Effect of hybrid iterative reconstruction technique on quantitative and qualitative image analysis at 256-slice prospective gating cardiac CT. 

 -  2012 
<br/><br/> CONCLUSIONS: Cardiac CT using hybrid iterative reconstruction yields higher CNR and better image quality than FBP.  KEY POINTS: * Cardiac CT helps clinicians to assess patients with coronary artery disease * Hybrid iterative reconstruction provides improved cardiac CT image quality * Hybrid iterative reconstruction improves the number of assessable coronary segments * Hybrid iterative reconstruction improves interobserver agreement on cardiac CT.  METHODS: Prospective cardiac CT images from 20 patients were analysed. Paired image sets were created using 3 reconstructions, i.e. filtered back projection (FBP) and moderate- and high-level iterative reconstructions. Quantitative parameters including CT-attenuation, noise, and contrast-to-noise ratio (CNR) were determined in both proximal- and distal coronary segments. Image quality was graded on a 4-point scale.  OBJECTIVES: To evaluate the effect of hybrid iterative reconstruction on qualitative and quantitative parameters at 256-slice cardiac CT.  RESULTS: Coronary CT attenuation values were similar for FBP, moderate- and high-level iterative reconstruction at 293 +/- 74-, 290 +/- 75-, and 283 +/- 78 Hounsfield units (HU), respectively. CNR was significantly higher with moderate- and high-level iterative reconstructions (10.9 +/- 3.5 and 18.4 +/- 6.2, respectively) than FBP (8.2 +/- 2.5) as was the visual grading of proximal vessels. Visualisation of distal vessels was better with high-level iterative reconstruction than FBP. The mean number of assessable segments among 289 segments was 245, 260, and 267 for FBP, moderate- and high-level iterative reconstruction, respectively; the difference between FBP and high-level iterative reconstruction was significant. Interobserver agreement was significantly higher for moderate- and high-level iterative reconstruction than FBP. 
<br/><br/><br/>English 
<br/><br/><label>ISSN: </label>0938-7994 
<br/><br/><label>Subjects--Topical Terms: </label><br/>*Algorithms<br/>*Coronary Angiography/mt [Methods]<br/>*Coronary Artery Disease/ra [Radiography]<br/>*Radiographic Image Interpretation, Computer-Assisted/mt [Methods]<br/>*Tomography, X-Ray Computed/mt [Methods]<br/>Adult<br/>Aged<br/>Cardiac-Gated Imaging Techniques<br/>Female<br/>Humans<br/>Male<br/>Middle Aged<br/>Radiographic Image Enhancement/mt [Methods]<br/>Reproducibility of Results<br/>Sensitivity and Specificity<br/>Young Adult
<br/><br/><label>Subjects--Geographic Terms: </label><br/>MedStar Health Research Institute<br/>MedStar Heart & Vascular Institute
<br/><br/><label>Index Terms--Function: </label><br/>Journal Article