Sagittal T2 Mapping Research Articles

Age and Sex Comparison of the Canine Supraspinatus Tendon Using Quantitative Magnetic Resonance Imaging T2 Mapping.

The normal canine supraspinatus tendon has properties commonly attributed to damage such as core hyperintensity and increased width. Little is published regarding the normal tendon, including how senescent changes and sex differences may affect the appearance. Conventional magnetic resonance imaging (MRI) techniques provide subjective analysis of tendons based on observer assessment of signal intensity and appearance. Quantitative MRI (qMRI) techniques such as T2 mapping provide an objective comparison of collagen orientation with analysis of a decay constant, T2. This study investigates age and sex related changes in the canine supraspinatus tendon using the qMRI technique of T2 mapping. In this study, 34 tendons of clinically sound male and female dogs (0.6-13 years) were imaged using qMRI T2 mapping techniques. Sagittal plane T2 maps of the supraspinatus tendon were depth-normalized, and profiles compared using two separate four-parameter logistic equations describing T2 mapping profiles as sigmoidal curves. Combined parameters evaluated included range of T2 values, curve steepness, vertical curve shift, lower bound of T2, upper bound of T2 and horizontal curve shift. A significant reduction in the most central portion of the supraspinatus tendon was found for every increased year in age (-1.56 ± 0.47 milliseconds [-2.56, -0.56, p = 0.004]). No significant difference in curve parameters was found between sexes. The reduction in T2 with age suggests a senescent change may be anticipated with the canine supraspinatus tendon.

Patellofemoral contact forces and knee gait mechanics 3 months after ACL reconstruction are associated with cartilage degradation 24 months after surgery

Evaluate patellofemoral cartilage health, as assessed by quantitative magnetic resonance imaging (qMRI) T2 relaxation times, 24-months after ACL reconstruction (ACLR) and determine if they were associated with patellofemoral contact forces and knee mechanics during gait 3 months after surgery. Thirty individuals completed motion analysis during overground walking at a self-selected speed 3 months after ACLR. An EMG-driven neuromusculoskeletal model was used to determine muscle forces, which were then used in a previously described model to estimate patellofemoral contact forces. Biomechanical variables of interest included peak patellofemoral contact force, peak knee flexion angle and moment, and walking speed. These same participants underwent a sagittal bilateral T2 mapping qMRI scan 24-months after surgery. T2 relaxation times were estimated for both patellar and trochlear cartilage. Paired t-tests were used to compare T2 relaxation times between limbs while Pearson correlations and linear regressions were utilized to assess the association between the biomechanical variables of interest and T2 relaxation times. Prolonged involved limb trochlear T2 relaxation times (vsuninvolved) were present 24-months after surgery, indicating worse cartilage health. No differences were detected in patellar cartilage. Significant negative associations were present within the involved limb for all the biomechanical variables of interest 3 months after ACLR and trochlear T2 relaxation times at 24-months. No associations were found in patellar cartilage or within the uninvolved limb. Altered involved limb trochlear cartilage health is present 24-months after ACLR and may be related to patellofemoral loading and other walking gait mechanics 3 months after surgery.

MRI Semi-Quantitative Evaluation of Clinical Features of Cartilage Injury in Patients with Osteoarthritis

This study aimed to investigate the correlation between magnetic resonance imaging (MRI) findings of articular cartilage and clinical symptoms in patients with osteoarthritis (OA). Eighty patients with OA were selected as the study subjects (OA group) and 80 healthy subjects during the same period were also selected as the control group. All subjects underwent knee sagittal PDW-SPAIR, sagittal T1WI-aTSE, sagittal T2WI-TSE, coronal PDW-SPAIR, sagittal 3D-WATSc, and sagittal T2 mapping scans. Thereafter, all subjects underwent clinical assessment. The whole-organ MRI score (WORMS) was adopted for MRI examination and semiquantitative analysis, and the T2 value was calculated. The correlation among T2 value, WORMS, and Western Ontario and Mc Master University OA Index (WOMAC) was then compared and analyzed. The correlation coefficients between T2 values and WORMS in each sub-region of patients with OA were 0.8, 0.55, −0.038, 0.811, and 0.743; the correlation coefficients between WORMS and WOAMC were 0.66, 0.71, 0.46, and 0.88; and the correlation coefficients between T2 values and WOAMC were 0.483, 0.33, 0.282, and 0.636, respectively. There was a significant positive correlation between the results of MRI semiquantitative analysis and clinical symptoms as well as disease severity in patients with OA.

