The American Association for the Surgery of Trauma (AAST) injury scoring scales are the most widely accepted and used system of classifying and categorizing traumatic injuries. Injury grade reflects severity, guides management, and aids in prognosis. Currently (early 2019), 32 different injury s...
The American Association for the Surgery of Trauma (AAST) renal injury scale, most recently updated in 2018, is the most widely used grading system for renal trauma.
The 2018 update incorporates "vascular injury" (i.e. pseudoaneurysm, arteriovenous fistula) into the imaging criteria for viscera...
The AAST (American Association for the Surgery of Trauma) liver injury scale, most recently revised in 2018, is the most widely used liver injury grading system 3.
The 2018 update incorporates "vascular injury" (i.e. pseudoaneurysm, arteriovenous fistula) into the imaging criteria for visceral ...
The American Association for the Surgery of Trauma (AAST) splenic injury scale, most recently revised in 2018, is currently the most widely used grading system for splenic trauma.
The 2018 update incorporates "vascular injury" (i.e. pseudoaneurysm, arteriovenous fistula) into the imaging criter...
Abdominal aortic injuries are a very rare form of traumatic aortic injury and are much less common than thoracic aortic injury.
Aortic injury occurs in <1% of blunt trauma patients, with abdominal aortic injury representing only ~5% of all aortic injuries 1. Males are more freque...
Abdominal compartment syndrome (ACS) is the life-threatening clinical state of increased intra-abdominal compartment pressure (IAP) of more than 20 mmHg. Radiological diagnosis is difficult and usually raised when a collection of imaging findings are present in the appropriate clinical setting o...
Abdominal trauma is usually divided into blunt and penetrating trauma.
Findings of abdominal trauma
splenic trauma: most common
gastrointestinal tract (bowel) trauma:
proximal jejunum is most commonly affected by blunt trauma,...
Abusive head trauma is a term that is used for inflicted head injury that has occurred by either shaking, impact head trauma, or both, as part of the spectrum of non-accidental injury (NAI).
Subdural hemorrhage in a child should be viewed with suspicion. Most o...
Acetabular fractures are a type of pelvic fracture, which may also involve the ilium, ischium, and/or pubis depending on fracture configuration.
Acetabular fractures are uncommon. The reported incidence is approximately 3 per 100,000 per year. This study reported a 63% to 37% male...
Acromioclavicular joint injuries are characterized by damage to the acromioclavicular joint and surrounding structures. Almost invariably traumatic in etiology, they range in severity from a mild sprain to complete disruption.
Acromioclavicular joint injuries usually occu...
Acromioclavicular joint (ACJ) injections under image guidance ensure precise delivery of an injectate into the joint. Ultrasound allows for real time visualization of the needle and administration of the injectate. Fluoroscopy is an alternative method of image guidance.
pain - art...
The acromion process is the lateral projection of the scapula spine that extends anteriorly. Fractures of the scapula are uncommon injuries and account for ~3% of all shoulder fractures 1,2 while isolated acromion fractures occur rarely and account for only 9% of all scapular fractures 3.
Acute aortic syndrome describes the presentation of patients with one of a number of life-threatening aortic pathologies that give rise to aortic symptoms.
The spectrum of these aortic emergencies include:
aortic intramural hematoma
penetrating atherosclerotic ulcer
Adrenal gland trauma most commonly results from blunt force trauma.
Adrenal gland trauma is present on 1-2% of CT imaging in blunt trauma although the occurrence is thought to be much higher as injury has been demonstrated at 28% in one autopsy series 1-4.
The right adrenal glan...
Allen and Ferguson classification is used for research purposes to classify subaxial spine injuries. It is based ofn the mechanism of injury and position of the neck during injury. This classification was proposed by Allen and Ferguson in 19823 and at the time of writing (July 2016) remains the ...
The American Academy of Orthopedic Surgeons classification of periprosthetic hip fractures divides the femur into three separate regions:
level I: proximal femur distally to the lower extent of the lesser trochanter
level II: 10 cm of femur distal to level I
level III: femur distal to level...
The term amputation refers to the disconnection of all or part of a limb from the body. Specifically, amputation is defined as the removal of the structure through a bone. This is in contrast to disarticulation, which is the removal of the structure through a joint.
