The test was conducted Friday at Northwestern Memorial Hospital. Cubs athletic trainer Mark O'Neal said Saturday the results explain why the pitcher has struggled to do anything, including playing catch.
Wood had undergone an MRI on June 26 in Cincinnati, but that did not include an arthrogram, which is more detailed and provides more information, O'Neal said. Wood was waking up at night with pain in his shoulder, and wasn't responding well to treatment.
"There's different thought processes on how to treat it, and that's to be determined," O'Neal said Saturday. "In all reality, there are significant number of people who have successfully returned conservatively. We're in the process of sending the films out and letting two or three of the specialists in the country look at it and see. That's what Kerry wants to do."
The options are conservative treatment or possible arthroscopic surgery on his shoulder.
"My gut feeling is saying no surgery and strengthen it," Wood said Saturday. "I've still got to get more opinions. Over the next couple weeks we'll do that and go from there."
It's been a frustrating season for Wood, 29, who underwent arthroscopic surgery on his right shoulder last Aug. 31 that entailed reinforcement of the labrum, debridement of the rotator cuff and debridement of the bursa. He did make four starts, but had to be shut down.
O'Neal said they may never know if Wood could've repaired the rotator cuff tear last August.
"What we're saying is that his MRIs have shown some irritation to the rotator cuff, which every pitcher has," O'Neal said. "The one he had done [Friday] had significant change from any one that we've seen prior to this one."
At least Wood knows something is wrong.
"Obviously, I'm not pleased, but at least we found something out," Wood said. "I knew something wasn't right for a little while. We got an answer. It's not what I was looking for, but we got an answer.
"I know I'm not crazy now," he said. "I guess it's a relief knowing. Obviously, I would've liked to have gone in and everything be fine and this is part of coming back from surgery and it's rough patches. That's not the case. There's something wrong in there and we'll go forward."
Technically, Wood has a partial thickness tear of the infraspinatus tendon, O'Neal said, and there is significant strain in the rotator cuff. His X-rays will be reviewed by other specialists, and then Wood, Cubs team orthopedic specialist Dr. Stephen Gryzlo and others will decide what to do next.
"If it's something that's handled surgically, the sooner the better," O'Neal said. "It's a very difficult procedure. That's one of the things Dr. Grzylo explained to Kerry. It's not going in and cleaning out the meniscus in his knee. This is a difficult procedure that needs to be thought about. It's not, 'Yeah, let's do it; no, let's don't.' They'll put a lot of heads together."
Wood now has to think about what's best for him and his career.
"If I want to keep playing baseball, I have to be positive and keep doing the work that it will take to get back," Wood said. "Yesterday was my feel-sorry-for-myself day. Today, it's time to get back to work."
And Wood's goal now?
"I haven't gotten that far yet," he said. "I've just been thinking about what we found out last night and how we're going to address it and how we're going to go forward. Obviously, my goal is to pitch again as soon as possible. That's the bottom line. Whether it's the end of this year, next year or three years from now, my goal is to get back and be successful in the big leagues."
As to whether Wood will come back as a starter or reliever, that's a decision to be made down the road.
"I've got to get throwing and healthy before I make that decision," he said.
"I'm not going to say it's a career-threatening thing," O'Neal said. "We can't get the arm 50 percent right now. This has got to heal enough for him to progress so he can pitch."
But where? This is the last year of Wood's contract with the Cubs. The right-hander, who burst onto the scene in 1998 with a 20-strikeout game in his fifth big-league start, and won the National League Rookie of the Year Award that season, has a 71-56 record and 3.68 ERA in 189 games. All with the Cubs.
"I'm realistic," he said of his future with the Cubs. "Business is business. The organization has been great to me. We'd love to finish it up here. That's talks that will come down the road, too."
Carrie Muskat is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.