Comparison of signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and Subjective image quality score for bronchial artery among images of three energy levels.

<p>Comparison of signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR) and Subjective image quality score for bronchial artery among images of three energy levels.</p

Scoring criteria for bronchial artery.

<p>Scoring criteria for bronchial artery.</p

A 68 years old male patient with cancer in the right lung.

<p>(A) Axial image with region-of-interest indications for measuring CT number and standard deviation: bronchial artery blood vessels (blue), adjacent tissues in mediastinum (green), and subcutaneous fat on chest wall (purple). (B) Plot of contrast-to-noise ratio(CNR) as function of photon energy showing the optimal energy level of 63keV to obtain the highest CNR for the bronchial artery. (C) Volume-rendering (VR) 140kVp image with image quality score of 3. (D) VR image at 70 keV with image quality score of 4. (E) VR image at the optimal 63 keV with image quality score of 5.</p