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Objective:To explore the feasibility of MRI to assist the early diagnosis of midfoot tendon and ligament injuries.Methods:Fifty-two patients with midfoot ligament and tendon injuries who visited Beijing Jishuitan Hospital from September 2016 to December 2021 were enrolled in the study, and 20 healthy volunteers were recruited as controls. All participants underwent mid foot coronal (short axis), sagittal, and axial (long axis) MRI T1 weighted imaging and proton fat suppression sequence examination. The MRI images were evaluated by 2 senior radiologists independently.Results:The consistency of the two radiologists in diagnosis of tendons, ligaments, bones, and soft tissues were good ( κ=0.916, 0.896, and 0.893, respectively). The tendons and ligaments of the midfoot in 20 healthy volunteers (40 feet) showed uniform bands of varying thickness with slightly low signal intensity; the anterior tibial tendon showed a thin line shape, the posterior tibial tendon showed a slightly thick band with uniform low signal intensity, and the calcaneonavicular ligament showed a thin line-like low signal intensity running in different directions. In 52 patients with midfoot tendon and ligament injuries, 18 had anterior tibial tendon injuries, 20 had posterior tibial tendon injuries, and 14 had calcaneonavicular ligament injuries. The injured tendon or ligament was characterized by uneven thickness, blurred edges, and continuous interruption on T1WI sequence, uneven enhancement of signal in the tendon or ligament running area on PD-FS sequence, accumulation of fluid in the tendon sheath, and partial tearing. The partial tear showed discontinuity and thickening of tendons, while the complete tear showed that the tendons were interrupted and retracted, the fiber structure disappeared and was filled with liquid, and the surrounding soft tissue edema was present. Conclusion:MRI can clearly display the course and anatomical structure of the attachment end of the midfoot tendon and ligament, which may assist in early diagnosis of midfoot tendon and ligament injuries.
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Objective:To evaluate the application high-resolution 3.0-T magnetic resonance imaging (MRI) in diagnosis of ligament and tendon injuries of the forefeet.Methods:From September 2014 to August 2020, 40 patients with forefeet injury (40 forefoot) and 20 healthy subjects (40 forefoot) meeting the including and excluding criteria were enrolled into this retrospective study. All subjects underwent MRI T1-weighted image (T1WI) and fat suppression proton density-weighted imaging (PD-FS) scan on coronal planes, sagittal planes and axial planes, respectively. Then the MRI characteristics of tendons in forefoot of healthy subjects and patients with forefoot injuries were compared. In patients the MR features of ligament and tendons injury were compared with the surgical findings or follow-up results.Results:In 20 normal subjects the tendons and ligament of the forefoot showed homogeneous low-signal-intensity on T1WI and PD-FS images. In the 40 patients with forefoot injuries, 22 cases were confirmed by surgical findings and 18 cases were confirmed by follow-up results. There were 8 cases of collateral ligament injuries, including 2 cases with complete tear, 3 cases with partial tear and 3 cases with sprain; 2 cases of extensor tendon with partial tear; 8 cases of flexor tendon injuries, including 3 cases with complete tear, 3 cases with partial tear and 2 cases with sprain; 3 cases of abductor tendon with partial tear; 13 cases of plantar plate injuries; and 6 cases of Lisfranc ligament injuries including 5 cases with complete tear and 1 case with partial tear. The injured ligament and tendons presented thicker and discontinuity in T1WI; and demonstrated heterogeneously increased signal intensity with edema in the surrounding soft tissues in PD-FS. The partially torn ligament and tendons showed discontinuity and thickening; and the completely torn ligament and tendons showed that they were interrupted and retracted, fiber structure disappeared and was filled with liquid, and edema in the surrounding soft tissue.Conclusion:High resolution magnetic resonance imaging of the forefoot can demonstrate the anatomy and features of ligament and tendon injuries in forefoot accurately, which has clinical application value for the early diagnosis and accurate treatment of the injury.
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Magnetic resonance based electrical properties tomography (MREPT) is a different method from proton density imaging, Bloch-Siegert shift (BSS) is used in this paper to reconstruct the radiofrequency (RF) field amplitude and calculate the distribution of the permittivity constant. The phase of the RF field is approximated by the phase component of the magnetization intensity, and the conductivity distribution is calculated. In the experiment, Bruker 7.0 T magnetic resonance device was used to image two water models and in vivo Balb/c mice to obtain the image of electrical characteristics. Experimental results show that the Bloch-siegert B1+ image is significantly more efficient than the double-angle B1+ image. The study can provide a reference for selecting appropriate B1 mapping technology for B1 field imaging of electrical characteristics organizations, and provide basic research support for promoting the practical application of magnetic resonance characteristics.
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Animals , Mice , Algorithms , Magnetic Resonance Imaging , Magnetic Resonance Spectroscopy , Phantoms, Imaging , TomographyABSTRACT
OBJECTIVE To establish an in vitro blood-cerebrospinal fluid barrier (BCB) model to investigate the underlying mechanism of lead-induced BCB injuries.METHODS The in vitro BCB model was established by Z310 cells.Different concentrations of Pb(AC)2 (2.5,5.0 and 10.0 mmol·L-1) were used for 24,48 and 72 h.Transendothelial electrical resistance (TEER) and flux of FITC-dextran were performed to determine the permeability of the in vitro BCB model.Western blotting and immunofluorescence methods were used to observe the expression of tight junction protein ZO-1 and occludin.RESULTS Compared with control group,Pb(AC)2 2.5,5.0 and 10.0 mmol· L-1 exposure for 48 h to Z310 cells had no significant effect on survival rate and density.TEER in different groups was gradually increasing.At the 12th day after Pb(AC)2 exposure,the values of TEER and flux of FITC-dextran in Pb(AC)2 5 and 10 mmol· L-1 groups were significantly decreased (P＜0.05).Western blotting and immunofluorescence images showed that the expression of ZO-1 and occludin were significantly decreased (P＜0.05) after Pb(AC)2 exposure for 48 h.CONCLUSION Lead exposure can cause the breakdown of BCB barriers,and this effect may be mediated by reducing the expression of ZO-1 and occludin proteins.