When due to trauma, traumati...
The Amsterdam wrist rules are validated clinical decision rules for determining which patients require radiographic imaging (wrist radiography) for acute wrist pain following trauma. The initial study evaluated 882 patients and were published in 2015 1. The decision rules assessed different clin...
The anatomy curriculum is one of our curriculum articles and aims to be a collection of articles that represent the core anatomy knowledge for radiologists and imaging specialists.
Head and neck anatomy
Abdominal and pelvic anatomy
The Anderson and D'Alonzo classification is the most commonly used classification of fractures of the odontoid process of C2.
fracture of the upper part of the odontoid peg (generally obliquely)
above the level of the transverse band of the cruciform ligament
Ankle fractures account for ~10% of fractures encountered in trauma, preceded only in incidence by proximal femoral fractures in the lower limb. They have a bimodal presentation, involving young males and older females. Ankle injuries play a major part in post multitrauma functional impairment t...
Anomalous insertion of the medial meniscus (AIMM) is an anatomical variation of the insertion of the anterior root of the medial meniscus.
Defined as a congenital variation in the insertion of the anterior root of the medial meniscus onto the anterior cruciate ligament (ACL). The...
Anterior cruciate ligament (ACL) avulsion fracture or tibial eminence avulsion fracture is a type of avulsion fracture of the knee. This typically involves separation of the tibial attachment of the ACL to variable degrees. Separation at the femoral attachment is rare 5.
It is mor...
Anterior cruciate ligament (ACL) tears are the most common knee ligament injury encountered in radiology and orthopedic practice.
Patients typically present with symptoms of knee instability, usually after acute trauma. The following signs and symptoms are common:
Anterior hip dislocation is much less common than a posterior hip dislocation. It constitutes only 5-18% of all hip dislocations.
While the posterior dislocation is often associated with fractures, the anterior dislocation is mostly an isolated injury 1.
It can be classifi...
Anterior shoulder dislocation is by far the commonest type of dislocation and usually results from forced abduction, external rotation and extension 1.
Broadly speaking, anterior shoulder dislocations occur in a bimodal age distribution. The first, and by far the more prevalent a...
Anterior subluxation of the cervical spine, also known as hyperflexion sprain, is a ligamentous injury of the cervical spine.
Patients present with severe, focal neck pain. There may be neurological symptoms due to spinal cord injury.
Anterior subluxation of t...
Anterior superior iliac spine (ASIS) avulsion injuries typically occur in athletes during forceful muscular contraction. ASIS is the site of attachment for sartorius and tensor fascia latae muscles.
ASIS avulsion, like other pelvic avulsion injuries, is a stable fracture.
The term anterolisthesis refers to anterior displacement (forward slip) of a vertebral body relative to the one below.
Its severity can be graded by the Meyerding classification and its etiology classified according to the Wiltse classification.
Implanted antibiotic beads are a form of microbiological treatment inserted during orthopedic procedures to aid with the treatment of chronic infection. They are also used as a local treatment for osteomyelitis.
The beads are radiopaque, thus lending themselves to visualization on all imaging m...
The AO classification of sacral injuries aims to simplify and universalise the process of classifying sacral injuries and improve interobserver and intraobserver reliability.
The AO sacral classification is broken into three subsections that follow a hierarchical structure similar to the AO cla...
The AO classification of subaxial injuries aims to simplify and universalise the classification of subaxial cervical spine fractures and improve interobserver and intraobserver reliability.
Although its existence is widely known among the relevant subspecialty groups, its day-to-day use ...
The AO classification of upper cervical injuries aims to simplify and universalise the process of classifying upper cervical injuries and improve interobserver and intraobserver reliability.
Although in routine clinical practice, at least in many institutions, injuries will be described ...
The aortic isthmus is the part of the aorta just distal to the origin of the left subclavian artery at the site of the ductus arteriosus.
This portion of the aorta is partly constricted in the fetus because of the lack of flow within the aortic sac and ascending aorta. It marks the partial sepa...
Aortic pseudoaneurysms typically occur as a result of trauma +/- intervention, a considered subset of traumatic aortic injury in the majority of cases. They can be acute or chronic.
