AIUM–ACR--SRU PRACTICE GUIDELINE FOR THE PERFORMANCE OF DIAGNOSTIC AND SCREENING ULTRASOUND OF THE ABDOMINAL AORTA IN ADULTS
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Table of Contents
I. Introduction
II. Qualifications and Responsibilities of Personnel
III. Indications/Contraindications
IV. Written Request for the Examination
V. Specifications of the Examination
VI. Documentation
VII. Equipment Specifications
VIII. Quality Control and Improvement, Safety, Infection Control, and Patient Education



I. INTRODUCTION
The clinical aspects contained in specific sections of this guideline (Introduction, Indications, Specifications of the Examination, and Equipment Specifications) were developed collaboratively by the American Institute of Ultrasound in Medicine (AIUM), the American College of Radiology (ACR), and the Society of Radiologists in Ultrasound (SRU). Recommendations for physician requirements, written request for the examination, procedure documentation, and quality control vary among the three organizations and are addressed by each separately.

These guidelines are intended to assist in the performance and interpretation of the dedicated sonographic examination of the abdominal aorta. The examination may be performed as a diagnostic or a screening study. Comprehensive population screening programs have not yet been developed in the United States but do exist elsewhere in the world [1,2]. While it is not possible to detect every abnormality, following this guideline will maximize the detection of abnormalities of the abdominal aorta.

II. QUALIFICATIONS AND RESPONSIBILITIES OF PERSONNEL

See the AIUM Official Statement Training Guidelines for Physicians Who Evaluate and Interpret Diagnostic Ultrasound Examinations and the AIUM Standards and Guidelines for the Accreditation of Ultrasound Practices.

III. INDICATIONS/CONTRAINDICATIONS

Indications for ultrasound of the abdominal aorta include, but are not limited to:

A. Diagnostic Evaluation for Abdominal Aortic Aneurysm
1. Palpable or pulsatile abdominal mass.
2. Unexplained lower back pain, flank pain, or abdominal pain.
3. Follow-up of a previously demonstrated abdominal aortic aneurysm.
4. Follow-up of patients with an abdominal aortic and/or iliac endoluminal stent graft.


B. Screening Evaluation for Abdominal Aortic Aneurysm
1. Men age 65 or older.
2. Women age 65 or older with cardiovascular risk factors.
3. Patients age 50 or older with a family history of aortic and/or peripheral vascular aneurysmal disease.
4. Patients with a personal history of peripheral vascular aneurysmal disease.

Groups with additional risk include patients with a history of smoking, hypertension, or certain connective tissue diseases (e.g., Marfan’s syndrome).

There are no absolute contraindications to ultrasound of the aorta. If aortic rupture or dissection is clinically suspected, ultrasound is usually not the examination of choice.


IV. WRITTEN REQUEST FOR THE EXAMINATION


The written or electronic request for an ultrasound examination should provide sufficient information to allow for the appropriate performance and interpretation of the examination.

The request for the examination must be originated by a physician or other appropriately licensed health care provider or under their direction. The accompanying clinical information should be provided by a physician or other appropriate health care provider familiar with the patient’s clinical situation and should be consistent with relevant legal and local health care facility requirements.




V. SPECIFICATIONS OF THE EXAMINATION

A. Diagnostic Examination
The examination includes the following, when feasible:

1. Abdominal aorta

a. Longitudinal images (along the long axis of the vessel)
  1. Proximal
  2. Mid
  3. Distal
b. Transverse images (perpendicular to the long axis of the vessel)
i. Proximal (near diaphragm)
ii. Mid
iii. Distal
c. Measurements
· Measurements of the proximal, mid, and distal aorta should be obtained. Measurements are taken at the greatest diameter of the aorta from outer edge to outer edge.
ii. If an aneurysm is present:
· The maximal size and location of the aneurysm should be documented and recorded.
· The relationship of the dilated segment to the renal arteries and to the aortic bifurcation should be determined if possible.
· A measurement of the length of the aneurysm is not necessary.

