Related Experiment Video
Updated: Dec 31, 2025
In vivo 19F MRI for Cell Tracking
Published on: November 25, 2013
In Vivo Magic Angle Magnetic Resonance Imaging for Cell Tracking in Equine Low-Field MRI
Carolin Horstmeier1, Annette B Ahrberg2, Dagmar Berner3
1Department for Horses, Faculty of Veterinary Medicine, University of Leipzig, An den Tierkliniken 21, 04103 Leipzig, Germany.
Abstract:
The magic angle effect increases the MRI signal of healthy tendon tissue and could be used for more detailed evaluation of tendon structure. Furthermore, it could support the discrimination of hypointense artefacts induced by contrast agents such as superparamagnetic iron oxide used for cell tracking. However, magic angle MRI of the equine superficial digital flexor tendon has not been accomplished in vivo in standing low-field MRI so far. The aim of this in vivo study was to evaluate the practicability of this magic angle technique and its benefit for tracking superparamagnetic iron oxide-labelled multipotent mesenchymal stromal cells. Six horses with induced tendinopathy in their forelimb superficial digital flexor tendons were injected locally either with superparamagnetic iron oxide-labelled multipotent mesenchymal stromal cells or serum. MRI included standard and magic angle image series in T1- and T2∗-weighted sequences performed at regular intervals. Image analysis comprised blinded evaluation and quantitative assessment of signal-to-noise ratio. The magic angle technique enhanced the tendon signal-to-noise ratio (P < 0.001). Hypointense artefacts were observable in the cell-injected superficial digital flexor tendons over 24 weeks and artefact signal-to-noise ratio differed significantly from tendon signal-to-noise ratio in the magic angle images (P < 0.001). Magic angle imaging of the equine superficial digital flexor tendon is feasible in standing low-field MRI. The current data demonstrate that the technique improves discrimination of superparamagnetic iron oxide-induced artefacts from the surrounding tendon tissue.
Insights
Magic angle MRI enhances equine tendon imaging and aids in distinguishing superparamagnetic iron oxide (SPIO) contrast agent artifacts. This technique is feasible for in vivo studies using standing low-field MRI.
Area of Science:
- Veterinary Medicine
- Biomedical Imaging
- Musculoskeletal Research
Background:
- The magic angle effect enhances MRI signal in healthy tendons, aiding structural evaluation.
- It can help differentiate hypointense artifacts from contrast agents like superparamagnetic iron oxide (SPIO) used in cell tracking.
- In vivo magic angle MRI of equine superficial digital flexor tendons in standing low-field MRI has not been previously achieved.
Purpose of the Study:
- To assess the feasibility of in vivo magic angle MRI for equine superficial digital flexor tendons.
- To evaluate the benefits of magic angle MRI for tracking SPIO-labeled multipotent mesenchymal stromal cells.
- To determine if magic angle MRI improves the discrimination of SPIO-induced artifacts.
Main Methods:
- Six horses with induced tendinopathy underwent local injections of SPIO-labeled cells or serum.
- MRI scans included standard and magic angle sequences (T1- and T2*-weighted) at regular intervals.
- Image analysis involved blinded evaluation and quantitative signal-to-noise ratio (SNR) assessment.
Main Results:
- The magic angle technique significantly increased tendon SNR (P < 0.001).
- Hypointense artifacts were visible in cell-injected tendons for up to 24 weeks.
- Artefact SNR significantly differed from tendon SNR in magic angle images (P < 0.001).
Conclusions:
- Magic angle imaging of the equine superficial digital flexor tendon is feasible in standing low-field MRI.
- The technique effectively enhances the discrimination of SPIO-induced artifacts from surrounding tendon tissue.
- This method offers improved evaluation of cell tracking and tendon pathology in equine models.
