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ABSTRACT: The carotid intima-media thickness (IMT) is a validated marker of cerebrovascular disease risk. This work presents a new parameter, the IMT variability (IMTV), and compares the IMT and IMTV in symptomatic and asymptomatic Italian patients. 142 patients were analyzed (age 59±11.2 years, 59% males), 42 of which suffered from TIA (transient ischemic attack) or minor stroke. The lumen-intima (LI) and media-adventitia (MA) interfaces were manually traced by a Reader, and automatically traced by an automated system (AutoEdge). These interfaces were then used to measure the IMT and IMTV along the carotid wall. Wilcoxon and Pearson correlation analyses were performed. There was about a 65% correlation between the manual and automated measurements of IMT. There was no statistical difference between the manual and automated IMTV measurements (Wilcoxon signed rank, p>0.7). The observed mean IMT for symptomatic patients (0.83±0.44 mm for Reader vs. 0.82±0.35 mm for AutoEdge) was higher compared to asymptomatic patients (0.78±0.45 mm for Reader vs. 0.74±0.30 mm for AutoEdge). The symptomatic IMTV was about 11% higher than the asymptomatic IMTV when using Reader tracings and 8% higher when using AutoEdge. AutoEdge was very accurate in measuring the IMT and IMTV both for symptomatic and asymptomatic patients. Results showed that the symptomatic subjects had comparable IMT with respect to asymptomatic subjects, but a higher IMTV value.
Conference proceedings: ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference 08/2012; 2012:2668-71.
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ABSTRACT: The carotid intima-media thickness (IMT) is a validated marker of cerebrovascular disease risk. This paper presents a new parameter, the IMT variability (IMTV), and compares it between symptomatic and asymptomatic patients taken from a cohort of Italian population. One hundred forty-two patients were analyzed (age 59 ± 112 years, 59% males), 42 of these patients suffered from TIA or minor stroke. The lumen-intima (LI) and media-adventitia (MA) interfaces of the far wall were manually traced by a Reader. We also used a computer-based automated system (called AutoEdge) to obtain the LI/MA interfaces. The LI/MA interfaces were used to measure the IMT and the IMTV along the distal wall of the common carotid artery. Wilcoxon and Pearson correlation analyses were performed. The agreement between the Reader's IMT and the AutoEdge IMT values was 98.7% for the symptomatic (0.83 ± 0.44 mm for Reader, 0.82 ± 0.35 mm for AutoEdge) and 94.9% for the asymptomatic patients (0.78 ± 0.45 mm for Reader, 0.74 ± 0.30 mm for AutoEdge). Correlation was 65% for symptomatic and 68% for asymptomatic patients, respectively. The IMT measured using AutoEdge was 1.2% lower compared to manual measurements in symptomatic population, while 5.12% lower in asymptomatic. The IMTV was 11% higher in symptomatic patients compared to asymptomatic when using manual delineations, 8% higher when using AutoEdge. There was no statistical difference between the manual and automated IMTV measurements (Wilcoxon signed rank, P > 0.7). We conclude that the IMT and IMTV values were very similar between Reader and AutoEdge software when studying symptomatic and asymptomatic patients in Italian population.
Echocardiography 07/2012; 29(9):1111-1119. · 1.24 Impact Factor
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Filippo Molinari,
Kristen M Meiburger,
Luca Saba,
U Rajendra Acharya, Giuseppe Ledda,
Guang Zeng,
Sin Yee Stella Ho,
Anil T Ahuja,
Suzanne C Ho,
Andrew Nicolaides,
Jasjit S Suri
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ABSTRACT: Automated and high performance carotid intima-media thickness (IMT) measurement is gaining increasing importance in clinical practice to assess the cardiovascular risk of patients. In this paper, we compare four fully automated IMT measurement techniques (CALEX, CAMES, CARES and CAUDLES) and one semi-automated technique (FOAM). We present our experience using these algorithms, whose lumen-intima and media-adventitia border estimation use different methods that can be: (a) edge-based; (b) training-based; (c) feature-based; or (d) directional Edge-Flow based. Our database (DB) consisted of 665 images that represented a multi-ethnic group and was acquired using four OEM scanners. The performance evaluation protocol adopted error measures, reproducibility measures, and Figure of Merit (FoM). FOAM showed the best performance, with an IMT bias equal to 0.025±0.225mm, and a FoM equal to 96.6%. Among the four automated methods, CARES showed the best results with a bias of 0.032±0.279mm, and a FoM to 95.6%, which was statistically comparable to that of FOAM performance in terms of accuracy and reproducibility. This is the first time that completely automated and user-driven techniques have been compared on a multi-ethnic dataset, acquired using multiple original equipment manufacturer (OEM) machines with different gain settings, representing normal and pathologic cases.
Computer methods and programs in biomedicine 05/2012; · 1.14 Impact Factor
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ABSTRACT: INTRODUCTION: The purpose of this study was to evaluate the potentialities of a semi-automated technique in the detection and measurement of the carotid artery plaque. METHODS: Twenty-two consecutive patients (18 males, 4 females; mean age 62 years) examined with MDCTA from January 2011 to March 2011 were included in this retrospective study. Carotid arteries are examined with a 16-multi-detector-row CT system, and for each patient, the most diseased carotid was selected. In the first phase, the carotid plaque was identified and one experienced radiologist manually traced the inner and outer boundaries by using polyline and radial distance method (PDM and RDM, respectively). In the second phase, the carotid inner and outer boundaries were traced with an automated algorithm: level-set-method (LSM). Data were compared by using Pearson rho correlation, Bland-Altman, and regression. RESULTS: A total of 715 slices were analyzed. The mean thickness of the plaque using the reference PDM was 1.86 mm whereas using the LSM-PDM was 1.96 mm; using the reference RDM was 2.06 mm whereas using the LSM-RDM was 2.03 mm. The correlation values between the references, the LSM, the PDM and the RDM were 0.8428, 0.9921, 0.745 and 0.6425. Bland-Altman demonstrated a very good agreement in particular with the RDM method. CONCLUSION: Results of our study indicate that LSM method can automatically measure the thickness of the plaque and that the best results are obtained with the RDM. Our results suggest that advanced computer-based algorithms can identify and trace the plaque boundaries like an experienced human reader.
Neuroradiology 05/2012; · 2.82 Impact Factor
