Cortical desmoids, also known as cortical avulsive injuries or the Bufkin lesion, are a benign self-limiting entity. This is a classic "do not touch" lesion, and should not be confused with an aggressive cortical/periosteal process (e.g. osteosarcoma).
Cortical desmoid is a misnom...
Costal cartilage fractures are fractures of the cartilage connecting the ribs anteriorly to the sternum.
There is little published data on costal cartilage fractures. Most reported cases are in males and resulted from blunt trauma or a fall 1,2.
In young ch...
The costochondral joints are the joints between each rib and its costal cartilage. They are primary cartilaginous joints. These joints represent the demarcation of the unossified and ossified part of the rib 1. The joint is held together by periosteum, with the lateral aspect of the costal ca...
The costoclavicular ligament or rhomboid ligament is the major stabilising factor of the sternoclavicular joint.
The costoclavicular ligament binds the inferior medial clavicle (via the rhomboid fossa) to the first costal cartilage and adjacent end of the first rib. It is compose...
The costovertebral joint is an articulation between the ribs and the vertebral column.
The ribs articulate with the thoracic vertebrae via two distinctly different joints:
costovertebral joint - articulation between the head of the rib and the vertebral body
The costoxiphoid ligaments, also known as the chondroxiphoid ligaments, are inconstant fibrous structures joining the anterior and posterior surfaces of the xiphoid to the respective surfaces of the adjacent seventh and, occasionally, sixth costal cartilages.
The cotton wool appearance is a plain film sign of Paget disease and results from thickened, disorganized trabeculae which lead to areas of sclerosis in a previously lucent area of bone, typically the skull. These sclerotic patches are poorly defined and fluffy.
Other Paget disease re...
Cowden syndrome, also known as multiple hamartoma syndrome, is characterised by multiple hamartomas throughout the body and increased risk of several cancers.
Type 2 segmental Cowden syndrome is the association of Cowden syndrome with a Cowden naevus, when it is considered a type o...
Coxa magna is the asymmetrical, circumferential enlargement and deformation of the femoral head and neck. Definitions in the literature vary but enlargement with asymmetry >10% in size is a reasonable cut-off for diagnosis 1.
Coxa plana is flattening of the femoral head epiphysis and is associated with many skeletal disorders:
multiple epiphyseal dysplasia
haemoglobinopathies, e.g. sickle cell ana...
Coxa profunda refers to a deep acetabular socket. On pelvis x-rays it is seen as the acetabular fossa being medial to the ilioischial line. It should be differentiated from protrusio acetabuli, where the femoral head is seen additionally medial to the ilioischial line. Coxa profunda is much more...
Coxa valga describes a deformity of the hip where there is an increased angle between the femoral neck and femoral shaft.
Coxa valga is often associated with shallow acetabular angles and femoral head subluxation.
neuromuscular disorders, e.g. cerebral palsy
Coxa vara describes a deformity of the hip where the angle formed between the head and neck of the femur and its shaft (Mikulicz angle) is decreased, usually defined as less than 120 degrees.
It can be congenital or acquired. The common mechansim in congenital cases is a failure of m...
Cozen fracture or phenomenon is the valgus angulation deformity of the tibia following a proximal tibial metaphyseal fracture in children.
This typically occurs as a late deformity in children aged 3-6 years.
Proposed causes include:
non-recognised or under...
Craniofacial fibrous dysplasia is one of four types of fibrous dysplasia and is characterised, as the name suggests, by involvement of the skull and facial bones.
For a general discussion of the underlying pathology, refer to the parent article fibrous dysplasia.
Although the term...
Craniosynostosis refers to premature closure of the cranial sutures. The skull shape then undergoes characteristic changes depending on which suture(s) close early.
There is a 3:1 male predominance with an overall incidence of 1 in 2000-2500. 8% of cases are syndromic or familial....
Craniotabes is defined as a softening of the skull bones that may be normally present in newborns.
Craniovertebral junction (CVJ) anomalies can be congenital, developmental or due to malformation secondary to any acquired disease process. These anomalies can lead to cranial nerve compression, vertebral artery compression and obstructive hydrocephalus.
The cranio-vertebral junctio...
The crescent sign of avascular necrosis is seen on conventional radiographs and refers to a linear area of subchondral lucency seen most frequently in the anterolateral aspect of the proximal femoral head (which is optimally depicted on the frog-leg radiographic view). It indicates imminent arti...
