Items tagged “cases”
5,514 results found
Article
Rhabdomyosarcoma (staging)
Rhabdomyosarcoma staging is based on the Lawrence/Gehan staging system, which comprises of a combination of pretreatment staging and postoperative clinical grouping.
Stage
stage I: orbit, eyelid, head and neck (excluding parameningeal), genitourinary (non-bladder, non-prostate), N0 or 1, M0
s...
Article
Rheumatic fever
Rheumatic fever is an illness caused by an immunological reaction following group A streptococcal infection.
Epidemiology
Risk factors include:
children and adolescents aged 5 to 15 years
developing nations where antibiotic prescription is low 1
poverty, overcrowding
Clinical presentation...
Article
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 ...
Article
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...
Article
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...
Article
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...
Article
Salter-Harris fracture classification (mnemonic)
Useful mnemonics for remembering the Salter-Harris classification system are:
SALTR
SMACK
SMETI
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 o...
Article
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...
Article
Saber-sheath trachea
Saber-sheath trachea refers to a 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...
Article
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 degene...
Article
Sentinel loop
A sentinel loop is a short segment of adynamic ileus close to an intra-abdominal inflammatory process. It is usually identified on abdominal radiography 4 and CT 3.
The sentinel loop sign may aid in localizing the source of inflammation. For example, a sentinel loop in the upper abdomen may ind...
Article
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...
Article
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...
Article
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...
Article
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 in...
Article
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...
Article
Stapedius muscle
The stapedius muscle is the tiny slender muscle in the middle ear that attaches to the stapes, which dampens excessive sound vibrations passed to the cochlea via the oval window.
Gross anatomy
The muscle is anchored within the petrous temporal bone. Its tendon emerges anteriorly from the holl...
Article
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 ...
Article
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...
Article
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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