User guide

86 Measurement publications and terminology
Acceleration Index (ACC)
Zwiebel, W.J. Introduction to Vascular
Ultrasonography
, 4th ed., W.B. Saunders Company,
(2000), 52.
ACC = abs (delta velocity/delta time)
Elapsed Time (ET)
ET = time between velocity cursors in milliseconds
Hip Angle/d:D Ratio
Graf, R. “Fundamentals of Sonographic Diagnosis of
Infant Hip Dysplasia.”
Journal of Pediatric
Orthopedics
, Vol. 4, No. 6: 735-740, 1984.
Morin, C., Harcke, H., MacEwen, G. “The Infant Hip:
Real-Time US Assessment of Acetabular
Development.”
Radiology 177: 673-677,
December 1985.
Intima Media Thickness (IMT)
Howard G, Sharrett AR, Heiss G, Evans GW,
Chambless LE, Riley WA, et al. “Carotid Artery
Intima-Medial Thickness Distribution in General
Populations As Evaluated by B-Mode Ultrasound.”
ARIC Investigators. Atherosclerosis Risk in
Communities.
Stroke . (1993), 24:1297-1304.
O’Leary, Daniel H., MD and Polak, Joseph, F., MD, et
al. “Use of Sonography to Evaluate Carotid
Atherosclerosis in the Elderly. The Cardiovascular
Health Study.”
Stroke . (September 1991),
22,1155-1163.
Redberg, Rita F., MD and Vogel, Robert A., MD, et
al. “Task force #3—What is the Spectrum of
Current and Emerging Techniques for the
Noninvasive Measurement of Atherosclerosis?”
Journal of the American College of Cardiology .
(June 4, 2003), 41:11, 1886-1898.
Percent Area Reduction
Taylor K.J.W., P.N. Burns, P. Breslau. Clinical
Applications of Doppler Ultrasound,
Raven Press,
N.Y., (1988), 130-136.
Zwiebel W.J., J.A. Zagzebski, A.B. Crummy, et al.
“Correlation of peak Doppler frequency with lumen
narrowing in carotid stenosis.”
Stroke , 3: (1982),
386-391.
% Area Reduction = (1 - A2(cm
2
)/A1(cm
2
)) *
100
where: A1 = original area of the vessel in
square cm
A2 = reduced area of the vessel in
square cm
Percent Diameter Reduction
Handa, Nobuo et al., “Echo-Doppler Velocimeter in
the Diagnosis of Hypertensive Patients: The Renal
Artery Doppler Technique,”
Ultrasound in Medicine
and Biology
, 12:12 (1986), 945-952.
% Diameter Reduction = (1 - D2(cm)/D1(cm)) *
100
where: D1 = original diameter of the
vessel in cm
D2 = reduced diameter of the
vessel in cm
Pressure Gradient (PGr) in mmHG
Oh, J.K., J.B. Seward, A.J. Tajik. The Echo Manual.
2nd ed., Lippincott, Williams, and Wilkins, (1999),
64.
4 * (Velocity)
2
Peak E Pressure Gradient (E PG)
EPG = 4 * PE
2
Peak A Pressure Gradient (A PG)
APG = 4 * PA2
Peak Pressure Gradient (PGmax)
PGmax = 4 * PV2
Mean Pressure Gradient (PGmean)
PGmean = 4 * Vmax
2