Development of a dedicated 3D printed myocardial perfusion phantom: proof-of-concept in dynamic SPECT

Abstract

We aim to facilitate phantom-based (ground truth) evaluation of dynamic, quantitative myocardial perfusion imaging (MPI) applications. Current MPI phantoms are static representations or lack clinical hard- and software evaluation capabilities. This proof-of-concept study demonstrates the design, realisation and testing of a dedicated cardiac flow phantom. The 3D printed phantom mimics flow through a left ventricular cavity (LVC) and three myocardial segments. In the accompanying fluid circuit, tap water is pumped through the LVC and thereafter partially directed to the segments using adjustable resistances. Regulation hereof mimics perfusion deficit, whereby flow sensors serve as reference standard. Seven phantom measurements were performed while varying injected activity of 99mTc-tetrofosmin (330–550 MBq), cardiac output (1.5–3.0 L/min) and myocardial segmental flows (50–150 mL/min). Image data from dynamic single photon emission computed tomography was analysed with clinical software. Derived time activity curves were reproducible, showing logical trends regarding selected input variables. A promising correlation was found between software computed myocardial flows and its reference ($$\rho$$ ρ = − 0.98; p = 0.003). This proof-of-concept paper demonstrates we have successfully measured first-pass LV flow and myocardial perfusion in SPECT-MPI using a novel, dedicated, myocardial perfusion phantom. Graphical abstract This proof-of-concept study focuses on the development of a novel, dedicated myocardial perfusion phantom, ultimately aiming to contribute to the evaluation of quantitative myocardial perfusion imaging applications.

A Multimodality Myocardial Perfusion Phantom: Initial Quantitative Imaging Results

“…These initial results demonstrated that zeolite indeed provides a certain amount of [13N]ammonia trapping, which appears to be controllable by using different tissue mimicking material compositions ( Figure 4 and Figure 7 ). As a result, the phantom heart contours were well recognized by the software, as with previous SPECT measurements [ 16 , 26 ]. No activity can occur at the location of the partitions in the myocardial tissue volumes of the phantom.…”

Development of a dynamic myocardial perfusion phantom model for tracer kinetic measurements

“…The phantom setup has emerged from the redesign of a previously described myocardial perfusion phantom [15]. Phantom redesign concerned a novel way of tissue simulation, integration of coronary branches in the phantom model and improved sealing to prevent leakage.…”

Quantitative myocardial perfusion imaging : a novel multimodality validation phantom

“…As a result, the phantom heart contours were well recognized by the software, as with previous SPECT measurements. 18,28 No activity can occur at the location of the partitions in the myocardial tissue volumes of the phantom. We have used these markings in the polar maps to facilitate standardized orientation and evaluation.…”

“…Yet, in recent decades, a shift towards dynamic imaging, hybrid imaging (for attenuation correction) and towards other imaging modalities is ongoing. 28,29 For example, magnetic resonance imaging (MRI) has become a common MPI method and possibilities with ultrasound (US) and computed tomography (CT) are being explored as well. Noteworthy is that current clinical implementation of these multimodal MPI procedures varies widely.…”

“…A one-day clinical protocol for dynamic rest and stress MPI also requires this software feature for the same reason. 28 Unfortunately, the usefulness of this clinical feature could not be further examined because of a small remaining percentage of recirculating tracer over time. The mean TRFs in Figure 5 highlight this effect, whereby a suggestion has been made on the expected course in the absence of tracer recirculation (assuming a linear increase starting from ~20 s).…”