Quantitative assessment of anterior talofibular ligament quality in chronic lateral ankle instability using magnetic resonance imaging T2* value.

OBJECTIVE: To determine T2* normal reference values for anterior talofibular ligament (ATFL) and to investigate the feasibility of the quantitative ATFL quality evaluation in chronic lateral ankle instability (CLAI) using T2* values. MATERIALS AND METHODS: This study enrolled 15 patients with CLAI and 30 healthy volunteers. The entire ATFL T2* values from the MRI T2* mapping were measured. The prediction equation (variables: age, height, and weight) in a multiple linear regression model was used to calculate the T2* normal reference value in the healthy group. T2* ratio was defined as the ratio of the actual T2* value of the patient's ATFL to the normal reference value for each patient. A Telos device was used to measure the talar tilt angle (TTA) from the stress radiograph. RESULTS: T2* values of ATFL in the healthy and CLAI groups were 10.82 ± 1.84 ms and 14.36 ± 4.30 ms, respectively, which are significantly higher in the CLAI group (P < 0.05). The prediction equation of the normal reference T2* value was [14.9 + 0.14 × age (years) - 4.7 × height (m) - 0.03 × weight (kg)] (R2 = 0.65, P < 0.0001). A significant positive correlation was found between the T2* ratio and TTA (r = 0.66, P = 0.007). CONCLUSION: MRI T2* values in patients with CLAI were higher than those in healthy participants, and the T2* ratio correlated with TTA, suggesting that T2* values are promising for quantitative assessment of ATFL quality preoperatively.

Ultra-Short Echo Time-MRI T2* Mapping of Articular Cartilage Layers Is Associated with Histological Early Degeneration.

OBJECTIVE: Ultra-short TE (UTE) sequences on MRI are a technique that improves the visualization of tissues with short T2 relaxation time, such as deep cartilage layers. In addition, T2* relaxation time calculated from the UTE has the potential to evaluate water molecules bound to the cartilage matrix. This study was performed to determine if there is an association between UTE-T2* relaxation time by cartilage layer and histological degeneration in knee osteoarthritis (OA). DESIGN: Seven knees that had undergone total knee arthroplasty (TKA) were included in the study, and the lateral tibial cartilage, which had the least degeneration of the resected bones, was used as the sample. The T2* relaxation time of 4 patients with no abnormal findings on MRI was the reference relaxation time. Histological degeneration of TKA samples was assessed by the Mankin score and graded as the early OA group (≤3 points) and the advanced OA group (≥4 points). The association between T2* relaxation time and Mankin grade in each cartilage layer was compared. The effect of angiogenesis to the tidemark on T2* relaxation time was also compared. RESULTS: T2* relaxation time of the cartilage layer was significantly longer in early OA than that in the control group. In the deep cartilage layer, the mean T2* relaxation time for angiogenesis (-) was 15.7 ms, whereas it was significantly shorter for angiogenesis (+) at 8.2 ms. CONCLUSIONS: The UTE-T2* relaxation time was associated with histological cartilage degeneration, suggesting a potential application in monitoring early cartilage degeneration.

Relationships of cross-sectional area of the thigh muscles before or after total knee arthroplasty with postoperative pain or patient satisfaction: A retrospective, exploratory study.

Background: It has been suggested that lower limb strength related to persistent postsurgical pain. The aim of the present study was to investigate the relationships of pre-operative or postoperative cross-sectional area (CSA) of the thigh muscles with knee pain or patient satisfaction after total knee arthroplasty (TKA). Methods: Twenty patients who had undergone TKA (3 men and 17 women; mean age 75.2 ± 8.7 years) were included. CSAs of the thigh muscle (THIGH) and quadriceps muscle (QUAD) were retrospectively measured at the CT slice 10-cm superior to the quadriceps tendon insertion at the proximal pole of the patella. THIGH CSA and QUAD CSA to body weight ratios (mm2/kg), THIGH/W and QUAD/W ratios, respectively, were calculated. Knee pain and patient satisfaction postoperatively were also quantified by patient-reported measurements based on the 2011 Knee Society Score (KSS). The correlations between the THIGH/W and QUAD/W ratios and the KSS were evaluated using Spearman's rank correlation coefficient. Results: The preoperative THIGH/W ratio was positively correlated with KSS-pain, (r = 0.58, p < 0.05). The preoperative QUAD/W ratio was positively correlated with KSS-pain (r = 0.52, p < 0.05) and KSS-satisfaction (r = 0.44, p < 0.05). The postoperative THIGH/W ratio was positively correlated with KSS-pain (r = 0.45, p < 0.05). The postoperative QUAD/W ratio was positively correlated with KSS-pain (r = 0.49, p < 0.05) and KSS-satisfaction (r = 0.48, p < 0.05). Conclusion: There were significant correlations between quadriceps or thigh muscle CSA and pain or patient satisfaction after TKA. This research may help relieve pain and increase patient satisfaction after TKA in the future.

