Multiparametric MR imaging reveals early cartilage degeneration at 2 and 8 weeks after ACL transection in a rabbit model

Abstract

In this study, the rabbit model with anterior cruciate ligament transection (ACLT) was used to investigate early degenerative changes in cartilage using multiparametric quantitative magnetic resonance imaging (qMRI). ACLT was surgically induced in the knees of skeletally mature New Zealand White rabbits (n = 14). ACL transected and contralateral knee compartments—medial femur, lateral femur, medial tibia, and lateral tibia—were harvested 2 (n = 8) and 8 weeks (n = 6) postsurgery. Twelve age‐matched nonoperated rabbits served as control. qMRI was conducted at 9.4 T and included relaxation times T1, T2, continuous‐wave T1ρ (CWT1ρ), adiabatic T1ρ (AdT1ρ), adiabatic T2ρ (AdT2ρ), and relaxation along a fictitious field (TRAFF). For reference, quantitative histology and biomechanical measurements were carried out. Posttraumatic changes were primarily noted in the superficial half of the cartilage. Prolonged T1, T2, CWT1ρ, and AdT1ρ were observed in the lateral femur 2 and 8 weeks post‐ACLT, compared with the corresponding control and contralateral groups (P < .05). Collagen orientation was significantly altered in the lateral femur at 2 weeks post‐ACLT compared with the corresponding control group. In the medial femur, all the studied relaxation time parameters, except TRAFF, were increased 8 weeks post‐ACLT, as compared with the corresponding contralateral and control groups (P < .05). Similarly, significant proteoglycan loss was observed in the medial femur at 8 weeks following surgery (P < .05). Multiparametric MRI demonstrated early degenerative changes primarily in the superficial cartilage with T1, T2, CWT1ρ, and AdT1ρ sensitive to cartilage changes at 2 weeks after surgery.

Evaluation of articular cartilage with quantitative MRI in an equine model of post‐traumatic osteoarthritis

“…It is known that degenerative OA changes in articular cartilage are progressive and commonly initiate from the superficial zone. [30][31][32] The results of this study suggest that degeneration in PTOA propagates from the lesions to the adjacent tissues starting from the superficial zones. These findings suggest the potential of qMRI parameters in tracking the progression of PTOA from a cartilage lesion towards the surrounding cartilage tissue.…”

Human Umbilical Mesenchymal Stromal Cells Mixed with Hyaluronan Transplantation Decreased Cartilage Destruction in a Rabbit Osteoarthritis Model

“…MRI can detect the cartilage in the early phase of its destruction in the rabbit OA model (can detect early at 4 weeks post-ACLT surgery) [ 45 ]. Recently, MRI was reported to detect cartilage lesions early at two weeks after surgery [ 46 ]. In our study, we only detected cartilage destruction at 6 weeks and 12 weeks after surgery.…”

“…Second, the resolution of MRI was low in our study. A high resolution, such as 9 T, would be better for the early detection of early cartilage defects [ 46 ]. Third, the IHC findings showed no significant results, which may be due to the small sample size.…”

Longitudinal T2 Mapping and Texture Feature Analysis in the Detection and Monitoring of Experimental Post-Traumatic Cartilage Degeneration

“…With the positive predictive value equally variable, morphologic MRI techniques are (i) not able to reliably indicate the presence (or absence) of cartilage lesions and (ii) particularly limited in detecting early, potentially reversible cartilage lesions. Consequently, quantitative MRI techniques such as T2 and T1ρ mapping have received ever-increasing scientific and clinical attention over the last decades [13,14]. These techniques quantify biophysical tissue properties on the compositional and ultrastructural level beyond mere morphology.…”

“…Widely available on clinical MRI scanners and conveniently acquired with an additional scan time of 5 min, the addition of a T2 mapping sequence to a routine imaging protocol improved sensitivity in the detection of (early) cartilage lesions [15]. T2 mapping is a robust, clinically and scientifically well-validated, and commonly used technique to assess cartilage status [13,14]. Moreover, T2 mapping is closely associated with relevant structural and compositional tissue features such as collagen content, collagen network organization and integrity, and water content [16].…”