Sagittal balance and intervertebral disc composition in patients with low back pain.

The aim of this study was to verify the relationship between quantitative T2 relaxation measurements of lumbar intervertebral discs (IVDs) and spinopelvic parameters in patients with chronic low back pain. The study was approved by the Clinical Hospital of the Ribeirao Preto Medical School (USP) Ethics Committee, and written consent was obtained from all patients. A total of 455 IVDs from 91 consecutive patients with chronic low back pain were included in this prospective study. All subjects were assessed using the Oswestry Disability Index and visual analogue scale questionnaires and were confirmed to have no other spine diseases except disc degeneration. Spinopelvic parameters including the pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), sagittal vertical axis (SVA), global tilt (GT), T1 pelvic angle (TPA), lumbar lordosis (LL), thoracic kyphosis (TK), pelvic incidence minus lumbar lordosis mismatch (PI-LL), and lack of lumbar lordosis (LLL) were measured. The study group was categorized according to the Roussouly classification. Sagittal T2 maps were acquired to extract the IVD relaxation times, and the complete manual segmentation of IVDs at all levels was performed using Display® software. Lumbar IVD T2 relaxation times showed significant correlation with PT (P<0.01), GT (P<0.01), TPA (P<0.01), PI-LL (P=0.01), and LLL (P=0.01). No difference was noted between Roussouly subtypes regarding T2 relaxation times at any disc level. Data from questionnaires showed no correlation with T2 relaxation times. Global tilt and T1 pelvic angle were correlated with IVD composition changes (T2 relaxometry). There was no correlation between clinical symptoms and IVD T2 relaxation times.

T2 Relaxation Time Changes in the Distal Femoral Condylar Cartilage of Children and Young Adults with Discoid Meniscus.

ObjectiveTo investigate compositional changes in the distal femoral condylar cartilage (FCC) of children and young adults with and without discoid meniscus by T2 relaxation time mapping.DesignWe retrospectively reviewed knee magnetic resonance images including sagittal T2 maps of distal FCC performed in patients with or without discoid meniscus. Combined meniscal pathology such as degeneration or tears was also reviewed. Regions of interest were selected, and T2 relaxation time profiles were generated according to medial and lateral and FCC and according to weight-bearing and non-weight-bearing FCC. Nonparametric comparison tests using median values were performed.ResultsSeventy-nine knees from 73 patients (2-20 years) including 45 knees with lateral discoid meniscus (discoid group) were studied. T2 values of FCC showed negative correlation with age in both the discoid and nondiscoid groups (P < 0.01), except for medial weight-bearing FCC. In the discoid group, T2 relaxation times of lateral weight-bearing FCC (median, 46.5 ms) were lower than those of lateral non-weight-bearing (median, 53.2 ms; P < 0.001) and medial weight-bearing (median, 50.5 ms; P = 0.012) FCC. Lateral weight-bearing FCC also showed lower T2 values than other areas in patients with meniscal pathology in the discoid group. However, T2 relaxation times did not differ between the discoid and nondiscoid groups in patients without meniscal pathology.ConclusionsChildren and young adults with discoid meniscus have lower T2 relaxation times in lateral weight-bearing FCC compared with non-weight-bearing or medial FCC, suggesting compositional changes have occurred in these patients.

Quantitative Analysis of Magnetic Resonance Image Sagittal T2 Mapping in Lumbar Spine Classification

