title: Contrast opacification on thoracic CT angiography: challenges and solutions.
abstract: Contrast flow and enhancement patterns seen on thoracic CT angiography (CTA) can often be challenging and may often reveal more than is immediately apparent. A non-diagnostic CTA following the initial contrast injection can be secondary to many causes; these include both extrinsic factors, such as injection technique/equipment failure (iv cannula, power injector), and intrinsic, patient-related factors. Contrast pressure and flow graphs often contain useful information regarding the etiology of a non-diagnostic scan. Understanding these graphs will help the radiologist plan a repeat contrast injection to overcome the deficiencies of the first injection and thus obtain a diagnostic scan. The current review article outlines normal and abnormal intravenous contrast dynamics, discusses how to recognize etiologies of non-diagnostic scans, and ultimately addresses techniques to overcome obstacles towards obtaining normal contrast opacification of the target vessel. In addition, there are some life-threatening findings, which unless sought for, may remain hidden in plain sight. Key Points • Using contrast enhancement and flow patterns to identify the cause of a non-diagnostic CTA.• Recognize life threatening causes of altered contrast dynamics such as cardiac asystole.• Non-target vessel opacification may hold key to underlying pathophysiology.
authors.affiliation: Department of Imaging Sciences, University of Rochester Medical Center, 601 Elmwood Ave, P.O. Box no. 648, Rochester, NY, 14642, USA. toabhic@gmail.com.
authors.forename: Abhishek
authors.initials: A
authors.lastname: Chaturvedi
authors.affiliation: Department of Imaging Sciences, University of Rochester Medical Center, 601 Elmwood Ave, P.O. Box no. 648, Rochester, NY, 14642, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Oppenheimer
authors.affiliation: Department of Radiology, University of Texas Southwestern, Dallas, TX, USA.
authors.forename: Prabhakar
authors.initials: P
authors.lastname: Rajiah
authors.affiliation: Department of Imaging Sciences, University of Rochester Medical Center, 601 Elmwood Ave, P.O. Box no. 648, Rochester, NY, 14642, USA.
authors.forename: Katherine A
authors.initials: KA
authors.lastname: Kaproth-Joslin
authors.affiliation: Department of Imaging Sciences, University of Rochester Medical Center, 601 Elmwood Ave, P.O. Box no. 648, Rochester, NY, 14642, USA.
authors.forename: Apeksha
authors.initials: A
authors.lastname: Chaturvedi
keywords: CT angiography; Cardiac asystole; Contrast dynamics; ECMO; Non-diagnostic CTA