Patellar tendinopathy refers to tendinopathic changes affecting the patellar tendon and can affect part of all of the tendon depending on various clinical scenarios.
Some forms can be associated with specific situations which include
chronic insertional injury of the posterior...
Cryoablation refers to the use of thermal energy in the form of very low temperatures to achieve targeted destruction of tumor cells. It is an image-guided technique, currently widely employed in the management of renal 1, hepatic 2 and lung tumors 3.
Historically, a rudimental form of cryosurg...
Inferior gluteal neuropathy or inferior gluteal nerve injury can be the result of nerve compression or traction injury of the inferior gluteal nerve.
Inferior gluteal nerve neuropathy like superior gluteal nerve neuropathy is rather uncommon and often associated with iatrogenic in...
Superior gluteal neuropathy or superior gluteal nerve injury can be the result of nerve compression or traction injury of the superior gluteal nerve under the roof of the greater sciatic foramen.
Superior gluteal nerve neuropathy is uncommon and often associated with iatrogenic in...
Sciatic neuropathy can be the result of nerve compression or traction injury of the sciatic nerve which might occur at several levels along its course. The peroneal division of the nerve is more commonly affected than the tibial division due to the more superficial location and two different fix...
Wrist arthrocentesis refers to the aspiration of an effusion in the radiocarpal joint. It serves primarily as a diagnostic modality to determine fluid composition, and may function secondarily to reduce pain associated with capsular stretch. The dynamic, ultrasound-guided technique will be descr...
Tubercle of Assaki (also known as tubercle of Asskay 3) is a small bony protuberance of the central part of glenoid fossa with accompanying thinning of articular cartilage in this location 1.
It is presumably caused by constant pressure of the humeral head exerted on the inferior gle...
Hip spine syndrome is one term used to describe the clinical association between hip osteoarthritis and degenerative lumbar spinal canal stenosis due to overlapping pain distribution.
Patients with hip spine syndrome have hip and lumbar spine degeneration and present wit...
Hepatic small vessel neoplasms (HSVN) are low-grade vascular lesions of uncertain malignant potential.
Although also referred to as hepatic small vessel hemangiomas 3, this term may wrongly mislead HSVN to represent a subtype of hepatic hemangiomas and, therefore, will be avoided ...
The lesser palatine artery is a small branch of the descending palatine artery (branch of the 3rd part of the maxillary artery). The vessel supplies the soft palate with small branches to the palatine tonsils 1,2. The vessel emerges through the lesser palatine foramen before traveling posterior ...
The descending palatine artery is a branch of the maxillary artery that supplies both the soft palate and hard palate as well as the palatine tonsils 1.
origin: 3rd part of the maxillary artery
course: descending through the pterygopalatine fossa before its branches enter either the ...
Saphenous neuropathy or saphenous nerve entrapment can be the result of nerve compression or traction injury of the saphenous nerve a pure sensory nerve terminal branch and the longest cutaneous branch from the femoral nerve that supplies the medial thigh, lower leg and foot 1-3.
The CT paranasal sinus protocol serves as an examination for the assessment of the study of the mucosa and bone system of the sinonasal cavities. It is usually performed as a non-contrast study. In certain situations, it might be combined or simultaneously acquired with a
Note: This article aim...
The ascending palatine artery is a branch of the facial artery that supplies part of the soft palate. In addition, the vessel also supplies the tensor veli palatini, uvular muscle, palatine tonsils, and palatopharyngeus 1,2. The posterior branch supplies the posterior and inferior soft palate es...
Sural neuropathy, also known as sural nerve entrapment, can be the result of nerve compression or traction injury of the sural nerve. This nerve is a purely sensory branch, usually formed by a confluence of branches from the tibial nerve and common peroneal nerve that supplies the lateral aspect...
The aerodigestive tract is a non-TA descriptive collective term for the respiratory tract and proximal portion of the digestive tract. As it is a non-standard term, its precise components vary somewhat with the context in which the term is being employed.