CREST syndrome (a.k.a. limited systemic sclerosis or limited scleroderma) is a variant of progressive systemic sclerosis (PSS) and stands for
C - Calcinosis
R - Raynaud phenomenon
E - oEsophageal dysmotility
S - Sclerodactyly
T - Telangiectasia
The critical zone of the rotator cuff is an area approximately 8-15 mm from the insertion of the rotator cuff tendons onto the greater tubercle of the humeral head, mainly within the supraspinatus tendon. This is a watershed zone between the anterior and posterior circumflex humeral, thoracoacro...
The crossing sign is seen on true lateral plain radiographs of the knee when the line of the trochlear groove crosses the anterior border of one of the condyle trochlea. It is a predictor of trochlear dysplasia. Trochlear dysplasia has been linked to recurrent patellar dislocation 1,2,4. The cro...
Crouzon syndrome is rare disorder characterised by premature craniosynostoses.
abnormal calvarial shape: in severe case can give a "cloverleaf skull"
shallow orbits with exopthalmos
mid facial hypoplasia
It carries an autosomal dominant ...
The crowned dens syndrome is an inflammatory condition resulting from crystal deposition in cruciform and alar ligaments surrounding the dens, appearing as a radiopaque 'crown' surrounding the top of the dens. It typically presents with pain and increased inflammatory markers.
The cruciate ligament of the atlas (also known as the cruciform ligament) is an important ligamentous complex that holds the posterior dens of C2 in articulation at the median atlantoaxial joint. It lies behind a large synovial bursa (surrounded by loose fibrous capsule) and consists of two band...
Crystal arthropathies are a group of joint disorders due to deposition of crystals in and around joints which lead to joint destruction and soft tissue masses.
The most common arthropathies are:
gouty arthropathy due to monosodium urate (MSU) deposition
pseudogout due to calcium py...
The C sign is an important radiological sign which may be seen on a lateral radiograph of the ankle in those with the talocalcaneal subtype of tarsal coalition.
A continuous C-shaped arc on a lateral ankle radiograph is formed by the medial outline of the talar dome an...
CT guided bone biopsy is a type of image guided biopsy.
It may be performed using the 'CT fluoroscopy' capabilities of modern CT scanners or with the traditional step-wise approach.
CT biopsies are usually performed using a co-axial needle technique to gain a stable position through which the ...
The cubital fossa is a triangular space which forms the transition between the arm and the forearm. It is located anterior to the elbow joint.
superior: the line joining the medial and lateral humeral epicondyles
lateral: medial border of brachioradialis
The cubital tunnel is a space through which the ulnar nerve passes posterior to the medial epicondyle of the humerus.
cubital tunnel retinaculum (also known as ligament or band of Osborne), extends from the olecranon to the medial epicondyle
Cubital tunnel syndrome is a type of ulnar nerve compression neuropathy which can occur from a pathological compression of the ulnar nerve at the cubital tunnel.
It is the second most common peripheral neuropathy of the upper extremity 1,3.
Ulnar nerve comp...
Cubitus varus (gunstock deformity) is a malalignment of the distal humerus that results in a change of carrying angle from the physiologic valgus alignment (5-15 degrees) of the arm and forearm to varus malalignment. Historically, it is a complication of supracondylar fractures with a frequency ...
The cuboid bone is one of the tarsal bones located lateral to the lateral cuneiform bone and has an important articulation with the calcaneus.
The cuboid is a wedge shaped bone, being widest at its medial edge and narrow at its lateral edge. It has three main articular...
Currarino-Silverman syndrome, also known as pectus carinatum type 2 deformity, is a rare disorder in which the patient has a high carinate chest deformity due to a premature fusion of the manubriosternal joint and sternal ossification centres. Congenital heart diseases have been described in mor...
The curtain sign (or draped curtain sign) in neuroimaging refers to the appearance of a vertebral body mass that extends to the anterior epidural space.
The posterior longitudinal ligament is strongly attached to the posterior vertebral body cortex in the midline and is more loosely attached la...
Cutaneous and subcutaneous metastases are not uncommon, occurring in ~5% (range 0.7-10.4%) of internal malignancies, and representing 2% of skin cancers. The Sister Mary Joseph nodule is a well known cutaneous metastasis.
These metastases can come from haematogenous or lymphatic spre...
Cutis laxa is a rare dermatological condition, characterised by elastic fibre loss, resulting in very lax skin. Patients can also develop emphysema.
