Alison Lozner, HMS IIIGillian Lieberman, MD

Aortic Dissection: Radiologic Findings

Alison Lozner, Harvard Medical School Year IIIGillian Lieberman, MD

January, 2004

2

Alison Lozner, HMS IIIGillian Lieberman, MD

Mr. JB’s

chest pain

•

80-year-old white male visiting his wife, who was scheduled for surgery, at BIDMC

•

Sudden onset of heavy, 8/10, substernal

chest pain•

Radiated from his mid-sternum to his jaw and to his left shoulder and arm

•

Tingling of his left arm•

Right eye blurriness

•

No radiation of pain to the back, no SOB

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Alison Lozner, HMS IIIGillian Lieberman, MD

Mr. JB’s

H and P

•

HTN•

Bradycardia

s/p

pacemaker

•

Stable abdominal aortic aneurysm•

On Norvasc

and HCTZ

•

Father died of AAA rupture. Brother treated for AAA rupture.

•

Vitals: T 96.1, P 57, BP 94/50, R 16, O2 95% RA

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Alison Lozner, HMS IIIGillian Lieberman, MD

DDx-

sudden onset chest pain

•

Cardiac (MI, angina)•

Vascular (aortic dissection, PE)

•

Pulmonary (pneumothorax)•

GI (GERD, esophageal spasm)

•

MSK (costochondritis)

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Alison Lozner, HMS IIIGillian Lieberman, MD

Mr. JB’s

DDx

•

Cardiac (MI, angina)

•

Vascular (aortic dissection, PE)•

Pulmonary (pneumothorax)

•

GI (GERD, esophageal spasm)•

MSK (costochondritis)

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Alison Lozner, HMS IIIGillian Lieberman, MD

Mr. JB’s

CXR

widened mediastinum

“apparent widening of the right superior mediastinum”

“underlying vascular injury/dissection cannot be excluded”

Image and text courtesy of BIDMC

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Alison Lozner, HMS IIIGillian Lieberman, MD

DDx-

Widened Mediastinum

•

Achalasia•

Neoplasm

•

LAD•

Hematoma or Hemorrhage

•

Vascular abnormality (e.g. dilated or tortuous aorta, aneurysm, dissection, coarctation, dilated SVC)

(Reeder, 1993)

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Alison Lozner, HMS IIIGillian Lieberman, MD

Aortic Dissection on CXR

•

Widening of the superior mediastinum•

Progressive widening of the aorta on serial films

•

Left pleural effusion (Miller, 2001)

•

According to the International Registry of Acute Aortic Dissection, 12.4% of patients have no abnormality on chest radiograph. (�Hagan, 2000)

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Alison Lozner, HMS IIIGillian Lieberman, MD

R ventricle

L atrium

Ascending Aorta& Intimal Flap

Mr. JB’s

CTA

Image courtesy of BIDMC

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Alison Lozner, HMS IIIGillian Lieberman, MD

Mr. JB’s

CTA

Aortic arch

Image courtesy of BIDMC

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Alison Lozner, HMS IIIGillian Lieberman, MD

Mr. JB’s

CTA

Descending Aorta

Image courtesy of BIDMC

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Alison Lozner, HMS IIIGillian Lieberman, MD

What Information Is Needed?

•

Presence of an aortic dissection•

Involvement of ascending aorta

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Alison Lozner, HMS IIIGillian Lieberman, MD

Classification of Aortic Dissections

Image courtesy of Cotran, 1999.

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Alison Lozner, HMS IIIGillian Lieberman, MD

What Information Is Needed?

•

Presence of an aortic dissection•

Involvement of ascending aorta

•

True vs. False lumen

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Alison Lozner, HMS IIIGillian Lieberman, MD

Identifying the True Lumen

•

Location of calcifications

True Lumen

• “Beak” or “Claw” sign

Image courtesy of BIDMC

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Alison Lozner, HMS IIIGillian Lieberman, MD

Identifying the True Lumen• Differing opacification

times

Image A Image B (seconds later)True lumen False lumen

Images courtesy of Neil Rofsky, M.D.

Patient 2

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Alison Lozner, HMS IIIGillian Lieberman, MD

Can you find the true lumen?

Image courtesy of BIDMC

Patient 3

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Alison Lozner, HMS IIIGillian Lieberman, MD

Can you find the true lumen?

True Lumen

Image courtesy of BIDMC

Patient 3

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Alison Lozner, HMS IIIGillian Lieberman, MD

What Information Is Needed?