Definitions of what precis...
A trefoil appearance of spinal canal (sometimes termed as a cloverleaf spinal canal appearance) is a particular appearance that is of congenital or acquired etiology. This is mainly described in the lumber region and can result in narrowing of the lateral recesess as well as at times involvement...
The frontalis muscle (TA: musculus frontalis) is a paired muscle extending from the supraorbital region to the level of the coronal suture. Flat and quadrilateral in shape, it is one of the facial muscles. Along with the occipitalis muscle, it forms the occipitofrontalis muscle due to a common t...
Lumbar spinal stenosis grading refers to systems for classifying the severity of central spinal canal narrowing around the cauda equina nerve roots.
The two most popular systems, both applied to visual assessment of MRI, are the Lee grading system, and the Schizas grading system. Both t...
Anterior instrumentation and fusion is a surgical procedure used in patients with adolescent idiopathic scoliosis to correct vertebral curvature. This technique is preferred to posterior instrumentation and fusion in skeletally immature patients with a Lenke 5C thoracolumbar or lumbar adolescent...
The anterior tarsal tunnel is a fibro-osseous canal found in the anterior aspect of the ankle.
The anterior tarsal tunnel is beneath the inferior extensor retinaculum of the foot and bordered by the following structures 1,2:
roof: inferior extensor retinaculum
Deep peroneal nerve entrapment or compression syndrome anterior is a nerve compression syndrome of the deep peroneal nerve and might occur within the anterior tarsal tunnel beneath the inferior extensor retinaculum as anterior tarsal tunnel syndrome.
Deep peroneal nerve entrapment...
Superficial peroneal nerve entrapment or compression syndrome is a nerve compression syndrome of the superficial peroneal nerve a mixed motor and sensory nerve providing the motor innervation of the peroneus longus and peroneus brevis muscles and sensory innervation of the dorsum of the foot and...
The solitary fibrous tumor of the orbit is a rare spindle-cell neoplasm originating from mesenchymal fibroblast-like cells histologically identical to solitary fibrous tumors found elsewhere
Solitary fibrous tumors occur in a wide age range reported from 9 to 76 years without a co...
Sacroiliac joint fusion (SIJ fusion) represents the surgical treatment for all patients with low back and/or buttock pain who do not respond to medical or physiotherapeutic treatment 1,2. The treatment shows excellent outcomes in these patients. Alongside the standard surgical treatment is minim...
Medial plantar nerve entrapment or compression syndrome, also known as jogger’s foot is a nerve compression syndrome of the medial plantar nerve either in the distal tarsal tunnel or beneath the plantar arch at the knot of Henry.
Medial plantar nerve entrapment is a rather rare ty...
Crizotinib associated interstitial pneumonitis is a type of drug-induced lung disease precipitated by a tyrosine kinase/anaplastic lymphoma kinase (ALK) inhibitor Crizotinib used in the treatment of certain forms of non-small cell lung cancer that have certain mutations including the ROS1 mutati...
The risorius muscle (TA: musculus risorius) is one of the muscles of the mouth, a subset of the facial muscles. It is often absent and has been described as an accessory muscle.
origin: fascia overlying the parotid, masseter and/or platysma muscles
insertion: modiolus at the angle of...
A mastoid bowl or mastoid cavity refers to a post surgical cavity that is created from the resection of mastoid air cells and intervening septae, usually during complex mastoidectomies such as canal wall up or canal wall down mastoidectomies, or other surgeries such as cochlear implantations. Th...
Glenoid bare spot also known as glenoid bare area is a small central or slightly eccentric area of inferior glenoid fossa, where the articular cartilage is markedly thinner or completely absent 2. It is considered to be a normal aging-related phenomenon 1.
Glenoid bare spot can be...
