3-T T2 mapping magnetic resonance imaging for biochemical assessment of normal and damaged glenoid cartilage: a prospective arthroscopy-controlled study

The clinical application value of 3.0T magnetic resonance T2 mapping imaging in evaluating the degree of acetabular cartilage degeneration in joint replacement surgery running title: MRI and acetabular cartilage degeneration

BACKGROUND

To explore and compare the values of 3.0T magnetic resonance imaging (MRI) T2 mapping in evaluating the degree of acetabular cartilage degeneration in hip replacement surgery.

METHODS

A total of 26 elderly patients with femoral neck fractures who were scanned in 3.0T MRI T2 mapping quantification technique were included. Basing on MRI images, the degree of acetabular cartilage degeneration was classified into Grade 0, 1, 2, 3 and 4, according to the International Cartilage Repair Society (ICRS) scores. In addition, 8 healthy volunteers were included for control group.

RESULTS

By comparison with health population, T2 relaxation values in the anterior, superior, and posterior regions of acetabular cartilage in patients with femoral neck fracture were obviously increased (P < 0.001). Among the patients with femoral neck fractures, there were 16 hip joint with Grade 1-2 (mild degeneration subgroup) and 10 hip joints with Grade 3-4 (severe degeneration subgroup), accounting for 61.54% and 38.46%, respectively. Additionally, T2 relaxation values in the anterior and superior bands of articular cartilage were positively related to the MRI-based grading (P < 0.05); while there was no significant difference of T2 relaxation values in the posterior areas of articular cartilage between severe degeneration subgroup and mild degeneration subgroup (P > 0.05). Importantly, acetabular cartilage degeneration can be detected through signal changes of T2 mapping pseudo-color images.

CONCLUSION

3.0T MRI T2 mapping technology can be used to determine the degree of acetabular cartilage degeneration, which can effectively monitor the disease course.

Increased water content in multifidus muscles of young adults with chronic nonspecific low back pain detected by dual-energy CT and MRI

OBJECTIVES

To demonstrate the feasibility of better diagnosing young adults with chronic nonspecific low back pain (CNLBP) by measuring water content in paraspinal muscles using water-muscle decomposition technique in dual-energy CT (DECT) and T2-mapping in MRI.

METHODS

This prospective cross-sectional study included 110 young individuals (56 with CNLBP at age of 25.7 ± 2.0 years and 54 of asymptomatic at age of 25.1 ± 1.9 years) who underwent both MRI and DECT on the spine. T2 values on T2 mapping in MRI and water density (WD) value on water(muscle) images in DECT were generated at the L1-L4 levels for erector spinae muscle and L2-L5 for multifidus muscle. Pain duration time, Oswestry Disability Index (ODI), Visual Analogue Scale (VAS) were recorded for CNLBP patients. Difference of T2 value and WD between the two patient groups, and correlations between T2 value and WD, and T2 value and WD with clinical indicators were analyzed.

RESULTS

Compared with asymptomatic participants, the mean WD of multifidus muscle at L4-L5 and mean T2 values of multifidus muscle at L5 were significantly higher in CNLBP patients (all P < 0.05). T2 values had moderate to strong positive correlations (r = 0.34-0.60, all P < 0.05) with DECT WD in CNLBP patients and healthy volunteers. There was a weak correlation between VAS and WD in L5-level multifidus muscle (r = 0.29, P < 0.05).

CONCLUSIONS

The T2 values in MRI and WD in DECT are higher in multifidus muscles of lower vertebra levels for young CNLBP patients, and there exists positive correlation between WD and T2 values, providing useful information for diagnosing CNLBP.

Difference in quantitative MRI measurements of cartilage between Wiberg type III patella and stable patella based on a 3.0-T synthetic MRI sequence

Purpose

The purpose of this study was to investigate the difference between the quantitative MRI values of Wiberg type III and stable patellar cartilage, and to improve the accuracy of MRI quantification in early patellar cartilage damage.

Methods

The knee joints of 94 healthy volunteers were scanned by a GE Signa Pioneer 3.0-T synthetic MRI machine. According to the Wiberg classification, the patella was divided into types I-III. Types I-II made up the stable patella group, and type III made up the unstable patella group. Two radiologists independently measured patellar cartilage thickness and quantitative synthetic MRI values (T1, T2, PD) in both groups. Interobserver agreement for quantitative variables was assessed using the Bland-Altman method. A third radiologist assessed differences in measurements.