Intravoxel Incoherent Motion Factors Affecting Collapse and Nonunion of Osteoporotic Vertebral Fracture.

STUDY DESIGN: Longitudinal study. OBJECTIVES: Intravoxel incoherent motion (IVIM), a magnetic resonance imaging (MRI) scanning technique that applies diffusion-weighted imaging (DWI), is effective for the quantitative assessment of malignant tumors of the vertebral bone. We hypothesized that IVIM parameters of vertebral bodies are associated with the prognosis of osteoporotic vertebral fracture (OVF). We aimed to explore the relationships between IVIM parameters for vertebral collapse and non-union after OVF and calculate the cut-off values of these parameters for vertebral collapse and non-union. METHODS: A total of 150 patients with acute OVF (150 women; mean age: 79.1 ± 7.4 years) were included and treated conservatively with bracing. MRI was performed at the time of injury. IVIM parameters, such as apparent diffusion coefficient (ADC), molecular diffusion coefficient (D), and perfusion-related diffusion (D*) were recorded. The patients were classified into 3 groups: low-collapse (height loss of ≤50%), high-collapse (height loss of >50%), and non-union. We compared ADC, D, and D* among the low-collapse, high-collapse, and non-union groups and performed a receiver operating characteristic (ROC) curve analysis to determine the boundary values of the high-collapse and non-union groups. RESULTS: The low-collapse, high-collapse, and non-union groups had no significant differences in ADC and D. However, D* differed significantly among the 3 groups. ROC analysis revealed cut-off values of 19.0 × 10-3 mm2/s and 12.3 × 10-3 mm2/s for the high-collapse and non-union groups, respectively. CONCLUSIONS: D* is a significant prognostic indicator for high-collapse and non-union groups with OVF. This suggests that D* should be considered when assessing OVF.

[Costal Cartilage Injury Using MRI: A Case Report].

A magnetic resonance imaging (MRI) scan was performed to rule out a sternal fracture in a woman in 30s. Short tau inversion recovery (STIR) coronal showed no signal change in the sternum but increased signal from the mediastinum to the anterior thoracic region. We could not detect significant findings until midway through the examination. T2-weighted fat-suppressed images revealed a suspected left first costal cartilage injury at the end of the examination. In addition, three-dimensional gradient-recalled echo (3D GRE) T1-weighted fat-suppressed images clearly revealed a lesion area with a high signal intensity in the costal cartilage and a low signal intensity in the surrounding tissue, and we diagnosed costal cartilage injury definitely. In case of MRI for posttraumatic chest pain, T1-weighted fat-suppressed images with 3D GRE may be useful for the detection of lesion area.

T1rho, T2, and T2* relaxation time based on grading of intervertebral disc degeneration.

BACKGROUND: Previous studies have explored the biochemical changes of disc degeneration and its relevance in low back pain using various quantitative magnetic resonance imaging (MRI) techniques. However, quantitative evaluation of intervertebral disc (IVD) with MRI such as T1rho, T2, and T2* have not been previously analyzed and compared directly in the same patients. PURPOSE: To investigate T1rho, T2, and T2* of IVD degeneration in the same patients, reveal the correlation coefficients of these values, and evaluate which values are more sensitive to detect the degree of IVD degeneration. MATERIAL AND METHODS: The participants were 55 patients who underwent MRI examinations which the investigator classified the degree of IVD degeneration according to the Pfirrmann classification. The T1rho, T2, and T2* values of IVD were analyzed for their classification and were compared. RESULTS: T1rho, T2, and T2* values were 74.3 ± 7.1, 61.2 ± 6.7, and 46.5 ± 16.3 ms (grade II); 61.6 ± 11.8, 48.9 ± 8.2, and 34.1 ± 11.8 ms (grade III); 50.8 ± 10.8, 38.9 ± 9.8, and 25.4 ± 8.1 ms, (grade IV); 44.5 ± 13.3, 34.8 ± 9.5, and 11.2 ± 6.6 ms (grade V), respectively. Those values significantly decreased with increasing grades, but T1rho and T2 values for grades IV and V were not different. CONCLUSION: The T1rho and T2 values were excellent for the evaluation of initial to moderate IVD degeneration with water and proteoglycan content. In contrast, the T2* value was suitable for detailed evaluation of progressive IVD, even with poor water content.

Optimal acceleration factor for image acquisition in turbo spin echo: diffusion-weighted imaging with compressed sensing.

