Tumoral calcinosis is a rare familial condition characterized by painless, periarticular masses. The term should be strictly used to refer to a disease caused by a hereditary metabolic dysfunction of phosphate regulation associated with massive periarticular calcinosis and should not be used to ...
There are a number of tumors of muscular origin, which overall are relatively uncommon, representing ~2% of benign soft tissue tumors and ~10% of malignant soft tissue tumors 1.
The tumors can be divided according to the type of muscle fiber:
Skeletal muscle origin
Tumors of the chest wall are varied, some of which are found most often in this region. They can be divided into benign and malignant tumors and into those which arise in the ribcage and those of soft tissue density.
Benign tumors include 1,3,4:
Tumors that metastasize to bone may be remembered using the mnemonic "lead kettle" spelled PBKTL (lead is Pb on the Periodic Table).
For females, breast and lung are the most common primary sites; nearly 80% of cancers th...
Turf toe is an extreme traumatic dorsiflexion (hyperextension) injury of the toe results in plantar plate injury from sprain to complete tear of the plantar plate capsuloligamentous complex and allows unrestricted range of motion of the first metatarsophalangeal (MTP) joint. It is common in prof...
Turner syndrome, also known as 45XO or 45X, is the most common of the sex chromosome abnormalities in females.
The incidence is estimated at 1:2000-5000 of live births, although the in utero rate is much higher (1-2% of conceptions) due to a significant proportion of fetuses with...
Turret exostoses are a benign osteocartilagenous lesion.
It is believed to arise from reactive periosteum following relatively mild trauma. It is usually seen a smooth dome-shaped parosteal bone proliferation.
Often seen in the phalanges but can also present in rare site...
The twelfth rib is an atypical rib. It is the shortest rib, and one of two floating ribs.
The 12th rib has a single facet on its head for articulation with the T12 vertebra. It has a short neck and no tubercle. It also lacks a costal groove and angle. internal surface ...
The two-slice-touch rule is a sign on MRI of the knee used to increase the sensitivity of diagnosing meniscal tears.
This rule states a meniscal tear is present if abnormal findings are present on two or more images - these do not have to be contiguous, e.g. can occur on sagittal and coronal sl...
The tympanic part of the temporal bone is situated inferiorly to the squamous part and anteriorly to the mastoid part.
The tympanic part surrounds the external auditory meatus, forming the anterior wall, floor and some of the posterior wall of the bony external acoustic meatus. The lateral bord...
Type 1 pelvic resections are complex surgeries that involve removing part of the pelvis, usually to resect malignant tumor.
Type 1 pelvic resections remove a varying amount of the iliac bone, and are classified in general terms as "partial" or "complete", depending on how much of the iliac bone...
Type II collagenopathies are a group of conditions collectively characterized by abnormalities in synthesis of collagen type II. This usually occurs due to a mutation in the COL2A1 gene.
Entities that fall under this group include:
achondrogenesis type II
platyspondylic lethal skeletal dyspla...
Of the seven cervical vertebrae, C3 through C6 have typical anatomy, while C7 looks very similar. C1 (atlas) and C2 (axis) have very distinct anatomical features. For a basic anatomic description of the structure a generic vertebra, see vertebrae.
small, oval-shaped vertebral bod...
Typical ribs are those numbered 2 to 10 with ribs 1, 11 and 12 considered atypical.
A typical rib is long and flat. They contain a:
Ribs have a rounded, smooth superior border. The inferior border is thin and sharp.
The ulna (plural: ulnae) is one of the two long bones of the forearm, located medially in the supinated anatomic position. It has a larger proximal end and tapers to a smaller distal end (opposite to the radius).
Prominent features of the ulna include:
The ulnar artery is a terminal branch of the brachial artery, arising at the proximal aspect of the forearm. Along with the radial artery, it is one of the main arteries of the forearm.
origin: terminal branch of the brachial artery
location: inferior aspect of the cubital fossa
Ulnar dimelia or mirror hand syndrome is a rare congenital anomaly of the upper limb characterized by absence of the radial ray (including thumb), duplication of the ulna and duplication of the ulnar halves of the carpals, metacarpals and phalanges 1.
The embryology of mi...
Ulnar hemimelia is a rare congenital upper limb anomaly characterized by complete or partial absence of the ulna bone.
Incidence is estimated at 1/100,000-150,000 live births, with a male to female ratio of 3:2.
Ulnar hemimelia may be associated with other skeletal ...
