3D M-FFE Sequence for Assessment of Osseous Abnormalities in the Knee

Background/Objectives: To evaluate the potential complementary value of the 3D multi fast field echo (M-FFE) sequence for knee bone assessment at 1.5T MRI, focusing on the visualization of osseous abnormalities and its potential to complement a standard knee MRI protocol. Methods: A standard knee MRI protocol supplemented with a 3D M-FFE sequence was performed at 1.5T MRI in 49 outpatients. Two observers independently evaluated image quality, visualization of six anatomical knee structures, and osseous abnormalities using a 5-point Likert scale. Intra- and interrater reliability was assessed using intraclass correlation coefficients and Cohen’s kappa. Eleven examinations were reassessed for intra-rater reliability. Diagnostic confidence with the 3D M-FFE sequence was evaluated. Results: Image quality was consistently high, with sharpness and artifact scores of 4–5 in >95% of examinations, while contrast showed greater variability, and no examinations scored below 3. Osseous abnormalities were identified in 18/49 patients by each observer, with agreement in 12 cases. A total of 28 and 25 abnormalities were identified by the observers, most commonly osteochondral lesions and bone islands. Abnormalities were assigned visualization scores of 4–5. Inter-rater agreement for osseous abnormalities ranged from fair to substantial (kappa = 0.40–0.76), while intra-rater agreement varied from slight to almost perfect depending on anatomical location. Both observers reported increased perceived diagnostic confidence in osseous abnormalities with the addition of the 3D M-FFE sequence. Conclusions: The 3D M-FFE sequence demonstrated high image quality, robust anatomical visualization, and potential complementary value for osseous assessment at 1.5T MRI. Further studies using an appropriate reference standard are needed to establish diagnostic accuracy.