Identification of C7; Evaluations of 2 Sonographic Methods Using a Transverse and a Sagittal Scan.

Convex transducer will be placed at patient's neck using paramedian sagittal scan and pointing toward the chest apex aiming to identify the first rib. Then move the transducer medially to identify the transverse process along with identify C7 transverse process will appear on the image as a hyperechoic shadow without continue to the rib laterally. Place the C7 spinous process on the midpoint of the probe and the spinous process correspondence to the midline will be marked as C7.

Linear transducer will be placed at patient's lateral neck using transverse scan. The unique characteristic of sonography of transvers process of C6 and C7 will be used to identify the transverse process of C6 and C7. C6 transverse process has a very prominence anterior tubercle (known as Chassaignac tubercle). While anterior tubercle of C7 is absent. After identifying the C7 transverse process, simultaneously the color Doppler mode will be activated to identify the vertebral artery for double confirmation.

C7 spinous process will be identified by counting down from C1 vertebral body and spinous process.