2. Common iliac arteries
a. Longitudinal images of the proximal right and left common iliac arteries (along the long axis of the vessel).
b. Transverse images (perpendicular to the long axis of the vessel) of the proximal common iliac arteries just below at the bifurcation.
c. Measurement of the widest visualized portion of each common iliac artery from outer edge to outer edge.
Color Doppler imaging and/or spectral Doppler with waveform analysis of the aorta and iliac arteries may provide additional information.
After endoluminal graft placement, color (or power) and spectral Doppler are required to document the presence or absence of endoleaks.

Interobserver measurements of an aortic aneurysm can vary by as much as 5 mm. This variation makes visual comparison with previous studies is particularly important to determine whether or not a significant change in size has occurred [3].


B. Screening Examination for Abdominal Aortic Aneurysm
1. Abdominal aorta
a. Longitudinal images (along the long axis of the vessel)
i. Proximal
ii. Mid
iii. Distal
b. Transverse images (perpendicular to the long axis of the vessel)
i. Proximal (near diaphragm)
ii. Mid
iii. Distal

C. Interpretation of the screening examination should include at least 3 categories:
1. Positive
a. Infrarenal abdominal aortic aneurysm greater than or equal to 3 cm in diameter or
b. Greater than or equal to 1.5 times the diameter of the more proximal aorta [4].
c. The latter definition is particularly important in women [5].
2. Negative – No infrarenal abdominal aortic aneurysm.
3. Indeterminate – Aneurysmal status not defined because of nonvisualization or only partial visualization of the infrarenal abdominal aorta.
The report should also state whether or not the suprarenal aorta was seen and, if seen, should reflect whether or not it is normal.


VI. DOCUMENTATION

Adequate documentation is essential for high-quality patient care. There should be a permanent record of the ultrasound examination and its interpretation.
· Images of all appropriate areas, both normal and abnormal, should be recorded.
· Variations from normal size should be accompanied by measurements.
· Images should be labeled with the
§ patient identification,
§ facility identification,
§ examination date, and the
§ side (right or left) of the anatomic site imaged.
o An official interpretation (final report) of the ultrasound findings should be included in the patient’s medical record. Retention of the ultrasound examination should be consistent both with clinical need and with relevant legal and local healthcare facility requirements.
Reporting should be in accordance with the AIUM Standard for Documentation of an Ultrasound Examination.
VII. EQUIPMENT SPECIFICATIONS
Abdominal aortic ultrasound should be performed with real-time scanners with transducers that allow for appropriate penetration and resolution, depending on the patient’s body habitus. Diagnostic information should be optimized, while keeping total ultrasound exposure as low as reasonably achievable.
VIII. QUALITY CONTROL AND IMPROVEMENT, SAFETY, INFECTION CONTROL, AND PATIENT EDUCATION

Policies and procedures related to quality control, patient education, infection control, and safety should be developed and implemented in accordance with the AIUM Standards and Guidelines for the Accreditation of Ultrasound Practices.

Equipment performance monitoring should be in accordance with the AIUM Standards and Guidelines for the Accreditation of Ultrasound Practices.
IX. As Low As Reasonably Achievable (ALARA) Principle
The potential benefits and risks of each examination should be considered. The as low as reasonably achievable (ALARA) principle should be observed when adjusting controls that affect the acoustic output and by considering transducer dwell times. Further details on ALARA may be found in the AIUM publication Medical Ultrasound Safety, Second Edition.
ACKNOWLEDGEMENTS
This guideline was revised by the American Institute of Ultrasound in Medicine (AIUM) in collaboration with the American College of Radiology (ACR) and the Society of Radiologists in Ultrasound (SRU) according to the process described in the AIUM Clinical Standards Committee Manual.

