Brachioradialis is a flexor at the elbow and works with biceps brachii and brachialis. It is located in the superficial layer of the posterior compartment of the forearm and is particularly useful in elbow stabilization.
Despite the bulk of the muscle being visible from the anterior surface of ...
Brachycephaly refers to a calvarial shape where the bi-parietal diameter to fronto-occipital diameter approaches the 95th percentile. It can result from a craniosynostosis involving the coronal and lambdoid sutures.
Brachycephaly can be associated with numerous syndrome...
Brachydactyly (BD) essentially refers to short digits. It is often inherited as an autosomal dominant trait (all the types). The clinical spectrum can widely range from minor digital hypoplasia to complete aplasia. As a group, it most commonly involves the middle phalanx 2.
Single or multiple b...
Brachydactyly type A1, also known as Farabee type brachydactyly, is a subtype of brachydactyly.
The anomaly is characterized by hypoplasia or aplasia of middle phalanges of the second to fifth digits in hands and feet and proximal phalanges of the thumbs and great toes...
Brachydactyly type A2 or Mohr-Wriedt type is characterized by hypoplasia/aplasia of the second middle phalanx of the index finger, second toe and sometimes little finger. There is radial deviation of the index finger and tibial deviation of the second toe.
Type A2 brachydactyly can b...
Brachydactyly type A3 is characterized by shortening of the middle phalanx of the little finger with radial deviation of distal phalanx. Slanting of the distal articular surface of the middle phalanx leads to radial deflection of the distal phalanx. However it is not always associated with clino...
Brachydactyly type A4 or Temtamy type is characterized by brachymesophalangy (absent or hypoplastic middle phalanx) of the second and fifth fingers. Other less common features include club foot, clinodactyly, ulnar deviation of the second finger.
Like other brachydactyly, type A4 is ...
Brachydactyly type A5 is characterized by absence of the middle phalanges and nail dysplasia with duplicated terminal phalanx of the thumb with resultant bifid thumb. Inheritance is suggested as autosomal dominant.
Brachymetatarsia (a.k.a. congenital short metatarsus) is a rare condition that develops from early closure of the growth plate.
Females are almost exclusively affected 1.
It typically involves the fourth ray or, less frequently, more than one metatarsal bon...
The Brahma bull sign (or Brahman) describes the appearance of the femoral neck when an osteochondroma is present, as Brahma bulls have an odd, camel-like hump along the dorsum of their neck resembling a femoral neck osteochondroma. Osteochondromas of the femoral neck, particularly when sessile, ...
Branchio-oculo-facial syndrome (BOFS) is a very rare autosomal dominant genetic disorder that is characterized clinically by abnormalities affecting the eyes, craniofacial structures, and branchial sinuses.
More than 80 cases have been reported in the global literature since its f...
Bridging (or fusion) of the pubic symphysis can be associated with various systemic and local causes, including 1-3:
The bright rim sign in anterior talofibular ligament injury refers to a sign seen on MRI. A cortical defect with a bright dot-like or curvilinear high-signal-intensity, usually at the fibular attachment site, is seen on MRI. It has been described as an indicator of ATFL injury 1.
The British Athletics muscle injury classification (BAMIC/BAC) is a five-point MRI-based system that is based on extent and site. It has been primarily based on hamstring injuries but is used in other muscle injuries. The classification system has been shown to have moderate inter- and intra-rat...
Brodie abscess is an intraosseous abscess related to a focus of subacute pyogenic osteomyelitis. Unfortunately, there is no reliable way radiographically to exclude a focus of osteomyelitis. It has a protean radiographic appearance and can occur at any location and in a patient of any age. It mi...
Brown adipose tissue (BAT) (also known as brown fat) is one of two types of adipose tissue (the other one being white fat) important for producing thermal energy (heat, non-shivering thermogenesis), especially in the newborn. It constitutes ~5% of body mass in the newborn and tends to reduce mar...
Brown tumor, also known as osteitis fibrosa cystica and rarely as osteoclastoma, is one of the manifestations of hyperparathyroidism. It represents a reparative cellular process, rather than a neoplastic process. Histologically brown tumors are identical to giant cell tumor (both are osteoclasto...
Brucellosis is a global zoonotic infection secondary to any of the four Brucella spp. that infect humans. It can be focal or systemic, but has a particular affinity for the musculoskeletal system.
