A CT scan can show doctors what a patient's blood vessel looks like. Meanwhile, researchers at the University of Sydney have found a way to take that image off the screen and turn it into a tiny physical replica.
The team developed a 3D-printing method that creates miniature models of patients' blood vessels from CT scans. The models allow researchers to introduce blood, observe its movement, and watch platelets behave under a microscope, giving them a closer look at processes that can contribute to dangerous blood clots.
The technology is not yet a test that can tell a patient whether they will have a stroke. For now, it is a research platform. But because the models can reproduce the anatomy of individual patients, they could help scientists investigate why clots form in some vessels and how treatments might affect that process.
Turning a Patient's Scan into a Miniature Artery
The researchers focused on the carotid arteries, major blood vessels in the neck that carry blood to the brain.
These arteries do not all have exactly the same shape. Damage caused by conditions such as atherosclerosis, which is the buildup of fatty material in artery walls, can also create irregular surfaces that alter how blood moves.
To study those differences, the researchers used CT scans from stroke patients as blueprints for their models.
The resulting structures were much smaller than the real vessels. While a carotid artery is several millimeters across, the printed models were reduced to roughly 200 to 300 micrometers and could be examined under a microscope.
That tiny scale was important because the researchers were interested in something that cannot easily be seen during a routine scan: what happens to blood as it moves through an irregular vessel.
The Researchers Could Watch Platelets Move
Blood clotting is normally a useful process. Platelets, tiny blood components that help stop bleeding, gather at the site of a damaged blood vessel and contribute to the formation of a clot.
The problem begins when a clot forms inside a blood vessel supplying the brain. A clot can obstruct blood flow and cause an ischaemic stroke.
Using the printed vessels, the researchers observed blood clot formation and platelet behavior in real time.
They found that the physical forces created as blood moved against the vessel wall affected how platelets traveled through the model. In areas where the vessel experienced higher stress, the researchers observed 7 to 10 times more platelet movement.
The finding gives researchers a way to examine how the shape and mechanical environment of a blood vessel may influence the events that occur before a clot forms.
Why Blood Flow Matters
Blood is not simply passing through a smooth pipe.
As it moves around curves, narrowed sections, and irregular areas of an artery, its speed and direction can change. The forces produced by that movement can also affect the vessel wall and the blood components traveling through it.
Reproducing those conditions has been one of the challenges of studying clot formation outside the body.
The University of Sydney researchers found that their printed models could reproduce aspects of natural blood-flow dynamics, allowing them to investigate these interactions in a controlled laboratory setting.
That makes the models useful for asking questions that a CT scan alone cannot answer.
A scan can reveal the structure of an artery. The miniature model can help researchers explore what blood may do as it moves through that structure.
The Models Can Be Made in About Two Hours
Speed was another important part of the development.
The researchers used a 3D microfabrication approach that enabled them to create anatomically accurate models from scans of stroke patients in about two hours, according to the University of Sydney.
That is considerably faster than some earlier approaches, which could take around 10 hours.
The quicker process could make it easier to produce multiple models for laboratory experiments and compare how different vessel shapes affect blood flow and clotting.
It also brings the researchers closer to their longer-term goal of creating models that reflect differences between individual patients.
Could Technology Eventually Help Predict Stroke Risk?
That possibility is still some distance away.
The researchers describe their models as a "physical twin" of a patient's blood vessel. Their longer-term plan is to combine this type of physical model with artificial intelligence to develop what they call a digital twin, a computer-based representation that could eventually help researchers assess stroke risk.
The idea is intriguing: a patient's CT scan could be used to reconstruct their vessel, while laboratory testing could reveal how blood behaves within that specific structure. AI could then be used to analyze the resulting information.
But that future application has not yet been established.
The current research demonstrates that patient-derived vessel anatomy can be reproduced in miniature and used to study blood-flow behavior and clot-related processes. It does not show that the models can currently predict when a person will have a stroke.
Further research will be needed to determine whether laboratory observations from these models reliably correspond to what happens in patients.
For now, the most useful achievement may be simpler: researchers have created a way to take a patient's vascular anatomy from a CT image and turn it into something they can physically study.
Instead of only asking what a damaged artery looks like, scientists can begin asking a more revealing question: what happens inside it when blood starts moving through it?
