Keywords: Osteoarthritis, MSK

Motivation: While radiomics has been applied to various MRI data to predict knee osteoarthritis (KOA) incidence, there is a lack of knowledge on the combination of radiomics features from different knee structures.

Goal(s): To assess the ability of MRI-based radiomic features extracted from automatically segmented femur, tibia, patella, and infrapatellar fat pad to predict KOA incidence.

Approach: 710 DESS MRIs were segmented using deep learning, trained with 30 manually delineated images. KOA incidence was predicted using Elastic Net, based on radiomic features from the four knee structures.

Results: The model combining features from the four knee structures resulted in a ROC AUC of 0.65.

Impact: While further research should be conducted to improve the accuracy of the developed radiomics pipeline in order to improve its applicability in clinical practice, radiomic features gathered from different knee structures are promising imaging biomarkers for early KOA prediction.

Keywords: Muscle, Fat, Muscle, fat fraction, fatty infiltration, hip OA

Motivation: Hip abductor muscles have a fundamental role in walking and other daily physical tasks. Relating hip abductor muscle fat fractions to patient-reported hip outcomes at a later timepoint could provide insights on exercise targets for patients with hip osteoarthritis who may become candidates for total hip arthroplasty.

Goal(s): The study seeks to determine if hip abductor muscle fat fractions predict patient-reported hip outcomes after 4 years.

Approach: Linear mixed-effects regressions were performed to investigate relationships between baseline hip abductor fat fractions and PROMS at follow-up.

Results: Higher baseline TFL fat fraction was associated with worse patient-reported hip pain scores at 4-year follow-up.

Impact: Our findings suggest performing further research into tensor fascia lata fat fraction in relation to future clinical outcomes for patients with hip osteoarthritis.

Keywords: Osteoarthritis, Osteoarthritis

Motivation: The three-dimensional ultrashort echo time adiabatic T1ρ (3D UTE-AdiabT1ρ) sequence can provide magic angle-insensitive evaluation of proteoglycan depletion in both short- and long-T2 tissues in the knee joint. 

Goal(s): Our goal was to assess its clinical performance. 

Approach: We applied this sequence to healthy volunteers and patients with different degrees of osteoarthritis.

Results: The sequence could be used for quantitative evaluation of meniscus degeneration. The UTE-AdiabT1ρ values in different subregions showed a significant positive relationship with WORMS, Stoller grades and KL groups. The 3D UTE-AdiabT1ρ biomarker can diagnose meniscal degeneration at an early stage.

Impact: The 3D UTE-AdiabT1ρ sequence allows quantitative imaging of the menisci. The UTE-AdiabT1ρ biomarker can diagnose meniscal degeneration at an early stage. Early detection of compositional changes in the menisci is of critical importance in avoiding or slowing down OA progression.

Keywords: Bone, fMRI

Motivation: Evaluation of sacroiliac subarticular bone marrow edema for active inflammation of ankylosing spondylitis（AS）before and after biologic treatment. 

Goal(s): MRI T2 mapping, DWI and SPARCC scores were used to compare the changes of BME in patients with AS before and after biologic treatment. 

Approach: DWI, SPARCC scores and T2mapping were compared to evaluate the changes of bone marrow edema in patients with sacroiliac arthritis alone or in combination. 

Results: The integrated diagnostic efficacy of DWI and T2 mapping demonstrates an optimal performance.

Impact: The combined application of magnetic resonance diffusion-weighted imaging (DWI), T2 mapping, and STIR-T2WI SPARCC scores provides an effective quantitative method for the clinical evaluation of the therapeutic efficacy of biologics in AS.

Keywords: Functional/Dynamic, fMRI (resting state)

Motivation: Understanding the neuropathological mechanisms of chronic ankle instability (CAI) is clearly of interest to both the practicing clinician and researchers on sports medicine.

Goal(s): Ankle proprioception deficits occur in patients with CAI. The underlying central neuropathology is unclear. This study examined cerebellar vermis structure/function in CAI patients vs controls and associations with proprioception deficits.

Approach: This research is a cross-sectional laboratory investigation.

Results: Patients with CAI showed reduced gray matter volume (VBM) and increased functional connectivity (fALFF) in cerebellar vermis subregions IV/V compared to controls. Proprioceptive deficits in CAI patients were associated with lower VBM and higher fALFF values in these subregions.

Impact: We hope the similar strategies could be applied to modulate our observed compensatory overactivation of vermis, make cerebellum more more efficient when handling the increased proprioceptive demands, and finally bring optimal clinical function to the patients with CAI.