Brucellosis occurs worldwide but is particularly prevalent in Mediterranean regions...
Brunelli procedure is a surgical procedure aiming to reconstruct a torn scapholunate ligament by reconnecting the scaphoid and lunate using the flexor carpi radialis tendon 1. In the modified Brunelli technique the tendon is sutured upon itself, thereby preventing the crossing of the distal radi...
Bucket handle fracture may refer to:
bucket handle fracture - non-accidental injury
bucket handle fracture of the pelvis
Bucket-handle meniscal tears are a type of displaced longitudinal meniscal tear where the inner part is displaced centrally. They more commonly occur in the medial meniscus and are often associated with anterior cruciate ligament (ACL) tears.
Bucket-hand tears can m...
Buckle rib fractures are typical of an anterior compressive force to the chest, most commonly external cardiac massage, but can be seen following any such traumatic injury.
Buckle rib fractures occur in all ages, even very elderly patients. Thus ribs are not the same as most adult lo...
Buford complex is a congenital glenoid labrum variant where the anterosuperior labrum is absent in the 1-3 o'clock position and the middle glenohumeral ligament is thickened (cord-like) and originates directly from the superior labrum at the base of the biceps tendon and crosses the subscapulari...
Bullet-shaped vertebra refers to the anterior beaking of the vertebral body.
It is seen in the following conditions:
mucopolysaccharidosis (Morquio disease, Hurler disease)
weapons and munitions inspired signs
A bunionette, also known as a tailor's bunion or metatarsus quintus valgus, is a bony prominence at the lateral 5th metatarsal head. It is the lateral counterpart of the more common bunion of the first metatarsophalangeal joint, and when they occur together (often with spreading of the other met...
Bursae are small fluid-filled sacs lined by a synovial membrane with an inner capillary layer of synovial fluid. It provides a cushion between bones and tendons and/or muscles around a joint. This helps to reduce friction between the bones and allows free movement. They may or may not communicat...
Bursitis is inflammation of a bursa, a synovial membrane-lined space, present overlying a number of joints. The inflammation may be acute or chronic, in the later case calcification may be apparent on plain radiographs. MRI best illustrates the bursa and related pathology.
Burst fractures are a type of compression fracture related to high-energy axial loading spinal trauma that results in disruption of the posterior vertebral body cortex with retropulsion into the spinal canal.
They usually present as back pain and or lower limbs neurologi...
Buschke-Ollendorff syndrome (BOS), also known as disseminated dermatofibrosis lenticularis 2, comprises of osteopoikilosis associated with disseminated connective tissue and cutaneous yellowish nevi, predominantly on the extremities and trunk 1. Recent genetic work has linked this syndrome to ...
Butterfly fragments are large, triangular fracture fragments seen commonly in comminuted long bone fractures. The term is commonly used in orthopedic surgery, and results from two oblique fracture lines meeting to create a large triangular or wedge-shaped fragment located between the proximal an...
Butterfly vertebra is a type of vertebral anomaly that results from the failure of fusion of the lateral halves of the vertebral body because of persistent notochordal tissue between them.
an anterior spina bifida, with or without an anterior meningocele
can be part of...
A button sequestrum is a small sequestrum of devascularised bone surrounded by lucency. Although classically described in osteomyelitis and eosinophilic granuloma it is also occasionally seen in fibrosarcoma and lymphoma.
C7, also known as the vertebra prominens, is the seventh cervical vertebra and looks like vertebra C3-C6, but has some distinct features making it one of the atypical vertebrae. The name vertebra prominens arises from its long spinous process, which is easily palpable.
Café au lait spots are a type of pigmented skin lesions which are classically described as being light brown in color.
Conditions associated with them include:
neurofibromatosis type 1 (NF1)
McCune-Albright syndrome: typically irregular which has been likened to t...
Caffey disease or infantile cortical hyperostosis is a largely self-limiting disorder which affects infants. It causes bone changes, soft-tissue swelling, and irritability.
It is distinct from physiological periostitis which can be seen involving the diaphyses of the tibiae, humeri, and femora ...
Calcaneal apophysitis, also known as Sever disease, is the painful inflammation of the apophysis of the calcaneus.
It typically presents in active young children and adolescents, especially those who enjoy jumping and running sports.
High plantar foot pressures are...
Calcaneal fractures are the most common tarsal fracture and can occur in a variety of settings.
