Premium
Comparison of grey scale median ( GSM ) measurement in ultrasound images of human carotid plaques using two different softwares
Author(s) -
Östling Gerd,
Persson Margaretha,
Hedblad Bo,
Gonçalves Isabel
Publication year - 2013
Publication title -
clinical physiology and functional imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.608
H-Index - 67
eISSN - 1475-097X
pISSN - 1475-0961
DOI - 10.1111/cpf.12049
Subject(s) - medicine , gsm , ultrasound , quartile , correlation coefficient , nuclear medicine , kappa , radiology , statistics , confidence interval , mathematics , telecommunications , computer science , geometry
Summary Grey scale median ( GSM ) measured on ultrasound images of carotid plaques has been used for several years now in research to find the vulnerable plaque. Centres have used different software and also different methods for GSM measurement. This has resulted in a wide range of GSM values and cut‐off values for the detection of the vulnerable plaque. The aim of this study was to compare the values obtained with two different softwares, using different standardization methods, for the measurement of GSM on ultrasound images of carotid human plaques. GSM was measured with A dobe P hotoshop ® and with A rtery M easurement S ystem ( AMS ) on duplex ultrasound images of 100 consecutive medium‐ to large‐sized carotid plaques of the B eta‐blocker C holesterol‐lowering A symptomatic P laque S tudy ( BCAPS ). The mean values of GSM were 35·2 ± 19·3 and 55·8 ± 22·5 for A dobe P hotoshop ® and AMS , respectively. Mean difference was 20·45 (95% CI : 19·17–21·73). Although the absolute values of GSM differed, the agreement between the two measurements was good, correlation coefficient 0·95. A chi‐square test revealed a kappa value of 0·68 when studying quartiles of GSM . The intra‐observer variability was 1·9% for AMS and 2·5% for A dobe P hotoshop. The difference between softwares and standardization methods must be taken into consideration when comparing studies. To avoid these problems, researcher should come to a consensus regarding software and standardization method for GSM measurement on ultrasound images of plaque in the arteries.