[1] SP Multispecial Hosp, Dept Radiol, Thiruvananthapuram, Kerala, India
[2] Amrita Univ, Amrita Inst Med Sci, Dept Radiol, Kochi, Kerala, India
[3] Amrita Univ, Amrita Inst Med Sci, Dept Head & Neck Surg, Kochi, Kerala, India
[4] Vydehi Inst Med Sci & Res Ctr, Dept Radiat Oncol, Bangalore 560066, Karnataka, India