The calcaneus is the most commonly fractured tarsal bone and accounts for about 2% of all fractures 2 and ~60% of all tarsal fractures 3.
Calcaneal fractures can be divided ...
The calcaneal inclination angle (also known as the calcaneal pitch) is drawn on a weight-bearing lateral foot radiograph between the calcaneal inclination axis and the supporting horizontal surface.
It is a measurement that reflects the height of the foot framework, but is affected by abnormal ...
The calcaneal inclination axis is drawn between the most inferior portion of the calcaneal tuberosity and the most distal and inferior point of the calcaneus at the calcaneocuboid joint on a weightbearing lateral foot radiograph.
It can be used to draw the calcaneal inclination angle.
A mnemonic for calcaneal lesions is:
B: bone cyst (unicameral)
I: intraosseous lipoma
G: ganglion (intraosseous)
G: giant cell tumor
The calcaneal tendon, commonly known as the Achilles tendon, is the strongest and largest tendon of the human body. It is also one of the commonest tendons to become injured due to its high biomechanical load but poor vascularity 2.
The calcaneal tendon forms by the merging of fi...
Avulsion fractures of the calcaneal tuberosity are rare, accounting for only 3% of all calcaneal fractures.
There are three mechanisms of action 4:
fall during plantarflexion
feet fixed on the ground with sudden muscular contraction
There is a s...
Calcaneal vascular remnant is a benign finding that may be seen on MRI of ankle and can be misinterpreted as an alarming bone lesion. It is typically located at the insertion site of sinus tarsi ligaments (cervical and interosseous ligaments).
The focus of signal alteration is believed to be pr...
The calcaneocuboid joint is part of the mid-tarsal (Chopart) joint. It is a synovial articulation between the calcaneus and the cuboid bones of the foot.
The calcaneocuboid joint involves the anterior surface of the calcaneus and the posterior surface of the cuboid. Its joint cap...
The calcaneofibular ligament (CFL) is the middle ligament of the lateral collateral ligament complex of the ankle and stabilizes both the ankle and subtalar joints.
The CFL is an extracapsular round cord measuring 20-25 mm long x 6-8 mm width. Its origin is distal to the anterior...
Calcaneonavicular coalition is one of the two most common subtypes of the tarsal coalition, the other being talocalcaneal coalition. As with any coalition it may be osseous (synostosis), cartilaginous (synchondrosis) or fibrous (syndesmosis).
This type of coalition is mor...
The calcaneus, also referred to as the calcaneum, (plural: calcanei or calcanea) is the largest tarsal bone and the major bone in the hindfoot. It articulates with the talus superiorly and the cuboid anteriorly and shares a joint space with the talonavicular joint, appropriately called the taloc...
Calcaneus axial view is part of the two view calcaneus series, this projection is best used to asses the talocalcaneal joint and plantar aspects of the calcaneus. The axial view has a diagnostic sensitivity of 87% for calcaneus fractures 1.
patient is supine or seated with th...
Calcaneus lateral view is part of the two view calcaneus series; this projection is used to assess the calcaneus, talocrural, talonavicular and talocalcaneal joint.
the patient is in a lateral recumbent position on the table
the lateral aspect of the knee and ankle joint shou...
The calcaneus series is comprised of a lateral and axial (plantodorsal) projection. The calcaneus is the most commonly fractured tarsal bone accounting for ~60% of all tarsal fractures 1. This series provides a two view investigation of the calcaneus alongside the talar articulations and talocal...
This is a basic article for medical students and other non-radiologists
A calcaneus x-ray, also known as calcaneus series or calcaneus radiograph, is a set of two x-rays of the calcaneus. It is performed to look for evidence of injury (or pathology) affecting the leg, often after trauma.
The calcar femorale is a normal ridge of dense bone that originates from the postero-medial endosteal surface of the proximal femoral shaft, near the lesser trochanter. It is vertical in orientation, and the ridge projects laterally toward the greater trochanter. This ridge of bone provides mech...
Calcific bursitis is the result of deposition calcium hydroxyapatite crystals. It is closely related to calcific tendinitis, and many authors refer to them as being the same condition.
Calcific myonecrosis refers to a rare post-traumatic phenomenon. It characterized by the latent formation of a dystrophic calcified mass occurring almost exclusively in the lower limb (it has been occasionally reported at other sites 5).
Plain radiographs typi...