Objective: To evaluate the significance of T2 value changes of nucleus pulposus and annulus fibrosus in intervertebral disc degeneration, and to discuss feasibility and effectivity of intervertebral disc classification through MRI sagittal T2 mapping (specifically based on sagittal multi-echo SE sequence T2 mapping). Methods : 35 healthy volunteers (including 20 males and 15 females, aged 20 to 48, average age is 36.8) were randomly selected and their intervertebral discs of L3/L4, L4/L5 and L5/S1, with a sum-up of 90 discs, were scanned by sagittal MRI using routine FSE sequence as well as multi-echo SE sequence. T2 mapping was handled by image post-processing and each intervertebral disc was classified. T2 values of nucleus pulposus and annulus fibrosus were measured and statistical analysis were performed to study the relationship between T2 values and ages, disc grades or disc locations. Results: In classification through MRI sagittal T2 mapping, the disc grade increased along with the decrease of disc location or the increase of age. T2 value of nucleus pulposus decreased along with the increase of age (P &lt; 0.05). There was a significant difference in T2 mean values of nucleus pulposus of different grades (P &lt; 0.05). Conclusion: MRI sagittal T2 mapping provides us with a classification of intervertebral disc based on T2 values. Through evaluation of T2 mapping and measurement of T2 values of nucleus pulposus and annulus fibrosus, early stage degeneration of intervertebral disc can be monitored and the its relationship with relevant factors can be studied.

Characterization of Intervertebral Disc Changes in Asymptomatic Individuals with Distinct Physical Activity Histories Using Three Different Quantitative MRI Techniques.

(1) Background: Assessments of intervertebral disc (IVD) changes, and IVD tissue adaptations due to physical activity, for example, remains challenging. Newer magnetic resonance imaging techniques can quantify detailed features of the IVD, where T2-mapping and T2-weighted (T2w) and Dixon imaging are potential candidates. Yet, their relative utility has not been examined. The performances of these techniques were investigated to characterize IVD differences in asymptomatic individuals with distinct physical activity histories. (2) Methods: In total, 101 participants (54 women) aged 25–35 years with distinct physical activity histories but without histories of spinal disease were included. T11/12 to L5/S1 IVDs were examined with sagittal T2-mapping, T2w and Dixon imaging. (3) Results: T2-mapping differentiated Pfirrmann grade-1 from all other grades (p < 0.001). Most importantly, T2-mapping was able to characterize IVD differences in individuals with different training histories (p < 0.005). Dixon displayed weak correlations with the Pfirrmann scale, but presented significantly higher water content in the IVDs of the long-distance runners (p < 0.005). (4) Conclusions: Findings suggested that T2-mapping best reflects IVD differences in asymptomatic individuals with distinct physical activity histories changes. Dixon characterized new aspects of IVD, probably associated with IVD hypertrophy. This complementary information may help us to better understand the biological function of the disc.

ROLE OF MRI T2 MAPPING IN ASSESSMENT OF ARTICULAR KNEE CARTILAGE IN OSTEOARTHRITIS

Background: T2 mapping of hyaline cartilage is an imaging technique for the qualitative and quantitative detection of thecartilage providing convincing color mapping and quantitative detection of the cartilage mainly regarding architecture and changes in water content, proteoglycan, and collagen matrix ultra-structure associated with early cartilage degeneration.Aim Of Work: This work aims at elucidating the role of MRI complementary T2 mapping in assessment of articular knee cartilage for improving sensitivity of early detection of Osteoarthritis. Also, compare the articular cartilage T2 relaxation values in normal subjects and patients with osteoarthritis. Patients And Methods: This prospective case-control study wasapproved by the Ethical Committee of Scientific Research in Ain Shams University, and the informed consent was obtained. The material of this study included sixty (60) subjects, divided into two groups, 50 patients (symptomatic group: 33 men and 17 women) with clinical evidence of osteoarthritis, and 10 normal control group (asymptomatic group 8 men and 2 women) were included in this study, with their ages ranged between 19-75 years. All patients and controls underwent MR imaging of the knee joint. MR imaging was performed at 1.5 Tesla by using a routine protocol with the addition of a sagittal, coronal, or axial T2 mapping sequence or all. The standard imaging planes of the knee were evaluated with articular cartilage assessment as intact or not. Thereafter, these standard planes were evaluated together with T2 maps and articular cartilage was again assessed as of normal (<48ms) or elevated (≥48ms) T2 value in terms of milliseconds. Generalized estimating equation models were used to compare the sensitivity and specificity of the routine MR imaging protocol and T2 maps. Results: Both sensitivities and specificities were 82% and 100%, respectively, for the routine MR protocol alone and 100% and 90% after the addition of the T2 mapping to the routine MR protocol. The addition of T2 maps to the routine MR imaging protocol significantly improved the sensitivity (Binary Diagnostic test, p = 0.01). AComparison between patients and controls as regards T2 values showed a highly statistically significant difference (Independent TTest, P<0 .001). Conclusion: A combination of both morphological and T2 mapping MRI, together with clinical evaluation represents a desirable multi-modal approach to the diagnosis of osteoarthritis. T2 mapping, as a biochemically sensitive MRI sequence of the knee improves sensitivity from 82% to 100% to detect early structural degeneration with better diagnostic information in the knee articular cartilage.

