Comparison of anterior orbital measurements obtained using standard frequency ultrasound, high frequency ultrasound and magnetic resonance

Aim
The aim was to compare the measurements of anterior orbital lesions obtained using magnetic resonance imaging with surface coil, as well as standard- and high-frequency ultrasound.

Material and methods
Patients were enrolled in this retrospective study, if they had all three imaging studies performed as a part of the diagnostic management. A high-frequency ultrasound was performed using and immersion add-on (ClearScan®, Ellex).

Results
The study group consisted of 7 men and 10 women at the mean age of 59 years. The lesions these subjects presented with included 5 (29.4%) haemangiomas, 3 (17.6%) varices, and 2 (11.8%) metastases. A mean anterior-posterior dimension was 8.87 mm, 7.59 mm and 7.50 mm in magnetic resonance imaging, standard-ultrasound and high-frequency ultrasound, respectively. A mean transverse dimension was 9.85 mm, 9.69 mm and 8.93 mm in magnetic resonance imaging, standard-ultrasound and high-frequency ultrasound, respectively. In 12 cases (70.6%), the difference between magnetic resonance imaging and high-frequency ultrasound measurements in anterior-posterior dimension was <1.0 mm, in 2 cases (11.8%), between 1.0 mm and 3.0 mm, and >3.0 mm in 2 cases (11.8%). For the transverse dimension, the difference was <1.0 mm in 7 cases (41.1%), between 1.0 mm and 3.0 mm in 7 cases (41.1%), and >3.0 mm in 3 cases (11.8%). The difference between magnetic resonance imaging and standard ultrasound measurements in anterior-posterior dimension was <1.0 mm in 12 cases (70.5%), between 1.0 mm and 3.0 mm in 4 cases (23.5%), and >3.0 mm in 1 case (5%). For the transverse dimension, the difference was <1.0 mm in 7 cases (41.1%), between 1.0 mm and 3.0 mm in 5 cases (29.4%), and >3.0 mm in 2 cases (11.8%).

Conclusions
The anterior-posterior dimension measured by magnetic resonance imaging and ultrasound was comparable in 82.3% of cases (the difference was within 3.0 mm), while a transverse measurement bore a higher error. High frequency ultrasound might represent an interesting alternative to orbital magnetic resonance imaging while maintaining the appropriate technique.