In this study, the change in the image quality and apparent diffusion coefficient (ADC) with increase in the acceleration factor (AF) was analyzed and the most optimal AF was determined to reduce the scan time while preserving the image quality. The AF was changed from 2 to 20 in the MR acquisitions. The similarities between the accelerated and reference images were determined based on the structural similarity (SSIM) index for DWI image and coefficient of variation (%CV) for ADC. The SSIM index decreased significantly when the AF ≥ 8 compared with when the AF = 2 (p < 0.05). In the reference image, the %CV of the ADC increased significantly when the AF ≥ 10 (p < 0.01). In conclusion, a remarkable decrease in the image quality and ADC was observed when the AF was > 8. Thus, an AF < 8 would be optimal for reducing the scan time while preserving the image quality.

3D MRI evaluation of morphological characteristics of lateral ankle ligaments in injured patients and uninjured controls.

BACKGROUND: With ultrasonography or 2D magnetic resonance imaging (MRI) of the lateral ankle ligament, it is particularly difficult to show the entire calcaneofibular ligament (CFL). The purpose of this study was to evaluate the morphological characteristics of the lateral ankle ligaments in injured patients and uninjured controls using 3D MRI. METHODS: A total of 64 ankles of 59 healthy volunteers and lateral ligament injury patients (mean age of 32.4 years) were examined. The 64 ankles included a healthy group of 11 ankles, an acute injury group of 12 ankles that underwent MRI a month after injury, and a chronic injury group of 41 ankles that underwent MRI more than 3 months after injury. Using a 3.0-T MRI system, imaging was done with fast imaging employing steady-state acquisition cycled phases. Oblique sagittal images that most clearly depicted the entire anterior talofibular ligament (ATFL) and CFL were prepared manually and evaluated using a workstation. RESULTS: In the healthy group, both the ATFL and CFL were clearly and entirely visualized. The mean width in the central portion was 4.0 ± 1.0 mm in the ATFL and 4.8 ± 0.6 mm in the CFL. 3D MRI in the acute injury group showed findings of diffuse swelling with hyperintensity in the ATFL of all patients. The CFL in 7 of 12 ankles showed findings of diffuse swelling with hyperintensity. In the chronic injury group, morphological abnormalities of the ATFL were seen in 19 of 41 ankles. The ligament signal disappeared in 2 ankles, thinned in 4 ankles, and showed swelling in 13 ankles. Morphological abnormalities of the CFL were seen in 17 of 41 ankles. The ligament signal disappeared in 1 ankle, thinned in 2 ankles, and showed swelling in 14 ankles. CONCLUSION: 3D MRI may be a useful modality to visualize both the ATFL and the CFL.

Morphological evaluation of the calcaneofibular ligament in different ankle positions using a three-dimensional MRI sequence.

PURPOSE: Evaluating images of the lateral ligament of the ankle is not easy, and evaluation of the calcaneofibular ligament (CFL) in particular is difficult. We prospectively conducted morphological measurements of the CFL in different ankle positions and obtain basic data for use in functional assessment of the CFL, diagnosis of CFL injury, and determination of treatment effects. METHODS: The subjects were ten healthy volunteers (ten ankles) with a mean age of 27.8 years and no history of ankle disease. Imaging was done using a 3-T magnetic resonance imaging (MRI) machine and fast imaging employing steady-state acquisition cycled phases (FIESTA-C), a three-dimensional (3D) sequence, with the ankle in a neutral position, maximum dorsiflexion, and maximum plantar flexion. 3D images of the CFL, peroneal muscle tendons, fibula, and calcaneus were prepared at a workstation, and morphological measurements of the CFL were made. RESULTS: In all positions, the CFL showed a gently curving course with the peroneal muscle tendons as a fulcrum. The tortuosity angle was significantly smaller in plantar flexion (30.0° ± 7.4°) than in the neutral position (41.7° ± 8.3°). CONCLUSIONS: 3D MRI sequences showed that, in all positions, the CFL curved due to the influence of the peroneal muscle tendons. With maximum plantar flexion, the CFL tortuosity angle was small, which was thought to have been due to the tension in the CFL.

Comparison with Magnetic Resonance Three-Dimensional Sequence for Lumbar Nerve Root with Intervertebral Foramen.

