It is smaller than an aspirin, but a tiny mass of blood vessels deep within a local teenager's brain has already caused huge problems and promises to do more harm. But what's worse, doctors can't get to the mass and it's too dangerous to operate.

So, a 13-year-old boy and his mother must put their trust in the newest technology at Harborview Medical Center in Seattle.

It's tough enough just being 13. Now, imagine being 13 and dealing with a stroke.

Kevin Rhee's nightmare began one morning at Alderwood Middle School with a nosebleed. By his third period class, an excruciating headache sent the quiet kid who never complained stumbling to the nurse's office - pale, in pain, and losing feeling on one side.

Her face was white as a sheet as she said, "I think he's had a stroke."

It was indeed a stroke. A tangle of veins deep within Kevin's brain began to bleed, and that was only the beginning of the bad news.

Evening Magazine

Kevin Rhee and his mom shortly after the procedure

The arteriovenous malformation – or AVM – sits in the motor skills section of Kevin's brain. Surgery could do more damage than good. But without treatment, Kevin's doctor says it will almost certainly bleed again.

His chances of having another bleed are very high, and next time it could be fatal. It's like living with a timebomb – a ticking timebomb.

The news was more than his single mom, Aejea, thought she could handle.

"I was very frightened. I was very scared, just like Kevin, but what I think what I need to be is encouraging to him, to think positively, we can overcome," she said.

The only chance to overcome is to diffuse the bomb.

So Kevin came to Harborview Medical Center where the latest in gamma-knife technology and a dedicated team would try to do just that.

Harborview Medical Center is one of the first sites in the country to offer the latest in Gamma Knife technology - the Model 4C, the second model in the U.S. of its kind.

Click on the video to follow the new procedure that gives so many new hope.

Update: Kevin's last MRI showed great progress, even better than doctors expected. His recovery from the stoke is going well, too. His mom says he's sometimes able to walk without his cane.