness, difference and ratio between involved and normal sternocleidomastoid muscle thickness, and elastographic score differed significantly between the patient and control groups. Of the 27 patients, 11 had isoechoic, 5 had heterogeneous and 11 had hyperechoic muscles. Congenital muscular torticollis patients with isoechoic muscle showed significantly higher elastographic scores than the control group, but there were no other significant differences by conventional US.ConclusionsAdding sonoelastography to conventional US is helpful for the diagnosis of congenital muscular torticollis, especially in patients with isoechoic sternocleidomastoid muscle.

Sonographic Appearances of Soft Tissue Angioleiomyomas Differences From Other Circumscribed Soft Tissue Hypervascular Tumors

The purpose of this study was to evaluate the sonographic features of angioleiomyomas with priority given to the vascular pattern to help in the differential diagnosis from other hypervascular soft tissue tumors.

Clinical correlation of a new practical MRI method for assessing cervical spinal canal compression.

OBJECTIVE The purpose of this study was to evaluate interobserver agreement and whether or not a new MRI grading system correlates with symptoms and neurologic signs for assessing spinal canal compression. MATERIALS AND METHODS One hundred patients (52 men and 48 women; mean age, 50 years) underwent MRI of the cervical spine at our institution and were evaluated by two musculoskeletal radiologists. The presence and grade of cervical canal stenosis at the maximal narrowing point was assessed according to the new grading system suggested by Kang et al. (Kang system). The results correlated with the clinical manifestations and neurologic examination. Statistical analysis was performed using kappa statistics, categoric regression analysis, and nonparametric correlation analysis (Spearman correlation). RESULTS Interobserver agreement in the grading of spinal stenosis between the two readers was almost perfect (κ = 0.925). Most of the patients with grade 0 cervical canal stenosis showed no neurologic manifestation, and patients with grades 2 and 3 cervical canal stenosis had positive neurologic manifestations. The correlation coefficient (R) of reader 1 between MRI grade (0, 1, 2, and 3) and neurologic manifestations (positive or negative) was 0.846. The R of reader 2 was 0.808. In the younger age group (< 50 years old), the R of reader 1 was 0.834 and the R of reader 2 was 0.745. In the older age group (≥ 50 years old), the R of reader 1 was 0.839 and the R of reader 2 was 0.839. CONCLUSION The interobserver agreement of the Kang system was almost perfect and was higher than in the study by Kang et al. Grade 0 cervical canal stenosis represents negative neurologic manifestations and grades 2 and 3 cervical canal stenosis represent positive neurologic manifestations. The Kang system and clinical manifestations are significantly correlated, especially in the older age group (≥ 50 years).