Calcific tendinitis (or calcific tendonitis) is a self-limiting condition due to the deposition of calcium hydroxyapatite within tendons, usually of the rotator cuff. It is a common presentation of the hydroxyapatite crystal deposition disease (HADD).
Typically this condition aff...
Calcific tendinitis of the longus colli muscles is an inflammatory/granulomatous response to the deposition of calcium hydroxyapatite crystals in the tendons of the longus colli muscle. It is sometimes more generically known as calcific prevertebral tendinitis or, less accurately, as retropharyn...
Calcified intra-articular lesions have a relatively limited differential, including:
impaction fracture fragments
intraarticular avulsion fractures
Calcinosis circumscripta is a condition involving calcium deposition in the subcutaneous tissues, muscles and fascia. It is considered a localized form of calcinosis cutis universalis most often seen in the hands and feet.
Patients present with firm white dermal papules, ...
Calcinosis universalis is a condition characterized by long bands or sheets of symmetrical subcutaneous calcification.
It usually presents <20 years of age, and is more common in women.
palpable calcific plaques in subcutaneous or deeper tissue
fatigue, muscle pain, and...
Calcium pyrophosphate dihydrate disease (CPPD), also known as pyrophosphate arthropathy or pseudogout, is defined by the co-occurrence of arthritis with evidence of CPPD deposition within the articular cartilage.
The terminology regarding CPPD disease has been confusing, with chon...
Calvarial thinning can result from many causes. They include:
craniofacial syndromes 1
focal calvarial thinning
Campomelic dwarfism, also known as campomelic dysplasia, is a rare form of skeletal dysplasia.
Campomelic dwarfism is rare with an estimated incidence of ~1:200,000 births.
genital malformations: may be present in ~66% of patients 6
Camptocormia (bent spine syndrome or cyphose hystérique) is a rare syndrome characterized by involuntary flexion of the thoracolumbar spine with weight-bearing which reduces when laying down, and is due to isolated atrophy of the paraspinal muscles.
In a small case series (n=16), ...
Camptodactyly is a clinical or imaging descriptive term where there is a flexion contracture (usually congenital). Classically this occurs at the proximal interphalangeal joint of the little finger of the hand, although any finger may be affected.
Prevalence ~1%; one-third unilate...
Camptodactyly arthropathy coxa vara pericarditis (CACP) syndrome is a rare condition principally characterized by
congenital or early-onset camptodactyly and childhood-onset non-inflammatory arthropathy
coxa vara deformity or other dysplasia associated with progressive hip disease
Camurati-Engelmann disease, also known as progressive diaphyseal dysplasia, is a rare autosomal dominant sclerosing bone dysplasia. It begins in childhood and follows a progressive course.
Common symptoms include extremity pain, muscle weakness, cranial nerve impairment a...
Canadian C-spine rules are a set of guidelines that help a clinician decide if cervical spine imaging is not appropriate for a trauma patient in the emergency department. The patient must be alert and stable.
There are three rules:
is there any high-risk factor present that requires cervical s...
The capitate, also known as the os magnum, is the largest of the carpal bones and sits at the center of the distal carpal row. A distinctive head shaped bone, it has a protected position in the carpus.
The capitate sits in a proximo-distal direction with a waist that...
Capitellum fractures are uncommon, but their prompt diagnosis and management are crucial due to the severity of the consequent functional impairment resulting from these intra-articular elbow fractures.
Capitellar fractures are relatively rare, with approximately 3-4% of distal h...
Capitohamate coalition is the second most common type of carpal coalition and represents congenital fusion of the capitate and the hamate. It represents ~5% of all carpal fusions 1 and is associated with Apert syndrome 2.
The capitolunate angle is the angle between the long axis of the capitate and the mid axis of the lunate on the sagittal imaging of the wrist. In a normal situation it should be less than 30° in the resting (neutral) position.
The angle is increased in carpal instability such as with a dorsal i...
There is variation in the relationship between the glenoid labrum and the anterior shoulder joint capsule. This has been divided into three types:
Type 1: capsule inserts into the labrum proper
Type 2: capsule inserts into the base of the labrum, or within 1 cm of the base
Type 3: capsule ins...
Carcinogens are substances known to cause cancer. They include:
Nasopharynx / nasal passage
ionizing radiation (not technically a substance)
polyaromatic hydrocarbons (PAH)
The carotid tubercle is a commonly used term referring to the paired anterior tubercles of the transverse processes of the sixth cervical vertebrae 1. The carotid tubercle serves as an important landmark with respect to performing regional anesthesia such as a brachial plexus and cervical plexus...