The levator labii superioris (LLS) muscle (TA synonym: musculus levator labii superioris) is one of the elevators of the upper lip, a subset of the facial muscles.
It is not to be confused with the levator labii superioris alaeque nasalis muscle, which has a very similar name, at least partiall...
The medial capsuloligamentous complex of the knee is comprised of three layers 1-3:
superficial layer (layer 1)
deep crural fascia
intermediate/middle layer (layer 2)
superficial medial collateral ligament
posterior oblique ligament
medial patellofemoral ligament
The interosseous (or interossei) muscles of the hand are a group of intrinsic hand muscles that lie near the metacarpals.
There are two sets:
dorsal interossei muscles (hand)
palmar interossei muscles (hand)
The palmar aponeurosis is the thickened strong part of the palmar fascia in the hand which is continuous with the flexor retinaculum and the tendon of palmaris longus tendon. It is superficial to the long flexor tendons and is an inverted triangle in shape, fanning over the palm and thinning med...
Muscles of the hand can be divided into:
extrinsic muscles whose tendons, which attach to structures within the hand, arise from muscle bellies from the forearm or distal humerus
intrinsic muscles (mnemonic) whose muscle bellies and tendons are located solely within the hand
Scoliosis surgery is indicated when conservative management has failed.
Cobb angle ≥45º (skeletally immature) or ≥40-50º (skeletally mature) 1,2
progressive scoliosis deformity
spinal functional compromise
pain not responsive to non-operative treatment
pulmonary function compro...
A mnemonic to remember the types of bone tumors with internal trabeculations or pseudotrabeculations is:
D: desmoplastic fibroma
C: chondromyxoid fibroma
H: hemangioma (intraosseous)
A: aneurysmal bone cyst
N: non-ossifying fibroma
G: giant cell tumor
Heel fat pad syndrome, also known as plantar fat pad syndrome or heel fat pad atrophy is a common but not well-known cause of heel pain in the adult population.
Heel fat pad syndrome is common. It is the second most common cause of plantar heel pain after plantar fasciitis It is t...
A pseudocyst of the glisson capsule is a form of subcapsular hepatic pseudocyst that has often been described in the setting of ventriculoperitoneal shunts. It may be seen as a cystic lesion abutting the hepatic capsule.
Renal artery calcifications, also known as renovascular calcifications, are deposits of calcium salts on the wall of a renal artery, found incidentally on imaging, usually CT 1. They are associated with extrarenal atherosclerosis and linked to hypertension 2.
The term “renal artery...
Degenerative spinal instability is frequent although somewhat controversial clinical entity with evolving theories on its clinical relevance, in particular, its role as a causative factor of low back pain (LBP). While radiographic instability may be evident, this does not always correlate with t...
Spinal instability is a broad term with no generally agreed-upon definition but can be thought of the potential for or actual abnormal segmental spinal motion.
Spinal microinstability refers to abnormal segmental movement without bony changes 1.
Spinal instability is ...
Aspirin, also known as acetylsalicylic acid (ASA), is a generic non-steroidal anti-inflammatory drug and antiplatelet agent. It is one of the most-widely if not the most commonly used drug in the world and is listed on the WHO Model List of Essential Medicines 1-4. It is used as an over-the-coun...
The lateral humerus view for pediatrics is part of the humerus series and is usually taken in a standing position. However, it can also be obtained in a supine position.
The projection demonstrates the humerus orthogonal to the AP view, allowing for adequate radiographic examination of the enti...
Skull base meningiomas can be located at the olfactory groove, tuberculum sella, sphenoid ridge, petroclival region, foramen magnum and jugular foramen 1.
Similar to typical meningiomas, they are slowly growing and usually asymptomatic. Apart from headache, they can pre...
Correct usage of punctuation is essential to ensure that there is a consistency of style on Radiopaedia.org.
