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DISCLOSURE

‘A’ is for ANATOMY

Aortic Arch &Major Vessels ofUpper Extremity

Aorta and Major Vessels of Abdomen

Major Vessels of Aorto-iliac Segment

Major Vesselsof LowerExtremity

Example of Normal AngiogramExample of Normal Angiogramof Lower Extremity (AP)of Lower Extremity (AP)

SG: Supreme SG: Supreme geniculargenicular

SLG: Superior SLG: Superior lateral genicularlateral genicular

SMG: Superior SMG: Superior medial genicular medial genicular

Example of Normal AngiogramExample of Normal Angiogramof Lower Extremity (AP) of Lower Extremity (AP)

SMG: Superior SMG: Superior medial genicular medial genicular

SLG: Superior SLG: Superior lateral genicularlateral genicular

SU: SuralSU: Sural

ILG: Inferior lateral ILG: Inferior lateral geniculargenicular

Longitudinal & Longitudinal & Transverse Transverse

views obtainedviews obtained

Anatomy Anatomy represented on represented on transverse views transverse views related to related to transducer transducer placementplacement

Vessel Size

The following factors effect size of vessels:Body sizeAgeB/PGender (identified in some studies)

1.5 – 2 times normal adjacent vessel: Ectatic> 2 times: Aneurysmal

Mean Arterial Diameter and PSV

Artery Diameter + SD (cm) Velocity + SD (cm/sec)

Aorta 1.90* (Suprarenal)1.57* (Infrarenal)

80 + 25

Celiac 0.8 + 0.3 160 + 90

SMA 0.6 + 0.15 160 + 60

Renal 0.59 + 1.2* 80 + 20

CIA 0.91 + 1.38* 119.3 + 21.7

(*Journal of Texas Heart Institute, 2006; 33[4]:463-468)

Mean Arterial Diameter and PSV

Artery Diameter + SD (cm) Velocity + SD (c/sec)

EIA 0.79 + 0.13 119.3 + 21.7

CFA 0.82 + 0.14 114.0 + 24.9

Prox SFA 0.60 + 0.12 90.8 + 13.6

Distal SFA 0.54 + 0.11 93.6 + 14.1

Popliteal 0.52 + 0.11 68.8 + 13.5

(Zierler RE, Zierler BK: Duplex sonography of lower extremity arteries)

Arterial Variants: Upper extremity

Common origin of Rt innominate & Lt CCA: Common origin of Rt innominate & Lt CCA:

22%22%

Radial A originates from Axillary Artery: 1Radial A originates from Axillary Artery: 1--3%3%

Ulnar A originates from Axillary A: 2Ulnar A originates from Axillary A: 2--3%3%

Early division of Brachial Artery: 19%Early division of Brachial Artery: 19%

Arterial Variants: Lower extremity

High bifurcation of the popliteal artery: 4%

High bifurcation of the popliteal artery w/

peroneal arising from the ATA: 2%

Absent PTA (may have distal reconstruction

at ankle from peroneal): 1-5%

Arterial Variants: Lower extremity

Hypoplasia or aplasia of ATA (with

resultant absence of DPA pulse): 4-12%

Anomalous location of DPA: 8%

Some of the more common Collateral Routes of Lower

Extremity…

Lower extremity

SFA or PopA obstruction:SFA or PopA obstruction:

DFA TO distal SFA or PopA DFA TO distal SFA or PopA

Distal SFA TO PopA or proximal Distal SFA TO PopA or proximal

trifurcation vessels in calftrifurcation vessels in calf

Genicular and/or sural arteries TO Pop Genicular and/or sural arteries TO Pop

or infrapop arteries dto or infrapop arteries dto

Example of Example of Collateralization:Collateralization:

Occluded Popliteal Occluded Popliteal Artery Artery

SU: SuralSU: Sural

rAT: Recurrent ATrAT: Recurrent AT

Lower extremity

Obstruction of AT/PT/Peroneal:

Non-obstructed proximal calf branches

TO distal arteries in the lower leg or

ankle

Distal peroneal branches TO distal ATA

or PTA

‘B’ means BY THE BOOK

Society for Vascular Ultrasound

4601 Presidents Drive, Suite 260, Lanham, MD 20706-4831 Toll-free: 800-788-8346

Telephone: 301-459-7550 Fax: 301-459-5651

svunet.org

Professional Performance Guidelines

Screening For Abdominal Aortic Aneurysms (AAA)(2/5/13)Mesenteric/Splanchnic Artery Duplex Imaging (2/5/13)Renal Artery Duplex Imaging (11/15/12)Lower Extremity Arterial Duplex Evaluation (8/10/12)Upper Extremity Vein Mapping for Creation of a Dialysis Access or Peripheral Vascular Bypass Graft (8/10/12)Transcranial Doppler in Pediatric Patients with Sickle Cell Anemia: (Non-Imaging) (04/11/12)Evaluation of Dialysis Access (04/11/12)Lower Extremity Arterial Segmental Physiologic Evaluation (04/11/12)