Role of MRI in Evaluation of Anterior Knee Pain

Abstract Background: MRI is well known for being particularly useful for scanning and detecting abnormalities in soft tissue structures like the cartilage tissues, tendons, and ligaments. Moreover, MRI can also aid in determining those patients with knee injuries who will require surgical intervention. MR imaging is recognized as a standard procedure and has replaced diagnostic arthroscopy as the primary diagnostic modality for many knee pathologies. Furthermore, MR images can be used to assess anatomic variants that may contribute to chronic patellar instability. Aim of Study: To go over several of the most common causes of Anterior Knee Pain (AKP), with emphasis on their MRI findings with the goal of allowing diagnosis that is more accurate and grading of some of the most common pathologies, for interpreting, reaching an efficient treatment and drastic improvement of this common complaint. Patients and Methods: This study included 25 patients (8 females and 17 males). Their ages ranging between 10-60 years (average age 30 years). All presented by anterior knee pain and were referred to Radiology Department of Ain Shams University Hospital or private centers for MRI examination after orthopedic consultation. This descriptive study was done to detect the role of MRI in the evaluation of anterior knee pain and apply advanced MRI techniques such as sagittal T2 mapping to visualize the articular cartilage of the knee. Most patients were subjected to MR imaging of the affected knee joints on high field strength scanners using Philips scanners Achieva or Intera (1.5T). Results: The present study revealed that 26% patellar tendon disorders which included (patellar Tendinopathy 21% and Osgood Schlatter disease 5%). Quadriceps tendon disorders represented 10% and they are including (Quadriceps Tendin-opathy 5% and Quadriceps tendon tear 5%). 69% of the sample size showed Patellar disorders represent and they are including (chondromalacia patella 32%, patellar instability 21%, transient patellar dislocation 11% and painful bipartite patella 5%). Hoffa's disease was demonstrated in 21% of the sample size and they are including (Hoffa impingement syndrome and Hoffa ganglion cyst), finally we have torn anterior horn of the lateral meniscus and they represent 5%. Conclusion: MRI is generally safe, accurate, and specific modality, which has been proven to be the modality of choice in the diagnosis of different knee pathologies that cause anterior knee pain in different age groups. Also it has a high specification in detecting the grades and types of some of these diseases or factors predispose to them as patella Alta and trochlear dysplasia.

Evaluation of Knee Cartilage Diurnal, Activity, and BMI-Related Variations Using Quantitative T2 Mapping MRI and Fitbit Activity Tracking.

The aim of this study is to evaluate diurnal variation in knee cartilage 3 Tesla magnetic resonance imaging (MRI) T2 mapping relaxation times, as well as activity- and body mass index (BMI)-dependent variability, using quantitative analysis of T2 values from segmented regions of the weight-bearing articular surfaces of the medial and lateral femoral condyles and tibial plateaus. Ten healthy volunteers' daily activity (steps) were tracked with Fitbit pedometers. Sagittal MRI T2 maps were obtained in the morning and afternoon on days 2 and 3. Mean T2 values were analyzed for variation related to the number of steps taken (activity), time of day (diurnal variation), and BMI using mixed effect model. Significant (albeit small) differences in the medial femoral and medial tibial cartilage regions were identified between morning and afternoon scans (diurnal variation). Daily activity did not result in significant changes and increasing BMI only demonstrated a slight increase in T2 values for the lateral tibial plateau. These findings suggest that it may be necessary to control diurnal variation when using quantitative MRI T2 mapping to assess articular cartilage longitudinally in healthy participants. Further investigation is needed to confirm these findings and determine if they also apply to symptomatic patients.