For further details, please see the following articles for discussion:
commas in body text lists
dashes and hyphens
full stops (periods)
The British use of commas and full-stops (periods) outside quotation marks (if not part of the original quotation) is preferred to the American use of punctuation within quotation marks:
British: The vessel has been termed the "innominate".
American: The vessel has been termed the "innominate."
The Van Assche index is a semiquantitative scoring system originally developed in 2003 to assess the severity and disease response in perianal fistulizing Crohn disease. In 2017 substantial changes were proposed to the original system, resulting in the modified Van Assche index. Both system rema...
Myometrial arterial calcification are thought to increase with advancing age and may represent calcification of radial or arcuate arteries of the uterus.
They may have an increased association with atherosclerosis elsewhere.
They may be seen as hyperechoic m...
Enchondroma protuberans, also known as ecchondroma, is a rare form with an exophytic growth pattern that leads to deformity/remodeling of the cortex, unlike 'typical` enchondromas' which are located within the intramedullary cavity.
Due to their cartilaginous origin, typ...
Amyloid related imaging abnormalities (ARIA) represent a variety of imaging features identified in patients with Alzheimer disease being treated with novel amyloid lowering therapies such as the monoclonal antibodies bapineuzumab, solanezumab and aducanumab 1-4.
In most ...
Low back pain, lumbar or lumbosacral pain is an extremely common clinical symptom and the most common musculoskeletal condition affecting the quality of life that can be found in all age groups. It represents the leading cause of disability worldwide 1-3.
Low back pain is a very c...
Cerebral palsy is a spectrum of developmental disorders that result from an insult to the developing brain in utero or early life. Characteristically, muscle tone and movement are affected but there is wide variation in the degree to which each individual is affected 1.
Pyothorax-associated lymphoma (PAL) is a non-Hodgkin lymphoma of exclusively B-cell phenotype developing in the pleural cavity of patients after a longstanding pyothorax / empyema.
Histologically PAL usually shows a diffuse proliferation of large cells of B-cell type (diffuse large B...
Immunosuppression is the impairment of the body's immune system which can alter the ability of the body's defense mechanisms to prevent diseases, particularly certain infections, including opportunistic infections, and cancers.
Patients with immunosuppression are said to be immuno...
Barrett's index (BI) is used to assess for dysthyroid optic neuropathy, a severe complication of thyroid-associated orbitopathy that can lead to permanent blindness 1.
Measurement is calculated on coronal CT or MRI imaging of the orbits at a point halfway between the posterior glob...
Discectomy is the most common surgery for lower back pain performed for the treatment of disk herniations. It is often combined with other spinal procedures as laminotomy or foraminotomy or artificial disk replacement and other forms of spinal fusion. Discectomy techniques can be generally subdi...
A zonary placenta also known as a ring-shaped placenta or annular placenta is an extremely rare variation in placental morphology where the placenta can appear as an annular ring. It can be a complete ring of placental tissue, but more often, tissue atrophy to part of the ring can result in a ho...
Exophytic sinonasal papillomas (ESP) or fungiform sinonasal papillomas are a form of Schneiderian papillomas and benign sinonasal tumors arising from the Schneiderian epithelium of the nasal septum.
Exophytic sinonasal papillomas are the second most common form of sinonasal papill...
Oncocytic sinonasal papillomas (OSP) or cylindrical cell papillomas are a rare form of Schneiderian papillomas and benign epithelial sinonasal tumors arising from the Schneiderian epithelium of the nasal cavity and paranasal sinuses.
Oncocytic sinonasal papillomas are the least fr...
Primary intraosseous carcinomas NOS (PIOC) are malignant epithelial odontogenic neoplasms of the jawbones with no clear benign analog.
Primary intraosseous carcinomas are rare tumors 1-4. They occur in a wide age range with the mean in the sixth decade of life. Men are more freque...
The term synostosis (plural: synostoses) refers to the fusion of bones usually at cartilaginous or fibro-osseous connections. Synostoses occur physiologically, as asymptomatic anatomical variants or might be abnormal and cause clinical symptoms as a functional loss. The latter is clinically sign...
