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Clinical Perspective on Dual Energy Computed Tomography
Published in Katsuyuki Taguchi, Ira Blevis, Krzysztof Iniewski, Spectral, Photon Counting Computed Tomography, 2020
Charis McNabney, Shamir Rai, Darra T. Murphy
In addition to determining renal stone size and location, DECT has recently been used to establish calculi composition of critical importance and influence for patient management. Uric acid calculi are treated medically whereas non-uric acid calculi (calcium, struvite, and cystine) tend to necessitate invasive approaches such as extracorporeal shockwave lithotripsy or percutaneous nephrolithotripsy (Kulkarni et al. 2013). The majority of renal stones contain two or more materials. DECT affords the ability for accurate quantification of uric acid and non-uric acid composition (Figure 3.2) to ensure proper management (Leng et al. 2016). DECT can also offer stone detection in nephrographic phase imaging and in contrast-filled collecting systems by the use of iodine subtraction techniques. This is not possible with SECT as contrast is likely to mask visualization of calculi; a further non-contrast study would be required to visualize calculi (Heye et al. 2012).
“Simple” Metrology and Microstructure Quantification
Published in Stuart R. Stock, MicroComputed Tomography, 2019
Several examples of pathological calcification have already been presented. Figure 4.6 shows a synchrotron and matched lab microCT slice of a mouse model of osteoarthritis; the highly porous bone on the right side resulted from the treatment. Calcifications as part of juvenile dermatomyositis have been studied (Stock, Ignatiev et al. 2004a, Stock, Rajamannan et al. 2004). Kidney stones have also been the subject of studies, both their microstructure and their location within the kidney (Stock, Rajamannan et al. 2004). Williams and coworkers studied calcium oxalate/apatite calculi attached to renal papilla (Williams Jr., Matlaga et al. 2006). Figure 6.14 shows a semitransparent 3D rendering of a human heart valve that became heavily calcified (Rajamannan, Nealis et al. 2005). Quantitative comparisons based on lab microCT data have shown statistically significant differences in the volume of calcification between control and disease-affected heart valves (Rajamannan, Subramanium et al. 2005). Other microCT studies of calcification gone wrong abound.
Simple Metrology and Microstructure Quantification
Published in Stuart R. Stock, MicroComputed Tomography, 2018
Several examples of pathological calcification have already been presented. Figure 4.6 shows a synchrotron and matched lab microCT slice of a mouse model of osteoarthritis; the highly porous bone on the right side resulted from the treatment. Calcifications as part of juvenile dermatomyositis have been studied (Stock et al., 2004b, 2004c). Kidney stones have also been the subject of studies, both their microstructure and their location within the kidney (Stock et al., 2004c). Williams and coworkers studied calcium oxalate/apatite calculi attached to renal papilla (Williams et al., 2006). Figure 6.14 shows a semitransparent 3D rendering of a human heart valve that became heavily calcified (Rajamannan et al., 2005a). Quantitative comparisons based on lab microCT data have shown statistically significant differences in the volume of calcification between control and disease-affected heart valves (Rajamannan et al., 2005b). Other microCT studies of calcification gone wrong abound.
Surface modification of ureteral stents: development history, classification, function, and future developments
Published in Expert Review of Medical Devices, 2023
Kaiguo Xia, Xudong Shen, Xiaojie Ang, Bingbing Hou, Yang Chen, Kaiping Zhang, Zongyao Hao
In recent years, the incidence of urinary tract diseases has been increasing, and ureteral stents are widely used in the surgical treatment of various diseases of the urinary system, such as urinary calculi, hydronephrosis, and obstruction at the ureteropelvic junction [1,2–6]. Stents are typically used to place preoperatively to aid intraoperative identification of the ureter, to assist in the treatment of upper urinary stones, to promote the discharge of residual stones, to support the ureter and drain the urinary tract, to relieve malignant or benign obstruction, to deal with ureteral stricture, to treat urine leakage, to promote the healing of the ureter, and to prevent postoperative complications [7–12]. However, many stent-related adverse effects such as renal colic, hematuria, urinary tract infection, biofilm formation, and stent encrustation also occur in the clinical application of ureteral stents (Figure 1) [13–15]. Among these, the most common complications were stent-related urinary tract infection and stent encrustation [16,17]. New research methods and ideas have been attempted to solve these problems. Some scholars propose to improve the material of ureteral stents, and put forward the concept of degradable ureteral stents; some scholars believe that drug coatings can be added to the surface of ureteral stents to further improve stent infection and encrustation-related problems.
Synthesize and characterization of CaOx crystals against various citrus waste peel extracts: an in vitro study
Published in Preparative Biochemistry & Biotechnology, 2023
V. Priscilla Pushparani, G. Baskar
Morphological properties of the synthesized crystals were observed under a light microscope for its regular shape. The sample synthesized was set to disperse clearly in 100×. FTIR study is used to analyze the CaOx crystals with the presence of phases of hydroxyl and carbon apatite, the characterization and the determination of the chemical composition were made by the FTIR on synthesized crystals. In the FTIR study of urinary calculi, the vibrational frequencies of Calcium oxalate monohydrate, dihydrate, uric acid, and struvite were studied. In the present study, a conventional FTIR spectral study was used without any further instrumental and software modifications to analyze the urinary calculi. The characteristic functional groups present in the synthesized crystals were analyzed using FTIR spectroscopy. It was characterized using a spectrum FT-IR (Perklin-Elmer) by mixing crystal powder with dried potassium bromide (proportion of 0.5–2%) and pressed at 10 ft/cm2. The spectral region investigation was from 4000 to 400 cm−1.[27]
Prospects for the research and application of biodegradable ureteral stents: from bench to bedside
Published in Journal of Biomaterials Science, Polymer Edition, 2018
Lin Wang, Ganggang Yang, Hua Xie, Fang Chen
Since the first introduction of the modern-day double-J ureteral stent in 1978 by Finney et al. [1], ureteral stenting has become one of the most commonly used procedures in urological practice. Currently, double-J ureteral stents are widely used in the surgical treatment of various diseases in the urinary system, such as upper urinary tract calculi, ureteropelvic junction obstruction, hydronephrosis [2–4]. It plays significant roles of ureter supporting and urine drainage, thus promoting ureteral healing, managing urinary leak, discharging residual stones and preventing occurrence of postoperative complications [5–7]. However, ureteral stent also causes many problems during clinical application, for example, biofilm formation, encrustation, lower urinary tract symptoms, and hematuria, etc [8–12]. Especially, biofilm and encrustation are prone to cause bacterial reproduction, and cause urinary tract infections, which often have strong resistance to routine antibiotics [13]. In addition, the forgotten long-time dwelling stent is also a serious complication that should not be ignored [14, 15]. As the currently used ureteral stents are all made of permanent materials, they require a second procedure for removal, which causes pain and discomfort in many patients. For children, general anesthesia is even necessary. Alternatively, biodegradable stents eliminate the need of a secondary procedure for their removal and hence, decrease patient pain, risk of complications, and health care cost.