Comparison of ultrasound and fluoroscopic guidance for injection in CT arthrography and MR arthrography of the hip.

OBJECTIVE: To evaluate the usefulness of ultrasound-guided versus fluoroscopy-guided injection in CT arthrography and MR arthrography.

MATERIAL AND METHODS: We reviewed all CT arthrography and MR arthrography studies done at our center between October 1, 2014 and October 1, 2015. We analyzed 32 studies: 26 with fluoroscopic guidance and 6 with ultrasound guidance. We compared the two techniques on the following parameters: presence of sufficient contrast material in the joint, extravasation or injection of contrast material in the soft tissues (presence of contrast material in the psoas or other soft tissues), and intra-articular gas bubbles. We used SPSS V. 20 to compare the techniques with Pearson's chi-square tests.

RESULTS: Contrast material was observed in soft tissues in 56.3% of ultrasound-guided injections, making 6.3% of the procedures invalid for diagnostic purposes. Extravasation of contrast material was observed in 53.8% of fluoroscopy-guided procedures, making 3.8% invalid for diagnostic purposes. Intra-articular gas was observed in 21.9% of ultrasound-guided studies and in 38.5% of fluoroscopy-guided studies. None of the differences between techniques were statistically significant at p<0.05.

CONCLUSIONS: Our study shows that ultrasound is as useful as fluoroscopy for injecting contrast material for CT arthroscopy and MR arthroscopy; ultrasound has the advantage of not using ionizing radiation.