Two hearts are better than one

Heart with blockages in main artery and two branches, resulting in poor blood flow, as depicted as (rings of) white segments of the heart muscle (Image: Medical Delta)

Medical Delta researchers have developed a technology that combines anatomical and functional data from the heart into one image.

It can hardly be a coincidence that Medical Delta researchers presented their unique and possibly lifesaving views of the heart on Valentine’s Day. Lead author, Hortense Kirisli MSc (Erasmus MC and Leiden University MC), will present a paper in Orlando, Florida, containing images made with a prototype workstation that combines anatomical information from a CT-scan, with functional information from an MRI, in one interactive, three-dimensional image of the heart. Not only does the image show which coronary arteries have been clogged up and to what extent, but it also reveals how the perfusion of the heart muscle fed by those arteries has been affected.

Heart patients are routinely scanned with both CT (X-ray computer tomography) and MRI or PET-scan. The CT scanning technique depicts the anatomy of the heart, while the latter two techniques map the actual perfusion – or nourishing flow of blood through the heart muscle. These scans may be taken days apart and at different locations. And yet a cardio-radiologist must consult and compare the separate images when deciding which arteries to clear in order to improve the heart’s condition. The researchers hope to assist this decision-making with their combined image.

The 3D-data sets of both technologies are fitted together based on the anatomy of the heart’s left ventricle, which shows up in both images. The images do not have to fit down to the last millimetre, says Dr Wiro Niessen (TU Delft’s faculty of Applied Sciences and Erasmus MC), who is coordinating the project with Dr Hans Reiber (LUMC). Perfusion data aren’t very sharp to begin with, but what must be visible is which artery feeds what part of the heart muscle.

Clever as this imaging may be, it has yet to prove its diagnostic value. Dr Niessen says the team is still working on the protocol for clinical evaluation. Essentially they want doctors to re-examine some older cases with the new technique to see if it improves their diagnoses.
The team presenting the paper consists of researchers from Erasmus MC, Leiden UMC and TU Delft, working together in the Medical Delta consortium. The work is part of the ‘Heart in 3D’ project.

H.A. Kirsli et al, W.J. Niessen: ‘A patient-specific visualization tool for comprehensive analysis of coronary CTA and perfusion MRI data’.