Carpal angle is defined by two intersecting lines, one in contact with the proximal surface of the scaphoid and the lunate and the other line through the proximal margins of the triquetrum and the lunate. Its normal value is between 130° and 137°.
It is increased (>139°) in:
Carpal bone fractures comprise a range of different fractures which carry varying outcomes. They can involve one or a combination of carpal bones and also be part of fracture-dislocations.
Individual fractures include
scaphoid fracture: 50-80%
lunate fracture: 3.9%
triquetral fracture: ~18%
The carpal bones are the eight bones of the wrist that form the articulation of the forearm with the hand. They can be divided in two rows:
The names and order of these bones can be rememb...
Mnemonics of the carpal bones are numerous and useful for memorizing the order and location of the bones.
Some mnemonics name the carpal bones in a circle, starting with the proximal row from the scaphoid towards the pinky (small finger) and then the distal row starting from the hamate towards ...
The carpal boss is a hypertrophied bony protuberance on the dorsal surfaces of the base of the second or third metacarpals, near the capitate and trapezium. It may be bilateral.
The condition may represent one or more of:
degenerative osteophyte formation
os styloideum (an accessor...
Carpal coalition refers to failure of separation of two or more carpal bones, and although the most commonly involved bones are the lunate and triquetrum, most combinations of adjacent bones can be found to be coalesced.
Carpal fusion is a misnomer, as it is the failure of normal ...
Carpal height is used to diagnose and assess the severity of carpal collapse. It is defined as the distance between the base of third metacarpal and the subchondral bony cortex of the distal radius. But due to variations between individuals, it is more appropriate to calculate the carpal height ...
The carpal tunnel is a fibro-osseous canal that acts as a passageway from the forearm to the anterior hand. It is found in the anterior wrist.
superficial border (roof): flexor retinaculum
deep border (floor): carpal groove (formed by palmar aspect of carpal bones)
Carpal tunnel syndrome results from compression of the median nerve within the carpal tunnel. It is a cause of significant disability and is one of three common median nerve entrapment syndromes, the other two being anterior interosseous nerve syndrome and pronator teres syndrome.
Carpal tunnel syndrome results from compression of the median nerve within the carpal tunnel. Its causes are numerous and varied.
A useful mnemonic to remember the causes is:
D: diabetes mellitus
Carpenter syndrome, also called acrocephalopolysyndactyly type II (ACPS type II) is an extremely rare autosomal recessive congenital disorder.
It is characterized by a number of features which include:
Carpometacarpal (CMC) joint dislocations are uncommon dislocations of the hand.
There is a strong younger male predominance. These injuries account for less than 1% of hand injuries 4 and are more common in the dominant hand.
Carrying angle is a small degree of cubitus valgus, formed between the axis of a radially deviated forearm and the axis of the humerus. It helps the arms to swing without hitting the hips while walking.
Normally it is 5-15o away from the body or 165-175o towards the body.
A decreased carrying ...
Cartilage interface sign, also referred to as double cortex sign, refers to the sonographic presence of a thin markedly hyperechoic line at the interface between the normally hypoechoic hyaline articular cartilage of the humeral head and an abnormally hypoechoic supraspinatus tendon. This arises...
Cartilaginous joints are a type of joint where the bones are entirely joined by cartilage, either hyaline cartilage or fibrocartilage. These joints generally allow more movement than fibrous joints but less movement than synovial joints.
Primary cartilaginous joint
These cartilaginous joints...
The differential for cartilaginous lesions includes:
The cases featured in these video lectures are specifically selected to teach important concepts in radiology over a broad range of topics. The tutorials vary in difficulty from basic to advanced. For maximum learning, try the cases for yourself in Radiopaedia quiz mode first.
We love this ser...
The Castellvi classification is used for lumbosacral transitional vertebra (LSTV):
type I: enlarged and dysplastic transverse process (at least 19 mm)
type II: pseudoarticulation of the transverse process and sacrum with incomplete lumbarization/sacralization; en...
The Caton-Deschamps index is a ratio that is used in everyday practice as well as in research to measure patellar height and allows the diagnosis of patella alta and patella baja.
The Caton-Deschamps index is the ratio between the distance between the lower pole of the pa...