Ulnar impaction syndrome, also known as ulnar abutment or ulnocarpal loading, is a degenerative wrist condition caused by the ulnar head impacting upon the ulnar-sided carpus with the injury to the triangular fibrocartilage complex (TFCC).
Ulnar impaction syndrome most commonly pr...
Ulnar impingement syndrome is a wrist condition caused by a shortened distal ulna impinging on the distal radius proximal to the sigmoid notch. The syndrome is distinct from ulnar impaction syndrome, which typically occurs due to a long ulna (positive ulnar variance) impacting upon the triangula...
The ulnar nerve is one of the terminal branches of the brachial plexus and has motor and sensory supply to the forearm and hand.
The ulnar nerve originates as a terminal branch of the medial cord of the brachial plexus with nerve root fibers from C8-T1.
Ulnar nerve blocks are an approach for delivering anesthesia to the ulnar nerve territory either as a standalone blockade or combined with brachial plexus, radial or median nerve block.
burns involving tissue in the ulnar nerve territory
rescue analgesia for failed brachial plexus...
Ulnar nerve dislocation is an uncommon cause of pain and paresthesias in the ulnar nerve distribution. It occurs if the ulnar nerve subluxates and then dislocates over the anterior aspect of the medial epicondyle during flexion and extension of the elbow.
Ulnar nerve dislocation occ...
There are several distinct ulnar-sided wrist impaction and impingement syndromes. Underlying anatomical causes exist for each syndrome, however, repetitive or excessive use of the forearm and wrist can also contribute.
ulnar impaction syndrome: positive ulnar variance
ulnar impingement syndrom...
Ulnar styloid fractures occur in association with ~60% of distal radius fractures. Most of these are small avulsion fractures involving the tip of the ulnar styloid.
Usually, this kind of fracture occurs as the result of a fall on an outstretched arm and is often associated with a di...
Ulnar styloid impaction syndrome refers to wrist pain due to a long ulnar styloid process impacting upon the triquetral bone.
An ulnar styloid >6 mm in length is commonly regarded as being long. Impaction results in chondromalacia of the opposing articular surfaces, i.e. the proximal...
Ulnar variance (also known as Hulten variance) refers to the relative lengths of the distal articular surfaces of the radius and ulna.
Ulnar variance may be:
neutral (both the ulnar and radial articular surfaces at the same level)
positive (ulna projects more distally)
negative (ulna projec...
The ulnomeniscal homologue (UMH) is an obliquely oriented, fibrocartilaginous structure, that forms part of the ulnar collateral ligament complex (ULC) of the wrist.
The UMH is located between the ulnar styloid process and the triquetrum. It adheres to the ulnar joint capsule and...
Ultrahigh field (UHF) magnetic resonance imaging refers to imaging done on any MRI scanner with a main magnetic field (B0) strength of 7 tesla or greater. Until recently purely a research tool, following the introduction of the first 7 T clinical scanner in 2017, there are now a slowly increasin...
Ultrasound elastography, also called as sono-elastography, is a modern evolutionary method of sonographic imaging. Techniques include shear wave elastography (also known as transient elastography) and strain elastography (also known as static or compression elastography). These techniques assess...
Ultrasound-guided biopsy is one form of image-guided biopsy, typically performed by a radiologist. It is the most common form of image-guided biopsy, offering convenience and real-time dynamic observation with echogenic markers on cannulae allowing for precise placement.
It can potentially be u...
Ultrasound of the elbow allows high-resolution imaging of elbow anatomy while simultaneously allowing dynamic evaluation of the joint, tendons, and ligaments.
There are multiple possible approaches to imaging the elbow with ultrasound. A typical protocol is as follows 1:
There are several approaches to ultrasound examination of the adult hip.
supine with the hip in mild external rotation
sagittal oblique plane parallel to the long axis of the femoral neck to assess femoral head and neck and for any joint effusio...
Ultrasound of the knee allows high-resolution imaging of superficial knee anatomy while simultaneously allowing dynamic evaluation of some of the tendons and ligaments. Knee ultrasound is somewhat limited compared with ultrasound examinations of other joints because the cruciate ligaments and th...
Ultrasound of the shoulder is a fast, relatively cheap and dynamic way to examine the rotator cuff and is particularity useful in diagnosing:
rotator cuff disorders
The examination requires attention to technique and appropriate patient positioning. ...
Ultrasound is a useful imaging modality for evaluation of the wrist, allowing high-resolution imaging of anatomy while simultaneously allowing dynamic evaluation of the joints, tendons, and ligaments.
