Feasibility of MRI with zero echo time (ZTE) sequence for personalized preoperative assessment of distances between critical nerves and glenoid landmarks.

PURPOSE: To assess the feasibility of MRI with zero echo time (ZTE) sequence for evaluating proximity of axillary and suprascapular nerves to glenoid landmarks relevant to shoulder surgery.

METHODS

Closest distances between axillary nerve and inferior glenoid rim (Parameter 1), between suprascapular nerve in suprascapular notch and superior glenoid rim (Parameter 2), and projectional distance between suprascapular nerve in spinoglenoid notch and glenoid articular surface (Parameter 3) were measured on shoulder ZTE MRI. Measurements were made by two observers on multiplanar reformatted ZTE images that showed osseous outline, employing triangulation on standard protocol images for nerves. Parameter 1 measurement was duplicated on a single fresh frozen cadaver.

RESULTS

This study included 211 consecutive patients (147 females [69.7%] and 64 males [30.3%]), with a mean age of 55.1 ± 15.2 years (range, 18–85). ZTE MRI was validated by corresponding cadaveric measurement, with Parameter 1 measuring 17.1 mm on ZTE MRI and 17.2 mm on the cadaver. Mean values for Parameters 1‒3 were 15.1 ± 3.9 mm (95% CI 14.6–15.6), 29.0 ± 3.3 mm (95% CI 28.5–29.4), and 13.4 ± 2.7 mm (95% CI 13.0–13.7), respectively. Inter-rater agreement was good or excellent (ICCs, 0.876–934) and intra-rater agreement was excellent (ICCs, 0.939–0.972). Males had higher values for Parameters 1 and 2 (p < 0.001), with no difference for Parameter 3 (p = 0.237).

CONCLUSION

MRI with ZTE is a feasible technique for preoperative measurements between glenoid landmarks and axillary or suprascapular nerves, potentially reducing the risk of iatrogenic injury during shoulder surgery without exposure to ionizing radiation.