From 1996 until 2002, she was a Research Fellow at Columbia University in New York, where she studied vascular reconstructive surgery. She completed a second OB/GYN residency program in the United States at Monmouth Medical Center in New Jersey in 2007. She practiced at St. Vincent Hospital in Manhattan after completing her US residency. Dr. Johnston is board certified in Obstetrics and Gynecology.

The Center for Women’s Health at Evergreen welcomed Dr. Johnston in September of 2008. She practices full scope Obstetrics and Gynecology, including laparoscopic surgery, infertility, and high risk pregnancies. She has published papers on the use of hysteroscopy in the detection of uterine cancer and for infertility treatment as well as studies for the Journal of Reconstructive Microsurgery.

Dr. Johnston is fluent in both English and Mandarin and welcomes a diverse population to her practice.