Aortic pseudoaneurysms are contained ruptures of the aorta in which the majority of the aortic wall ha...
Differentiation of aortic pseudoaneurysm from ductus diverticulum is critical, particularly in the trauma setting. A traumatic aortic pseudoaneurysm is a surgical emergency whereas a ductus diverticulum is a normal anatomic variant.
The following are differentiating features:
An aortic transection, also known as a traumatic aortic rupture, is a type of traumatic aortic injury. It is considered the second most common cause of death associated with motor vehicle accidents.
It occurs from a near-complete tear through "all the layers" of the aorta due to trau...
The AO spine classification of thoracolumbar injuries is one of the more commonly used thoracolumbar spinal fracture classification systems and aims to simplify and universalise the process of classifying spinal injuries and improve interobserver and intraobserver reliability 3.
Unlike the othe...
The AO Spine classification systems is a group of imaging morphology-based classification system, combined with clinical factors for injury of spinal trauma. It is designed to be a simple and reproducible method of describing injury patterns.
At the time of writing (Oct 2018), the four publishe...
Apophyseal avulsion fractures of the pelvis and hip are relatively common among physically active adolescents and young adults.
Pelvic and hip apophyseal injuries typically occur in the 14 to 25 year age range.
Kicking sports, such as soccer, and gymnastics are frequen...
Arthrofibrosis is a complication of injury or trauma to a joint. It can also be iatrogenic e.g. post knee surgeries. It consists of excessive scar tissue formation within the joint capsule, resulting in pain, stiffness, and swelling, that are greater than expected in the given clinical scenario....
Atlanto-axial subluxation is a disorder of C1-C2 causing impairment in rotation of the neck. The anterior facet of C1 is fixed on the facet of C2. It may be associated with dislocation of the lateral mass of C1 on C2.
Down syndrome (20%)
Atlanto-occipital dissociation injuries are severe and include both atlanto-occipital dislocations and atlanto-occipital subluxations.
The tectorial membrane and alar ligaments provide most of the stability to the atlanto-occipital joint, and injury to these ligaments results in inst...
The aubergine sign (also known as egg-plant sign or deformity) is a clinical sign of a fractured penis. Hemorrhage beyond the tunica albuginea produces swelling and bruising of the penis simulating the appearance of an aubergine.
Aviator astragalus is an antiquated reference to a pattern of isolated fracture/dislocation injury of the talus. Fractures included under this name include compression fractures of the talar neck, fractures of the body, posterior process or fracture-dislocation injuries.
More specifically the t...
Avulsion fracture of the 5th metatarsal styloid, also known as a pseudo-Jones fracture or a dancer fracture, is one of the more common foot avulsion injuries and accounts for over 90% of fractures of the base of the 5th metatarsal.
Despite what should be a simple entity, controversy exists, as ...
Avulsion fractures of the knee are numerous due to the many ligaments and tendons inserting around this joint. They include 1:
anterior cruciate ligament avulsion fracture
posterior cruciate ligament avulsion fracture
avulsion of the medial collateral ligament
origin of MCL avulsion fracture...
Avulsion injuries or fractures occur where the joint capsule, ligament, tendon or muscle attachment site is pulled off from the bone, usually taking a fragment of cortical bone. Avulsion fractures are commonly distracted due to the high tensile forces involved. There are numerous sites at which ...
The Bado classification is one of the more widely used classifications for Monteggia fracture-dislocations and mainly focuses on the radial component. Four types are recognized and are generally based on the principle that the direction in which the apex of the ulnar fracture points is the same ...
A banana fracture refers to a complete, horizontally oriented pathological fracture seen in deformed bones affected by Paget disease. This term is often used to describe incremental fractures that occur in Paget disease as well, which represent a type of insufficiency fracture.
The former of th...
Bankart lesions are injuries specifically at the anteroinferior aspect of the glenoid labral complex and represent a common complication of anterior shoulder dislocation. They are frequently seen in association with a Hill-Sachs lesion.
Strictly speaking, a "Bankart lesion" refers...
Barton fractures are fractures of the distal radius. It is also sometimes termed the dorsal type Barton fracture to distinguish it from the volar type or reverse Barton fracture.
