ABSTRACT
I. Introduction 88
II. Acquisition Technique 89
A. Inspiratory Breath-hold 89
B. Dyspneic Patients 89
C. Scan Range 90
D. Scan Direction 90
E. Scanning Parameters 91
F. Dose Issues 94
III. Contrast Material Injection 96
A. Venous Access 96
B. Injection Parameters 96
C. Scan Delay 96
D. Saline Flush 97
IV. CT Venography 98
V. Image Evaluation and Postprocessing 98
A. Axial Sections 99
B. Multiplanar Planar Reformations 99
C. Maximum Intensity Projections 99
D. Volume Rendering 100
E. Lung Density Maps 100
VI. Acute Pulmonary Thromboembolism 100
A. Other Imaging Techniques 102
B. Findings at CTA 104
C. Artifacts and Pitfalls 108
D. Results of CTA 113
E. Role of CTA 115
F. Diagnostic Algorithms 118
G. CT Venography 119
VII. Chronic Thromboembolic Pulmonary Hypertension 120
A. Findings at CTA 121
B. Differential Diagnosis 123
VIII. Other Causes of Pulmonary Hypertension 125
A. Findings on CTA 126
IX. Arteriovenous Shunting 126
A. Findings on CTA 128
X. Pulmonary Aneurysms 129
A. Findings on CTA 130
XI. Vasculitis 131
A. Findings on CTA 132
XII. Tumors Involving the Pulmonary Vessels 132
A. Findings on CTA 134
XIII. Summary 134
References 135
I. Introduction
Since its introduction in 1992 (1), computed tomography angiography (CTA) of
the pulmonary arteries has become the main diagnostic test for the evaluation of
pulmonary embolism (PE). Pulmonary CTA, however, is not limited to evaluat-
ing embolism but can be used for a multitude of other diseases of the pulmonary
vascular bed. It is a relatively simple technique that can rapidly solve a vast
number of clinical questions. It is even able to detect extravascular reasons for
a patient’s complaints because it always includes the information from the
surrounding structures as well.
