Stroke: 4D brain perfusion accelerates treatment

In an ischaemic stroke, rapid treatment is essential. In this moment good imaging data is particularly important to enable doctors to make the best possible  decision for therapy. Modern CT scanners are increasingly being used to assess stroke patients because they can show the blood flow to the brain over time.

In an interview with MEDICA-tradefair.com, Daniel Barion talks about high-end CT scanners, the advantages of 4D perfusion measurement and the future of image data processing in hospitals.

Mr. Barion, what can CT do for the brain today, especially in stroke?

Daniel Barion: Thanks to volume CT development, it is now possible to capture the entire brain in one rotation. This has the advantage that the examination only takes a fraction of a second and also takes place in a sequential acquisition, since there is no need for patient movement in the z-direction. The results of this acquisition technique compared to the spiral technique are sharper images. Especially in stroke diagnostics, volume CTs have a decisive advantage: they record perfusion isophasically. This means that the CT records information in the skull at any position at the same time. This is different with the so-called joggle or shuttle technique.

In addition, follow-up examinations, such as angiography of the carotides in an examination protocol can be combined with brain perfusion and the administration of a contrast agent, which in turn saves valuable time, as "time is brain" applies to stroke diagnostics.

What does "volume coverage" mean?

Barion: "Volume coverage" means that the CT has a wide detector. Canon Medical Systems offers in the Aquilion ONE Genesis platform the most innovative detector with 640 layers and 0.5 millimeter detector elements over 16 cm. This makes it possible to detect a relatively large volume, such as entire organs, within a single rotation. The examination time of a cardiac CTA, for example, only takes 138 milliseconds.

A large coverage is also an enormous advantage in neuroimaging. The examination time to exclude a stroke-induced infarct with extensive bleeding up to subarachnoid hemorrhage or ruptured aneurysms is possible within 275 milliseconds.

What is the challenge for doctors in evaluating the images?

Barion: Thanks to modern high-performance post-processing consoles, the radiologists have access to all the results of the perfusion cards, including penumbra, in just two minutes.

In addition, the 4D-CTA of the head vessels is also displayed isophasically, allowing the user to get an exact picture of the physiological processes in the patient's head, similar to the DSA. This enables a clear and dynamic overview of the brain-supplying arteries and thus shortens the time required for therapy planning or execution.

What are the benefits for patients?

Barion: Clearly, a faster diagnosis and treatment for stroke patients. Due to the excellent clinical results of the embolectomies, i.e. the mechanical re-canalization, CT perfusion is again becoming more important in the diagnosis of acute stroke, even after the actual time window has elapsed.

What the trends do you see for the processing and presentation of image data in hospitals?

Barion: The trend is clearly moving from stand-alone workstations to server-based solutions. These post-processing solutions are fully PACS-integrated and allow any number of users to access and process patient images at different workstations in the department or hospital. This makes it possible to make timely and location-independent diagnoses and initiate early therapies. Today, these server-client solutions are high-performance computers that perform fully automatic processing and make the finished results available to the radiologist.

Big Data, Deep Learning and Artificial Intelligence are a new trend in radiology and will significantly support, but not replace, the three major areas of acquisition, reconstruction and reporting in an existing radiological environment.