•

Presence of an aortic dissection•

Involvement of ascending aorta

•

True vs. False lumen•

Extent of dissection

•

Sites of entry and re-entry•

Involvement of branch vessels

•

Aortic insufficiency•

Pericardial effusion (Cigarroa, 1993)

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Alison Lozner, HMS IIIGillian Lieberman, MD

Comparison of Modalities for AD Diagnosis

•

CT•

MRI

•

TEE

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Alison Lozner, HMS IIIGillian Lieberman, MD

Pros and Cons of CTPros:•

Noninvasive

•

Equipment generally available on an emergent basis

•

Operator IN-dependent•

Helpful for identifying other causes of mediastinal

wideningCons:•

Requires IV contrast

•

Sensitivity: 94%, Specificity: 87% (Nienaber, 1993)

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Alison Lozner, HMS IIIGillian Lieberman, MD

MRI

Image courtesy of Neil Rofsky, M.D.

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Alison Lozner, HMS IIIGillian Lieberman, MD

Pros and Cons of MRIPros:•

Sensitivity: 98%, Specificity: 98% (Nienaber, 1993)

•

Noninvasive and no IV contrast required•

Multiple planes of view help with dx

•

Cine-MRI can identify aortic insufficiencyCons:•

Contraindicated for some patients

•

Patients are relatively inaccessible during the MRI•

MRI may not be available emergently

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Alison Lozner, HMS IIIGillian Lieberman, MD

Image courtesy of Cigarroa, 1993.

Transesophageal

Echo

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Alison Lozner, HMS IIIGillian Lieberman, MD

Pros and Cons of TEEPros:•

Sensitivity: 98%, Specificity: 77% (Nienaber, 1993)

•

Widely available at the bedside•

Doppler can identify aortic insufficiency

Cons:•

Semi-invasive

•

Operator dependent•

Image quality comparatively poor for surgical planning

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Alison Lozner, HMS IIIGillian Lieberman, MD

Summary: Dx

Aortic Dissection

•

Choose modality (TEE, CT, or MRI) based on availability and expertise

•

Identify an intimal

flap•

Type A or Type B dissection?

•

Which is the true lumen?–

intimal

calcifications

–

“beak” or “claw” sign–

differing times to opacification

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Alison Lozner, HMS IIIGillian Lieberman, MD

References

•

Cigarroa

et al. 1993. “Medical Progress: Diagnostic Imaging in the Evaluation of Suspected Aortic Dissection--Old Standards and New Directions.”

N Engl J Med. 328 (1):35-43.•

Cotran, et al. 1999. Robbins Pathologic Basis of Disease. 6th ed. NY: WB Saunders Company.•

Hagan et al. 2000. “The International Registry of Acute Aortic Dissection (IRAD): New Insights Into an Old Disease.”

JAMA. 283(7): 897-903.•

Ledbetter et al. 1999. “Helical (Spiral) CT in the Evaluation of Emergent Thoracic Aortic Syndromes: Traumatic Aortic Rupture, Aortic Aneurysm, Aortic Dissection, Intramural Hematoma, and Apenetrating

Atherosclerotic Ulcer.”

The Radiologic Clinics of North America: Advances in Emergency Radiology I. 37(3): 575-590.

•

Miller, W. ed. 2001. Seminars in Roentgenology: Thoracic Aortic Aneurysms. 36(4).•

Nienaber

et al. 1993. “The Diagnosis of Thoracic Aortic Dissection By Noninvasive Imaging Procedures.”

N Engl J Med. 328 (1):1-9.•

Nienaber, C. and Kim Eagle. 2003. “Aortic Dissection: New Frontiers in Diagnosis and Management Part 1: From Etiology

to Diagnostic Strategies.”

Circulation. 108: 628-635.•

Reeder, M. 1993. Reeder and Felson’s Gamut’s In Radiology Comprehensive Lists of Roentgen Differential Diagnoses. 3d ed. NY: Springer-Verlag.

•

Sarasin et al. 1996. “Detecting Acute thoracic Aortic Dissection in the Emergency Department: Time Constraints and Choice of the Optimal Diagnostic Test.”

Annals of Emergency Medicine. 28(3): 278-288.

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Alison Lozner, HMS IIIGillian Lieberman, MD

Acknowledgements

•

Daniel Cornfeld, MD•

Neil Rofsky, MD

•

Larry Barbaras, Webmaster•

Gillian Lieberman, MD

•

Pamela Lepkowski, Clerkship Coordinator