Professional Performance Guidelines

Radial Artery Assessment for Coronary Artery Bypass(04/11/12)Intracranial Cerebrovascular Evaluation Transcranial Doppler (Non-Imaging) and Transcranial Duplex Imaging (TCDI) (04/11/12)Quality Assurance Guidelines for Accuracy of Examinations in the Vascular Laboratory (3/13/12)Upper Extremity Arterial Segmental Physiologic Evaluation (Arterial, TOS, Cold) (revised 12/22/11)Upper Extremity Arterial Duplex Evaluation (revised 11/11)Abdominal Aortoiliac Duplex Evaluation (revised 11/11)Extracranial Cerebrovascular Duplex Ultrasound Evaluation (revised 06/11)

Scope of Practice

Diagnostic Ultrasound Professionals…Perform patient assessmentsAcquire and analyze data obtained using

ultrasound and related diagnostic technologiesProvide a summary of findings to the physician to

aid in patient diagnosis and managementUse independent judgment and systematic

problem solving methods to produce high quality diagnostic information and optimize patient care.

Intersocietal Commission on the Accreditation of Vascular Laboratories

(ICAVL)

6021 University Blvd, Suite 500, Ellicott, MD 21043

Toll-free: 800-838-2110 Fax: 866-663-5663

Intersocietal.org/vascular

3.6.3B Duplex ultrasound of lower extremity arteries (if performed) must include:

3.6.3.1B Grayscale and/or color Doppler images must be documented as required by the protocol and must include at a minimum:

i. common femoral artery; ii. superficial femoral artery; iii. proximal deep femoral artery; iv. popliteal artery; and v. aorta, common and external iliac arteries and tibial

arteries (when appropriate); vi. bypass graft(s) when present including anastomoses.

3.6.3B Duplex ultrasound of lower extremity arteries (if performed) must include:

3.6.3.2B Spectral Doppler waveforms and velocity measurements must be documented as required by the protocol and must include at a minimum waveforms from:

i. common femoral artery; ii. superficial femoral artery; iii. proximal deep femoral artery; iv. popliteal artery; v. tibial arteries; vi. aorta, common and external iliac arteries (when

appropriate); and vii. bypass graft when present, including proximal and

distal anastomoses, inflow and outflow arteries.

Remember to ‘Think Outside the Box’…

Protocols are guidelines that represent ‘best practice’ in the majority of patient situations.

Thinking Outside the Box…

Atypical signs/symptoms or unusual findings compel you to obtain additional information, e.g., more anatomic images and/or flow patterns than stated in protocol.Innovative surgical procedures may require additional documentation in post-op or surveillance studies.Our goal should be to help answer the clinical question whether it follows a ‘protocol’ or not.

‘C’ COMPLETES THE PROCESS

Did you help answer the clinical question/s?

“Listen to your patients, at least 90% of your diagnosis is based on the history and physical examination. The other 10% depends on diagnostic tests”

D. Eugene Strandness, Jr., M.D.

A Critical Component of All Noninvasive Evaluations…

Requires thinking outside the box: Truly listening to the patientA willingness to do more than what is stated in the protocol

Diagnostic Tests: Noninvasive Evaluations…

Serves to refine the clinical evaluation by providing objective information about anatomy and physiologyRequires knowledge of:

Differential diagnosesNormal anatomy & anatomic variantsNormal & abnormal blood flow patterns

Normal Blood Flow Patterns

As a general rule…

Normal flow in theperiphery is high-resistant

Tri-phasicLittle-to-no flow at end diastoleSharp upstroke with narrow peakYou can’t fake ‘normal’

Potential Sources Of Error

Improper probe position

Motion of probe and/patient

Poor angle

Excessive pressure

Insufficient period of rest

Normal Blood Flow Patterns

As a general rule…

Flow to organs islow-resistance (Fasting SMA is an exception)

High metabolic needsBlood required throughout cardiac cycle Sharp upstroke expected

Blood Flow Patterns

Diastolic flow documents the status of the distal vascular bedIf diastolic flow different from expected,

ask why…Normal physiologic response? Reflective of a diseased state?

Altered Diastolic Flow Patterns

A peripheral vessel may have low resistance flowfor a variety of reasons, e,g,

StenosisHyperemia related to healingHyperemia secondary to cellulitisDistal arteriovenous fistulaExercise

Altered Diastolic Flow Patterns

A normally low-resistantvessel may have high-resistance flow for avariety of reasons, e,g,

Distal occlusionOrgan failureNonfunctioning dialysis accessVasospasm/vasoconstriction