Results

The medial T2 and T1 value of Wiberg III patella did not show a normal distribution (all P > 0.05). Compared with the stable group, the Wiberg type III group had thinner cartilage of the medial surface of the patella (P < 0.05), lower cartilage T2 and PD values (P < 0.05), but a similar cartilage T1 value (P > 0.05). There was no significant difference in the cartilage thickness, T1, T2, or PD value of the lateral patella between the Wiberg type III and the stable group (P > 0.05).

Conclusion

There were certain differences in the cartilage thickness of the medial surface of the patella and the quantitative value of synthetic MRI in Wiberg type III patellas. Quantitative studies of patellar cartilage MRI measurements need to consider the influence of patellar morphology.

3-Tesla T2 Mapping Magnetic Resonance Imaging for Evaluation of SLAP Lesions in Patients with Shoulder Pain: An Arthroscopy-Controlled Study

This study investigated the ability of T2 mapping to assess the glenoid labrum and to differentiate between healthy labral substances and superior labral anterior posterior (SLAP) lesions using arthroscopy as the gold standard. Eighteen patients (mean age: 52.4 ± 14.72 years, 12 men) with shoulder pain were examined using 3-Tesla T2 mapping. All the patients underwent shoulder arthroscopy. Using morphological sequences for correlation, regions of interest covering the entire labral substance were placed in the corresponding T2 maps. The diagnostic cutoff values, sensitivities, and specificities, as well as the inter-reader correlation coefficients (ICCs) determined by two independent radiologists, were calculated. The mean T2 value was 20.8 ± 2.4 ms for the healthy labral substances and 37.7 ± 10.63 ms in the patients with SLAP lesions. The maximum T2 value in normal labrum (21.2 ms) was lower than the minimum T2 value in the patients with SLAP lesions (27.8 ms), leading to sensitivities, specificities, and positive and negative predictive values of 100% (95% CI 54.1-100.0) for all the cutoff values between 21.2 and 27.8 ms. The ICCs ranged from 0.91 to 0.99. In summary, the data suggest that evaluation and quantification of the labral (ultra)structural integrity using T2 mapping may allow discrimination between arthroscopically confirmed SLAP lesions and a healthy glenoid labrum. T2 mapping may therefore be helpful in diagnosing patients with suspected labral damage.

Quantitative T2 mapping monitoring the maturation of engineered elastic cartilage in a rabbit model

BACKGROUND

Cartilage tissue engineering provides a promising approach to reconstruct craniofacial defects, and a noninvasive method is needed to assess its effectiveness. Although magnetic resonance imaging (MRI) has been used to evaluate articular cartilage in vivo, few studies focused on its feasibility in monitoring engineered elastic cartilage (EC).

METHODS

Auricular cartilage, silk fibroin (SF) scaffold, and EC consisting of rabbit auricular chondrocytes and SF scaffold were transplanted subcutaneously into the rabbit back. In eight weeks after transplantation, grafts were imaged by MRI using PROSET, PDW VISTA SPAIR, 3D T2 VISTA, 2D MIXED T2 Multislice, and SAG TE multiecho sequences, followed by histological examination and biochemical analysis. Statistical analyses were performed to identify the association between T2 values and biochemical indicator values of EC.

RESULTS

In vivo imaging shows that 2D MIXED T2 Multislice sequence (T2 mapping) clearly distinguished the native cartilage, engineered cartilage and fibrous tissue. T2 values showed high correlations with cartilage-specific biochemical parameters at different time points, especially the elastic cartilage specific protein elastin (ELN, r= -0.939, P < 0.001).

CONCLUSION

Quantitative T2 mapping can effectively detect the in vivo maturity of engineered elastic cartilage after subcutaneously transplantation. This study would promote the clinical application of MRI T2 mapping in monitoring engineered elastic cartilage in the repair of craniofacial defects.

