Items tagged “cases”

5,336 results found
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Rosette-forming glioneuronal tumors

Rosette-forming glioneuronal tumors (RGNTs) are rare, usually midline, tumors that involve the fourth ventricle and/or aqueduct of Sylvius.  Although relatively well circumscribed on MRI and clinically indolent, they often invade surrounding tissues, involving the cerebellum, pons and even the ...
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Rotator cuff

The rotator cuff is a group of four muscles and their tendons, important in stabilizing the glenohumeral joint: supraspinatus: abduction infraspinatus: external rotation teres minor: external rotation subscapularis: internal rotation Other structures that stabilize the glenohumeral joint in...
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Rotator cuff interval

The rotator cuff interval is a triangular space between the tendons of subscapularis and supraspinatus and the base of the coracoid process. Gross anatomy The combination of the coracohumeral ligament and superior glenohumeral ligament has a complex relationship with the long head of biceps te...
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Rotator cuff tear grading (MRI)

One method of grading rotator cuff tears on MRI is as follows: grade 0: normal grade I: increased T2 signal with normal morphology grade II: increased T2 signal with abnormal morphology (thickening, or irregularity of the tendon) grade III: defined tear (e.g. partial or full-thickness, compl...
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Salter-Harris fracture classification (mnemonic)

Useful mnemonics for remembering the Salter-Harris classification system are: SALTR SMACK Fortunately, this is also the order of prognosis (from best to worse) Mnemonics SALTR S: slipped (type I) A: above or away from joint (type II) L: lower (type III) T: through or transverse or toget...
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Oral cavity carcinoma (staging)

Oral cavity carcinoma staging refers to TNM staging of carcinomas involving the oral cavity. The vast majority of applicable cases are squamous cell carcinomas, but other epithelial and minor salivary gland cancers are also included. The following article reflects the 8th edition published by th...
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Saber-sheath trachea

Saber-sheath trachea refers to diffuse coronal narrowing of the intrathoracic portion of the trachea with the concomitant widening of the sagittal diameter. It is not uncommon and is pathognomonic for chronic obstructive pulmonary disease (COPD) 1.  The sagittal:coronal diameter is over 2:1 2 a...
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Sacroiliac joint injection

Sacroiliac joint injections can be performed using a posterior approach into the sacroiliac (SI) joint under fluoroscopic or CT guidance. It is often performed bilaterally. Indications diagnostic: relief of pain after injection of local anesthetic therapeutic: to relieve pain from degenerativ...
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Sentinel loop

A sentinel loop is a short segment of adynamic ileus close to an intra-abdominal inflammatory process. When seen, it is usually identified on abdominal radiography. The sentinel loop sign may aid in localizing the source of inflammation. For example, a sentinel loop in the upper abdomen may ind...
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Sergeant stripes sign (cerebellum)

The sergeant stripes sign refers to the oblique direction of the cerebellar tonsillar folia a feature sometimes visible in cases of Chiari I malformation on sagittal imaging. It is unclear which insignia this is meant to represent as the direction of the chevrons depends on nationality. For exam...
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Solitary bone cyst of the mandible

Solitary bone cysts of the mandible (also known as traumatic bone cyst of the jaw, hemorrhagic cyst of the mandible, extravasation cyst, progressive bone cavity or unicameral bone cyst) are an uncommon nonepithelial lined lucent mandibular lesion. It is one of a myriad of potential mandibular le...
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Spiculated periosteal reaction

Spiculated periosteal reaction represents spicules of new bone-forming along vascular channels and the fibrous bands that anchor tendons to bone (Sharpey fibers). Pathology A spiculated periosteal reaction signifies a rapid underlying process that prevents the formation of new bone under the r...
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Spinal epidural injection

Epidural spinal injections are one of the more frequently performed spinal interventional procedures. Three approaches to the epidural space exist:​ caudal epidural injection (via the sacral hiatus) interlaminar epidural injection cervical interlaminar epidural injection lumbar interlaminar ...
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Spinal epidural mass

The differential diagnosis for a spinal epidural mass includes: epidural metastasis epidural abscess herniated nucleus pulposus epidural hematoma epidural arteriovenous malformation epidural angiolipoma epidural lipomatosis
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Spondylolisthesis grading system

A commonly adopted method of grading the severity of spondylolisthesis is the Meyerding classification. It divides the superior endplate of the vertebra below into 4 quarters. The grade depends on the location of the posteroinferior corner of the vertebra above. This classification was original...
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Stapedius muscle

The stapedius muscle is the tiny muscle in the middle ear that attaches to the posterior aspect of the neck of the stapes, which when contracted dampens vibrations passed to the cochlea via the oval window. The muscle is anchored within the petrous temporal bone and emerges anteriorly into the m...
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Stewart-Treves syndrome

Stewart-Treves syndrome refers to an angiosarcoma seen in the setting of lymphedema 1. It was classically attributed to lymphedemas induced by radical mastectomy to treat breast cancer. Nowadays, we know that it can arise in chronically lymphedematous regions of any cause 2.  The incidence is ...
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Stiff person syndrome

Stiff person syndrome, previously known as stiff man syndrome, is a very rare neuromuscular disease. Epidemiology Onset is usually between 30 and 50 years of age. An association with autoimmune disease and various malignancies is described and these are thought to play a role in the pathophysi...
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Strawberry gallbladder

Strawberry gallbladder refers to the surface appearance (not shape) of the mucosa of the gallbladder due to multiple small collections of triglycerides and cholesterol esters within the lamina propria of the gallbladder wall (gallbladder wall cholesterolosis).  Strawberry gallbladder represents...
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Strawberry skull

Strawberry skull refers to the shape of the head on an antenatal ultrasound. Epidemiology Associations In general, strawberry skull is considered one of the non-specific 'soft markers' for abnormal fetal development. It is considered more closely associated with trisomy 18 (Edward syndrome). ...