Items tagged “refs”
2,967 results found
Article
Intracholecystic papillary neoplasm
Intracholecystic papillary neoplasms, previously known as intracystic/intraductal papillary tubular neoplasms 2, are rare, pre-invasive neoplasms of the gallbladder.
On imaging, these lesions resemble adenomas of the gallbladder or have features suspicious for gallbladder carcinoma, which usual...
Article
Cracking thyroid
Cracking thyroid is a term given to a very rare complication of thyroid fine needle aspiration (FNA) biopsy where there is acute pain and transient but marked thyroid swelling characterized by hypoechoic avascular septations on ultrasound 1,2. Onset is within a few minutes to a few hours post pr...
Article
Sinus of Morgagni
The sinus of Morgagni is a defect in the anterior aspect of the pharyngobasilar fascia. It transmits the Eustachian tube and levator veli palatini muscle and allows communication between the nasopharynx and middle ear.
Terminology
Not to be confused with the foramen of Morgagni, an anterior th...
Article
Woodruff plexus
Woodruff plexus is a venous plexus located in the posterior end of the inferior meatus on the lateral wall of the nasal cavity 1-3. It accounts for between 5-10% of epistaxis episodes. These bleeds do not respond to anterior nasal packing.
Despite George H. Woodruff's original description (1949...
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Training, testing and validation datasets
The division of the input data into training, testing and validation sets is crucial in the creation of robust machine learning algorithms. Firstly, machine learning algorithms require a training set to be trained on. Each iteration, it calculates the difference between the predicted and actual ...
Article
Imaging data sets (artificial intelligence)
The aggregation of an imaging data set is a critical step in building artificial intelligence (AI) for radiology. Imaging data sets are used in various ways including training and/or testing algorithms. Many data sets for building convolutional neural networks for image identification involve at...
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Confusion matrix
Confusion matrices, a key tool to evaluate machine learning algorithm performance in classification, are a statistical tool.
Contingency tables, a type of confusion matrix, are used in the evaluation of many diagnostic exams for sensitivity, specificity, positive and negative predictive values....
Article
Spinal subependymoma
Spinal subependymomas are very rare low-grade tumors (WHO I) of the spinal cord. Like intracranial subependymomas, that are far more common, spinal subependymomas are slow-growing, discrete tumors with little if any contrast enhancement.
Epidemiology
Due to the small number of cases reported ...
Article
HRCT chest (protocol)
High-resolution CT (HRCT) of the chest, also referred to as HRCT chest or HRCT of the lungs, refers to a CT technique in which thin-slice chest images are obtained and post-processed in a high-spatial-frequency reconstruction algorithm. This technique obtains images with exquisite lung detail, w...
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Machine learning processes
The specifics of how a machine learning algorithm is trained to recognize certain features and thereby become able to make accurate predictions on new examples varies depending on the type of data being used and the algorithm architecture. Four of the most commonly used learning processes are:
...
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Models (machine learning)
Each machine learning model will vary whilst being determined in part by the type of problem being solved. Although much of the recent work in the field of image processing generally, and more specifically radiology, has focussed on convolutional neural networks, a type of neural network, a numb...
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Neural network architectures
Artificial neural networks can be broadly divided into different architectures, feedforward or recurrent neural architectures.
Feedforward neural networks are more readily conceptualised in 'layers'. The first layer of the neural network is merely the inputs of each sample, and each neuron in e...
Article
Arterial vasocorona
The arterial vasocorona is part of the spinal cord blood supply and is formed by pial anastomoses between the anterior and posterior spinal arteries on the surface of the spinal cord. It encircles the cord and supplies the peripheral lateral aspect of the spinal cord.
Engorgement of arterial v...
Article
Ventricular assist device
Ventricular assist devices (VAD) are a mechanical circulatory support device, which is providing an effective therapy for a significant number of patients with advanced heart failure. There are mostly left VADs, although right VADs are also implanted.
Device elements
inflow cannulas
electri...
Article
Musculus compressor nuda
Musculus compressor nuda is a small striated musculotendinous sling of the bulbocavernosus muscle, which extends from the anterior and lateral surfaces of the proximal bulbous urethra.
Musculus compressor nuda causes the proximal bulbous urethra to form a symmetric convex cone shape where the t...
Article
Beam steering
Beam steering refers to altering the angle of the ultrasound beam with respect to the transducer without moving the probe. Beam steering allows a point on an image to be insonated from multiple angles from a single probe and a single position of the probe. Beam steering is accomplished by adding...
Article
Cardiac calcification
Cardiac calcification is a broad term for any calcification affecting the valves, coronary arteries, aortic root, endocardium, myocardium, and/or pericardium.
Pathology
Causes of cardiac calcification are:
coronary artery disease (most common)
coronary artery aneurysms, e.g. in Kawasaki dise...
Article
Decompression illness
Decompression illness (DCI) encompasses decompression sickness (DCS) and arterial gas embolism. The term decompression illness refers to inert bubble-induced dysbaric disease regardless of the location of the bubbles, which may be in the tissues or in the intravascular spaces. The bubbles arise ...
Article
Skeletogenesis
Skeletogenesis begins with the migration of multipotent mesenchymal cells, derived from ectoderm and mesoderm, to the locations of the future bones.
The mesenchymal cells then complete bone formation and generation through either endochondral ossification or intramembranous ossification.
Article
Single linear regression
Single linear regression, also known as simple linear regression, in statistics, is a technique that maps a relationship between one independent and one dependent variable into a first-degree polynomial. Linear regression is the simplest example of curve fitting, a type of mathematical problem i...
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