Barton fractures extend through the dorsal aspect to the articular surface but not to the volar aspect. Therefore, i...
Basilar fractures of the skull, also known as base of skull fractures, are a common form of skull fracture, particularly in the setting of severe traumatic head injury, and involve the base of the skull. They may occur in isolation or often in continuity with skull vault fractures or facial frac...
Battle sign is an eponymous term given to mastoid ecchymosis (bruising of the scalp overlying the mastoid process) and is strongly suggestive of a base of skull fracture, most commonly a petrous temporal bone fracture.
History and etymology
Mr William Henry Battle (1855-1936) was an English s...
Benign post-traumatic pseudopneumoperitoneum is the presence of ectopic gas typically between the 5th-10th intercostal spaces after high-energy trauma in the absence of other causes of pseudopneumoperitoneum such as pneumomediastinum 9.
Occurs with an incidence of 5% post-trauma...
A Bennett fracture is a fracture of the base of the thumb resulting from forced abduction of the first metacarpal. It is defined as an intra-articular two-part fracture of the base of the first metacarpal bone.
two piece fracture of the base of the thumb...
The Biffl scale or grade illustrates the spectrum of blunt cerebrovascular injury (BCVI) seen on angiography (both CTA and DSA). Some authors refer to the grading scale as the Denver scale, which is not to be confused with the Denver criteria, a series of clinical indications and risk factors fo...
A bilateral facet dislocation is an unstable flexion distraction type of dislocation of the cervical spine, often a result of buckling force. Occasionally, the bilateral facet dislocation has been named a 'doubly-locked' vertebral injury giving the impression of stability. However, due to comple...
A bipartite scaphoid is a rare example of a divided carpus. There is controversy whether this condition is congenital (i.e. normal variant) or post-traumatic. Bipartite scaphoids may be unilateral or bilateral.
Diagnostic criteria have been proposed 3:
no history of traumatic injury
Birth fractures of the clavicle occur in 0.5-1% of vaginal deliveries and are the most frequent birth-related fracture. They are most commonly seen following normal, uncomplicated births but there is recognized increased incidence with high birth weight babies, forceps delivery and shoulder dyst...
Birth trauma (a.k.a. birth injury) relates to those conditions caused by both physical/mechanical and hypoxic injuries.
Birth trauma occurs in ~5 per 1000 births 2.
Blast injuries are injuries sustained due to the energy released during a rapid chemical or nuclear reaction or the escape of gas under high pressure. They can affect numerous organ systems.
Blast injuries may occur in any number of situations including in combat, in industrial ac...
The blood pressure (BP) is defined as the force exerted by the circulating blood on the walls of the blood vessels. Fundamentally the blood pressure depends upon the interaction of:
compliance of the arterial walls
Blood pressure is traditionally measured i...
Most commonly a result of sudden deceleration or direct precordial impact, blunt cardiac injury (BCI) encompasses a spectrum of structural and functional cardiac derangements which may occur after trauma to the heart 7.
While sometimes referred to with general terms such as "cardia...
Blunt cerebrovascular injury (BCVI) is an uncommon but serious consequence of blunt trauma to the head and neck.
It is often part of multi-trauma with a significant series of blunt trauma CTA reporting an incidence of approximately 1% 3. A large systematic review and meta-analysis...
Blunt traumatic neck injury is uncommon because it is usually protected by the head, shoulders, and chest. This term is generally used to refer to injuries of the neck besides to cervical spine injuries, which are common.
Blunt injury to the neck is most commonly from motor vehicle ...
Body imaging is the term assigned to cross-sectional imaging of the body, which radiologically refers to the chest, abdomen and pelvis. It is often used by radiologists who report this region (sometimes known as body imagers/radiologists) to differentiate their primary area of interest from othe...
Bone bruise (also known as bone contusion, trabecular microfracture) is an osseous injury which results from compression of bone structures.
Bone contusions represent trabecular microfractures with hemorrhage and without a discrete fracture line or contour abnormality 4. They typical...
The term Bosworth fracture is no longer used. However, it was classically used to refer to a fracture-dislocation of the ankle in which there was fracture of the fibula and posterior dislocation of the talus.
