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Rationalizing of Morphological Renal Parameters and eGFR for Chronic Kidney Disease Detection
Published in J. Dinesh Peter, Steven Lawrence Fernandes, Carlos Eduardo Thomaz, Advances in Computerized Analysis in Clinical and Medical Imaging, 2019
Deepthy Mary Alex, D. Abraham Chandy, Anand Paul
Echogenicity can be defined as the amount of sound that is being reflected back to the probe; it is dependent on the amplitude of incident sound, how much of the sound is absorbed, how much is reflected and the angle of reflection. Evaluation of only cortical echogenicity can be done and qualitatively it should be less than the liver or spleen. Corticomedullary differentiation is the ability to differentiate the cortex and medullae but in some cases it is difficult to view the medullae, hence difficult to differentiate from ultrasound images even in healthy adults. It is to be noted that the prominence of the medullae is usually abnormal, generally indicating increased echogenicity of the cortex. Total kidney volume is calculated using the ellipsoidal formula. In the longitudinal scan of the kidney, the two poles, that is, the superior and inferior poles are identified. The renal length (L) is determined as the longest distance between the two poles. The thickness or the anteroposterior diameter (AP) is also determined in the longitudinal scan. AP is marked as the maximum distance between the anterior and posterior walls at the mid-third of the kidney. For calculating the renal width (W), transverse scan is considered. W is the maximum transverse diameter and it was taken at the hilium. Centimeter (cm) is taken as the unit of measurement. Total volume can be determined using the following equation (Kim et al. 2008):
Role of Photoacoustic and Ultrasound Imaging in Photothermal Therapy
Published in Lihong V. Wang, Photoacoustic Imaging and Spectroscopy, 2017
Shah Jignesh, Suhyun Park, Salavat Aglyamov, Stanislav Emelianov
The ultrasound images of the tissue sample injected with gold nanoparticles 10 mm away from the left-side surface of the tissue, recorded before (Figure 39.8a) and after (Figure 39.8b) laser irradiation of tissue, demonstrate the spatial location and extent of thermal lesion created during photothermal therapy. Therapy was performed for 3 min using laser irradiation at 3 W/cm2. The thermal map (Figure 39.8c) at the end of therapy shows temperature increased by over 25°C in the therapeutic zone. After the therapy, there was an increase in echogenicity at the thermally damaged tissue and corresponding shadowing effect below the hypoechoic region (Figure 39.8b). Thus, the progression of tumor necrosis was monitored by evaluating the change in echogenicity at the tumor site in the ultrasound frames captured during therapy. Analysis of thermal and ultrasound images revealed a rounded lesion located at 10 mm distance from the tissue surface. Furthermore, visual inspection of the sample (Figure 39.8d) confirmed the position and extent of the thermal lesion.
Introduction to medical imaging
Published in David A Lisle, Imaging for Students, 2012
Solid organs, fluid-filled structures and tissue interfaces produce varying degrees of sound wave reflection and are said to be of different echogenicity. Tissues that are hyperechoic reflect more sound than tissues that are hypoechoic. In an US image, hyperechoic tissues are shown as white or light grey and hypoechoic tissues are seen as dark grey (Fig. 1.10). Pure fluid is anechoic (reflects virtually no sound) and is black on US images. Furthermore, because virtually all sound is transmitted through a fluid-containing area, tissues distally receive more sound waves and hence appear lighter. This effect is known as ‘acoustic enhancement’ and is seen in tissues distal to the gallbladder, the urinary bladder and simple cysts. The reverse effect, known as ‘acoustic shadowing’, occurs with gas-containing bowel, gallstones, renal stones and breast malignancy.
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.
Numerical modelling and theoretical analysis of the acoustic attenuation in bubbly liquids
Published in Engineering Applications of Computational Fluid Mechanics, 2023
Yanghui Ye, Mengda Song, Yangyang Liang, Sheng Li, Cong Dong, Zhongming Bu, Guilin Hu
The measurements of α can be used to obtain the shell parameters of UCAs. UCAs are around resonances under the most common frequencies of medical ultrasound (1-7 MHz) (Gorce et al., 2000), thus their dynamics are greatly dependent on R0. For small-amplitude oscillations, RP type equations can be simplified to linear equations of motion, based on which αtheo can be obtained. Gorce et al. (2000) divided UCAs into groups and theoretically analysed the influence of R0 on echogenicity and attenuation based on the simplification of linear oscillation. Segers et al. (2016) measured the scattering and attenuation of sorted UCAs at higher driving pressure, and calculated αtheo by solving the RP type equation to capture the nonlinear behaviours. At medium β, the dependences of α and V on β need to be considered. Silberman (1957) conducted experimental measurements of α and V in a standing wave tube at β above 0.03%. Wijngaarden (1972) proposed a continuum approach to model the wave propagation in bubbly liquids. Commander and Prosperetti (1989) developed a linear model to predict α and V at small driving pressure and medium β, and good agreements were obtained with the experiments by Silberman (1957) et al. Leroy et al. (2009) experimentally measured the transmission coefficients of ultrasound through a single layer of bubbles and found that the resonant frequency increased with the bubble concentration, which was contrary to the conclusion of traditional theoretical analyzes (Ida et al., 2007; Yasui et al., 2008; Yasui et al., 2009).
Overview of the application of inorganic nanomaterials in breast cancer diagnosis
Published in Inorganic and Nano-Metal Chemistry, 2022
Asghar Ashrafi Hafez, Ahmad Salimi, Zhaleh Jamali, Mohammad Shabani, Hiva Sheikhghaderi
Ultrasound or sonography is a diagnostic imaging technique, or therapeutic application of ultrasound. It is used to create an image of internal body structures such as blood vessels, internal organs, muscles, tendons and joints.[44] Sonography is a diagnostic imaging method that is used for ultrasound source to recognize the origins of the disease within internal organs or structures. Correspondingly, sound waves frequencies in ultrasound are safe and higher than those audible to humans.[45] Therefore, the pulses of the sound wave were sent into the tissue by probe and the sound echoes off the tissue product ultrasonic images. The production of an image from the sound wave is done in three steps – producing a sound wave, receiving echoes, and interpreting those echoes.[45] In addition, ultrasonic mode includes A-mode,[46] B-mode,[47] C-mode,[48] M-mode,[49] pulse inversion mode,[50] Doppler mode[51] and harmonic mode.[52] Further, using the contrast agent with US technique led to the increase of echogenicity in the technique which this development was known as the contrast-enhanced ultrasound.[52] In detail this method was carried out by microbubbles-based contrast agent intravenously in the patient blood steam during the Sonography.[53] Namely, a typical clinical of the contrast-enhanced ultrasound is to detect of hyper-vascular metastatic tumor from the healthy tissue surrounding the tumor. In this case the contrast agent accumulated into metastatic tumor more than the healthy tissue.[54,55] Likewise, other applications of the contrast-enhanced ultrasound are in molecular imaging particularly to detect malignant cancers such as malignant breast and prostate cancer.[56,57] To emphasize the comparison with other methods in molecular imaging US low portable cast, it does not use harmful material or hazardous radiation. Conversely, some disadvantages of the mentioned method involve difficulty imaging structures behind bone and its dependence on a skilled operator.[8]