Spectral detector CT-derived virtual non-contrast images: comparison of attenuation values with unenhanced CT

• Published in: Abdominal imaging 2017-03, Vol.42 (3), p.702-709
• Main Authors: Ananthakrishnan, Lakshmi, Rajiah, Prabhakar, Ahn, Richard, Rassouli, Negin, Xi, Yin, Soesbe, Todd C., Lewis, Matthew A., Lenkinski, Robert E., Leyendecker, John R., Abbara, Suhny
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; Female; Gastroenterology; Hepatology; Humans; Imaging; Invited Article; Male; Medicine; Medicine & Public Health; Middle Aged; Prospective Studies; Radiographic Image Interpretation, Computer-Assisted; Radiography, Abdominal - methods; Radiography, Dual-Energy Scanned Projection - methods; Radiology; Tomography, X-Ray Computed - methods
• ISSN: 2366-004X; 2366-0058
• DOI: 10.1007/s00261-016-1036-9

Purpose To assess virtual non-contrast (VNC) images obtained on a detection-based spectral detector CT scanner and determine how attenuation on VNC images derived from various phases of enhanced CT compare to those obtained from true unenhanced images. Methods In this HIPAA compliant, IRB approved prospective multi-institutional study, 46 patients underwent pre- and post-contrast imaging on a prototype dual-layer spectral detector CT between October 2013 and November 2015, yielding 84 unenhanced and VNC pairs (25 arterial, 39 portal venous/nephrographic, 20 urographic). Mean attenuation was measured by one of three readers in the liver, spleen, kidneys, psoas muscle, abdominal aorta, and subcutaneous fat. Equivalence testing was used to determine if the mean difference between unenhanced and VNC attenuation was less than 5, 10, or 15 HU. VNC image quality was assessed on a 5 point scale. Results Mean difference between unenhanced and VNC attenuation was