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Hypertension and Correlation to Cerebrovascular Change: A Brief Overview
Published in Ayman El-Baz, Jasjit S. Suri, Cardiovascular Imaging and Image Analysis, 2018
Heba Kandil, Dawn Sosnin, Ali Mahmoud, Ahmed Shalaby, Ahmed Soliman, Adel Elmaghraby, Jasjit S. Suri, Guruprasad Giridharan, Ayman El-Baz
Contrast enhanced ultrasound (CEUS) uses microbubble-based contrast agents, and current technology offers a sensitivity that can identify a single bubble [80]. Injected microbubbles improve the echogenicity of blood. This technique captures the vascular lumen (vessel interior) and vascular wall, which improves vascular related diagnostics in the brain as well as other organs. Continuing research includes targeted microbubbles with use of ligands [81]. Currently, this technology offers visibility in parenchymal microcirculation, which allows characterization of lesions, and research has included its use in left ventricular pressure quantification [82]. Some imaging modalities, such as CE-MRA, can be used to measure shear stress against the inner vessel walls. Low shear stress increases the risk for development of atherosclerotic plaques. In the future, measurement of this cerebrovascular condition may also be researched as a correlating marker (esp. in conjunction with measurements of tortuosity) in the risk for developing hypertension or vascular dementia.
Novel computer aided diagnostic system using hybrid neural network for early detection of pancreatic cancer
Published in Automatika, 2023
Normal abdominal ultra sonography is used to detect pancreatic masses, and contrast enhanced ultrasound (CEUS) in addition to contrast enhanced computer tomography (CECT) are used to diagnose and evaluate patients who visit a tertiary referral centre. Using a transab dominal and an endoscopic technique, contrast enhanced ultrasound (CEUS) demonstrated good efficiency for diagnosis and characterization of strong pancreatic lesions. Zanaty and Ghoniemy [22](2016) planned an innovative technique designed for automated threshold used for segmenting MRI images if images by means of low contrast have an opportunity of bringing up the rear information in boundaries to address the difficulty of losing information in boundaries. For datasets of grey matter or white matter MRI, the homogeneity criteria and likelihood are determined for each pixel to get more accurate segmentation [12].
Ultrasound-triggered imaging and drug delivery using microbubble-self-aggregate complexes
Published in Journal of Biomaterials Science, Polymer Edition, 2022
In Jae Chung, Hyungwon Moon, Seong Ik Jeon, Hak Jong Lee, Cheol-Hee Ahn
The ultrasound image of GC@MBs was obtained with various ultrasound intensities to investigate whether GC@MBs were capable of producing signals based on the ultrasound-induced resonance and cavitation effect. It was reported that the resonance frequencies for the oscillation of lipid-based MBs with sizes 1–5 μm are approximately 1–5 MHz [34], and hence, the echogenicity and cavitation effect of GC@MBs were evaluated at 3 MHz under the contrast-enhanced ultrasound (CEUS) mode. In the ultrasound imaging (mechanical index = 0.08), GC@MBs and free MBs were stably visualized and there was no significant difference between them. As shown in Figure 5, signals of both MBs were gradually reduced with the irradiation of intense ultrasonic waves in the manual flash mode (mechanical index = 0.68) because the high-energy ultrasound induced the collapse of MBs. When the manual flash was applied five times, the echogenicity of the GC@MBs and the free MBs were decreased to 59.2% and 35.9%, respectively (Figure 5(b)). As the number of irradiation times increased, however, GC@MBs and free MBs showed similar tendencies on the decrease of their echogenicity. The changes in the cavitation effect depending on the conjugation of GC-SAs on the MB shell were considered to be negligible. In addition, it was found that GC@MBs were applicable not only for diagnosis but also for inducing the cavitation effect even with conventional ultrasonic diagnostic devices, as they collapsed under the same ultrasonic conditions as free MBs.
A systematic review of diagnostic techniques to determine tissue perfusion in patients with peripheral arterial disease
Published in Expert Review of Medical Devices, 2019
Kirsten F. Ma, Simone F. Kleiss, Richte C.L. Schuurmann, Reinoud P.H. Bokkers, Çagdas Ünlü, Jean-Paul P.M. De Vries
It is also important to consider the different technical working mechanisms of the diagnostic techniques described in this systematic review. Most of these techniques measure the blood flow or blood circulation in a specific region of interest in tissue. Examples are contrast-enhanced ultrasound, MRI perfusion, laser Doppler perfusion monitoring, LSCI, NIR fluorescence imaging with ICG, and spectrophotometry. For the measurement of tissue composition or the concentration of oxyhemoglobin and deoxyhemoglobin NIRS, hyperspectral imaging, VOTI, or TcPo2 measurements should be used. Local skin temperature is a result of various physiological factors, such as blood flow, blood circulation, tissue composition and oxygen saturation, and may therefore also indicate tissue perfusion. However, this review was limited to techniques that are indicative for one of these physiological factors. Thermal imaging, which can be measured with various techniques, including microwave radiometry thermometry [58] or infrared thermography [59] is therefore not included in this systematic review.