| 1. |
- Persson, Magnus, et al.
(författare)
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A new non-invasive ultrasonic method for simultaneous measurements of longitudinal and radial arterial wall movements: first in vivo trial.
- 2003
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Ingår i: Clin Physiol Funct Imaging. - Blackwell Publishing. - 1475-0961. ; 23:5, s. 247-251
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Tidskriftsartikel (refereegranskat)abstract
- During recent years, the radial movement of the arterial wall has been extensively studied, and measurements of the radial movement are now an important tool in cardiovascular research for characterizing the mechanical properties of the arterial wall. In contrast, the longitudinal movement of vessels has gained little or no attention as it has been presumed that this movement is negligible. With modern high-resolution ultrasound, it can, however, be seen that the intima-media complex of the arterial wall moves not only in the radial direction, but also in the longitudinal direction during pulse-wave propagation. This paper describes a new non-invasive ultrasonic method that is able to measure simultaneously two dimensionally arterial vessel wall movements. The method is demonstrated in a limited in vivo trial. Results from the in vivo trial show that, apart from the well-known radial movement, there is a distinct longitudinal movement in the human common carotid artery with, in this case, the intima-media complex moving substantially as compared with the region of the tunica adventitia. Two-dimensional evaluation of the vessel-wall movements, taking not only the radial movement, but also the longitudinal movement into account, may provide novel information of importance in the evaluation of vessel-wall function.
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| 2. |
- Persson, Magnus, et al.
(författare)
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Non-invasive measurement of arterial longitudinal movement
- 2002
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Ingår i: Proceedings of the IEEE Ultrasonics Symposium. - Institute of Electrical and Electronics Engineers Inc.. - 1051-0117. ; 2, s. 1783-1786
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Konferensbidrag (refereegranskat)abstract
- In arterial vessel wall characterisation the longitudinal movements of vessels have gained little or no attention. It has been presumed that the arterial vessels move very little in the longitudinal direction. With modern high resolution ultrasound it can, however, be seen that arterial vessels move not only in the circumferential, but also in longitudinal direction. This paper describes a non-invasive, ultrasound based method which estimates the longitudinal and the circumferential movement, respectively. The method is demonstrated in a limited in vivo study of the common carotid artery. Results show that, apart from the well known circumferential movement, there is a distinct longitudinal movement.
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| 3. |
- Cinthio, Magnus, et al.
(författare)
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Evaluation of an algorithm for arterial lumen diameter measurements by means of ultrasound.
- 2010
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Ingår i: Medical & biological engineering & computing. - 1741-0444. ; 48, s. 1133-1140
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Tidskriftsartikel (refereegranskat)abstract
- We have developed an algorithm for arterial luminal diameter measurement by means of ultrasound and evaluated the algorithm on agar vessel phantoms and in vivo. The algorithm utilises relative threshold detection on the inner slopes of the arterial walls before the resolution is improved by solving the equation of a straight line between the samples around the threshold value. Further, correction distances added to compensate for the underestimation when using the inner slopes were found to be 304 mum for the near wall and 415 mum for the far wall. The measured mean diameters of ten consecutive images of 3-, 6- and 9-mm phantoms were 3,006 mum (SD 4), 5,918 mum (SD 1) and 8,936 mum (SD 2), respectively. The mean differences between the images were 0.19, 0.04 and 0.37 mum, respectively. In vivo, the intra- and inter-observer variabilities were -64 mum (2SD 358) and -57 mum (2SD 366), respectively.
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| 4. |
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| 5. |
- Gottsäter, Anders, et al.
(författare)
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Cardiovascular autonomic neuropathy associated with carotid atherosclerosis in Type 2 diabetic patients.
- 2003
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Ingår i: Diabetic Medicine. - Blackwell Publishing. - 0742-3071. ; 20:6, s. 495-499
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Tidskriftsartikel (refereegranskat)abstract
- AimsTo clarify if cardiovascular autonomic neuropathy is associated with carotid artery atherosclerotic plaques in Type 2 diabetic patients. MethodsCardiovascular autonomic nerve function was related to carotid artery ultrasound in 61 Type 2 diabetic patients 5-6 years after diagnosis of diabetes. ResultsCardiovascular autonomic neuropathy abnormal age corrected expiration/inspiration (E/I) ratio or acceleration index (AI) was found in 13/61 (21%) patients. Patients with cardiovascular autonomic neuropathy showed increased degree of stenosis in the common carotid artery (24.6 ± 13.2% vs. 14.7 ± 9.2%; P = 0.014) and a tendency towards a higher plaque score (4.0 ± 1.7 vs. 3.2 ± 1.6; P = 0.064). Controlled for age, AI correlated inversely with degree of stenosis (r = -0.39; P = 0.005), plaque score (r = -0.39; P = 0.005), and mean (r = -0.33; P = 0.018) and maximum (r = -0.39; P = 0.004) intima-media thickness in the common carotid artery. In contrast, E/I ratio correlated only slightly with mean intima-media thickness in the common carotid artery (r = -0.28; P = 0.049). ConclusionsCardiovascular autonomic neuropathy was associated with carotid atherosclerosis in Type 2 diabetic patients. Abnormal E/I ratios reflect efferent structural damage to parasympathetic nerves whereas abnormal AI reflects afferent autonomic dysfunction possibly due to impaired baroreceptor sensitivity secondary to carotid atherosclerosis.
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