STUDY DESIGN: Prospective study based on magnetic resonance (MR) imaging of the lumbar spinal root of the intervertebral foramen. PURPOSE: This study was to compare MR three-dimensional (3D) sequences for the evaluation of the lumbar spinal root of the intervertebral foramen. OVERVIEW OF LITERATURE: The diagnosis of spinal disorders by MR imaging is commonly performed using two-dimensional T1- and T2-weighted images, whereas 3D MR images can be used for acquiring further detailed data using thin slices with multi-planar reconstruction. METHODS: On twenty healthy volunteers, we investigated the contrast-to-noise ratio (CNR) of the lumbar spinal root of the intervertebral foramen with a 3D balanced sequence. The sequences used were the fast imaging employing steady state acquisition and the coherent oscillatory state acquisition for the manipulation of image contrast (COSMIC). COSMIC can be used with or without fat suppression (FS). We compared these sequence to determine the optimized visualization sequence for the lumbar spinal root of the intervertebral foramen. RESULTS: For the CNR between the nerve root and the peripheral tissue, these were no significant differences between the sequences at the entry of foramen. There was a significant difference and the highest CNR was seen with COSMIC-FS for the intra- and extra-foramen. CONCLUSIONS: In this study, the findings suggest that the COSMIC-FS sequences should be used for the internal or external foramen for spinal root disorders.

Effect of ankle flexion on the quantification of MRS for intramyocellular lipids of the tibialis anterior and the medial gastrocnemius.

Muscle proton magnetic resonance spectroscopy (MRS) has been developed for non-invasive measurement of intramyocellular lipid (IMCL) levels. The majority of previous studies measuring IMCL with MRS have been performed on the calf muscle. The appearance of muscle MRS is influenced by bulk magnetic susceptibility and residual dipolar couplings, which depend on the angle between the muscle fibers and the main magnetic field. Our objective in this study was to evaluate the effect of ankle flexion and of the pennation angle on IMCL quantification in the calf muscle using proton MRS. The subjects comprised ten healthy male volunteers. In proton MRS, the ankle flexion angle was changed, and the pennation angle was measured from the tibialis anterior (TA) and the medial gastrocnemius (MG), respectively. We considered the relationship between the quantification of IMCL with (1)H MRS and the pennation angle by ankle flexion angle. The pennation angle of the TA and MG changed with the ankle flexion angle. The IMCL on the TA decreased significantly with plantar flexion (p < 0.05). However, the IMCL on the MG demonstrated no significant difference. The MR spectrum and IMCL quantitation changed with the pennation angle. Therefore, when spectra of individual subjects in longitudinal studies or between subjects are compared in cross-sectional studies, the foot position or calf muscle orientation must be considered.

Investigation of intervertebral disc and facet joint in lumbar spondylolisthesis using T2 mapping.

PURPOSE: We measured T2 relaxation time of the intervertebral discs (IVD) and facet joints (FJ) in patients with degenerative spondylolisthesis (DS) and no spondylolisthesis (NS) and investigated the characteristics of these parts in DS. METHODS: In 40 patients with DS and 40 patients with NS, we measured T2 relaxation time of the IVD and FJ and compared them between groups. In the group with DS, we also examined the relationship between the degree of slippage using Meyerding grade and T2 relaxation of each part in the IVD and FJ. RESULTS: T2 relaxation time of the IVD tended to be lower in the DS than NS group and differed significantly (P < 0.01) within the anterior annulus fibrosus. T2 relaxation time in the FJ was significantly higher in the DS than NS group. T2 relaxation time in the FJ was significantly higher for those assessed Meyerding Grade II than Grade I, although we observed no significant differences in T2 relaxation time in any area of the IVD. CONCLUSION: T2 relaxation time decreased in the anterior annulus fibrosus of the IVD and increased in the FJ in patients with DS, suggesting an association of IVD and FJ degeneration with the development of lumbar DS.

Visualization of the foramen intervertebral nerve root of cervical spine with 3.0 tesla magnetic resonance imaging: a comparison of three-dimensional acquisition techniques.

Identification of the compression factor in cervical disc herniation and cervical spondylotic radioculopathy is often problematic when using two-dimensional magnetic resonance imaging (MRI). This prompted us to compare and examined three-dimensional sequences, coherent oscillatory state acquisition for the manipulation of image contrast (COSMIC), fast imaging employing steady state acquisition (FIESTA) and T2 star weighted MR angiography (SWAN) with 3.0-Tesla (T) MRI to visualize the foramen intervertebral nerve root for the cervical spine. Fat-suppressed COSMIC (FS-COSMIC) sequence gave the highest signal intensity ratio (1.85 ± 0.06) of the nerve root and vertebral arch. A significant difference in signal intensity ratio of the nerve root was found between FS-COSMIC and FIESTA sequences. No significant difference was found between the FS-COSMIC and FIESTA sequences in the cerebrospinal fluid and the spinal cord. The FS-COSMIC sequence proved to be the most suitable sequence for intra and extra dura matter.