Collaborative Committee
ACR AIUM
Raymond E. Bertino, MD, FACR Lin Diacon, MD
Lincoln L. Berland, MD, FACR David M. Paushter, MD, FACR
Edward I. Bluth, MD, FACR Carl C. Reading, MD, FACR
SRU
Mark E. Lockhart, MD, MPH
Laurence Needleman, MD, FACR
Hisham Tchelepi, MD

AIUM Clinical Standards Committee
David M. Paushter, MD, Chair
Leslie Scoutt, MD, Vice Chair
Susan Ackerman, MD
Lisa Allen, BS, RDMS, RDCS, RVT
Mert Ozan Bahtiyar, MD
Harris L. Cohen, MD
Jude Crino, MD
William Lindley Diacon, MD, RDMS
Judy Estroff, MD
Kimberly Gregory, MD, MPH
Charlotte Henningsen, MS, RT, RDMS, RVT
Charles Hyde, MD
Christopher Moore, MD, RDMS, RDCS
Olga Rasmussen, RDMS
Carl Reading, MD
Daniel Skupski, MD
Jay Smith, MD
Joseph Wax, MD

Comments Reconciliation Committee
Beverly G. Coleman, MD, Co-Chair, FACR
Richard N. Taxin, MD, Co-Chair, FACR
Kimberly E. Applegate, MD, MS, FACR
Lincoln L. Berland, MD, FACR
Raymond E. Bertino, MD, FACR
Edward I. Bluth, MD, FACR
Lin Diacon, MD
Howard B. Fleishon, MD, MMM, FACR
Mary C. Frates, MD, FACR
David I. Hammond, MD, FACR
Alan D. Kaye, MD, FACR
Paul A. Larson, MD, FACR
Deborah Levine, MD, FACR
Lawrence A. Liebscher, MD, FACR
Mark E. Lockhart, MD, MPH
Laurence Needleman, MD, FACR
David M. Paushter, MD, FACR
Carl C. Reading, MD, FACR
Hisham Tchelepi, MD
E. Kent Yucel, MD, FACR


REFERENCES

1. Adams DC, Tulloh BR, Galloway SW, Shaw E, Tulloh AJ, Poskitt KR. Familial abdominal aortic aneurysm: prevalence and implications for screening. Eur J Vasc Surg 1993;7:709-712.
2. Ashton HA, Buxton MJ, Day NE, et al. The Multicentre Aneurysm Screening Study (MASS) into the effect of abdominal aortic aneurysm screening on mortality in men: a randomised controlled trial. Lancet 2002;360:1531-1539.
3. Comstock CE, Bluth EI, Peattie RA, Schrader T, Leslie BR. Inter-observer variability in ultrasonic evaluation of abdominal aortic aneurysms. J La State Med Soc 1994;146:526-530.
4. Johnston KW, Rutherford RB, Tilson MD, Shah DM, Hollier L, Stanley JC. Suggested standards for reporting on arterial aneurysms. Subcommittee on Reporting Standards for Arterial Aneurysms, Ad Hoc Committee on Reporting Standards, Society for Vascular Surgery and North American Chapter, International Society for Cardiovascular Surgery. J Vasc Surg 1991;13:452-458.
5. Isselbacher EM. Thoracic and abdominal aortic aneurysms. Circulation 2005;111:816-828.
Suggested Reading (Additional articles that are not cited in the document but that the committee recommends for further reading on this topic)
6. Long-term outcomes of immediate repair compared with surveillance of small abdominal aortic aneurysms. N Engl J Med 2002;346:1445-1452.
7. Ebaugh JL, Garcia ND, Matsumura JS. Screening and surveillance for abdominal aortic aneurysms: who needs it and when. Semin Vasc Surg 2001;14:193-199.
8. Fleming C, Whitlock EP, Beil TL, Lederle FA. Screening for abdominal aortic aneurysm: a best-evidence systematic review for the U.S. Preventive Services Task Force. Ann Intern Med 2005;142:203-211.
9. Frame PS, Fryback DG, Patterson C. Screening for abdominal aortic aneurysm in men ages 60 to 80 years. A cost-effectiveness analysis. Ann Intern Med 1993;119:411-416.
10. Wilmink AB, Quick CR, Hubbard CS, Day NE. Effectiveness and cost of screening for abdominal aortic aneurysm: results of a population screening program. J Vasc Surg 2003;38:72-77.