Articles

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16,854 results found
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Cannulated screws

Cannulated screws are a common method of fixation used by orthopedic surgeons for multiple fracture patterns. These screws may be cannulated or "hollow" to allow them to be placed over a guidewire facilitating better alignment prior to drilling or screw insertion. The guidewire is then removed a...
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Coracoclavicular ligament

The coracoclavicular (CC) ligament is the major vertical stabilizing factor of the acromioclavicular joint. Gross anatomy The coracoclavicular ligament can be divided into two parts: the more medial conoid ligament and the more lateral trapezoid ligament.  conoid ligament origin: knuckle of ...
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Pathognomonic

The term pathognomonic in radiology, as well as clinical medicine in general, refers to a finding or a sign that is only found in a single specific condition or specific group of conditions, i.e. the finding has 100% specificity. Thus by implication, a pathognomonic finding cannot and does not h...
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Spatial resolution

Spatial resolution refers to the ability of an imaging modality to differentiate two adjacent structures as being distinct from one another. Other related terms include definition or visibility of detail. Spatial resolution is expressed in line pairs per mm (lp mm). The absence of spatial reso...
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Ventricular tachycardia

Ventricular tachycardia is a type of ventricular arrhythmia with at least three consecutive ventricular beats occurring at greater than 100 beats per minute. If left untreated, ventricular tachycardia can lead to ventricular fibrillation and cardiac arrest. Epidemiology  Ventricular tachycardi...
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Corpus callosum

The corpus callosum (plural: corpora callosa) is the largest of the commissural fibers, linking the cerebral cortex of the left and right cerebral hemispheres. It is the largest white matter tract in the brain. Summary located inferior to the cerebral cortices, and superior to the thalamus co...
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Skeletal survey (overview)

The skeletal survey is a radiographic series performed to survey the entire skeleton (axial skeleton, upper and lower limbs) for pathology or injury. Specific projections vary depending on the clinical indication and the institution's protocol. There are various clinical indications that may wa...
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Bowl of grapes sign

The bowl of grapes sign has been described in synovial sarcoma. It refers to the characteristic multilobulated lesion subdivided by multiple septa, forming large cystic foci with regions of hemorrhage.
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Psoriasis

Psoriasis is an inflammatory dermatological disease with several variants. The most common variant is plaque psoriasis, other variants of the disease are guttate, erythrodermic and pustular psoriasis 1. Epidemiology There is a geographic variation in the prevalence of psoriasis such that popul...
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Extradural neural axis compartment

Extradural neural axis compartment (EDNAC) exists from the tip of the coccyx all the way to the back of the globe, and yet it is relatively unknown as a concept. It is bounded externally by the periosteum of the vertebrae and sacrum inferiorly and the skull superiorly, and the visceral (meningea...
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Right lower lobe collapse

Right lower lobe (RLL) collapse has distinctive features, and is usually relatively easily identified. The smaller overlying heart shadow obscures less lung compared with left lower lobe collapse.  Findings of lower lobe collapse can be grouped together as they are almost identical on both side...
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Os odontoideum

Os odontoideum (plural: ossa odontoidea) is an anatomic variant of the odontoid process of C2 and needs to be differentiated from persistent ossiculum terminale and from a type 2 odontoid fracture. It can be associated with atlantoaxial instability.  Although it was originally thought to be a c...
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Anderson and Montesano classification of occipital condyle fractures

The Anderson and Montesano classification is a widely used system for describing occipital condyle fractures. It divides injuries into three types based on morphology and mechanism of injury 1-5. Classification type I: impacted type occipital condyle fracture morphology: comminution of the co...
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Caput medusae sign (developmental venous anomaly)

The caput medusae sign also sometimes known as a palm tree sign refers to developmental venous anomalies of the brain, where a number of veins converge centrally into a single draining vein.  The sign is seen on both CT and MRI when contrast medium is administered. Angiographically the caput me...
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Shear wave elastography

Shear wave elastography is a developing variation of ultrasound imaging. The concept is similar to strain elastography, but instead of using transducer pressure to compare a shift in an ultrasound A-line (thereby measuring changes in strain), a higher intensity pulse is transmitted to produce s...
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Germ cell tumors of the ovary

Germ cell tumors of the ovary account for approximately 15-20% of all ovarian tumors. In children and adolescents, up to 60% of ovarian tumors can be of germ cell origin. They include: ovarian teratoma(s): commonest primary benign tumor of ovary and commonest germ cell tumor: mature (cystic) ...
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Aortic arch

The aortic arch represents the direct continuation of the ascending aorta and represents a key area for a review of normal variant anatomy and a wide range of pathological processes that range from congenital anomalies to traumatic injury. Summary origin: continuation of the ascending aorta at...
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Orthopantomography

The orthopantomogram (also known as an orthopantomograph, pantomogram, OPG or OPT) is a panoramic single image radiograph of the mandible, maxilla and teeth. It is often encountered in dental practice and occasionally in the emergency department; providing a convenient, inexpensive and rapid way...
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Flame sign (carotid)

The flame sign refers to a gradual tapering of contrast opacification in the mid-cervical internal carotid artery, sparing the carotid bulb. The sign can be observed on angiography (digital subtraction angiography 1, CT angiography 1, or contrast-enhanced MR angiography 2) in either of two scena...
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Spinoglenoid notch ganglion cyst

Spinoglenoid notch ganglion cysts are a location-specific form of ganglion cysts that arise in the region of the spinoglenoid notch. Epidemiology They are generally rare and may be slightly more common in males 2. Associations glenoid labral tears: especially SLAP lesions 5 Clinical present...

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