The whiteboard listing the day's patients could have been at any MRI center:

"10:30 a.m. Gus, brain scan. No. 2,291."

The procedure was routine, too. Gus lay motionless in a tube for about 45 minutes while technicians performed the MRI, or magnetic resonance imaging, which allows doctors to see cross sections of the anatomy from virtually every angle.

The twist is that Gus is a basset hound. He was at the Iams Pet Imaging Center in Vienna recently for a scan that would help his veterinarian determine the cause of the dog's seizures.

Pet MRIs are a relatively new trend in the treatment of sick animals. The Iams center is rare, too; some of its clients travel to Vienna from other states.

The technology is the same as for human scans: Magnetic energy and radio waves create detailed images of tissues that help diagnose diseases of the brain, spine, skeleton, joints, chest, abdomen, blood vessels and some forms of cancer.

The cost of a scan, $1,000 or more, can be a barrier. Specialists say that people willing to spend that much money on an animal generally are devoted to them -- the kind of people who insist that a dog or cat be included in the annual family photo, for example.

Cindy Martin, of the District, is typical. She found Gus through an animal rescue agency. At first she worked with Gus's veterinarian to determine the cause of the dog's seizures. That veterinarian referred her to a neurologist at SouthPaws Veterinary Referral Center in Springfield, who ran additional tests.

But the usual blood tests and other diagnostic procedures could not identify all of the possible causes of Gus' seizures. So Martin brought the animal to Iams.

"Right now we're trying to determine if it is epilepsy or if there's something triggering the seizures," Martin said. "The assumption is that he has epilepsy, and he's on an anticonvulsant."

Later, the results from the MRI ruled out a tumor, which aided veterinarians in determining how to treat Gus, who Martin said is 3 to 5 years old.

A key difference between human and pet MRIs is that the animal usually is sedated before going into the tube, because it is unlikely it would remain motionless for 20 to 45 minutes.

On this recent day, a technician shaved part of Gus's leg and inserted an IV catheter as Gus lay on a stainless steel table. An anesthesiologist administered enough anesthesia to keep Gus still during the MRI.

Gus then was intubated, placed on a gurney and wheeled into a room housing a large magnetometer. He was strapped to a table that would carry him inside the machine's tube. From there, MRI technician Tiffany Garrison took over.

"The principles of MRI are the same; the concept is the same. What is different is how you're going to put an animal in the scanner and the coil placement," said Garrison, who joined the Iams center when it opened in 2001 after performing MRIs on humans for seven years.

"I had to learn the anatomy of the animals, and then there is the image orientation that is different," Garrison said. "Dogs and cats stand horizontal and humans stand vertical. So anatomic position changes things a little."

The center, whose clients are referred by veterinarians, usually has a 24-hour turnaround time. Appointments are scheduled 30 minutes before what the center refers to as "magnet time," and patients are back out the door in less than two hours.

While the Iams center offers help to household pets, it also participates in larger projects, such as monitoring the health of 24 dogs that performed search and rescue work at the sites of the Sept. 11, 2001, terrorist attacks in New York and at the Pentagon.

Rookie, a 9-year-old German shepherd handled by Officer Joaquin Guerrero of the Saginaw, Mich., Police Department, was one of the dogs that was monitored. He died of cancer June 30.

A police K-9 utility dog, Rookie was trained in obedience, handler protection, building, area and evidence searches, tracking, narcotics, canine SWAT and canine therapy.

Guerrero said that he and Rookie arrived at the World Trade Center on Sept. 12, 2001, and worked 10- to 14-hour days searching for bodies. There was a veterinary unit set up near Ground Zero, where dogs coming off the "line" would get their eyes cleaned, vital signs checked and receive subcutaneous fluids, Guerrero said.

He said he has worked with the University of Pennsylvania and the American Kennel Club Canine Health Foundation in a research study to determine if the Sept. 11 rescue dogs developed cancer at higher rates than dogs that did not participate in the rescue efforts.

While removing a cyst from Rookie's tail and performing a routine teeth cleaning, doctors found a bump on his jaw. X-rays showed what Rookie's regular veterinarian thought was an abscessed tooth, and a biopsy indicated no cancer.

One of the vets treating Rookie told Guerrero that Iams was doing a study on the search dogs, so the officer brought Rookie to the Vienna center in January this year.

An MRI showed Rookie in fact had cancer in the mouth and neck.

"And here I am getting ready to go to work with him," Guerrero said. "That Monday morning I had to let our chief know and told everyone that this didn't look good for Rookie. And Iams stepped up to the plate and said that they wanted to help save Rookie."

After two surgeries and several rounds of chemotherapy, Rookie's cancer was in remission, and he was back on the job. He worked as recently as June 28, but Guerrero said that after his shift he could tell the dog was not well.

"Rookie was courageous and fought to the end," said Saginaw City Police Chief Donald F. Pussehl Jr., the Associated Press reported.

MRI technician Tiffany Garrison, left, places Milo, a 5-year-old wirehaired dachshund, into position under the supervision of medical director Julie Smith at the Iams Pet Imaging Center. Milo was sedated so he would remain motionless for the 20- to 45-minute scan.Above, Julie Smith prepares Milo for the MRI. Below, Milo's owners, Sheila and Max Daout, comfort their pet as he wakes up from anesthesia after the procedure. The Vienna imaging center opened in 2001.Julie Smith carries a sedated Milo to the room where he will be placed into the MRI scanner.