[Retracted] Clinical Comparison of Endoscopic Ultrasonography and CT in Preoperative TN Staging of Esophagogastric Junction Cancer

Table 1

Propagation velocity table of ultrasonic waves between various tissues of the human body.

Human tissue	Transmission speed	Characteristic impedance (kgm^−2s^−1)
Blood	1570 m/s	1.60 × 10^6
Brain tissue	1540 m/s	1.59 × 10^6
Fat	1540 m/s	1.39 × 10^6
Liver	1550 m/s	1.65 × 10^6
Muscle	1590 m/s	1.71 × 10^6
Skull	4000 m/s	7.79 × 10^6
Soft tissue	1540 m/s	1.62 × 10^6