Uterine restricted diffusion refers to a hyperintense signal involving the endometrium, myometrium, or cervix on DWI images with a corresponding low signal on ADC images, with a mean cut-off ADC value for malignancy of 1.15 x 10-3 mm2/s 7.
Endometrial restricted diffusion
Anterior vertebral body tethering (AVBT) is a fusionless technique for treating and managing idiopathic scoliosis in skeletally immature patients to reduce the typical side effects of rigid posterior fusion (such as loss of spinal motion and risks adjacent segment degeneration later in life) 1,3...
The oblique thumb view in pediatrics is an additional projection for thumb imaging. Typically, this view is not performed unless specified by the referring doctor or radiologist.
For pediatrics, this oblique view is only indicated when specifically requested. This view may help to...
Nerve compression syndromes or nerve entrapment neuropathies are a group of several nerve disorders associated with sensory and/or motor loss resulting from nerve compression.
Nerve compression syndromes are common 1-5 and can account for 10-20% of cases in specialist clinics of n...
Vertical expandable prosthetic titanium rib (VEPTR) procedure is a surgical technique that was initially developed to treat thoracic insufficiency syndrome and then it was used in congenital scoliosis with rib abnormalities, and has since been successfully used to treat early-onset scoliosis wit...
In situ contouring is a surgical technique used in thoracolumbar scoliosis surgery and thoracolumbar fracture reduction and fixation.
Thoracolumbar scoliosis surgery
The key of this technique is to " make the rod take the shape of the spine and then to make the spine take the shape...
In situ spinal fusion is, as the name suggests, where fusion is performed without a change in alignment. It is a technique used to treat:
isthmic spondylolisthesis 1
osteogenesis imperfecta 2
Intercritical gout is the asymptomatic stage between attacks of acute gouty arthritis.
During the asymptomatic phase, the joints may be non-tender and without erythema or swelling. Patients can experience multiple gout attacks with asymptomatic periods of several months i...
Posterior dynamic lumbar stabilization is an alternative instrumented method to rigid spinal fusion aiming to improve segmental stability. Purported advantages of this technique include reduced posterior element and intervertebral disc loading reducing symptoms and potentially allowing for disc ...
A central vein refers to a major vein close to the center of the circulation, i.e. the heart. It originally referred to those large veins in which the distal tip of a catheter could lie for central venous pressure monitoring. To accurately measure the central venous pressure, which is the pressu...
A mnemonic to remember the commonest causes of cavitating lesions seen in a chest x-ray is:
W: Wegener's granulomatosis (granulomatosis with polyangiitis)
E: embolism (pulmonary, septic)
I: infection (anaerobes, pneumocystis, TB)
R: rheumatoid arthritis (necrobiotic no...
A mnemonic to remember the commonest microorganisms responsible for urinary tract infections (UTIs) is:
K: Klebsiella spp.
E: Enterococcus faecalis / Enterobacter cloacae
E: Escherichia coli
P: Pseudomonas aeruginosa / Proteus mirabilis
S: Staphylococcus saprophyticus / Se...
A mnemonic to remember the commonest clinical signs of Parkinson disease is
S: shuffling gait
M: mask-like facies
A mnemonic to remember the basic indications of dialysis is
H: hyperkalemia (refractory)
A: acidosis (refractory)
V: volume overload
E: elevated BUN > 35 mM
E: edema (pulmonary)
A mnemonic to remember the commonest causes of hematuria is:
I PEE RBCS
P: pseudohaematuria (menses, dark urine)
E: external trauma
R: renal glomerular disease
B: benign prostatic hypertrophy
A mnemonic to remember the nerve supply to the scalp is:
G: greater occipital nerve / greater auricular nerve
L: lesser occipital nerve
A: auriculotemporal nerve
S: supratrochlear nerve
S: supraorbital nerve
Please note that other nerves also contribute, see anatomy articl...
