title: Impact of iterative reconstruction on CNR and SNR in dynamic myocardial perfusion imaging in an animal model.
abstract: OBJECTIVE
  To evaluate a new iterative reconstruction (IR) algorithm for radiation dose, image quality (IQ), signal-to-noise-ratio (SNR), and contrast-to-noise-ratio (CNR) in multidetector computed tomography (MDCT) dynamic myocardial perfusion imaging (MPI).
  
  
  METHODS
  ECG-gated 256-slice MDCT dynamic MPI was performed in six pigs after subtotal balloon occlusion of one artery. Two 100 kVp protocols were compared: high dose (HD): 150 mAs; low dose (LD): 100 mAs. HD images were reconstructed with filtered back projection (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.
  
  
  RESULTS
  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, respectively. Mean CNR values were 8.9, 6.3, 7.8, 9.3, and 12.8. IQ was scored as 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).
  
  
  CONCLUSIONS
  Appropriate levels of iterative reconstruction can improve SNR and CNR, facilitating radiation dose savings in CT-MPI without influencing diagnostic quality.
  
  
  CONCLUSIONS
  Iterative reconstruction (IR) can reduce radiation dose in myocardial perfusion CT. Our study also demonstrated improvements in image quality (noise, SNR, and CNR). Dynamic CT-MPI could help determine the hemodynamic significance of coronary artery disease. With dynamic CT MPI, myocardial blood flow can be determined quantitatively.
authors: Institut für Radiologie, Klinikum rechts der Isar der Technischen Universität München, Ismaningerstrasse 22, 81675, München, Deutschland. bettina.gramer@tum.de
authors: B M
authors: BM
authors: Gramer
authors: D
authors: D
authors: Muenzel
authors: V
authors: V
authors: Leber
authors: A-K
authors: AK
authors: von Thaden
authors: H
authors: H
authors: Feussner
authors: A
authors: A
authors: Schneider
authors: M
authors: M
authors: Vembar
authors: N
authors: N
authors: Soni
authors: E J
authors: EJ
authors: Rummeny
authors: A M
authors: AM
authors: Huber
mesh_terms: D000241:Adenosine / Q000494:pharmacology; D000465:Algorithms; D000818:Animals; D021721:Balloon Occlusion; D055424:Cardiac-Gated Imaging Techniques / Q000379:methods*; D003287:Contrast Media / Q000008:administration & dosage; D003324:Coronary Artery Disease / Q000000981:diagnostic imaging*; D004195:Disease Models, Animal; D007479:Iopamidol / Q000008:administration & dosage / Q000031:analogs & derivatives; D055414:Myocardial Perfusion Imaging / Q000379:methods*; D011446:Prospective Studies; D011829:Radiation Dosage; D011857:Radiographic Image Interpretation, Computer-Assisted; D059629:Signal-To-Noise Ratio; D018709:Statistics, Nonparametric; D013552:Swine; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; C057937:iomeprol; D007479:Iopamidol; D000241:Adenosine