Alexandre Bridoux, Abstract Co-Author: Nothing to Disclose

Jean-Baptiste Faivre MD, Abstract Co-Author: Nothing to Disclose

Julien Pagniez, Abstract Co-Author: Nothing to Disclose

Antoine Hutt MD, Presenter: Nothing to Disclose

Jacques Remy MD, Abstract Co-Author: Research Consultant, Siemens AG

Martine J. Remy-Jardin MD, PhD, Abstract Co-Author: Research Grant, Siemens AG

 To evaluate the influence of optimized temporal resolution (TR) in pediatric standard chest CT imaging.

93 consecutive children less than 4 years of age (mean age: 1 yr, mean weight: 7.73 kg) underwent a chest CT angiographic examination for non-cardiac indications on a dual-source CT system. No sedation was performed and no β-blocker used. The examinations were obtained with a non-ECG-gated dual-source, single-energy mode using the following parameters: collimation: 64x2x0.6 mm; rotation time: 0.28 s; 70 kVp and 80 mAs; pitch: 2.0. From each dataset, two series of images were systematically reconstructed on a prototype workstation: images with a TR of 140 ms (i.e., standard TR) (Group 1) and images with a TR of 75 ms (i.e., optimized TR) (Group 2). Using a 5-point scale, two radiologists independently analyzed the detection and sharpness of proximal and mid segments of the right (RCA) and left (LCA) coronary arteries (total number of coronary segments examined: n= 651). These anatomical structures, highly sensitive to motion artifacts in otherwise uncooperative patients, were chosen to analyze the impact of an optimized TR.

Interobserver agreement for coronary artery analyzability was excellent (Group 1: kappa=0.86 [95% CI: 0.82-0.89]) (Group 2: kappa=0.86 [95% CI: 0.83-0.90]). The mean rate of detection and grade of analyzability of all coronary segments were significantly higher in Group 2 than in Group 1 (p<0.001). The rate of detection of the proximal RCA (26/93; 28% versus 18/93; 19.35%; p=0.0114) and left main (LM) artery (60/93; 64,52% versus 54/93 ;58,06% p=0,0339) were significantly higher in Group 2 than in Group 1. Group 2 images provided the best image quality for 64,52% of LM (60/93) and 35,48% of proximal RCA (33/93) whereas Group 1 images were found to be the best reconstruction for only 5,38% of LM (5/93) and 1,08% (1/93) proximal RCA.

Optimized TR improves image quality in standard paediatric chest CT, still perfectible at 75 ms.

Optimization of TR improves image quality of standard chest examinations in children.

Bridoux, A, Faivre, J, Pagniez, J, Hutt, A, Remy, J, Remy-Jardin, M, Is It Worth Improving Temporal Resolution (TR) in Paediatric Chest CT?.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14017018.html