Rofo 2012; 184 - TNE18
DOI: 10.1055/s-0031-1300919

Comparison of Assessment of Myocardial Perfusion by CT-based Dynamic Myocardial Perfusion Imaging and Single-Phase High-Pitch Acquisitions in a Porcine Animal Model with Various Degrees of Coronary Artery Stenosis

F Schwarz 1, T Sandner 1, R Marcus 1, E Baloch 1, R Hinkel 2, M Reiser 1, T Johnson 1, K Nikolaou 1, F Bamberg 1
  • 1Ludwig-Maximilians-Universität München, Institut für Klinische Radiologie, München
  • 2Ludwig-Maximilians-Universität München, Medizinische Klinik und Poliklinik I, München

Purpose:

To determine the correlation between myocardial blood-flow (MBF) derived from CT-based dynamic myocardial perfusion imaging and enhancement on single-phase using high-pitch scans (SPE) in a porcine animal model with variable coronary artery stenosis.

Methods and Materials:

Country pigs underwent stent placement to the proximal left anterior descending artery, in which a balloon catheter was inflated to simulate luminal narrowing (50% and 75% diameter stenosis, verified by flow-wire measurement). All animals underwent adenosine-mediated dynamic stress- and rest-CT-imaging using a Dual-Source CT-system. In addition, at each perfusion state a single-phase high-pitch scan was performed using a delay optimized for myocardial enhancement. MBF was derived using a model-based parametric deconvolution technique and enhancement on single-phase-acquisition was measured for every myocardial segment in blinded fashion.

Results:

All 6 animals (35±6kg) completed the protocol without complications. Among 96 myocardial segments, 6 were rendered non-evaluable due to wire artifacts. There was a strong positive correlation between MBF and SPE (r=0.71, p<0.01). While at rest there were no differences of MBF or SPE between poststenotic and reference myocardium (both p>0.05), they were significantly lower under stress conditions (MBF: 50±13 vs. 78±16ml/100ml/min, p=0.01; and SPE: 95±10 vs. 150±28 HU, p=0.03). Moreover, this finding was accentuated at 75%-stenosis (MBF: 70±12 vs. 39±9ml/100ml/min and SPE: 70±33 vs. 170±42 HU in poststenotic vs. normal myocardial segments).

Conclusions:

CT-derived MBF correlates with myocardial enhancement on single-phase-scans. Using optimal bolus-timing a single phase may be sufficient to detect different myocardial perfusion states pertaining to different degrees of coronary stenosis.