There are multiple possible approaches to imaging the wrist with ultrasound. The exa...
The umbilical folds are a series of 5 folds of parietal peritoneum on the deep surface of the anterior abdominal wall and consist of:
a single midline median umbilical fold,
bilateral medial umbilical folds, and
bilateral lateral umbilical folds
Umbilical hernias are the most common ventral abdominal wall hernia and occur in the midline through the umbilicus.
Ten times more common in females 2 and represent ~5% of all abdominal hernias 4.
Umbilical hernias present in the midline as painless or pain...
The umbilicus is the fibrous remnant of the fetal attachment of the umbilical cord after birth.
All layers of the anterior abdominal wall fuse at the umbilical ring, a small round defect in the linea alba located just inferior to the midpoint between the xiphoid process of the st...
The uncinate process of the cervical spine is a hook-shaped process found bilaterally on the superolateral margin of the cervical vertebral bodies of C3-C7.
The uncinate processes are more anteriorly positioned in the upper cervical spine and more posteriorly location in the lower cervical spin...
Uncovertebral joints, also called Luschka’s joints, are seen bilaterally between adjacent cervical vertebrae, identified by the cat ear shaped uncinate processes of the C3-7 vertebrae (C1 and C2 have no uncinate processes).
The articulation forms between the uncina...
Undifferentiated pleomorphic sarcoma (UPS), previously known as malignant fibrous histiocytoma (MFH), is considered the most common type of soft tissue sarcoma. It has an aggressive biological behavior and a poor prognosis.
As in the majority of the cases, UPS affects the extremities, this arti...
Undifferentiated pleomorphic sarcomas (UPS), previously known as malignant fibrous histiocytoma (MFH), are an uncommon tumor overall but are considered as one of the most common types of primary retroperitoneal neoplasms.
For a broad discussion of this type of a tumor, which commonly involves ...
Undifferentiated spondyloarthritis (uSpA), also known as undifferentiated arthritis, is a non-specific mono- or polyarthropathy that lacks the clinical, serological and radiological features that would allow specific diagnosis. It often turns out to be an early presentation of a more well-known ...
Unfused spinous process, which is really failure of fusion of the neural arch, is a relatively common anatomical variant and is part of the spectrum of spina bifida occulta.
This should be differentiated from accessory ossicles of the spinous process, which appear after non-fusion of the secon...
Fusion of sternal body segments is usually complete by 25 years of age. But non-fusion of sternal body segments can be seen in older age group.
Unicameral bone cysts (UBC), also known as simple bone cysts, are common benign non-neoplastic lucent bony lesions that are seen mainly in childhood and typically remain asymptomatic. They account for the S (simple bone cyst) in FEGNOMASHIC, the commonly used mnemonic for lytic bone lesions.
Unilateral facet dislocation is a relatively stable type of facet dislocation.
Flexion/distraction associated with rotation. The inferior articular facet of vertebral above moves over the superior facet of the vertebral below and becomes locked. It usually affects C4-C5 or...
Upper extremity dislocations are relatively common on account of the great range of motion the upper limb is capable of (a general principle is that the greater the range of motion of a joint, the more prone it is to dislocation). In many instances dislocations are associated with fractures eith...
The upper limb sustains a wide variety of fractures that range significantly in demographics, treatment and functional impact.
blade of scapula fracture
coracoid process fracture
Upper limb anatomy encompasses the anatomy of the shoulder, arm, elbow, forearm, wrist and hand.
This anatomy section promotes the use of the Terminologia Anatomica, the international standard of anatomical nomenclature.
Upper limb radiography is the radiological investigation of the shoulder girdle, humerus, ulna, radius, carpals and metacarpals of the hand. It is often utilized in the context of trauma to rule out fractures and dislocations.
The upper subscapular nerve, also known as the short or superior subscapular nerve, arises from the posterior cord of the brachial plexus and supplies the subscapularis muscle.
The upper subscapular nerve branches from the posterior cord of the brachial plexus with fibers...
Vacuum phenomena describe aseptic gas collections (e.g. nitrogen and traces of oxygen and or carbon dioxide) within different specific tissues 1-3. Usually, they are seen within the intervertebral discs, the bones and within different joints, but can also be seen in other usually adjacent locati...
Vacuum phenomenon in the shoulder refers to the presence of intra-articular gas in the shoulder joint. It is a very common occurrence, particularly in external rotation. This can cause circular or linear areas of low signal intensity on GRE MR images of the shoulder obtained with external rotati...