Keywords: Cartilage, Quantitative Imaging

Motivation: It is important to examine and correct inter-scanner variability of T1rho/T2 values to improve the accuracy of longitudinal studies

Goal(s): To evaluate the inter-scanner variability of T1rho/T2 values and measure longitudinal changes in hip cartilage T1rho/T2 values after calibration.

Approach: TCalibrate the hip cartilage T1rho/T2 values using Voxel-based relaxometry  and Z-score normalization techniques

Results: The T1rho/T2 values showed that there was no statistically significant cartilage region (p<0.05) between the scanners. The longitudinal results showed an increase in number of subjects showing positive slope was increased in T1rho/T2 values after calibration (36.84 and 34.21%) compared without calibration (15.8% for both T1rho/T2).

Impact: The technique used for reducing the inter-scanner variability of T1rho/T2 values may benefit the longitudinal assessments of hip OA, specifically for evaluating disease progression over time on different scanners/before and after scanner upgrades

Keywords: Cartilage, Quantitative Imaging

Motivation: Validation of compressed sensing accelerated T1rho dispersion measurement of spontaneously degenerated human cartilage tissue samples. 

Goal(s): To study the effect the data reduction has on the ability to detect differences between the intact and degenerated articular cartilage specimens at different spin-lock amplitudes.

Approach: T1rho dispersion measurement with compressed sensing technique for reconstruction.

Results: Four-fold acceleration of T1rho dispersion measurement by compressed sensing approach was feasible without loss in the sensitivity to osteoarthritic changes within the articular cartilage. Differences were significant between intact and OA groups in the superficial and transitional zones, and T1rho correlated moderately with the reference methods.

Impact: Compressed sensing allowed reducing the scan-time required for measurement of T1rho dispersion, while still retaining the ability to detect degenerative changes in articular cartilage. Thus, the study brings T1rho dispersion measurements closer to clinical viability.

Keywords: Other Musculoskeletal, MSK

Motivation: 3D DIR-UTE can provide high short T2 contrast that is useful in knee imaging, however with a prohibited long acquisition time. 

Goal(s): The goal is to maintain high short-T2 contrast while significantly reducing the acquisition time.

Approach: The approach involves employing an accelerated IR-prepared fat-saturation UTE sequence along with advanced compressive sensing reconstruction.

Results: This approach achieved a threefold acceleration without sacrificing image quality and produced high short-T2 contrast, making structures like the meniscus and ligament clearly visible.

Impact: This technique holds potential for various musculoskeletal applications, such as in the early detection of conditions such as osteochondral junction alterations, osteoarthritis and meniscal tears.

Keywords: Osteoarthritis, Contrast Agent

Motivation: There is still a lack of noninvasive technique in quantifying the acidic extracellular pH of damaged cartilage in early osteoarthritis (OA).

Goal(s): We aimed to fabricate an advance reactive oxygen species (ROS) responsive CEST-MRI contrast agent for damaged cartilaged imaging and treatment in OA.

Approach: We use CEST-MRI to investigate whether our sythesized PLGE-TK-PEG@PDA-SA nanoparticles repond to ROS accumulating in damaged cartilage could result in the exsistance of CEST signal, while no CEST signal would be tested in normal cartilage without excessive ROS.

Results: The PLGA-TK-PEG@PDA-SA nanoparticles could effectively respond to ROS and then produce significant CEST effect for precisely pH measurement.

Impact: The novel PLGA-TK-PEG@PDA-SA CEST- MRI contrast  could be used to noninvasively monitor the extracellular pH of cartilage in osteoarthritis, and eliminate excessive ROS to defend against its damage to cartilage. This smart, sensitive ROS-responsive nanoprobe is promising for OA theranostics.

Keywords: Other Musculoskeletal, MSK

Motivation: MRI-based texture features have been used to identify abnormalities within the infrapatellar fat pad (IPFP) of middle-aged to elderly adults, yet no existing investigations have evaluated IPFP quality in young athletes.

Goal(s): To quantify and compare texture features of the IPFP in collegiate athletes comprised of men and women basketball players and swimmers.

Approach: Image texture features of the IPFP were calculated from bilateral MRIs acquired at 2 time points. (baseline and 1 yr. follow-up) for collegiate men and women basketball and swimming athletes.

Results: The IPFP of collegiate basketball players significantly differed from the swimmers, with greater global and local image homogeneity.

