Byong-Kyu Kim, Jung-Nam Cho, Hye-Jin Park, Seung-Pyo Hong, Ja-Yung Son, Jin-Bae Lee, Jae-Keun Ryu, Ji-Yong Choi, Sung-Guk Chang, Kee-Sik Kim

J Cardiovasc Ultrasound.2011;19(4):221-223.   Published online 2011 December 27     DOI: http://dx.doi.org/10.4250/jcu.2011.19.4.221