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International Journal of Computer... Oct 2019We aim to perform generation of angiograms for various vascular structures as a mean of data augmentation in learning tasks. The task is to enhance the realism of...
PURPOSE
We aim to perform generation of angiograms for various vascular structures as a mean of data augmentation in learning tasks. The task is to enhance the realism of vessels images generated from an anatomically realistic cardiorespiratory simulator to make them look like real angiographies.
METHODS
The enhancement is performed by applying the CycleGAN deep network for transferring the style of real angiograms acquired during percutaneous interventions into a data set composed of realistically simulated arteries.
RESULTS
The cycle consistency was evaluated by comparing an input simulated image with the one obtained after two cycles of image translation. An average structural similarity (SSIM) of 0.948 on our data sets has been obtained. The vessel preservation was measured by comparing segmentations of an input image and its corresponding enhanced image using Dice coefficient.
CONCLUSIONS
We proposed an application of the CycleGAN deep network for enhancing the artificial data as an alternative to classical data augmentation techniques for medical applications, particularly focused on angiogram generation. We discussed success and failure cases, explaining conditions for the realistic data augmentation which respects both the complex physiology of arteries and the various patterns and textures generated by X-ray angiography.
Topics: Angiography; Diagnostic Techniques, Cardiovascular; Humans; Image Processing, Computer-Assisted
PubMed: 31286396
DOI: 10.1007/s11548-019-02022-z -
Computerized Medical Imaging and... 1988One of the most revolutionary recent imaging advances is the use of magnetic resonance to study and produce morphologic representations of flowing blood vessels known as...
One of the most revolutionary recent imaging advances is the use of magnetic resonance to study and produce morphologic representations of flowing blood vessels known as MR angiography. The ability to produce an image of even moderate spatial resolution of the three dimensional course of blood vessels with MR could have significant advantages over conventional invasive angiography which requires ionizing radiation and contrast material injection. By definition, MR angiography does not require the addition of any intravascular contrast agents and the images are produced entirely by the effect of the radio frequency pulses and magnetic field gradients on the spinning protons. Several researchers are already producing relatively high resolution MR angiograms using a variety of techniques. Essentially all techniques of MR angiography use variations of three steps to produce the image: (1) a projection image, (2) suppression of background static material, and (3) production of a flow sensitive image. This report will survey some of the more commonly used approaches to MR angiography that are currently under investigation.
Topics: Angiography; Humans; Magnetic Resonance Imaging; Subtraction Technique
PubMed: 3052793
DOI: 10.1016/0895-6111(86)90002-9 -
European Journal of Radiology Sep 2015To evaluate the utility of a novel non-contrast enhanced, vessel-selective magnetic resonance angiography (MRA) approach based on superselective pseudo-continuous...
PURPOSE
To evaluate the utility of a novel non-contrast enhanced, vessel-selective magnetic resonance angiography (MRA) approach based on superselective pseudo-continuous arterial spin labeling (ASL) for the morphologic assessment of intracranial arteries when compared to a clinically used time-of-flight (TOF) MRA.
MATERIALS AND METHODS
Three sets of selective ASL angiographies (right and left internal carotid artery, basilar artery) as well as one TOF data set were obtained from each of the five volunteers included in this study on a clinical 1.5T system. The depiction of arterial segments as well as their delineation was evaluated and independently analyzed by two radiologists. Additionally, the ASL angiography approach was performed in two patients suffering from arterio-venous malformations (AVM) in order to illustrate potential applications in a clinical setting.
RESULTS
In both angiography techniques, intracranial arteries and their segments (distal branches up to A5 segments of the anterior cerebral arteries, M8 segments of the middle cerebral arteries, and P5 segments of the posterior cerebral arteries) were continuously depicted with excellent inter-reader agreement (κ>0.81). In AVM patients, reconstructed images of the TOF angiography presented similar information about the size and shape of the AVM as did superselective ASL angiography. In addition, the acquired ASL angiograms of selected vessels allowed assessing the blood supply of individually labeled arteries to the AVM which could also be confirmed by digital subtraction angiography.
CONCLUSION
Superselective ASL angiography makes it possible to visualize arterial trees of selected vessels, thereby, providing information about the macrovascular blood supply and flow territories of intracranial arteries. Similar image quality is achieved when compared to clinically used TOF angiography with respect to the identification and delineation of arterial segments. Initial application of superselective ASL angiography in two patients with AVM's demonstrates the ability to gather additional important information about feeding vessels and blood supply.
Topics: Adult; Aged; Angiography, Digital Subtraction; Arteriovenous Malformations; Cerebral Arteries; Female; Humans; Magnetic Resonance Angiography; Male; Observer Variation; Reproducibility of Results; Spin Labels; Young Adult
PubMed: 26113163
DOI: 10.1016/j.ejrad.2015.05.034 -
Clinical Neuroradiology Sep 2022Spinal dural arteriovenous fistulas (SDAVFs) represent the most common indication for a spinal angiography. The diagnostic reference level (DRL) for this specific...