The importance of level stratification for quantitative MR studies of lumbar intervertebral discs: a cross-sectional analysis in 101 healthy adults

PurposeTo investigate whether quantitative T2-times depend on lumbar intervertebral disc (IVD) level.MethodsThe lumbar spine (Th12/L1–L5/S1) of 101 participants (53.5% female, 30.0[± 3.6]years, 173.5[± 9.6]cm and 69.9[± 13.4]kg), without history of back pain, was examined on a 3T scanner with sagittal T2-mapping. All IVDs were stratified according to Pfirrmann grade and lumbar level, with mean T2-time determined for the entire IVD volume and in five subregions of interests.ResultsSignificant level-dependent T2-time differences were detected, both for the entire IVD volume and its subregions. For the entire IVD volume, Pfirrmann grade 2 IVDs displayed 9–18% higher T2-times in Th12/L1 IVDs compared to L2/L3–L5/S1 IVDs (0.001 > p < 0.004) and significantly different T2-times in L1/L2–L2/L3 IVDs compared to most of the IVDs in the lower lumbar spine. In Pfirrmann grades 1, 3 and 4 IVDs, no significant level-dependent T2-time differences were observed for the entire IVD. More pronounced results were observed when comparing IVD subregions, with significant level-dependent differences also within Pfirrmann grade 1 and grade 3 IVDs. For example, in posterior IVD subregions mean T2-time was 80–82% higher in Th12/L1 compared to L3/L4–L4/L5 Pfirrmann grade 1 IVDs (p < 0.05) and 10–14% higher in L5/S1 compared to L3/L4–L4/L5 Pfirrmann grade 3 IVDs (0.02 > p < 0.001).DiscussionSignificant level-dependent T2-time differences within several Pfirrmann grades, both for the entire IVD volume and for multiple IVD subregions, were shown in this large cohort study. The T2-time differences between levels existed in both non-degenerated and degenerated IVDs. These findings show the importance of stratifying for lumbar level when quantitative IVD studies are performed using T2-mapping.Graphic abstractThese slides can be retrieved under Electronic Supplementary Material.

Method for co-registration of high resolution 3Tmagnetic resonance imaging with standing 0.5T magnetic resonance imagingto investigate weight bearing joints

Method for co-registration of high resolution 3Tmagnetic resonance imaging with standing 0.5T magnetic resonance imagingto investigate weight bearing joints

Prediction of Lumbar Disk Herniation and Clinical Outcome Using Quantitative Magnetic Resonance Imaging: A 5-Year Follow-Up Study.

The aim of this study was to assess the predictive value of T2 mapping at baseline with regard to the development of disk herniation and clinical outcome at a 5-year follow-up in patients with low back pain. Twenty-five symptomatic patients (13 male; mean age, 44.0 years; range, 24-64 years at baseline) were examined at 3 T magnetic resonance imaging, with a 5-year follow-up. Region of interest analysis was performed on 125 lumbar intervertebral disks on 2 central sagittal T2 maps. Absolute T2 relaxation times and a T2 value ratio of the posterior annulus fibrosus as a percentage of the nucleus pulposus (NPAF) were evaluated for each disk. All disks were graded morphologically using the Pfirrmann score. Roland-Morris Disability Questionnaires (RMDQ) and a visual analogue scale (VAS) were assessed for each patient at follow-up as a clinical end point and compared with diagnosed lumbar disk herniation. Statistical analysis was conducted by a biomedical statistician. Using the baseline NPAF ratio, follow-up development of herniation was predicted with an area under the curve (AUC) of 0.893 in a receiver operating characteristic curve. The same was done using the baseline nucleus pulposus T2, resulting in an AUC of 0.901. Baseline and follow-up NPAF, as well as baseline and follow-up nucleus pulposus T2, differed significantly (P < 0.001) between disks with no herniation, disks with herniation at baseline, and disks with new herniation at follow-up. Difference was still significant (all P < 0.001), when only testing for difference in degenerated discs with Pfirrmann score III to V. Calculating sensitivity and specificity for herniation prediction only in discs with Pfirmann III to V using a receiver operating characteristic, AUC was 0.844 with baseline herniations excluded.The lowest baseline nucleus pulposus T2 per patient correlated significantly with follow-up RMDQ (r = -0.517; P = 0.008) and VAS (r = -0.494; P = 0.012). The highest baseline NPAF correlated significantly with RMDQ (r = 0.462; P = 0.020), but not VAS (r = 0.279; P = 0.177). Quantitative T2 mapping may serve as a clinically feasible, noninvasive imaging biomarker that can indicate disks at risk for herniation and correlates with clinical outcome and subjective patient burden in a representative cohort of patients with low back pain.