Cutis laxa may be inherited (autosomal dominant, autosomal recessive, or X-linked recessive) or may occur sporadically.
A cyamella is a rare sesamoid bone that exists as a normal variant within the popliteus tendon, characteristically located at the lateral aspect of the distal femur in the popliteal groove.
Cyamella is best seen on the AP view of plain radiograph as opposed to fabella, which is best appreciated...
The cyclops lesion, also known as localised anterior arthrofibrosis, is a painful anterior knee mass that arises as a complication of anterior cruciate ligament (ACL) reconstruction, although has rarely been reported in patients with ACL injuries that have not been reconstructed.
A cyma line refers to the union of two curved lines in architecture. In a radiological context it refers to the smooth joining of the midtarsal joint lines of the talonavicular and calcaneocuboid joints on both AP and lateral views.
A disruption of the cyma line can indicate true shortening of ...
Cystic angiomatosis is a not so well understood condition which presents with multiple bony cystic lesions in combination with visceral and / or soft tissue cystic lesions. There has been a long standing confusion over the terminology.
A subgroup of patients presenting with this condition prese...
Cysticercosis is a parasitic tissue infection caused by ingestion of tapeworm eggs through a fecal-oral transmission or auto-infection. Humans act as a definitive host in this disease.
CNS manifestations are discussed individually on neurocysticercosis.
The disease is endemic in ...
The musculoskeletal manifestations of cystic fibrosis are uncommon compared to the well known respiratory manifestations.
Symptoms are non-specific and include joint pain, joint swelling, back pain, and myalgia. These may mimic rheumatic symptoms, however, they do not me...
There is broad differential for cyst like lesions around the knee.
The list includes:
popliteal synovial cyst - Baker's cyst
intra-articular ganglion cyst
ACL ganglion cyst
PCL ganglion cyst
Hoffa fat pad ganglion cyst
extra-articular ganglion cyst
The dagger sign is a radiographic feature seen in ankylosing spondylitis as a single central radiodense line on frontal radiographs related to ossification of the supraspinous and interspinous ligaments.
Dameron-Lawrence-Bofte classification of proximal fifth metatarsal fractures divides fractures into three zones based on anatomy:
zone 1: tuberosity of 5th metatarsal
avulsion fracture of tuberosity (pseudo-jones fracture)
zone 2: meta-diaphyseal junction
zone 3: proximal dia...
Danon disease is an X-linked dominant cause of debilitating cardioskeletal myopathy.
Although considered rare, the exact incidence is unknown 1.
Danon disease is characterised by the triad of 1-4:
the most prominent clinical feature, and ma...
A dedifferentiated chondrosarcoma is a combined tumour made up to two components which are often sharply demarcated from one another (thus raising the possibility of it representing a collision tumour).
conventional chondrosarcoma (low grade)
dedifferentiated high grade areas
Deep bursae are those bursae that are located deep to the fibrous fascia and are normally located between muscles or muscle and bone. These bursae form in utero alongside synovial joint formation 1.
In contrast, superfical bursae are located superficial to the fibrous fascia.
The deep peroneal (fibular) nerve is one of two terminal branches of the common peroneal nerve.
origin: the terminal branch of common peroneal nerve in the lateral compartment of the leg
course: passes into the anterior compartment of the leg, where it courses inferiorly into the dors...
The deep posterior compartment of the leg is one of the four compartments in the leg between the knee and foot. Muscles within this compartment primarily produce ankle plantarflexion and toe flexion, with exception of the popliteus which acts on the knee. Of the two posterior compartments, the d...
The term deep vein thrombosis (DVT) is practically a synonym for clots occuring in the lower limbs. However, it can also be used for those that occur in the upper limbs and neck veins. Other types of venous thrombosis, such as intra-abdominal and intracranial, are discussed in separate articles....
Degenerative disc disease (DDD) is an exceedingly common entity in the spine, encountered with increasing frequency throughout life and becoming almost universal in late adulthood to a varying degree. It is related to a combination of biomechanical stresses and genetic predisposition which alter...
Degloving injuries can refer to a number of conditions:
degloving soft tissue injury
Morel-Lavallee lesion (closed degloving soft tissue injury)
intramuscular degloving injury
degloving bowel injury
Degloving soft tissue injuries can be extensive and quite severe conditions. These may be open or, less commonly, closed injuries, which are known as Morel-Lavallee lesions. This article focuses on open injuries with closed injuries discussed in the Morel-Lavallee lesion article.
