Items tagged “refs”

2,959 results found
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Falling snow sign (spermatocele)

The falling snow sign describes the appearance of movement of internal echoes in spermatoceles away from the transducer, resulting in an appearance similar to falling snow when color Doppler is applied. The sign can be used to aid in the diagnosis of a spermatocele.
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Acute bronchitis

Acute bronchitis (plural: bronchitides) refers to acute-onset, short-term bronchial inflammation. It is usually self-limiting and often the result of a viral infection. Chest radiography is rarely necessary. Epidemiology Acute bronchitis can affect people of all ages, but it is commonest in ch...
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Extra-adrenal myelolipoma

Extra-adrenal myelolipomas are extremely rare myelolipomas that occur outside the adrenal glands, with the most common sites being the retroperitoneum (especially presacral region 7), perirenal space and the thorax. Epidemiology The exact incidence is unknown. Less than 60 reported cases were ...
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Image normalization

Image normalization is a process, often used in the preparation of data sets for artificial intelligence (AI), in which multiple images are put into a common statistical distribution in terms of size and pixel values; however, a single image can also be normalized within itself. The process usua...
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Scaling

Scaling is a linear transformation that changes the size of a mathematical object. The mathematical objects of interest to radiologists that can be scaled are usually image matrices. This simple type of spatial normalization is a common step in image normalization for creating an image data set ...
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Convolution

Convolution is a mathematical concept that implies the product of two functions. In practical terms for radiology, convolution implies the application of a mathematical operation to a signal such that a different signal is produced. Convolutions are applied in image processing for CTs and MRIs. ...
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Cardiogenic pulmonary edema

Cardiogenic pulmonary edema is a subtype of pulmonary edema where the underlying etiology is due to left ventricular dysfunction. Pathology Etiology left heart failure congestive cardiac failure mitral regurgitation aortic stenosis arrhythmias myocardial pathology myocarditis cardiomyo...
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RAPADILINO syndrome

RAPADILINO syndrome is a rare autosomal-recessive syndrome that results from mutations in the RECQL4 gene 1. Epidemiology RAPADILINO syndrome is a rare condition, prevalence is unknown. It is, however, more common and was first described in Finnish populations 2. Pathology The acronym RAPADI...
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Brain morphometry

Brain morphometry is the act of measuring various dimensions (typically volume) of parts of the brain. Historically, this was only performed post-mortem.   In modern practice, this is performed in vivo using MRI. A volumetric scan of the brain (typically T1 weighted) is obtained and segmented i...
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Early structural scan

An early structural scan is a first trimester obstetric ultrasound performed around 12-16 weeks gestation. It can have some similarity to the 11-13 week antenatal ultrasound and assess limited fetal anatomy. However, a formal evaluation of nuchal translucency is not part of this ultrasound asses...
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Corkscrew sign (disambiguation)

Corkscrew sign can refer to: corkscrew sign (corkscrew cochlea) corkscrew sign (diffuse esophageal spasm) corkscrew sign (midgut volvulus) corkscrew sign (ureteric tuberculosis)
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Bridging of the sella turcica

Bridging of the sella turcica is the fusion of the anterior and posterior clinoid processes. Epidemiology The prevalence of a sella turcica bridge in a healthy population is estimated to be ~4% (range 1.75-6%) in anatomical and radiographic studies. Pathology It has been reported to occur in...
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Apodia

Apodia is a rare non-syndromic transverse terminal lower limb defect characterized by the congenital absence of the foot and ankle. The remainder of the lower limb is present including both the tibia and fibular epiphyses. It can be unilateral or bilateral. See also acheiria hemimelia
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Radial beak

The radial beak, also known as an epiphyseal spur, is a benign anatomical osseous variation of the distal radius. Radiographic appearance The radial beak manifest as a bony protrusion at the lateral aspect of the distal radius along the line of the fused/closing growth plate 1. It is typically...
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Lateral tentorial artery

The lateral tentorial artery also known as lateral tentorial arcade, is a branch of the meningohypophyseal trunk. which arises from the cavernous segment of the internal carotid artery. The lateral tentorial artery runs along the lateral edge of the tentorium cerebelli. Radiographic appearance ...
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Acetabular fossa

The acetabular fossa, also known as the cotyloid fossa, is the central aspect of the medial wall of the acetabulum that hosts the ligamentum teres and the fibrofatty pulvinar. It is the nonarticular portion inside the U-shaped labrum that extends to the acetabular notch 1. The acetabular fossa i...
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Watering-can perineum

Watering-can perineum is the result of multiple fistulae extending from the urethra to open within the perineum. In these patients, urine can exit through these perineal openings 1,2. The fistulae can be detected with voiding cystourethrography, however, the definite cause can be determined with...
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Trapeziectomy

Trapeziectomy refers to the surgical removal of the trapezium. It may be performed in conjunction with a ligament reconstruction and tendon interposition. It is typically performed as a treatment for severe inflammatory arthritis and/or osteoarthritis of the 1st carpometacarpal joint.
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Trisomy 8

Trisomy 8 is a chromosomal anomaly where there are three copies of chromosome 8. Complete trisomy 8 causes severe effects on the developing fetus and can be a cause of miscarriage. However, trisomy 8 can occur as a mosaic form, Warkany syndrome, that can be compatible with life.
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Trisomy 8 mosaic

Trisomy 8 mosaicism or Warkany syndrome is a less severe variant of trisomy 8 and individuals with a low proportion of affected cells may exhibit a comparatively mild range of physical abnormalities and developmental delay. They are more likely to survive into childhood and adulthood but can exh...

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