Pearls and Pitfalls in Cardiovascular Imaging Book contents
- Frontmatter
- Contents
- List of contributors
- Preface
- Section 1 Cardiac pseudotumors and other challenging diagnoses
- Section 2 Cardiac aneurysms and diverticula
- Section 3 Anatomic variants and congenital lesions
- Section 4 Coronary arteries
- Section 5 Pulmonary arteries
- Section 6 Cardiovascular MRI artifacts
- Section 7 Acute aorta and aortic aneurysms
- Case 54 Pitfalls in arterial enhancement timing
- Case 55 Misdiagnosis of acute aortic syndrome in the ascending aorta due to cardiac motion
- Case 56 Aortic pseudodissection from penetrating atherosclerotic ulcer
- Case 57 Ductus diverticulum mimicking ductus arteriosus aneurysm
- Case 58 Pericardial recess mimicking traumatic aortic injury
- Case 59 Neointimal calcifications mimicking displaced intimal calcifications on unenhanced CT
- Case 60 The value of non-contrast CT in vascular imaging
- Case 61 Shearing of branch arteries in intramural hematoma: a mimic of active extravasation
- Case 62 Imaging features of aortic aneurysm instability
- Case 63 Aortoenteric fistula
- Case 64 Infammatory aortic aneurysm
- Case 65 Incorrect aneurysm measurement due to aortic tortuosity
- Section 8 Post-operative aorta
- Section 9 Mesenteric vascular
- Section 10 Peripheral vascular
- Section 11 Veins
- Index
- References
Case 65 - Incorrect aneurysm measurement due to aortic tortuosity
from Section 7 - Acute aorta and aortic aneurysms
Published online by Cambridge University Press: 05 June 2015
- Frontmatter
- Contents
- List of contributors
- Preface
- Section 1 Cardiac pseudotumors and other challenging diagnoses
- Section 2 Cardiac aneurysms and diverticula
- Section 3 Anatomic variants and congenital lesions
- Section 4 Coronary arteries
- Section 5 Pulmonary arteries
- Section 6 Cardiovascular MRI artifacts
- Section 7 Acute aorta and aortic aneurysms
- Case 54 Pitfalls in arterial enhancement timing
- Case 55 Misdiagnosis of acute aortic syndrome in the ascending aorta due to cardiac motion
- Case 56 Aortic pseudodissection from penetrating atherosclerotic ulcer
- Case 57 Ductus diverticulum mimicking ductus arteriosus aneurysm
- Case 58 Pericardial recess mimicking traumatic aortic injury
- Case 59 Neointimal calcifications mimicking displaced intimal calcifications on unenhanced CT
- Case 60 The value of non-contrast CT in vascular imaging
- Case 61 Shearing of branch arteries in intramural hematoma: a mimic of active extravasation
- Case 62 Imaging features of aortic aneurysm instability
- Case 63 Aortoenteric fistula
- Case 64 Infammatory aortic aneurysm
- Case 65 Incorrect aneurysm measurement due to aortic tortuosity
- Section 8 Post-operative aorta
- Section 9 Mesenteric vascular
- Section 10 Peripheral vascular
- Section 11 Veins
- Index
- References
Summary
Imaging description
In patients with tortuous aortas due to aging or atherosclerotic disease, measurements of aneurysm on axial images can lead to falsely elevated aneurysm diameters. Figure 65.1 shows an axial CT image of the ascending thoracic aorta in a 64-year-old woman, which measured 3.9cm. However, when the aneurysm is evaluated on double oblique, sagittal, and coronal multiplanar reformatted images (MPRs), it becomes apparent that the actual size is 3.5cm. The thoracic aorta has a candycane configuration, which may necessitate measurements using MPRs to accurately determine the cross-sectional diameter. Similarly, Figure 65.2 shows a 64-year-old man with an abdominal aortic aneurysm, the course of which is not entirely perpendicular to the z-axis of the scan. Accordingly, to accurately determine the diameter, the measurements must be made on MPRs tailored to reflect the actual cross-sectional diameter perpendicular to the aortic centerline.
Importance
One of the primary roles of CT in the patient with aortic aneurysm is aneurysm measurement, as the risk of rupture directly correlates with aneurysm size. Surgical thresholds have been defined based on anatomic segment. For the ascending thoracic aorta it is 5.5cm, for descending thoracic aorta 6.5cm, and for abdominal aorta 5.5cm. Serial imaging is critical to evaluate for rate of growth, an additional risk factor that reflects an increased risk of rupture. Aneurysms that grow more than 5–7mm in 6 months or 1cm in one year are considered rapidly enlarging and may warrant repair. Accordingly, accurate methods of measurement are critical to patient management.
As shown in this case, axial CT images should not be relied upon for thoracic aortic and abdominal aortic aneurysm measurements. Tortuosity of the aorta results in a course that is no longer directly perpendicular to the axial plane. In these cases, MPRs or 3D renderings are required to generate accurate bi-dimensional aneurysm measurements orthogonal to the aortic lumen centerline. Either manual double oblique MPRs or short-axis images generated from software-based automated centerline tracking are recommended for the most reliable aneurysm measurement.
- Type
- Chapter
- Information
- Pearls and Pitfalls in Cardiovascular ImagingPseudolesions, Artifacts, and Other Difficult Diagnoses, pp. 210 - 212Publisher: Cambridge University PressPrint publication year: 2015