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Our Radiation Environment
Published in T. D. Luckey, Radiation Hormesis, 2020
Of special concern are embryos during organogenesis and patients with repeated exposures, such as computed tomography and fluoroscopic movies.87,272,344,423 Somatic and genetic risks from computed tomography become real.272 Fluoroscopy diagnosis requires over 1000 X-rays for the movies used to study blood vessels or the alimentary tract. Dose rates were 2 to 5 cGy/m for a total of 2 to 9 cGy. These have been decreased with digital subtraction angiography (DSA); DSA requires hundreds of X-rays, particularly if more than one view is taken simultaneously.847 Single photon emission computed tomography (SPECT) involves digital computer processing of photographs made with commercially available radionuclides. The great sensitivity of computed data greatly reduces patient risk.
Imaging of Thrombosis
Published in Hau C. Kwaan, Meyer M. Samama, Clinical Thrombosis, 2019
Albert A. Nemcek, Robert L. Vogelzang
Digital subtraction angiography (DSA) refers to a variety of digital computer-based techniques used to achieve visualization of contrast-filled blood vessels. In this technique, the fluoroscopic image of a region of interest is obtained prior to the injection of contrast and stored in computer memory in a digital form. Subsequent images are obtained following contrast opacification of vessels in the region of interest. The information from the first noncontrast images is electronically subtracted from the contrast-filled images and, in the ideal situation, the resultant image consists only of contrast-filled vessels without overlap of other anatomic structures. Sophisticated manipulation of the data can be performed to improve the chances for realization of this ideal. Detailed discussions of physics and technical considerations for DSA, inlcuding more sophisticated methods of subtraction, are given elsewhere.120–125
Vessel Wall Imaging
Published in George C. Kagadis, Nancy L. Ford, Dimitrios N. Karnabatidis, George K. Loudos, Handbook of Small Animal Imaging, 2018
Intra-arterial digital subtraction angiography (DSA) is performed through the acquisition of images before and after the intra-arterial injection of an extracellular contrast agent. Although DSA is the “gold standard” imaging modality for the evaluation of small animal vessel lumen stenosis, only limited information on the vessel wall morphology and pathology, such as the presence of vessel wall dissection or rupture and calcifications, could be demonstrated (Badea et al. 2008). DSA enables the distinction between non-flow-limiting and flow-limiting dissections because of its realtime flow-evaluation capability. Such flow-based characterizations are not accurate using conventional contrast-enhanced micro-CT.
Hepatic arterial infusion chemotherapy and sequential ablation treatment in large hepatocellular carcinoma
Published in International Journal of Hyperthermia, 2022
Huimin You, Xingyi Liu, Jiandong Guo, Yinsheng Lin, Yan Zhang, Chengzhi Li
HAIC procedure has been described in the previous report [17]. The catheter was inserted into the femoral artery using the Seldinger technique and advanced into the celiac artery. A micro-catheter was inserted and located in the feeding hepatic artery. All procedures were performed using digital subtraction angiography (Philips, type FD 20 1250 mA, Amsterdam, the Netherlands). The artery sheath catheter was inserted into the femoral artery using the modified Seldinger technique. A 5-Fr Yashiro catheter (Terumo, Tokyo, Japan) was advanced into the celiac trunk and superior mesenteric artery to assess the feeding hepatic artery. 2.7-Fr micro-catheter (Terumo, Tokyo, Japan) was inserted in the feeding artery. The chemo-drugs were given by hepatic arterial infusion through the micro-catheter. A modified FOLFOX6 regimen, including oxaliplatin (130 mg/m2 infusion for 3 h on day 1), leucovorin (200 mg/m2 for 3–5 h on day 1) and Fluorouracil (400 mg/m2 in bolus, and then 2,400 mg/m2 continuous infusion 46 h) was applied. Treatment was repeated every 21 days and commonly 4–6 cycles unless intrahepatic lesions progressed or toxicity became unacceptable.
MRI-guided endovascular intervention: current methods and future potential
Published in Expert Review of Medical Devices, 2022
Bridget F. Kilbride, Kazim H. Narsinh, Caroline D. Jordan, Kerstin Mueller, Teri Moore, Alastair J. Martin, Mark W. Wilson, Steven W. Hetts
MRI has been adopted over other modalities for diagnosis and management of multiple oncologic diseases because of superior soft tissue contrast and the ability to obtain multiparametric tissue characterization. Recent research has found value in MRI during osmotic blood–brain barrier opening (OBBBO) to increase treatment efficacy of intra-arterial therapies for primary and metastatic disease in the brain. The current gold standard for such procedures is x-ray digital subtraction angiography (DSA), though it has yet to gain popularity despite being introduced over 4 decades ago [140]. Primary reasons behind the lack of traction could be outcome variability and a lack of real-time validation of blood–brain barrier permeability. Initial studies have shown that dynamic contrast susceptibility (DSC) MRI defines catheter perfusion territory and contrast-enhanced images delineated OBBBO territory [140]. A first-in-human study by Zawadzki et al. demonstrated safety and feasibility of real-time MRI guidance for intra-arterial therapy delivery following OBBBO [141,142]. Authors emphasized that superselective IA delivery of therapy, in conjunction with real-time MRI guidance and validation, decreased volume of the enhancing mass, rapidly improved neurological status, and potentially improved survival in a rapidly declining patient with glioblastoma [141].
Three-Dimensional in Vivo Anatomical Study of Female Iliac Vein Variations
Published in Journal of Investigative Surgery, 2022
Wenling Zhang, Chunlin Chen, Guidong Su, Hui Duan, Zhiqiang Li, Ping Shen, Jiaxin Fu, Ping Liu
The traditional vascular research method is vascular casting; however, the number of cadaveric specimens is limited, and the vascular anatomical parameters of cadavers and living humans are different. In recent years, digital subtraction angiography, CTA and magnetic resonance imaging angiography have rapidly developed, and among them, CTA is relatively noninvasive and has a short scanning time. In this study, using a large sample size and classification simplification, CTA 3 D reconstruction was used to determine the variation in blood vessels in the surgical area of patients before surgery to improve the surgical accuracy and ensure surgical safety. However, there are still limitations. First, this study was a retrospective study, and the variation was not combined with the clinical operation; thus, there was no intraoperative comparison, and the risk coefficient of which variation type was higher was not verified. Although intraoperative anatomy can provide the most accurate data under the physiological conditions of the human body, to better expose the variation in target blood vessels, the risk of unintentional injury to other surrounding blood vessels may increase due to the limitation of the spatial structure. The number and location of the inferior vena cava in this study were normal, and an abnormal iliac vein caused by variation in the left inferior vena cava and double inferior vena cava was not discussed in the present study.