Color-coded vessels and airways printed in polyurethane show the delicate relationships interventionists need to plan for when implanting a device .
Soft models mimic the feel of cardiac structures and help surgeons get a visual and tactile sense of a patient ’ s anatomy before they operate .
Dr . Morgan thought 3DRA imaging could be enough . Cutting out traditional biplane imaging would mean less radiation , both for the patient and for everyone in the lab . It would mean less procedural time , a quicker recovery , less time in the hospital .
But 3DRA is tricky , a complicated setup further complicated by the fact that the heart beats . By the time contrast is injected , the team has about one second , maybe two , to get the image before the contrast floats away . Some cath teams have dealt with that by pacing the heart so fast it effectively doesn ’ t move blood .
Dr . Morgan wasn ’ t a fan of that approach . “ It ’ s not very good for you ,” he says . “ Plus if you stop the heart pumping you ’ re not getting true anatomy . The heart ’ s pumping all the time . We want to know what it ’ s doing when it ’ s doing that .”
“ It took us probably two years of trial and error ,” says Dr . Zablah . “ Optimizing the amount of contrast , where to give it , with which catheter , based on size and lesion .”
It helped to work in a high-volume center — the team at Children ’ s Colorado performs more than a thousand catheterizations
every year . They tested minute variations on hundreds of cases , validating 3DRA against traditional angiograms until they knew without a doubt they were just as accurate , even better . Dr . Zablah literally wrote the protocols .
“ We ’ re doing pulmonary valve placement with 75 % less radiation than any other center ,” Dr . Zablah says . “ Sometimes with no contrast at all .”
Their 3DRA capability got so good , so precise and so fast , in fact , Dr . Zablah started thinking about how to make it do more . Then she woke up one morning with an idea .
Technologically , 3DRA and CT have a lot in common . Both rotate X-ray around a central axis . But where CT is diagnostic and logistically cumbersome , requiring radiology support and an additional appointment of at least 45 minutes , 3DRA happens in about 5 seconds as a routine part of every cath procedure at Children ’ s Colorado . If Dr . Zablah could segment those images like CT scans , she reasoned , she could build detailed 3D models , even print them . They could use them to practice procedures and give them to surgeons for planning operations .
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