Yes, it's true! Lenna attended the 50th Anniversary IS&T conference in Boston held in May 1997.
According to all reports, the event went spectacularly. Everyone was excited to finally meet Lenna in person and get her autograph. And she got a chance to meet some of the many people who have been using her picture as the basis of their research.
Check out the coverage from Playboy, Wired, and more from Playboy.
Also, check out page 171 of the September 1997 issue of Playboy. (The one with Pam Anderson on the cover). It has a small news story with a picture of Lenna looking at the posters at the conference.
Here is a picture of Lenna Soderberg (Sjööblom) and Jeff Seideman taken in May 1997 at IS&T's 50th Anniversary conference:
Here is a picture of Lenna (with Dr. James Owens of Eastman Kodak) examining posters which describe research which used her picture:
Click here to see the original picture from Playboy. WARNING contains nudity.