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Automated Methods for Vessel Segmentation in X-ray Coronary Angiography and Geometric Modeling of Coronary Angiographic Image Sequences: A Survey
Published in Kayvan Najarian, Delaram Kahrobaei, Enrique Domínguez, Reza Soroushmehr, Artificial Intelligence in Healthcare and Medicine, 2022
Zijun Gao, Kritika Iyer, Lu Wang, Jonathan Gryak, C. Alberto Figueroa, Kayvan Najarian, Brahmajee K. Nallamothu, Reza Soroushmehr
Robust Principal Component Analysis (PCA) approaches have also been used for layer separation to aid angiographic coronary segmentation. Ma et al. (2017) proposed an automatic online layer separation approach that robustly separates interventional X-ray angiograms into three layers: a breathing layer, a quasi-static layer, and a vessel layer that contains information of coronary arteries and medical instruments. The method used morphological closing and an online robust PCA algorithm to separate the three layers. The potential of the proposed approach was demonstrated by enhancing the contrast of vessels in X-ray images with low vessel contrast, which would facilitate the use of a reduced amount of contrast agent to prevent contrast-induced side effects such as itching and contrast-induced nephropathy. Qin et al. (2019) proposed a similar method using robust PCA known as VRBC-t-TNN (vessel region background completion with twist tensor nuclear norm). In this approach, a logarithmic mapping was used to create an X-ray attenuation sum model. A combination of robust PCA and spatially adaptive filtering was performed on the X-ray attenuation sum model to separate the vessel structures from the background. t-TNN was used to complete the background image where the vessels had been removed, and the vessels were recovered from the original X-ray angiography image by subtracting the t-TNN completed background image.
Acute coronary syndrome in special populations
Published in K Sarat Chandra, AJ Swamy, Acute Coronary Syndromes, 2020
CKD patients are unlikely to get the usual revascularisation strategy in ACS due to fear of CI-AKI. The risk of contrast-induced nephropathy (CIN) depends on multiple factors like age, GFR, DM, HTN female gender, volume of contrast and hemodynamic instability. Adequate hydration remains the mainstay of CIN prevention. High-dose statins are also found to be beneficial in the secondary prevention (Tables 22.1 and 22.2). It is strongly recommended to keep total contrast volume GFR ration < 3.7 for better outcome [9].
Cardiovascular system
Published in A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha, Clark’s Procedures in Diagnostic Imaging: A System-Based Approach, 2020
A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha
There are two drawbacks to this technique. Firstly, if the artery is full of blood, then the OCT catheter is unable to visualise the wall of the artery as haemoglobin reflects all of the light back. This is countered by injecting contrast media (which is clear and colourless) at a high rate into the vessel at the time of acquisition. Clearly, if many imaging sequences are performed, the volume of contrast media can increase the likelihood of contrast-induced nephropathy. The second and less important drawback is that unlike IVUS, the light energy does not penetrate the walls of the artery to a significant extent. Thus, we get exquisite imaging of the three muscle layers, but no view of what lies beyond.
A risk prediction model for contrast-induced nephropathy associated with gadolinium-based contrast agents
Published in Renal Failure, 2022
Huanhuan Zheng, Guolang Wang, Qianqian Cao, Wenkai Ren, Lingyuan Xu, Shuangshan Bu
With the increasing incidence of coronary heart disease, coronary angiography and percutaneous coronary interventions have gradually improved. One study indicated that approximately 8,000,000 L of contrast agents are used worldwide every year [1]. However, with the application of contrast agents, contrast-induced nephropathy (CIN) is a growing concern. CIN is an acute renal injury after the administration of contrast agents, and it is the third most frequent cause of acute renal failure in hospitalized patients, which leads to increased medical expenses, irreversible renal injuries, prolonged hospital stays, and increased mortality [2]. The incidence of CIN varies widely in different reports. In a meta-analysis that included 29 randomized controlled trials, the incidence of CIN varied from 2% to 25% [3]. The incidence rate depends on the diagnostic criteria of CIN, the risk factors, the amount and type of contrast agent used, the type of radiographic operation, etc. For patients with preexisting renal damage or with high-risk factors such as diabetes, the incidence can even reach 50%. At present, there is no clear treatment for CIN, so preventive measures should be actively taken to avoid its occurrence, especially in high-risk patients. Therefore, CIN has become a great concern for nephrologists, cardiologists, radiologists, angiologists, and interventionalists.
Successful treatment of cholesterol crystal embolism with anti-proprotein convertase subtilisin/kexin type 9 (PCSK9) antibody: a case report
Published in Renal Failure, 2020
Junki Morino, Keiji Hirai, Shohei Kaneko, Saori Minato, Katsunori Yanai, Yuko Mutsuyoshi, Hiroki Ishii, Momoko Matsuyama, Taisuke Kitano, Mitsutoshi Shindo, Akinori Aomatsu, Haruhisa Miyazawa, Kiyonori Ito, Yuichiro Ueda, Susumu Ookawara, Yoshiyuki Morishita
CCE is a systemic disease characterized by occlusion of small arteries due to CCEs derived from aortic atheromatous plaques, affecting the skin, subcutaneous tissue, brain, eyes, kidneys, gastrointestinal system, and visceral organs [11]. It most commonly occurs iatrogenically after an intravascular procedure or cardiovascular surgery [11]. The kidneys are particularly frequent target organs for CCE, and renal involvement is observed in approximately 70% of patients exhibiting CCE [12]. Among them, 40–60% progress to end-stage renal disease [13,14]. In our case, the patient developed acute kidney injury after carotid artery stenting. Renal function started to rapidly decline 9 weeks after CT angiography, which is not compatible with the course of contrast-induced nephropathy, because serum creatinine concentration usually rises within 24 h after contrast agent administration, peaks at around 3–5 days, and returns to baseline in 7–10 days in contrast-induced nephropathy [15]. All markers of vasculitis were negative, and there was no history of taking nephrotoxic medicine (e.g., analgesics). No findings of renal artery stenosis were noted. Urinalysis showed no hematuria and mild proteinuria, which were compatible with urinary findings of CCE, because hematuria is not often observed and proteinuria is usually in the non-nephrotic range in renal disease caused by CCE [16]. Hence, renal CCE was the most probable cause of his acute renal injury, although we could not exclude the possibility of other renal disease because we did not perform a renal biopsy.
Spectral CT, Low Contrast Dose and Annular Sizing: Spotting the Ghost in the Fog
Published in Structural Heart, 2020
Jonathan R. Weir McCall, Julia Sun
There is ongoing debate about the true incidence and implications of contrast induced nephropathy, particularly in the outpatient environment with stable renal function.17 This is particularly true for newer iodinated contrast agents, even in those with CKD.18,19 Nonetheless, until safety in this vulnerable population is unequivocally demonstrated, it behooves us to minimize the potential harm of our medical procedures. In this regard the authors are to be congratulated for an effective proof of concept for the benefits that spectral CT may bring to our patients in the future. With a 67% reduction in contrast dose whilst maintaining image quality, the future looks bright for spectral imaging technology.