Blood Flow Patterns

Systolic flow represents the status of the proximal vesselsIf systolic flow different from expected,

ask why…Unilateral change probably attributed

to proximal arterial diseaseBilateral alterations may be related to

vessels and/or cardiac status

Altered Systolic Flow Patterns

Objective measurements:Pulsatility indexAcceleration time /Rise time

> 133 msec in CFA consistent with inflow disease> 100 msec in Kidney consistent with

renal artery disease

Subjectively applied to most vessels in the body

Remember…

Systolic upstroke provides information about where the blood came fromDiastolic flow patterns provide informationabout where the blood is going to

Velocity

Physical Principles

Calculating for Velocity V = c Df 2Fo Cos Ø

– V = Calculated value– C = Speed of US in soft tissue– Df = Known value, measured by duplex;

Proportional to velocity of source– Fo = Carrier frequency/transducer frequency

– Cos Ø = Angle determined from image

Effects of Stenosis

Stenosis Profile

Pre-stenosis: Reduced velocities with alteration in diastolic flow

Stenosis: Elevated velocities with severe spectral broadening

Post-stenosis: Turbulence (e.g., flow reversals, eddy currents, vortices)

General Guidelines: Peripheral Vessels

Abnormal: (Compare stenotic to pre-stenotic)

– 2:1 ratio = > 50% DR– 4:1 ratio = > 75% DR– PSV >400 cm/s = > 75% DR

– Never accept value of numbers alone; should see post-stenotic turbulence

General Guidelines: Renal Artery

RAR: Highest Renal A PSVAorta PSV

Normal: < 3.5

Abnormal: bnormal: > 3.5 ( > 60% DR)

Cannot use RAR if AAA detected

Cannot use RAR if aortic PSV >90 or <40 cm/s

Renal A PSV: >180 - 200 cm/sec = > 60% (“Stenosis profile”)

General Guidelines: Kidney

� EDR: End Diastolic V Normal = > 0.2PSV Abnormal = < 0.2

� RI: PSV - EDV Normal = < 0.8PSV Abnormal = > 0.8

General Guidelines: Mesenteric Arteries

SMA CeliacNormal PSV: 110-177 cm/s 50-160 cm/s

Stenosis >275 cm/s >200 cm/sCriteria: predicts predicts

> 70% DR > 70% DR

(DR = Diameter Reduction)

General Guidelines: ICA(University of Washington)

% Stenosis PSF EDF PSV EDV

0-15% <4 NA < 125 NA

16-49% <4 NA < 125 NA

50-79% >4 <4 > 125 < 140

80-99% >4 >4 > 125 > 140

Carotid Duplex Consensus Conference

Suggested Criteria For Doppler Diagnosis of ICA Ste nosis

Additional Parameters

Stented VesselsStented Vessels

Elevated velocities are expectedElevated velocities are expected

However, greatly elevated However, greatly elevated velocities are abnormalvelocities are abnormal

Image and velocity measurements Image and velocity measurements are critical in the evaluation of are critical in the evaluation of stented vesselsstented vessels

Additional Data Obtained…

Pressure Measurements

Four cuff method

Three cuff method

Interpretation: LE Pressures

Ankle/brachial Index (ABI): divide ankle BP by higher brachial BP

> 1.0 = Normal

>0.9 - 1.0 = May be within normal limits

0.8 - 0.9 = Mild arterial disease

0.5 - 0.8 = Claudication (moderate disease)

< 0.5 = Rest pain (severe disease)(Incompressible vessels can cause falsely elevated BP)

Additional Guidelines:

Segmental P drops of >30 mmHg between 2 adjacent levels is significant

Horizontal P difference of >20-30 mmHg suggests obstructive disease

Interpretation: UE Pressures

15-20 mmHg difference from arm - arm

>15-20 mmHg drop from upper arm to forearm suggests…– Brachial A obstruction distal to upper cuff– Obstruction in both radial and ulnar A– Obstruction in single forearm A

>20 mmHg between radial and ulnar

Interpretation: Digits

UE digits : Finger/brachial indices 0.8-0.9

LE digits :Toe/brachial indices 0.6-0.8

Interpretation: Penile Pressures

Normal = > 0.75

Marginal = 0.65 – 0.74

Abnormal = < 0.65

Completing the Process Includes…

Generating waveforms, gray-scale images, color-flow Doppler, and variouscalculations Knowing when additional information is needed to help answer the clinical question

The Process isn’t Complete Until the Paperwork is Done…

Storing/processing the diagnostic information obtainedProviding preliminary reportCompleting billing documentsSubmitting data for final report

In conclusion...In conclusion...

Know the A, B, Cs of arterial testingKnow the A, B, Cs of arterial testing …It will help you provide important diagnostic information critical to the medical and/or surgical management of your patient.However, the value of that information is directly related to your knowledge, skill, and willingness to sometimes ‘think outside the box’ in order to answer the clinical question.

YOU make the Difference...YOU make the Difference...

Between an adequate study and an exceptional oneDetermining whether additional diagnostic information is neededAssisting with possible treatment optionsEvaluating the success of traditionaland/or non-traditional treatment

YOU make the Difference...YOU make the Difference...

Did you help the patient?

That’s the real reason we’re here!