OBJECTIVE To prospectively determine if tortuosity assessment by a computer program (ROPtool) that traces retinal blood vessels and measures their tortuosity was more accurate than that of individual pediatric ophthalmologists. METHODS One hundred eighty-five high-quality RetCam images from premature infants were circulated to 3 retinopathy of prematurity (ROP) experts and 3 other pediatric o...

BACKGROUND Tortuous blood vessels are commonly seen in the cerebral arteries. The association between vertebrobasilar artery tortuosity and vascular vertigo remains obscure. CASE PRESENTATION We describe two patients with vascular vertigo who had bilateral curving and spiral looping in multiple segments of the vertebral arteries and also exhibited basilar artery tortuosity. Both patients had ...

PURPOSE The present study aimed to identify the types of curved lesions that are difficult to place Carotid Wallstent (CWS). MATERIALS AND METHODS The study targeted 31 consecutive carotid artery (CA) stenosis underwent carotid artery stenting using CWS. CWS placement success rate, stenosis location, lesion tortuosity, and relationship with stent placement failures were investigated. Lesion t...

Atherosclerosis in the superficial femoral artery (SFA) resulting in peripheral arterial disease is more common in men than women and shows a predilection for the region of the adductor canal. Blood flow patterns are related to development of atherosclerosis, and we investigated if curvature and tortuosity of the femoral artery differed between young men and women and if differences resulted in...

The clinical recognition of abnormal vascular tortuosity is important in the diagnosis of many diseases. Metrics based on three-dimensional (3D) curvature, using approximating polynomial spline-fitting to "data balls" centered along the mid-line of the vessel, minimize digitization errors and give tortuosity values largely independent of the resolution of the imaging system. We applied two of t...

OBJECTIVES Arterial tortuosity is a frequent manifestation of vascular disease and collateral vessel growth, but its causes are poorly understood. This study was designed to assess the relationship between the development of tortuosity and the mechanical forces that are imposed on arterial tissue. METHODS AND RESULTS Axial strain in rabbit carotid arteries was reduced from 62+/-2% to 33+/-2% ...

The clinical recognition of abnormal vascular tortuosity is important in the diagnosis of many diseases. This paper presents a novel approach to the quantification of vascular tortuosity, using robust metrics based on unit speed parameterizations of three-dimensional (3D) curvature. The use of approximating polynomial spline-fitting obviates the need for arbitrary filtering of mid-line data whi...

The goal of this work is to produce nanocomposite film with low oxygen permeability by casting an aqueous solution containing xylan, sorbitol and nanocrystalline cellulose. The morphology of the resulting nanocomposite films was examined by scanning electron microscopy and atomic force microscopy which showed that control films containing xylan and sorbitol had a more open structure as compared...

Abstract The paper describes the so-called Waterfall Algorithm, which may be used to calculate a set of parameters characterising spatial structure granular porous media, such as shift ratio, collision density consolidation path length and minimum tortuosity. study is performed for 1800 different two-dimensional random pore structures. In each geometry, 100 individual paths are calculated. impa...

Abstract Many different definitions of tortuosity can be found in literature. In addition, also many methodologies are nowadays available to measure or calculate tortuosity. This leads confusion and misunderstanding scientific discussions the topic. this chapter, a thorough review all relevant types is presented. Thereby, underlying concepts, associated theories discussed detail for each type s...