MR-Guided Percutaneous Intradiscal Thermotherapy (MRgPIT): Evaluation of a New Technique for the Treatment of Degenerative Disc Disease in Cadaveric Lumbar Spine.
Cardiovasc Intervent Radiol 2019;
43:505-513. [PMID:
31773189 DOI:
10.1007/s00270-019-02382-8]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 11/19/2019] [Indexed: 10/25/2022]
Abstract
PURPOSE
Evaluation of MR feasibility and real-time control of an innovative thermoablative applicator for intradiscal thermotherapy and histological analysis of laser annuloplasty in human ex vivo intervertebral discs.
MATERIALS AND METHODS
We evaluated a new MR-compatible applicator system for MR-guided percutaneous intradiscal thermotherapy (MRgPIT) in an open 1.0-T MRI-system. Needle artefacts and contrast-to-noise ratios (CNR) of six interactive sequences (PD-, T1-, T2w TSE, T1-, T2w GRE, bSSFP) with varying echo-times (TE) and needle orientations to the main magnetic field (B0) were analysed. Additionally, five laser protocols (Nd: YAG Laser, 2-6 W) were assessed in 50 ex vivo human intervertebral discs with subsequent histological evaluation.
RESULTS
In vitro, we found optimal needle artefacts of 1.5-5 mm for the PDw TSE sequence in all angles of the applicator system to B0. A TE of 20 ms yielded the best CNR. Ex vivo, ablating with 5 W induced histological denaturation of collagen at the dorsal annulus, correlating with a rise in temperature to at least 60 °C. The MRgPIT procedure was feasible with an average intervention time of 17.1 ± 5.7 min.
CONCLUSION
Real-time MR-guided positioning of the MRgPIT-applicator in cadaveric intervertebral disc is feasible and precise using fast TSE sequence designs. Laser-induced denaturation of collagen in the dorsal annulus fibrosus proved to be accurate.
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