John William Nance MD, Presenter: Nothing to Disclose

U. Joseph Schoepf MD, Abstract Co-Author: Speakers Bureau, Bracco Group Speakers Bureau, General Electric Company Speakers Bureau, Bayer AG Speakers Bureau, Siemens AG Medical Advisory Board, Siemens AG Medical Advisory Board, Bayer AG Research grant, Bayer AG Research grant, Bracco Group Research grant, General Electric Company Research grant, Siemens AG

Gorka Bastarrika MD, Abstract Co-Author: Nothing to Disclose

Sebastian Vogt, Abstract Co-Author: Employee, Siemens AG

Thomas G. Flohr PhD, Abstract Co-Author: Employee, Siemens AG

Balazs Ruzsics MD, PhD, Abstract Co-Author: Nothing to Disclose

Dual-energy CT (DECT) based on dual-source CT has been proposed for the comprehensive assessment of coronary artery stenosis and myocardial perfusion. However, DECT traditionally required reducing the temporal resolution of cardiac studies from 83msec to 165msec, so that coronary artery evaluation suffered. We evaluated a reconstruction algorithm that preserves high temporal resolution at cardiac DECT.

12 consecutive patients (3 women, mean age 64±10 years) with abnormal SPECT underwent invasive coronary angiography (ICA) and cardiac DECT. DECT studies were reconstructed using the standard algorithm with 165msec temporal resolution and a hybrid algorithm combining both, quarter- and half-rotation reconstructions with high- and low-pass filtering techniques, providing 83msec temporal resolution. Two observers rated all studies for coronary image quality and motion artifacts using a four-point scale. Accuracy for stenosis detection was compared with ICA. DECT and SPECT were compared for perfusion defects.

A total of 168 (82%) coronary artery segments were evaluated. With standard 165msec reconstruction 95% of segments were rated as diagnostic compared with 100% using 83msec hybrid reconstruction. Image quality was rated significantly (p<0.05) better with hybrid reconstruction compared to standard reconstruction. The hybrid reconstruction algorithm had 91.4% sensitivity, 94.7% specificity, 82.1% positive (PPV), and 97.7% negative predictive value (NPV) for detecting significant stenosis versus 85.7%, 93.2%, 76.9%, and 96.1% with standard reconstruction. Compared with SPECT, overall sensitivity, specificity, PPV, and NPV of DECT for detecting any type of perfusion defect were 100%, 96.4%, 95%, and 100%, respectively.

Hybrid image reconstruction mitigates the former limitations in temporal resolution of cardiac DECT and strengthens the potential role of this technique for the comprehensive analysis of coronary artery morphology and myocardial perfusion with a single modality.

The hybrid reconstruction algorithm evaluated here decreases motion artifacts and increases diagnostic accuracy of DSCT in DECT mode and is recommended for routine use in cardiac DECT studies.

Nance, J, Schoepf, U, Bastarrika, G, Vogt, S, Flohr, T, Ruzsics, B, Dual Energy Computed Tomography of the Heart Using a High Temporal Resolution Reconstruction Algorithm: Initial Experience.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9004073.html