PURPOSE
Spinal dural arteriovenous fistulas (SDAVFs) represent the most common indication for a spinal angiography. The diagnostic reference level (DRL) for this specific endovascular procedure is still to be determined. This single-center study provides detailed dosimetrics of diagnostic spinal angiography performed in patients with SDAVFs.
METHODS
Retrospective analysis of all diagnostic spinal angiographies between December 2011 and January 2021. Only patients with an SDAVF who had baseline magnetic resonance angiography (MRA), diagnostic digital subtraction angiography (DSA), treatment and follow-up at this institution were included. Dose area product (DAP, Gy cm) and fluoroscopy time were compared between preoperative and postoperative angiographies, according to SDAVF locations (common versus uncommon), MRA results at baseline (positive versus negative) and DSA protocols (low-dose, mixed-dose, normal-dose). The 75th percentile of the DAP distribution was used to define the local DRL.
RESULTS
A total of 62 spinal angiographies were performed in 25 patients with SDAVF. Preoperative angiographies (30/62, 48%) yielded a significantly higher DAP and longer fluoroscopy time when compared to postoperative angiographies (32/62, 53%) (p < 0.01). The local DRL was 329.41 Gy cm for a nonspecific (n = 62), 395.59 Gy cm for a preoperative and 138.6 Gy cm for a postoperative spinal angiography. Preoperative angiography of uncommonly located SDAVFs yielded a significantly longer fluoroscopy time (p = 0.02). The MRA-based fistula detection had no significant impact on dosimetrics (p > 0.05). A low-dose protocol yielded a 61% reduction of DAP.
CONCLUSION
The results of the present study suggest novel DRLs for spinal angiography in patients with SDAVF. Dedicated low-dose protocols enable radiation dose optimization in these procedures.
Topics: Angiography, Digital Subtraction; Central Nervous System Vascular Malformations; Fluoroscopy; Humans; Radiation Dosage; Retrospective Studies
PubMed: 34994809
DOI: 10.1007/s00062-021-01130-1 -
Physica Medica : PM : An International... Jan 2013The aim of this paper is to clarify some physical-mechanical aspects involved in the carbon dioxide angiography procedure (CO₂ angiography), with a particular...
The aim of this paper is to clarify some physical-mechanical aspects involved in the carbon dioxide angiography procedure (CO₂ angiography), with a particular attention to a possible damage of the vascular wall. CO₂ angiography is widely used on patients with iodine intolerance. The injection of a gaseous element, in most cases manually performed, requires a long training period. Automatic systems allow better control of the injection and the study of the mechanical behaviour of the gas. CO₂ injections have been studied by using manual and automatic systems. Pressures, flows and jet shapes have been monitored by using a cardiovascular mock. Photographic images of liquid and gaseous jet have been recorded in different conditions, and the vascular pressure rises during injection have been monitored. The shape of the liquid jet during the catheter washing phase is straight in the catheter direction and there is no jet during gas injection. Gas bubbles are suddenly formed at the catheter's hole and move upwards: buoyancy is the only governing phenomenon and no bubbles fragmentation is detected. The pressure rise in the vessel depends on the injection pressure and volume and in some cases of manual injection it may double the basal vascular pressure values. CO₂ angiography is a powerful and safe procedure which diffusion will certainly increase, although some aspects related to gas injection and chamber filling are not jet well known. The use of an automatic system permits better results, shorter training period and limitation of vascular wall damage risk.
Topics: Angiography; Aortography; Carbon Dioxide; Humans; Injections; Mechanical Phenomena; Pressure; Quality Control; Risk
PubMed: 22138139
DOI: 10.1016/j.ejmp.2011.11.003 -
Clinical Anatomy (New York, N.Y.) Nov 2022The number of studies on the anatomy of the costocervical trunk (CCT) is scarce, and the actual prevalence of this structure is unknown. Therefore, the authors of the... (Review)
Review
The number of studies on the anatomy of the costocervical trunk (CCT) is scarce, and the actual prevalence of this structure is unknown. Therefore, the authors of the present study would like to propose a set of four types of CCT, which were created based on observations of computed tomography angiographies (75 CCTs). A retrospective study was conducted to establish variations and the morphometric properties of the CCT. The results of 55 consecutive patients who underwent neck and thoracic computed tomography angiography (CTA) were analyzed in March 2022. The analysis was performed on a total of 75 CCTs. Of these, 32 were from women (42.7%) and 43 were from men (57.3%). Branching variations of each CCT were thoroughly analyzed. A classification of the branching pattern of the CCTs was made and consisted of four types. In the present study, the variety of branching and morphology of CCT was analyzed, proposing its novel classification based on the four most frequently observed types. Type 1 was the most prevalent (76.1%), having a similar origin and branching pattern as described in the major anatomical books. CCT was found to be absent in 23.94% of the cases, making it a somewhat less consistent branch of the SA. Understanding the variability of the anatomy of the CCT can be a great tool for physicians performing endovascular procedures in the cervical region.
