A quality audit of MRI knee exams with the implementation of a novel 2‐point DIXON sequence

Abstract

Introduction The objective of this study was to evaluate the effect on diagnostic image quality and acquisition time utilising a DIXON sequence to replace two standard proton density (PD) fat saturation (FS) sequences in routine magnetic resonance (MR) evaluation of the knee. Methods Thirty‐one consecutive patients referred for an MR examination of the knee were examined using the routine departmental protocol along with the addition of a DIXON sequence. The sequences were all evaluated by a senior radiologist and feedback provided via both written and scored responses. The sequences were then repackaged for two additional reviewers with the sagittal PD FS (Chemical Shift Selective Fat Saturation or CHESS) and sagittal PD removed and replaced with the DIXON (fat suppressed and in‐phase, respectively) sequence equivalents. Scored and written responses were tabled and reviewed to assess the suitability of sequence replacement. Results The DIXON‐based images were judged as being comparable replacements for the sagittal PD fat sat and PD sequences. There was no report of any loss in diagnostic confidence across the 31 patients (total of 32 knees) with a time saving of just over 10% gained. The most common issues raised affecting image quality, though not affecting diagnostic attributes, were patient motion and a minor chemical shift artefact. Conclusion The use of the DIXON technique in place of the PD sequences was of equivalent diagnostic quality with’good’ to ‘outstanding’ fat suppression observed for the majority of cases using the DIXON sequence with an incremental time saving obtained.

Fast 3D Isotropic Proton Density-Weighted Fat-Saturated MRI of the Knee at 1.5 T with Compressed Sensing: Comparison with Conventional Multiplanar 2D Sequences

“…For instance, variations of the DIXON method in 2D sequences were recently implemented in routine musculoskeletal protocols [21,22]. Likewise, Bastian-Jordan et al evaluated a 2-point DIXON sequence that achieved a slight scan time reduction with a better fat saturation at the cost of increased movement artifacts and chemical shift artifacts [23].…”

MRI evaluation of the peripheral attachments of the lateral meniscal body: the menisco-tibio-popliteus-fibular complex

“…The knee was placed in extension, neutral rotation, with 15° degrees of lexion. This is the protocol used in the musculoskeletal radiology center due to the Dixon images having equivalent anatomical identiication abilities with in-phase images to that of FSE T2WI for meniscal, cartilage, and ligament injuries of the knee joint [1,24]. The images are also comparable in terms of their diagnostic performance.…”