title: Artifacts at Cardiac CT: Physics and Solutions.
abstract: Computed tomography is vulnerable to a wide variety of artifacts, including patient- and technique-specific artifacts, some of which are unique to imaging of the heart. Motion is the most common source of artifacts and can be caused by patient, cardiac, or respiratory motion. Cardiac motion artifacts can be reduced by decreasing the heart rate and variability and the duration of data acquisition; adjusting the placement of the data window within a cardiac cycle; performing single-heartbeat scanning; and using multisegment reconstruction, motion-correction algorithms, and electrocardiographic editing. Respiratory motion artifacts can be minimized with proper breath holding and shortened scan duration. Partial volume averaging is caused by the averaging of attenuation values from all tissue contained within a voxel and can be reduced by improving the spatial resolution, using a higher x-ray energy, or displaying images with a wider window width. Beam-hardening artifacts are caused by the polyenergetic nature of the x-ray beam and can be reduced by using x-ray filtration, applying higher-energy x-rays, altering patient position, modifying contrast material protocols, and applying certain reconstruction algorithms. Metal artifacts are complex and have multiple causes, including x-ray scatter, underpenetration, motion, and attenuation values that exceed the typical dynamic range of Hounsfield units. Quantum mottle or noise is caused by insufficient penetration of tissue and can be improved by increasing the tube current or peak tube potential, reconstructing thicker sections, increasing the rotation time, using appropriate patient positioning, and applying iterative reconstruction algorithms.©RSNA, 2016.
authors: From the Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, Ohio (K.K., J.B.); Department of Radiology, Cardiothoracic Imaging, UT Southwestern Medical Center, E6.120 B, Mail Code 9316, 5323 Harry Hines Blvd, Dallas, TX 75390-8896 (S.S.S., S.A., P.R.); and Philips Healthcare, Cleveland, Ohio (S.H.).
authors: Kevin
authors: K
authors: Kalisz
authors: From the Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, Ohio (K.K., J.B.); Department of Radiology, Cardiothoracic Imaging, UT Southwestern Medical Center, E6.120 B, Mail Code 9316, 5323 Harry Hines Blvd, Dallas, TX 75390-8896 (S.S.S., S.A., P.R.); and Philips Healthcare, Cleveland, Ohio (S.H.).
authors: Ji
authors: J
authors: Buethe
authors: From the Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, Ohio (K.K., J.B.); Department of Radiology, Cardiothoracic Imaging, UT Southwestern Medical Center, E6.120 B, Mail Code 9316, 5323 Harry Hines Blvd, Dallas, TX 75390-8896 (S.S.S., S.A., P.R.); and Philips Healthcare, Cleveland, Ohio (S.H.).
authors: Sachin S
authors: SS
authors: Saboo
authors: From the Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, Ohio (K.K., J.B.); Department of Radiology, Cardiothoracic Imaging, UT Southwestern Medical Center, E6.120 B, Mail Code 9316, 5323 Harry Hines Blvd, Dallas, TX 75390-8896 (S.S.S., S.A., P.R.); and Philips Healthcare, Cleveland, Ohio (S.H.).
authors: Suhny
authors: S
authors: Abbara
authors: From the Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, Ohio (K.K., J.B.); Department of Radiology, Cardiothoracic Imaging, UT Southwestern Medical Center, E6.120 B, Mail Code 9316, 5323 Harry Hines Blvd, Dallas, TX 75390-8896 (S.S.S., S.A., P.R.); and Philips Healthcare, Cleveland, Ohio (S.H.).
authors: Sandra
authors: S
authors: Halliburton
authors: From the Department of Radiology, University Hospitals Cleveland Medical Center, Cleveland, Ohio (K.K., J.B.); Department of Radiology, Cardiothoracic Imaging, UT Southwestern Medical Center, E6.120 B, Mail Code 9316, 5323 Harry Hines Blvd, Dallas, TX 75390-8896 (S.S.S., S.A., P.R.); and Philips Healthcare, Cleveland, Ohio (S.H.).
authors: Prabhakar
authors: P
authors: Rajiah
mesh_terms: D000465:Algorithms; D016477:Artifacts; D057791:Cardiac Imaging Techniques / Q000379:methods*; D055424:Cardiac-Gated Imaging Techniques / Q000379:methods*; D003951:Diagnostic Errors / Q000517:prevention & control*; D019317:Evidence-Based Medicine; D006801:Humans; D009038:Motion; D019736:Prostheses and Implants; D011856:Radiographic Image Enhancement / Q000379:methods*; D015203:Reproducibility of Results; D055425:Respiratory-Gated Imaging Techniques / Q000379:methods*; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*