Bettina Marion Gramer MD, Presenter: Nothing to Disclose

Daniela Muenzel MD, Abstract Co-Author: Nothing to Disclose

Vivian Leber MD, Abstract Co-Author: Nothing to Disclose

Mani Vembar MS, Abstract Co-Author: Employee, Koninklijke Philips Electronics NV

Alexander André Fingerle MD, Abstract Co-Author: Nothing to Disclose

Ernst J. Rummeny MD, Abstract Co-Author: Nothing to Disclose

Armin Michael Huber MD, Abstract Co-Author: Nothing to Disclose

To evaluate a new iterative reconstruction (IR) algorithm for radiation dose, image quality (IQ), signal-to-noise (SNR) and contrast-to-noise ratio (CNR) in multidetector computed tomography (MDCT) dynamic myocardial perfusion imaging (MPI).

ECG-gated 256-slice MDCT dynamic MPI scans were performed in 6 pigs for after subtotal balloon occlusion of one coronary artery. Two 100 kVp protocols were compared: (‘high dose’ (HD): 150 mAs; ‘low dose’ (LD): 100 mAs). HD images were with reconstructed filtered backprojection (FBP), LD images with FBP and different strengths of IR (L1, L4 and L7). IQ (5-point-scale), SNR and CNR (ischemic vs. normal myocardium) values derived from the HD (FBP) images and the different LD images were compared.

Mean SNR values for myocardium were 16.3, 11.3, 13.1, 17,1 and 28,9 for the HD, LD (FBP), LD (L1), LD (L4) and LD (L7) reconstructions. Mean CNR values were 8.9, 6.3, 7.8, 9.3 and 12.8. IQ was 4.6, 3.3, 4.4, 4.7 and 3.4, respectively. A significant loss of IQ was observed for the LD (L7) images compared to the HD (FBP) images (p < 0.05).

Appropriate levels of IR can improve SNR and CNR, facilitating radiation dose savings in CT-MPI without impacting diagnostic quality.

The iterative reconstruction algorithm is promising for future reduction of radiation dose in CT perfusion imaging of the myocardium.

Gramer, B, Muenzel, D, Leber, V, Vembar, M, Fingerle, A, Rummeny, E, Huber, A, Impact of Iterative Reconstruction on CNR and SNR in a 256-slice MDCT Dynamic Myocardial Perfusion Imaging in an Animal Model.  Radiological Society of North America 2012 Scientific Assembly and Annual Meeting, November 25 - November 30, 2012 ,Chicago IL. http://archive.rsna.org/2012/12043396.html