Ultrasonographic Images of Nasal Bone Fractures with Water Used as the Coupling Medium

Abstract

Background: Ultrasonography can show local and superficial fractures of the nasal bone. However, it is difficult to see the whole nasal bone. We used water as the coupling medium for ultrasonography.

Methods: This method was used in 76 nasal bone fracture cases from July 2011 to March 2013, and we could obtain clear images of the entire nasal bone and surrounding bones. However, in some images, there were artifacts and blurred areas. The patterns of blurring were classified and their causes were analyzed.

Results: The 6 patterns of artifacts and blurred images were (1) Blurred side wall of the nasal bone in 68 cases, (2) air bubbles in the water in 68 cases, (3) unclear deep portions by attenuation in 23 cases, (4) distorted images caused by shaking of the probe in 44 cases, (5) parallel shadows due to multiple reflections in 18 cases, and (6) mysterious shadows caused by side lobes of the ultrasound beams in 55 cases. Almost all of them could be avoided by adding some small changes of techniques.

Conclusions: Our methods can provide whole clear images of the nasal bone and surrounding bones in 1 field. Almost all the artifacts and blurred images which occurred during the performance of our methods could be avoided by adding some small changes, for example, tilting the probe, pouring the water slowly, and moving the probe closer to the nose.

Fig. 1.

The apparatus for ultrasonography with water as the coupling medium. A, A plastic container with a sponge attached to its bottom. A waterproof seal wraps them. The sponge can close the nostrils. B, The ultrasound probe can be applied through the pool of saline without adding pressure to the nasal bone fracture.

Fig. 2.

Ultrasound images, with saline used as a coupling medium, of a 16-year-old boy who had a nasal bone fracture. A, Axial view. B, Sagittal view.

Fig. 3.

Six kinds of blurred image patterns seen during this study.

Fig. 4.

Blurred images of the side walls. They were thought to be caused by reflection and interference of the ultrasound signals.

Fig. 5.

Arrows of this figure are air bubbles. When water was poured speedily, the air bubbles were scattered in the water and on the nasal skin. When water was poured slowly, they were not recognized.

Fig. 6.

Unclear deep portions. The images of the deep portion tend to become unclear because ultrasound signals are attenuated despite the low attenuation index of the water. A, An unclear image of the deep portion. B, A clear image of the shallow portion.

Fig. 7.

Distorted images caused by shaking the probe in the water.

Fig. 8.

Parallel shadows under the nasal bone image were caused by multiple reflections.

Fig. 9.

Mysterious artifacts caused by the side lobes of ultrasound beams.

Fig. 10.

The protocol of our methods.