Regional variation of ankle and hindfoot cartilage T2 mapping values at 3 T: A feasibility study

ObjectiveTo develop a method for T2 mapping of the entire tibiotalar/hindfoot articular surfaces and to examine regional T2 variation in asymptomatic volunteers, establishing necessary methods for future T2 mapping work in patients with ankle/hindfoot injury. Materials and methodsTwenty-six asymptomatic volunteers (11 female/13 male, aged 23–64 years in final analysis) underwent sagittal T2 mapping. Tibiotalar and hindfoot cartilage surfaces were segmented by two raters. The tibiotalar joint cartilage was divided into subregions to assess T2 variation across the joint. The articular surface and subregion mean T2 values were compared using Tukey post hoc pairwise comparisons to test for statistical significance. Results and conclusionMean ankle/hindfoot cartilage T2 ranged from 37 ± 3 to 47 ± 7 ms. Tibial plafond mean T2 was significantly different from the middle and posterior subtalar cartilage T2 (both articular surface comparisons resulted in P < .05). Talar dome mean T2 was significantly different from the posterior calcaneal-side and talar-side subtalar cartilage, and middle calcaneal-side subtalar cartilage (P < .05 for all comparisons). Tibial plafond middle versus lateral, anterior versus middle, middle versus posterior, and anterior versus posterior subregion T2 values were significantly different (P < .05 for all comparisons). Talar dome medial versus middle, middle versus lateral, anterior versus middle, and middle versus posterior subregion T2 values were significantly different (P < .05 for all comparisons). Ankle/hindfoot joint cartilage T2 mapping and segmentation was found to be feasible for all cartilage surfaces except the anterior subtalar joint facet. Mean T2 differed significantly between ankle/hindfoot joint and subregion cartilage in asymptomatic volunteers.

Maturation-Related Changes in T2 Relaxation Times of Cartilage and Meniscus of the Pediatric Knee Joint at 3 T.

The objective of our study was to use a T2 mapping sequence performed at 3 T to investigate changes in the composition and microstructure of the cartilage and menisci of the pediatric knee joint during maturation. This retrospective study was performed of MRI examinations of 76 pediatric knees without internal derangement in 72 subjects (29 boys [mean age, 12.5 years] and 43 girls [mean age, 13.0 years]) who were evaluated with a sagittal T2 mapping sequence. T2 relaxation time values were quantitatively measured in eight cartilage subregions and in the medial and lateral menisci. Wilcoxon rank sum and Kruskal-Wallis tests were used to analyze the relationship between cartilage and meniscus T2 relaxation time values and sex and skeletal maturation, respectively. A multivariate linear regression model was used to investigate the independent association between cartilage T2 relaxation time values and age, weight, and body mass index (BMI [weight in kilograms divided by the square of height in meters]). There were no significant sex differences (p = 0.26-0.91) in T2 relaxation time values for cartilage or meniscus. T2 relaxation time values in each individual cartilage subregion significantly decreased (p < 0.001) with progressive maturation. T2 relaxation time values in the lateral meniscus significantly increased (p = 0.001) with maturation, whereas T2 relaxation time values in the medial meniscus did not significantly change (p = 0.82). There was a significant association (p < 0.001) between cartilage T2 relaxation time values and age independent of weight and BMI, but no significant association between cartilage T2 relaxation time values and weight (p = 0.06) and BMI (p = 0.20) independent of age. Cartilage T2 relaxation time values significantly decreased in all cartilage subregions and meniscus T2 relaxation time values significantly increased in the lateral meniscus during maturation. These changes in T2 relaxation time values reflect age-related changes in tissue composition and microstructure.

Juvenile Osteochondritis Dissecans: Cartilage T2 Mapping of Stable Medial Femoral Condyle Lesions.