Dehiscence is a general term referring to 'splitting open' and is used in a variety of contexts in medicine generally and radiology more specifically.
The two most common usages are:
splitting open of a wound (e.g. sternal dehiscence)
loss of bone separating one structure from another (e.g. ...
A generalised retardation in skeletal maturation has different causative or aetiological factors, these can be classified as follows:
chronic ill health
congenital heart disease (especially cyanotic)
chronic renal disease
inflammatory bowel disease
malnutrition: failure to thrive (FTT)
Delayed onset muscle soreness (DOMS) refers to the muscular pain and swelling that follows unaccustomed exertion.
Patients may have an ache in affected muscles with reduced strength 4.
DOMS is thought to occur from reversible microstructural muscle injury that...
Deltoid ligament injuries involve the deltoid ligament that forms the medial part of the ankle joint. It attaches the medial malleolus to multiple tarsal bones.
Mechanism of injury
It occurs due to eversion and/or pronation injury, or can be associated with lateral ankle fractures.
The deltoid ligament or medial collateral ligament of the ankle forms the medial part of the ankle joint. It attaches the medial malleolus to multiple tarsal bones.
The ligament is composed of two layers. The superficial layer has variable attachments and crosses two joints whil...
The deltoid muscle is the largest of the shoulder muscles. The muscle is composed of three heads (clavicular, acromial and spinous), although electromyography suggests that there are at least seven control regions that could act independently 1.
origin: lateral 1/3 of the clavicle, acr...
Denervation changes in muscles can be observed in a number of settings.
in the very early stage, muscle signal may be normal
earliest change is increased T2 signal (best seen on a fat saturated T2WI such as STIR)
chronic changes are marked by muscle atrophy and fat...
The differential diagnosis for a dense base of the skull includes:
Van Buchem disease
The differential diagnosis of dense metaphyseal bands is wide.
chronic anaemia, e.g. sickle cell disease, thalassemia
chemotherapy, e.g. methotrexate
growth acceleration lines following growth arrest due to systemic illness or stress in infancy or childhood, e....
Densitometric vertebral fracture assessment (VFA) is an image of the lumbar and thoracic spine acquired on dual energy x-ray absorptiometry (DXA) scanners, for the purpose of diagnosing osteoporotic vertebral fractures.
The technique is available on DXA scanners under a variety of...
Depressed skull fractures result in the bone of the skull vault being folded (depressed) inward into the cerebral parenchyma. It is usually the result of a high energy impact to the skull.
These mostly (~75%) occur in the frontoparietal region 3.
There are number of as...
De Quervain tenosynovitis, also known as washerwoman's sprain/strain, is a painful stenosing tenosynovitis involving the first extensor (dorsal) tendon compartment of the wrist (typically at the radial styloid). This compartment contains the abductor pollicis longus (APL) and extensor pollicis b...
Dercum disease, also known as adiposis dolorosa, is a rare disorder of subcutaneous tissue characterised by multiple painful lipomas.
Although the exact incidence is unclear, Dercum disease affects women more than men 1,2. It is usually sporadic, however, autosomal dominant forms ...
Dermatofibrosarcoma protuberans (DFSP) is an uncommon exophytic, slow growing, low grade, spindle cell tumour arising in the dermal and subcutaneous tissues, particularly of the trunk region with excellent outcome after complete surgical resection.
The tumour occurs in patients of...
Dermatographia, also known as skin writing, refers to a skin condition in which skin scratches causes linear red marks. The cause is unknown, however, it is related to penicillin use and mastocytosis.
Dermatomyositis is an autoimmune inflammatory myositis.
There is a recognised female predilection. It has a bimodal age of presentation depending on the variant:
juvenile dermatomyositis (JDM): affects children and tends to be more severe
adult dermatomyositis (ADM): typically a...
A derotational screw is an orthopaedic device used for internal fixation of fractures to, unsurprisingly, limit rotation of the fracture.
They are applied across fractures at risk of rotation and hence avascular necrosis.
Describing a bone lesion is an essential skill for the radiologist, used to form an accurate differential diagnosis for neoplastic entities, and occasionally non-neoplastic. In addition to patient demographics, the radiographic features of a bone lesion are often the primary determinant of non-h...
Describing a fracture is a basic requirement when making an assessment of a plain radiograph. There are many ways to approach the assessment of the radiograph; this is just one approach.
I: Describe the film
What film (or films) are you looking at? Check the who, what, why, when, and where.
