Nonuniform contrast opacification of vasculature is frequently encountered on thoracic computed tomographic angiography. The purpose of this pictorial essay is to discuss the appearance of, and factors underlying mixing artifacts, which we term “smoke.” We provide an approach to distinguish it from pathology including pulmonary embolism, aortic dissection, and thrombus. Smoke results from a combination of technical factors, abnormal physiology, or inflow of unopacified blood. Smoke produces ill-defined filling defects that may be confidently diagnosed in many cases if these fundamentals are applied.
*Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco
∥Department of Radiology, University of California San Diego, San Diego, CA
†Department of Radiology, Brigham and Women’s Hospital, Harvard Medical School
‡Department of Radiology, Massachusetts General Hospital, Boston, MA
§Department of Diagnostic Radiology, University of Utah, Salt Lake City, UT
¶Department of Radiology, University of Wisconsin School of Medicine and Public Health, E3/366 Clinical Science Center, Madison, WI
The authors declare no conflicts of interest.
Correspondence to: Travis S. Henry, MD, Department of Radiology and Biomedical Imaging, University of California San Francisco, 505 Parnassus Avenue, M-396, San Francisco, CA 94143 (e-mail: email@example.com).