Topics: Angiography; Female; Humans; Male; Neck; Retrospective Studies; Subclavian Artery; Tomography, X-Ray Computed
PubMed: 35796160
DOI: 10.1002/ca.23929 -
Scientific Reports Jul 2023Coronary artery tortuosity is usually an undetected condition in patients undergoing coronary angiography. This condition requires a longer examination by the specialist...
Coronary artery tortuosity is usually an undetected condition in patients undergoing coronary angiography. This condition requires a longer examination by the specialist to be detected. Yet, detailed knowledge of the morphology of coronary arteries is essential for planning any interventional treatment, such as stenting. We aimed to analyze coronary artery tortuosity in coronary angiography with artificial intelligence techniques to develop an algorithm capable of automatically detecting this condition in patients. This work uses deep learning techniques, in particular, convolutional neural networks, to classify patients into tortuous or non-tortuous based on their coronary angiography. The developed model was trained both on left (Spider) and right (45°/0°) coronary angiographies following a fivefold cross-validation procedure. A total of 658 coronary angiographies were included. Experimental results demonstrated satisfactory performance of our image-based tortuosity detection system, with a test accuracy of (87 ± 6)%. The deep learning model had a mean area under the curve of 0.96 ± 0.03 over the test sets. The sensitivity, specificity, positive predictive values, and negative predictive values of the model for detecting coronary artery tortuosity were (87 ± 10)%, (88 ± 10)%, (89 ± 8)%, and (88 ± 9)%, respectively. Deep learning convolutional neural networks were found to have comparable sensitivity and specificity with independent experts' radiological visual examination for detecting coronary artery tortuosity for a conservative threshold of 0.5. These findings have promising applications in the field of cardiology and medical imaging.
Topics: Coronary Angiography; Coronary Vessels; Artificial Intelligence; Deep Learning; Research Design
PubMed: 37429940
DOI: 10.1038/s41598-023-37868-6 -
Clinical Orthopaedics and Related... Dec 1984Angiography may play an important role in the understanding of the cause and treatment of Perthes' disease. Angiograms were performed in 30 patients, including 26...
Angiography may play an important role in the understanding of the cause and treatment of Perthes' disease. Angiograms were performed in 30 patients, including 26 aortographies and six selective angiographies. The major angiographic alterations were: general decrease of blood flow in the affected hip, lack of a patent medial circumflex artery, an atrophic medial circumflex artery or obstruction of its branches, distended vessels in subluxations of the hip joint, and almost complete absence of the obturator artery. These anatomic differences between normal and pathologic hips suggest a deficient blood supply in the affected side and an ischemic epiphysis. Surgical treatment is indicated in cases in which distention of the circumflex vessels is noted and the condition progresses to massive necrosis. There were no differences in circulation of the hip between men and women afflicted with Perthes' disease.
Topics: Adolescent; Angiography; Aorta, Abdominal; Aortography; Child; Child, Preschool; Female; Femur Head Necrosis; Hip; Humans; Legg-Calve-Perthes Disease; Male; Sex Factors
PubMed: 6499314
DOI: No ID Found -
Ophthalmologica. Journal International... 1975The authors present the results of their color fluorescein angiographies carried out with a pocket retinograph equipped with new interferential filters. After the...
The authors present the results of their color fluorescein angiographies carried out with a pocket retinograph equipped with new interferential filters. After the graphic examination, they propose to use these same filters mounted on different instruments for binocular and monocular angioscopy. Their results show that retinal vessels are translucid and that their color changes according to their background. The authors termed this change 'versicolored effect'. Moreover, color angiography with these new filters eliminates pseudofluorescence and adds to the fluoroscopic examination an element of analytic perfection, thus giving a new opening to differential diagnosis in endo-ocular diseases.
Topics: Color; Fluorescein Angiography; Fundus Oculi; Humans; Optic Nerve; Retinal Vessels
PubMed: 1153165
DOI: 10.1159/000307249 -
Critical Care Nursing Clinics of North... Mar 2010In critical care, nurses are expected to react quickly to urgent and emergent situations. It is imperative that nurses have the ability to recognize signs and symptoms...
In critical care, nurses are expected to react quickly to urgent and emergent situations. It is imperative that nurses have the ability to recognize signs and symptoms in patients that require diagnostic intervention. This article begins with a brief description of angiography and its role in the critical care environment. This is followed by a description and comparison of several modalities used to evaluate the cerebral and carotid vessels. A related case study, from a patient's perspective, provides the context for this discussion.
Topics: Adult; Angiography; Angiography, Digital Subtraction; Attitude to Health; Cerebral Angiography; Critical Care; Female; Humans; Magnetic Resonance Angiography; Monitoring, Physiologic; Nurse's Role; Nursing Assessment; Patient Education as Topic; Tomography, X-Ray Computed
PubMed: 20193880
DOI: 10.1016/j.ccell.2009.10.007