Valgus extension overload syndrome, also known as pitcher's elbow, refers to a constellation of symptoms and pathologies commonly seen in overhead throwing athletes secondary to high repetitive tensile, shear and compressive forces generated by the overhead throwing motion.
The syndrome may cor...
The terms valgus and varus refer to angulation (or bowing) within the shaft of a bone or at a joint.
It is determined by the distal part being more medial or lateral than it should be. Whenever the distal part is more lateral, it is called valgus. Whenever the distal part is more medial, it is ...
Van Buchem disease (VBD) is an extremely rare hereditary sclerosing bone dysplasia, also known as hyperostosis corticalis generalisata. This disease is characterized most notably by mandibular enlargement and thickening of the skull.
Less than 30 cases have been reported in the li...
The Vancouver classification of periprosthetic hip fractures proposed by Duncan and Masri is the most widely used classification system. It takes into account the fracture site, the status of the femoral implant, and the quality of surrounding femoral bone stock.
type A: fractures involve the t...
The vastus intermedius muscle is one of the four quadriceps muscles in the anterior compartment of the thigh. The others are the vastus medialis, the vastus lateralis, and the rectus femoris.
origin: upper two-thirds of the anterior and lateral surfaces of the femur
The vastus lateralis is largest of the four quadriceps muscles in the anterior compartment of the thigh. The others are the rectus femoris, the vastus intermedius, and the vastus medialis.
lateral part of intertrochanteric line
margin of greater trochanter
The vastus medialis muscle is one of the four quadriceps muscles in the anterior compartment of the thigh. The others are the rectus femoris, the vastus intermedius, and the vastus lateralis.
medial part of intertrochanteric line
medial lip of the linea ...
Vaughan-Jackson syndrome describes a rare syndrome of sequential atraumatic extensor tendon ruptures in the hand, usually in the setting of rheumatoid arthritis of the distal radioulnar joint.
The presentation is with reduced extension of the fingers 1-5. Typically, the f...
There are many signs in radiology which are vegetable- and plant-inspired, they include:
celery stalk (disambiguation):
celery stalk sign anterior cruciate ligament
celery stalk metaphysis
Christmas tree intestinal atresia
coconut left atrium
coffee bean sign
The anatomy of the venous drainage of the lower limbs is extremely variable. However, there is order in the variability. The veins of the lower extremities are arranged in three systems: the superficial, the deep, and the perforating venous systems. These are located in two main compartments: th...
The term venous lakes may refer to:
cutaneous venous lakes, often occurring on the lower lip 1
osseous venous lakes occurring in the skull 2
placental (venous) lakes 3
Venous lakes in the skull are an anatomical variant of enlarged emissary veins within the diploic space.
Venous lakes appear as round-to-oval lucencies, often in the inner table, that demonstrate vivid post-contrast enhancement 1.
Ventral trochlear prominence describes and measures the bony surplus in the anterior femoral surface at the most superior or proximal aspect of the trochlea.
Ventral trochlear prominence is used for the assessment of trochlear dysplasia, a risk factor for patellofemoral instability 1-4 i...
Version is the measure of the rotation of a joint socket along its transverse axis, and is the opposite of torsion, which measures the rotation of a long bone along its longitudinal axis. Abnormal angulation of a joint socket results in early mechanical dysfunction, instability, impingement, and...
The vertebra (plural: vertebrae) is the fundamental segmental unit of the vertebral column (also known as the spine).
Vertebrae, apart from those that are atypical, have a similar basic structure which can be described as an anterior vertebral body and a posterior neural (or vert...
The vertebral column is affected by a range of anatomical variants of the body and/or neural arch as well as accessory ossicles. Knowledge of basic vertebral anatomy and ossification is essential for describing and understanding the range of anomalies.
The differential diagnosis for a vertebral body mass is broad and may range from a completely benign, sclerotic enostosis (bone island) to a malignant primary bone tumor.
Broadly, these lesions can be separated into:
primary bone tumors
Vertebral body pathological fracture occurs as a result of infiltration of the vertebral body by a neoplastic process (primary or secondary). Vertebral bodies are one of the most common sites of pathological fractures.
As with other types of vertebral fractures, they pre...
Vertebral body squaring refers to the loss of normal concavity of the anterior border. It is seen in a variety of conditions including:
Ankylosing spondylitis is the most common cause of vertebral body squaring. It usually involves multiple level...
Vertebral hemangiomas are the most common benign vertebral neoplasms. They are usually asymptomatic and incidentally detected due to their characteristic features on imaging for other reasons. Rarely, they can be locally aggressive (see: aggressive vertebral hemangioma).