Quantitative analysis of triangular fibrocartilage complex injury by 3.0T MR 3D VIBE and T2 mapping techniques

To evaluate triangular fibrocartilage complex (TFCC) injury based on quantitative analysis of fibrocartilage by 3.0T MR 3D VIBE and T2 mapping techniques. In this study, 25 patients with TFCC (15 patients with unilateral injury and 10 patients with bilateral injury) and 30 healthy subjects were enrolled. All 55 participants underwent bilateral wrist joint routine plain scan + enhanced scan, 3D VIBE and T2 mapping sequence scan. The 2 hands were divided into the dominant group and the non-dominant hand group. Pseudo-color images of T2 mapping were obtained through the post-processing workstation. Except for the meniscus homologue, there were statistical differences in the overall mean T2 value of all other regions between the injured group and the healthy group (P < .001). The T2 value of each region in the injury group was statistically different in the pairwise comparison (all P < .02). There was no statistical difference in the overall mean T2 value between the dominant hand group and the non-dominant hand group. 3.0T MR 3D VIBE and T2 mapping techniques are helpful for the evaluation of TFCC injury and the quantitative analysis of fibrocartilage. The parameters can reflect molecular changes of fibrocartilage injury, and T2 values are not affected by dominant hand, age and gender.

The Cartilage Wear Index: A new evaluation method to improve patient selection in surgical treatment of recurrent posterior glenohumeral instability

Background

The purpose of this study was to validate glenoid cartilage lesions as a negative prognostic factor and to define a new image-based preoperative evaluation method to identify surgical candidates for arthroscopic labral refixation with suture anchors in posterior shoulder instability.

Methods

Twenty-six patients who underwent arthroscopic posterior labral repair for shoulder instability were evaluated. Only patients with structural dynamic posterior instability were included. We evaluated on preoperative magnetic resonance arthrogram: glenoid version, humeral head subluxation, type of capsular insertion, and the cartilage lesions using the new Cartilage Wear Index (CWI). Two subgroups were analyzed with regard to the preoperative CWI and shoulder outcome scores: Single Assessment Numerical Evaluation (SANE) and Western Ontario Shoulder Instability Index (WOSI).

Results

The median age at operation was 28 (interquartile range = 21-33) years. Median overall postoperative outcome assessment demonstrated a SANE of 90 and a WOSI of 385. The median CWI was 1.02. Subgroup analysis revealed worse median WOSI and SANE scores in patients with a CWI >1.02 and a strong correlation between a high preoperative CWI and a higher postoperative WOSI score (R = 0.58; P = .038).

Conclusion

The CWI can be useful to identify patients who might obtain better outcomes when treated with arthroscopic labral repair in posterior shoulder instability.

Quantitative T2 mapping of the glenohumeral joint cartilage in asymptomatic shoulders and shoulders with increasing severity of rotator cuff pathology

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Glenohumeral cartilage T2 values were correlated to increasing rotator cuff pathology severity.

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Massive tear versus lesser injury differences were most evident in superior humeral cartilage.

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Sagittal T2 mapping best captures superior humeral head cartilage change in massive tear patients.

Purpose

To examine the relationship between glenohumeral cartilage T2 mapping values and rotator cuff pathology.

Method

Fifty-nine subjects (age 48.2 ± 13.5 years, 15 asymptomatic volunteers and 10 tendinosis, 13 partial-thickness tear, 8 full-thickness tear, and 13 massive tear patients) underwent glenohumeral cartilage T2 mapping. The humeral head cartilage was segmented in the sagittal and coronal planes. The glenoid cartilage was segmented in the coronal plane. Group means for each region were calculated and compared between the groups.

Results

Massive tear group T2 values were significantly higher than the asymptomatic group values for the humeral head cartilage included in the sagittal (45 ± 7 versus 32 ± 4 ms, p <  .001) and coronal (44 ± 6 versus 38 ± 1 ms, p =  0.01) plane images. Mean T2 was also significantly higher for massive than full-thickness tears (45 ± 7 versus 38 ± 5 ms, p =  0.02), massive than partial-thickness tears (45 ± 7 versus 34 ± 4 ms, p <  0.001), and massive tears than tendinosis (45 ± 7 versus 35 ± 4 ms, p =  0.001) in the sagittal-images humeral head region and significantly higher for massive tears than asymptomatic shoulders (44 ± 6 versus 38 ± 1 ms, p =  0.01) in the coronal-images humeral head region.

Conclusion

Humeral head cartilage T2 values were significantly positively correlated with rotator cuff pathology severity. Massive rotator cuff tear patients demonstrated significantly higher superior humeral head cartilage T2 mapping values relative to subjects with no/lesser degrees of rotator cuff pathology.