Impact: While the texture features of swimmer IPFPs remained consistent across sexes and timepoints, swimmers had significantly greater texture heterogeneity than basketball players at baseline. Observed variability indicates the need for further longitudinal investigation of IPFP structure within low impact sports.

Keywords: Other Musculoskeletal, MSK

Motivation: The detection of structural damage of the sacroiliac joint is essential for diagnosing axial spondyloarthritis.

Goal(s): To assess the diagnostic performance of FRACTURE sequence in detecting structure lesions compared to CT.

Approach: A retrospective study was conducted on 83 patients with definite axial SpA who underwent MRI and CT scans of the sacroiliac joint between 2021 and 2022.  An overall impression of sacroiliitis grade was also provided according to the scoring system of the modified New York criteria.

Results: When compared to CT as the standard, FRACTURE demonstrated high agreement with AUC values of 0.908, 0.943, 0.918 and 0.944 for sacroiliitis grade.

Impact: FRACTURE can evaluate structural lesions and demonstrate good diagnostic performance in patients with SpA.

Keywords: Other Musculoskeletal, MSK, Implant mode scan, Prescan, Calibration, Mavric

Motivation: Patients are often unaware of the presence and location of metal implants, which may be confirmed only after localizer scan, thus potentially disrupting workflow.  

Goal(s): To detect the presence of metal implant within the first few seconds of prescan and further characterize the location and shape of the metal from the calibration.

Approach: Prescan data of phantom with metal screws and human volunteer with metallic implants were used.

Results: The skewness of the center frequency signal is from 1.37 to 4.47 for implants, while for normal subjects, the signal is very symmetric and the calculated skewness is <0.3.

Impact: Automated MR scanning workflow for the patients with implants to improve efficiency of the MR technologists.

Keywords: Cartilage, Inflammation

Motivation: Cartilage abnormalities of the sacroiliac joints (SIJs) in spondyloarthritis(SpA) manifest as degeneration, fragmentation and erosions, fibrosis, and ossification.

Goal(s): To test whether MULTIPLEX(MTP) sequence of the sacroiliac joints (SIJs) might help identifying patients with SpA.

Approach: This study included 20 patients with axial SpA and 20 controls who prospectively underwent SIJs MRI using an oblique coronal MTP sequence.

Results: The PD and T2* values of cartilage in patients with SpA were significantly higher than those of healthy volunteers, p<0.05. There was no statistical difference between SpA and healthy group in T1 values of SIJ cartilage, P>0.05.

Impact: The MTP sequence represents a significant advancement in the imaging of SpA. By providing quantitative PD and T2* values of the SIJ cartilage, it offers a novel  tool for the early diagnosis of SpA.

Keywords: Cartilage, Quantitative Imaging

Motivation: Combing T2 mapping with routine knee MRI increase diagnostic efficacy especially early identification of joint degeneration.

Goal(s): To explore the feasibility of high-resolution deep-learning reconstruction (DLR) synthetic MRI with equivalent to higher diagnosis performance using conventional routine knee MRI as reference.

Approach: To test reliability of T2 mapping for in vitro phantom and in vivo human knees and explore the image quality of DLR synthetic contrast MR images in comparison with conventional MR images.

Results: DLR synthetic MRI offer reliable T2 mapping and provide sufficient image quality for diagnosis of knee.

Impact: There has been always a demand for high-resolution knee MRI acquisition and straightforward diagnosis in clinics. DLR synthetic MRI is a rapid-acquisition and high-image-quality contrast images and quantitative maps and may improves diagnosis, prognosis and follow-ups. 

Keywords: Cartilage, MSK, cartilage, osteoarthritis, IR-ZTE MR imaging

Motivation: The recently developed IR-ZTE MR technique is being proposed to have osteochondral junction (OCJ) region detection capability. The signal source in IR-ZTE imaging of the OCJ remains to be investigated. Validation by histology would provide strong corroboration of the signal sources. 

Goal(s): Our goal was to evaluate the correlation between the knee cartilage signal using IR-ZTE and degree of histological degeneration. 

Approach: Three patients were imaged using IR-ZTE before total knee replacement. Histological analysis was performed using the OARSI osteoarthritis cartilage histopathology assessment system.

Results: Results demonstrated that the signal changes of IR-ZTE was correlated strongly degree of histological degeneration in knee cartilage.

Impact:  IR-ZTE signal seems to serve as an in vivo indicator of the cartilage degeneration in knee OA progression.