History and etymology
Named after David M Bosworth (1897-1979), orthopedic surgeon fr...
Bowel and mesenteric trauma can result from blunt force, penetrating and iatrogenic trauma.
The bowel and mesentery are injured in ~2.5% (range 0.3-5%) of blunt force abdominal trauma 1,3,5,8. However not surprisingly, bowel and mesenteric injuries are more frequent after penetrat...
Bowing fractures are incomplete fractures of tubular long bones in pediatric patients (especially the radius and ulna) that often require no intervention and heal with remodeling.
Bowing fractures are almost exclusively found in children. However, there have been several case repo...
Boxer fractures are minimally comminuted, transverse fractures of the 5th metacarpal neck, and are the most common type of metacarpal fracture.
A boxer's knuckle is a separate entity, which is a tear of the metacarpophalangeal joint sagittal band that causes subluxation of the associated exten...
Brachial plexus injuries are a spectrum of upper limb neurological deficits secondary to partial or complete injury to the brachial plexus, which provides the nerve supply of upper limb muscles.
Trauma, usually by motor vehicle accidents, involves severe traction on the ...
The broken heart sign describes the appearances of incudomalleolar disarticulation.
This sign is identified on CT in the coronal plane, being formed by the widening of the incudomalleolar joint and lateral displacement of the short process of the incus relative to the head of the malleus 1,2.
A mnemonic for the features of a bronchial fracture on a chest radiograph is:
Ps (or written as PPP or PPPP)
Ps: progressive or persistent pneumothorax or pneumomediastinum
Bucket handle fracture may refer to:
bucket handle fracture - non-accidental injury
bucket handle fracture of the pelvis
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...
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...
A burst lobe is an uncommonly used description of traumatic lobar intraparenchymal hemorrhage of the brain that ruptures into the subdural space and communicates with subdural hemorrhage 1.
As traumatic hemorrhages are more common in the frontal and temporal lobes, these lobes are the most affe...
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...
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 ...
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...
The Canadian CT head rule (CCTHR) is a validated clinical decision rule to determine the need for CT head in adult emergency department patients with minor head injuries.
Patient has suffered minor head trauma with resultant:
loss of consciousness
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...
Caroticocavernous fistulas (CCF) represent abnormal communication between the carotid circulation and the cavernous sinus. They can be classified as direct or indirect which are separate conditions with different etiologies.
Direct CCFs are often secondary to trauma, and as such...
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.
Central cord syndrome is the most common type of incomplete spinal cord syndrome, usually, the result of trauma, accounting for ~10% of all spinal cord injuries. As the name implies, this syndrome is the result of damage to the central portion spinal cord and in the setting of trauma most common...
Cerclage wire refers to a type of orthopedic fixation/stabilization wire placed to approximate fractured bone fragments.
full - 360° circumferential wire used in diaphysis segments of long bones
hemicerclage - wire is placed through one of the main fractured bone fragments, as used in t...
Cerebral hemorrhagic contusions are a type of intracerebral hemorrhage and are common in the setting of significant head injury. They are usually characterized on CT as hyperdense foci in the frontal lobes adjacent to the floor of the anterior cranial fossa and in the temporal poles.
Cerebral herniation, also referred to as acquired intracranial herniation, refers to shift of cerebral tissue from its normal location, into an adjacent space as a result of mass effect. It is a life-threatening condition that requires prompt diagnosis.
There are a number of differe...
Convenient mnemonics for the causes of cerebral ring enhancing lesions are:
MAGIC DR or DR MAGIC
DR MAGIC L
MAGIC DR or DR MAGIC
I: infarct (subacute phase), inflammatory - neurocysticercosis (NCC), tuberculoma
A floating pillar, also referred as pedicolaminar fracture-separation injury, is characterized by fractures through the pedicle and lamina of a cervical spine vertebrae creating a free-floating articular pillar fragment. It is an unstable cervical spine fracture that results from hyperflexion–la...
There are several cervical spine fracture classification systems:
Anderson and D'Alonzo classification (odontoid fracture)
Roy-Camille classification (odontoid fracture)
Levine and Edwards classification (for traumatic injuries to axis)
Allen and Ferguson classification (subaxial spine injur...