Purpose To determine whether a T2 mapping sequence could depict early changes in the composition and microstructure of cartilage overlying stable lesions of the medial femoral condyle in patients with juvenile osteochondritis dissecans (JOCD). Materials and Methods This retrospective study analyzed a sagittal T2 mapping sequence performed between September 1, 2015, and March 31, 2017, on 16 patients (10 boys and six girls; median age, 11.5 years) with 18 stable medial femoral condyle JOCD lesions and 18 age-, sex-, and skeletal maturation-matched control participants (11 boys and seven girls; median age, 11.5 years). Cartilage T2 values were quantitatively measured within regions of interest placed around the cartilage within and overlying the JOCD lesion in patients with JOCD and around the cartilage on the weight-bearing medial femoral condyle in patients with JOCD and controls. Wilcoxon signed rank and Wilcoxon rank sum tests were used to compare T2 values. Results T2 values were significantly higher (P < .001) for cartilage within the JOCD lesion than for cartilage overlying the JOCD lesion in patients with JOCD. However, there were no significant differences in T2 values between cartilage overlying the JOCD lesion and cartilage on the weight-bearing medial femoral condyle in patients with JOCD (P = .67) or in T2 values of the cartilage on the weight-bearing medial femoral condyle between patients with JOCD and controls (P = .30). Conclusion There were no significant quantifiable differences in T2 values of cartilage overlying stable JOCD lesions and normal cartilage on the medial femoral condyle, suggesting no substantial changes in cartilage composition and microstructure.

Feasibility of sagittal T2 mapping of the median nerve in patients with carpal tunnel syndrome

Purpose: To evaluate patients with carpal tunnel syndrome (CTS) by using 3-Tesla magnetic resonance imaging (MRI) sagittal T2 mapping of the median nerve for localization of abnormal regions. Material and Methods: Nine hands of seven patients with CTS and five hands of five healthy volunteers were evaluated using sagittal T2 mapping and axial spoiled gradient-echo (SPGR) images. Three regions of interest (ROIs) at the carpal tunnel (ROI-1 to ROI-3) and one control ROI distal to the carpal tunnel (ROIC) were defined on the median nerve and T2-ratios at ROI-1 to ROI-3 relative to ROI-C were calculated. The flattening ratio (F-ratio; width/height of the median nerve) was also calculated from the axial SPGR images. Results: On sagittal T2 mapping, the medial nerve of normal volunteers showed constant T2 values at all ROIs. In the patients with CTS, there was large variation in T2 among the ROIs and the region of highest T2 value varied among the patients. T2-ratios at ROI-2 and -3 and the F-ratios along all carpal tunnel levels were significantly higher in the patients with CTS than in the normal volunteers. A significant correlation was found between terminal latency and T2-ratio at ROI-2 but not between terminal latency and F-ratio. Conclusion: Sagittal T2 mapping was feasible for the localization of abnormal T2 regions of the median nerve in patients with CTS.

Quantitative mapping of glenohumeral cartilage in asymptomatic subjects using 3T magnetic resonance imaging.

The purpose of this study was to develop quantitative T2 mapping methodology in asymptomatic shoulders for the entire mappable region of the glenohumeral cartilage in the coronal and sagittal planes, to assess the feasibility and limitations of the development of a diagnostic tool for future application in symptomatic patients. Twenty-one asymptomatic volunteers underwent sagittal and coronal glenohumeral T2 mapping, as the spherical geometry of the humeral head obviates the need to evaluate the entire glenohumeral cartilage in a single plane. The humeral head cartilage orthogonal to the mapping plane was manually segmented in the sagittal and coronal planes, whereas the glenoid cartilage was segmented in the coronal plane. Cartilage T2 summary statistics were calculated and coverage in each mapping plane was qualitatively assessed. The mean ± standard deviation of the glenoid cartilage T2 was 38 ± 2ms. The coronal and sagittal mapping planes captured different regions of the humeral head with some overlap: inferior-medial to superior-lateral versus superior/superior-lateral to anterior-lateral and posterior-lateral respectively. The mean humeral head cartilage T2 in the coronal plane was 41 ± 3ms, which was significantly different (p < 0.05) from the sagittal plane mean of 34 ± 2ms. This study measured characteristic glenoid and humeral head cartilage T2 values over the area mappable with two planes. Importantly, this study demonstrated that two-dimensional mapping in a single plane or two combined planes cannot capture the entirety of the semi-spherical humeral head cartilage. This highlights the need for three-dimensional T2 mapping techniques in the shoulder.