Please refer to the art...
Differential diagnosis of vertebral lesions includes:
Lesion originating in vertebral body
vertebral body osteomyelitis
giant cell tumor
Langerhans cell histiocytosis
Vertebral metastases represent the secondary involvement of the vertebral spine by haematogenously-disseminated metastatic cells. They must be included in any differential diagnosis of a spinal bone lesion in a patient older than 40 years.
This article will focus only on the metastasis involvin...
Vertebral pneumatocysts are gas-filled cavities within the spinal vertebrae. They are most common at cervical levels. In general, vertebral pneumatocysts are less common than intraosseous pneumatocysts in the pelvis, especially adjacent to the sacroiliac joint.
Although not comple...
Vertebral scalloping is a concavity to the posterior (or less commonly anterior) aspect of the vertebral body when viewed in a lateral projection. A small amount of concavity is normal, as is concavity of the anterior vertebral body (see vertebral body squaring).
Vertebral vascular foramina, also known as Hahn canal or cleft, are normal findings seen on cross-sectional imaging and should not be mistaken for a fracture, especially in the setting of trauma. They transmit:
basivertebral veins (forms Hahn's canal): foramen is seen on the posterior surface o...
Vertebra plana (pleural: vertebrae planae), also known as the pancake or silver dollar or coin-on-edge vertebra, is the term given when a vertebral body has lost almost its entire height anteriorly and posteriorly, representing a very advanced compression fracture.
It can occur in a ...
Mnemonics to remember the causes of vertebra plana include:
E: eosinophilic granuloma
F: fracture (trauma)
E: eosinophilic granuloma
T: tumor (e.g. metastases, myelom...
Vertebroplasty is an imaging-guided procedure which entails percutaneous injection of surgical polymethylmethacrylate (PMMA) cement into a diseased vertebral body. Vertebroplasty provides pain relief and strengthening of the bone of vertebrae weakened by disease.
It can be used as ...
Very bizarre generalized lesions of bone tend to make you exclaim "Oh my! What is going here?" Although there are numerous potential causes, in this situation it is worth thinking of a number of entities:
skeletal dysplasias and metabolic diseases
Vickers ligament is a ligamentous structure connecting the lunate bone and TFCC to the distal radius and is seen in the vast majority of patients with Madelung deformity 1.
Release of this thickened ligament may help in improving symptoms associated with Madelung deformity 2.
Vitamin A are a group of fat-soluble vitamers (the retinoids) required for many physiological functions, mainly vision, reproduction and epithelial maintenance. In the retina, a specific retinoid, 11-cis-retinal, is formed by photoisomerisation within the rods and cones.
Vitamin C (ascorbic acid) is a water soluble vitamin that is a coenzyme for the formation of the structure protein collagen, particularly creating cross-linking of collagen fibers which greatly increases its tensile strength. It also acts as an antioxidant.
History and etymology
Vitamin C was ...
Vitamin D (calciferol) is used to describe a group of five fat-soluble secosteroid vitamins required for the homeostasis of serum calcium and phosphorus. Vitamin D exists in two main forms (vitamers) in humans: ergocalciferol (vitamin D2) and cholecalciferol (vitamin D3).
Vitamin D3 acts by re...
Vitamin D deficiency (also known as hypovitaminosis D) is common, and untreated, may result in serious sequelae. Traditionally its pathological manifestations have been regarded through the lens of skeletal maturity:
rickets in children
osteomalacia in adults
However it has become increasingl...
Volar intercalated segmental instability (VISI) is a type of instability involving the wrist. It is less often encountered than dorsal intercalated segmental instability (DISI).
It presents in most cases with nonspecific wrist pain and a "clunking" on the ulnar deviation ...
Volar plate avulsion injuries are a type of avulsion injury. The volar plate of the proximal interphalangeal (PIP) joint is vulnerable to hyperextension injury, in the form of either a ligament tear or an intra-articular fracture.
The volar plate forms the floor of the PIP joint ...
The volar radioulnar ligament is one of the primary stabilizers of the distal radioulnar joint (DRUJ) and forms part of the triangular fibrocartilage complex (TFCC) 1,2.
location: extending from the anterior margin of the ulnar notch at the distal radius to the anterior portion of the ...
A Volkmann ischemic contracture refers to a complex and variable flexion deformity involving distal limbs (typically the wrist and fingers) resulting from fibrosis and contracture of flexor muscles.
A number of deformities can occur. In the upper extremity, this includes ...