A mnemonic to remember the contraindications to abdominal paracentesis is:
C: coagulopathy (INR >2.0)
A: abdominal wall cellulitis
S: surgical abdomen (absolute contraindication) / severe thrombocytopenia (platelet count <50 x 103/μL)
I: intra-abdominal adhes...
Anasarca refers to a state of generalized edema.
Some definitions of anasarca focus on the presence of subcutaneous (body wall and/or extremity) edema 1,2,7, while others focus on pleural effusions and ascites 3. An overarching definition is the accumulation of fluid (water retent...
A mnemonic to remember the basic features of Marfan syndrome is:
M: mitral valve prolapse
A: aortic dissection / aortic aneurysm
R: regurgitant aortic valve / retinal detachment
F: fibrillin-1 mutation
A: arm span > height / arachnodactyly
N: near-sightness / nasal voice...
A mnemonic to remember the criteria for forceps delivery is:
F: fetus alive
O: os dilated
R: ruptured membrane / rotation complete
C: cervix take-up
E: engagement of head
P: presentation suitable
S: sagittal suture in AP diameter of inlet
A mnemonic to remember the basic risk factors of postpartum hemorrhage is:
P: prolonged labor / polyhydramnios / previous C-section
R: recent Hx of bleeding
U: uterine fibrosis
The Pediatric Appendicitis Score (PAS) is a clinical decision rule and predictor of the likelihood of acute appendicitis in the pediatric population 1.
cough/percussion/hopping tenderness in right lower quadrant (+2)
nausea or emesis (+1)
tenderness in rig...
A mnemonic to remember the most important signs of endocarditis is:
R: Roth's spots
O: Osler's nodes
M: murmur of heart
J: Janeway lesions
N: nail hemorrhage
A mnemonic to remember the characteristics of Edwards syndrome is:
E: Eighteen (trisomy)
D: digit overlapping flexion
W: wide head
A: absent intellect (mental retardation)
R: rocher-bottom feet
D: diseased heart
S: small lower jaw
A mnemonic to remember the basic differential diagnosis of acute abdominal pain is:
B: biliary tract disease
O: ovarian disease
I: intestinal obstruction
N: nephritic disorders
A: acute pancreatitis
L: liquor (ethano...
A mnemonic to differentiate between central and peripheral cyanoses is:
C: cold (peripheral)
O: obstruction (peripheral)
L: LVF and shock (peripheral)
D: decreased cardiac output (peripheral)
P: polycythemia (central)
A: altitude (central)
L: lung disease (central)
Felty syndrome is a rare condition that involves rheumatoid arthritis, decreased white blood cell count and spleen enlargement.
A mnemonic to remember the basic components of Felty syndrome is:
A: arthritis (rhe...
A mnemonic to remember the commonest causes of thrombocytopenia is:
P: platelet disorders (DIC, TTP, ITP)
E: enlarged spleen
L: liver disease
T: toxicity (heparin, aspirin, chemotherapy, benzene)
A mnemonic to remember the severity criteria for acute pancreatitis is:
P: PAO2 <8 kpA
A: age >55 years
N: neutrophilia (WBC >15 x 109 / L)
C: calcium <2 mmol/L
R: renal (urea >16 mmol/L)
E: enzymes (LDH >600 IU/L and AST >200 IU/L)
A: albumin (serum) <32 g/L
A mnemonic to remember the commonest causes of anion gap metabolic acidosis is:
G: glycols (ethylene glycol and propylene glycol)
R: renal failure
A mnemonic to remember the commonest causes of tinnitus is:
A: anemia / acoustic neuroma
M: migraine / Menière's disease
M: medication (quinine, NSAIDs, streptomycin)
E: ear pathology (wax, foreign body, otitis media)
R: rare (temporomandibular joint ...