A Brit boy, who became the first patient in the world to have a valve in his heart widened using an MRI scan rather than X-ray imaging is said to be recovering well.
Jack Walborn was born with the heart condition pulmonary valve stenosis, a condition in which the outflow of blood from the right side of the heart is obstructed, restricting flow to the lungs.
Surgeons decided he needed an operation called a valvuloplasty to widen the valve and increase blood flow.
This is done by inserting a catheter into a blood vessel in the arm or groin and guiding it to the heart.
At the tip of the catheter is a balloon, which is gently inflated to widen the narrowed valve.
X-ray imaging is usually used to track the progress of the catheter through the body.
However, a team at the King's Health Partners Academic Health Sciences Centre in London has developed a way to use MRI scanning instead.
Previously, the magnetic field used in MRI caused problems with the metal guide wires used for cardiac catheterisation, making them move around inside the body and heating them up.
The King's team has come up with a glass fibre wire alternative with small iron markers along it that can be seen on the scan.
Using MRI means patients are not exposed to radiation - particularly important for children.
The scan also provides a clearer image, and information about the body's tissues, in real time during surgery.
"At first I was unsure about allowing Jack to be the first person to have this operation, but once I had spoken to the doctors I felt much more at ease as I knew he was in safe hands," the BBC quoted Jacks's mother as saying.
"His surgery was a great success and within an hour of coming out of theatre he was running around and back to being his lively self," she added.
Judy O'Sullivan, a senior cardiac nurse at the British Heart Foundation, said: "Technology is advancing at a great pace and in the future we hope that many more patients will benefit from the use of MRI scans rather than X-ray imaging, as MRI avoids exposure to radiation."