Quantitative evaluation of knee cartilage and meniscus destruction in patients with rheumatoid arthritis using T1ρ and T2 mapping

ObjectiveTo calculate T1ρ and T2 values of articular cartilage and menisci in knee joints of patients with RA, and compare the values between RA patients and healthy volunteers, to gain insight into the pathogenesis of cartilage and meniscus degradation in patients with RA. Materials and methodsNine patients with RA and knee joints symptoms were enrolled in the study, twenty healthy volunteers without knee joint diseases were included as controls. Sagittal fat-saturated T1ρ and T2 mapping images were obtained on a 3T MR scanner (GE750, GE Healthcare, Waukesha, WI), using a dedicated 8-channel knee coil. In the T1rho mapping sequence, the amplitude of the spin-lock pulse was 500Hz, spin lock durations=10/20/30/50ms. In the T2 mapping sequence,TR/TE were 1794/6.5, 13.4, 27, 40.7ms. Both sequences were performed with the following parameters: flip angle (FA)=90°, matrix: 320×256, FOV: 16×16cm2, slice thickness: 3mm, bandwidth: 62.5kHZ, and a total scan time of 5:11min. T1ρ- and T2-mapping images were used for the segmentation of the articular cartilage of the patella, femoral trochlea, medial and lateral femoral condyle, medial and lateral tibial plateau. These images were also used for the segmentation of the anterior and posterior horns of the medial and lateral menisci with livewire semi-automatic segmentation algorithm of MATLAB. A Mann–Whitney U test was performed to compare the T1ρ and T2 values of the above mentioned regions between the two groups. ResultsT1ρ (Z=−3.913 to −2.121, P=0.000–0.034) and T2 (Z=−3.866 to −2.216, P=0.000–0.026) values of knee cartilage in patients with RA were higher than that in healthy volunteers, except the cartilage of the patella (T1ρ: Z=−1.273, P=0.203,T2: Z=−0.236, P=0.814) and lateral tibial plateau (T1ρ:Z=−1.037, P=0.317). The T1ρ (Z=−1.462 to 0.572, P=0.095–0.908) and T2 (Z=−1.461 to 0.278, P=0.153–0.764) values of medial and lateral menisci showed no difference between the two groups. ConclusionPatients with RA exhibit diffuse knee cartilage destruction in the medial and lateral tibiofemoral joints and in the femoral trochlea. However, we found no increase in T1ρ and T2 values in menisci, this finding warrants further investigation.

Correlation Between Expression of High Temperature Requirement Serine Protease A1 (HtrA1) in Nucleus Pulposus and T2 Value of Magnetic Resonance Imaging.

BackgroundDegrading enzymes play an important role in the process of disc degeneration. The objective of this study was to investigate the correlation between the expression of high temperature requirement serine protease A1 (HtrA1) in the nucleus pulposus and the T2 value of the nucleus pulposus region in magnetic resonance imaging (MRI).Material/MethodsThirty-six patients who had undergone surgical excision of the nucleus pulposus were examined by MRI before surgery. Pfirrmann grading of the target intervertebral disc was performed according to the sagittal T2-weighted imaging, and the T2 value of the target nucleus pulposus was measured according to the median sagittal T2 mapping. The correlation between the Pfirrmann grade and the T2 value was analyzed. The expression of HtrA1 in the nucleus pulposus was analyzed by RT-PCR and Western blot. The correlation between the expression of HtrA1 and the T2 value was analyzed.ResultsThe T2 value of the nucleus pulposus region was 33.11–167.91 ms, with an average of 86.64±38.73 ms. According to Spearman correlation analysis, there was a rank correlation between T2 value and Pfirrmann grade (P<0.0001), and the correlation coefficient (rs)=−0.93617. There was a linear correlation between the mRNA level of HtrA1 and T2 value in nucleus pulposus tissues (a=3.88, b=−0.019, F=112.63, P<0.0001), normalized regression coefficient=−0.88. There was a linear correlation between the expression level of HtrA1 protein and the T2 value in the nucleus pulposus tissues (a=3.30, b=−0.016, F=93.15, P<0.0001) and normalized regression coefficient=−0.86.ConclusionsThe expression of HtrA1 was strongly related to the T2 value, suggesting that HtrA1 plays an important role in the pathological process of intervertebral disc degeneration.