Desmoid tumours are benign, non-inflammatory fibroblastic tumours (see WHO 2002 classification of soft tissue tumours) with a tendency for local invasion and recurrence but without metastasis.
The terms desmoid tumour and aggressive fibromatosis are occasionally used synonymously b...
Desmoplastic fibromas are extremely rare bone tumours that do not metastasise but may be locally aggressive. They are considered to be a bony counterpart of soft tissue desmoid tumours and are histologically identical.
Incidence is ~0.3%. The most common areas of involve...
Developmental dysplasia of the hip (DDH), or in older texts congenital dislocation of the hip (CDH), denotes aberrant development of the hip joint and results from an abnormal relationship of the femoral head to the acetabulum. There is a clear female predominance, and it usually occurs from lig...
Developmental stages of the spheno-occipital synchondrosis take place in a number of predictable steps.
Fusion of the spheno-occipital synchondrosis was well underway by the age of 15 years and is complete by 17-18 years.
Fusion begins superiorly and progresses inferiorly.
Persistence of a ...
Diabetic myonecrosis is an uncommon complication of diabetes mellitus, occurring in patients with chronic poor glycemic control.
There is a slight predilection for females and patients with type 1 diabetes. The average age of presentation is 40 years.
Diaphragmatic eventration refers to an abnormal contour of the diaphragmatic dome. It typically affects only a segment of the hemidiaphragm, compared to paralysis/weakness where the entire hemidiaphragm is typically affected.
Diaphragmatic eventration is congenital in nature and due...
Diaphragmatic paralysis can be unilateral or bilateral.
Clinical features are highly variable according to underlying aetiological factor:
unilateral paralysis: asymptomatic in most of the patients as the other lung compensates
may have dyspnoea, headaches, fatigue, ins...
Diaphyseal lesions are unsurprisingly predominantly found centred in the diaphysis.
simple bone cyst
myeloma / plasmacytoma
round cell tumour, e.g. Ewing sarcoma (children)
A mnemonic for a short list of diaphyseal lesions is:
C: bone cysts
E: enchondroma/Ewing sarcoma
M: bone metastasis
E: eosinophilic granuloma
N: non-ossifying fibroma (NOF)
The diaphyses (singular: diaphysis), sometimes colloquially called the shafts, are the main portions of a long bone (a bone that is longer than it is wide) and provide most of their length.
The diaphysis has a tubular composition with a hard outer section of hard cortical bone and a central po...
Diarthroses are a functional class of joint that are freely mobile. All synovial joints are considered diathroses.
Diastasis recti (rectus diastasis) is a stretching of the linea alba with abnormal widening of the gap between the two sides of the rectus abdominus muscle (inter-recti distance).
The degree of widening needed for the diagnosis is controversial, with the degree of abdominal protrusion (rather t...
Diastrophic dysplasia (DTD) is a type of short limb skeletal dysplasia (micromelic dwarfism). Adult patients have a stature between 100 and 140 cm.
There may be a relatively increased prevalence in Finland ref.
Typically there is limb shortening, hitchhiker thu...
Die-punch fractures result from an axial loading force on the distal radius. It is an intra-articular fracture of the lunate fossa of the distal radius 1. It is by definition depressed or impacted and is named after the machining technique of shearing a shape, depression or hole in a material wi...
Dietrich disease is the eponymous name given to osteonecrosis involving a metacarpal head 1.
The condition is rare and most often spontaneous but may be associated with trauma, systemic lupus erythematosus or steroid use. Any metacarpal may be affected however the long metacarpals...
The difference in vertical mid-vertical angle is the difference in the vertical mid-vertebral angle (VMVA) between the caudal segment angle and the adjacent cephalad segment angle of the three most caudal segments of the lumbar spine as measured on a mid-sagittal MRI or a lateral radiograph.
Forefoot pain in the metatarsal region is a common complaint and may be caused by a number of conditions. It is worthwhile for a radiologist to have some knowledge of the potential causes and their imaging features.1
plantar plate disruption
Diffuse bone sclerosis can result from a number of causes. They include:
sickle cell disease
diffuse osteosclerosing myeloma: rare
metabolic bone disorders
Useful mnemonics for remembering causes of diffuse bony sclerosis include:
3 M's PROOF
Regular Sex Makes Occasional Perversions Much More Pleasurable And Fantastic 1
3 M's PROOF
metastases (osteoblastic metastases)