Hiccups (or hiccoughs), medical term singultus, are an unpleasant phenomenon, experienced by everyone on occasion, and usually self-limiting. However the much rarer intractable chronic form can be extremely debilitating.
Hiccups are a symptom that has probably been experienced by ...
Listeria rhombencephalitis is a particular form of listerial encephalitis that affects primarily the hindbrain (brainstem and cerebellum). Listeria monocytogenes is cited as the most common aetiology for rhombencephalitis, typically seen in the elderly, and resulting in significant morbidity and...
Lateral medullary syndrome, (or Wallenberg syndrome) is an acute ischemic infarct due to occlusion of the vessels supplying the lateral medulla oblongata; most commonly occlusion of intracranial portion of the vertebral artery followed by PICA and its branches 1-3. This syndrome is characterised...
Jefferson fracture is the eponymous name given to a burst fracture of C1. It was originally described as a four-part fracture with double fractures through the anterior and posterior arches, but three-part and two-part fractures have also been described.
A typical mechanis...
Artifacts can present in a variety of ways including abnormal shadow noted on a radiograph or degraded image quality and have been produced by artificial means from hardware failure, operator error and software (post-processing) artifacts.
There are common and distinct artifacts for film, comp...
The Couinaud classification (pronounced kwee-NO) is currently the most widely used system to describe functional liver anatomy. It is the preferred anatomy classification system as it divides the liver into eight independent functional units (termed segments) rather than relying on the tradition...
Craniopharyngiomas are relatively benign (WHO grade I) neoplasms that typically arise in the sellar/suprasellar region. They account for ~1-5% of primary brain tumours, and can occur anywhere along the infundibulum (from the floor of the third ventricle, to the pituitary gland).
There are two p...
Dysphagia refers to subjective awareness of difficulty or obstruction during swallowing. It is a relatively common and increasingly prevalent clinical problem. Odynophagia is the medial term for painful swallowing.
Fluoroscopy is the mainstay of imaging assessment but manometry can help evaluat...
The AO classification of thoracolumbar injuries aims to simplify and universalise the process of classifying spinal injuries and improve interobserver and intraobserver reliability 3.
The AOSpine thoracolumbar classification system consists of only three classes of thoracolumbar injuries. Unlik...
CT guided percutaneous drainage is one form of image-guided drainage, allowing minimally invasive treatment of collections, potentially anywhere in the body. Although less commonly used than ultrasound guidance, it is particularly valuable in gaining access to deeper or more posterior parts of t...
Ureterocoeles represent congenital dilatation of the distal-most portion of the ureter. The dilated portion of the ureter may herniate into the bladder secondary to the abnormal structure of vesicoureteric junction (VUJ).
Most ureterocoeles are congenital, usually associated with ...
Extreme lateral interbody fusion (XLIF) is a form of lumbar surgical spinal fusion developed in 2001 to be a safer alternative to the older anterior lumbar interbody fusion (ALIF) developed in the 1950s 1,2.
Unlike an ALIF, an XLIF is performed from a lateral trans-psoas approach and does not r...
Spinal fusion is a broad term to denote the joining of two or more adjacent vertebral segments. Fusion can be congenital or acquired as a direct result of disease or deliberately following spinal surgery.
Fusion of two or more adjacent segments is encountered either as an is...
The thoracolumbar injury classification and severity score (TLICS), also sometimes known as the thoracolumbar injury severity score (TISS), was developed by the Spine Trauma Group in 2005 to overcome some of the perceived difficulties regarding the use of other thoracolumbar spinal fracture clas...
The two most commonly currently used thoracolumbar spinal fracture classification systems are the AO classification and the TLICS although a number of other classification systems have been proposed over the years 1. Each has benefits and drawbacks and each incorporates various features in an at...
Klippel-Feil syndrome is a complex heterogeneous entity that results in cervical vertebral fusion. Two or more non-segmented cervical vertebrae are usually sufficient for diagnosis.
There is a recognised female predilection 1. Klippel-Feil syndrome has an incidence of 1:40,000-42,...
Fibroxanthoma of bone is a confusing term that is sometimes used to encompass non-ossifying fibroma and fibrous cortical defect, and at other times synonymously with just non-ossifying fibromas. As non-ossifying fibroma and fibrous cortical defect are histologically the same, and differ only in ...
Page kidney refers to the phenomenon of hypertension that develops following long-standing compression of renal parenchyma by subcapsular renal collection, e.g. haematoma, seroma, urinoma.
Compression of the renal parenchyma results in compression of the renal vessels, which leads to...
This article contains a list of commonly used medical abbreviations and acronyms that start with the letter X and may be encountered in medicine and radiology (please keep in alphabetic order).
A - B - C - D - E - F - G - H - I - J - K - L -M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z ...
Dravet syndrome, previously known as severe myoclonic epilepsy of infancy (SMEI), is a rare form of epilepsy usually presenting in the first 1-2 years of life.
The typical presentation occurs during the first six months to one year of life as tonic-clonic seizures in a fe...
Klinefelter syndrome (KS) is a chromosomal anomaly, which in most cases is characterised by 47 chromosomes instead of the usual 46.
The estimated incidence is 0.15-0.2% of live births.
the testes are normal prior to puberty and small in post pubertal testes...
Fetal valproate syndrome (FVS) is a potential embryopathy that can occur as a result from maternal intake of valproic acid (sodium valproate) during pregnancy.
There is a wide clinical spectrum which includes
neural tube defects
LI-RADS (Liver Imaging Reporting and Data System) is both a set of standardised terminology and a classification system for imaging findings in liver lesions. The LI-RADS score for a liver lesion is an indication of its relative risk for hepatocellular carcinoma (HCC). The classification system ...
Popliteal venous aneurysms are rare than those of the popliteal artery and are mostly asymptomatic. However, due to the disturbance of the venous blood flow, they can lead to potentially life-threatening consequences, such as deep vein thrombosis (DVT) and pulmonary embolism (PE).
Chronic kidney disease (CKD), also known as chronic renal failure, is a progressive loss of glomerular function caused by a long-standing renal parenchymal disease. It is present when the glomerular filtration rate (GFR) is less than 60 ml/min/1.73 m2 for three consecutive months or greater than...
With the growing incidence of obesity in the western world, ultrasound-guided anaesthesia is becoming more common. Spinal anaesthesia is traditionally administered by identifying relevant surface anatomy and imaging is rarely used for pre-procedural identification of structures.
Valproate-induced hyperammonaemic encephalopathy (VHE), also known as valproic acid-induced hyperammonaemic encephalopathy, is a rare type of non-cirrhotic hyperammonaemic encephalopathy caused by use of sodium valproate, a drug commonly used as an anti-epileptic and mood stabiliser.
Hepatic encephalopathy, also known as portosystemic encephalopathy, refers to a spectrum of neuropsychiatric abnormalities occurring in patients with liver dysfunction and portal hypertension. It results from exposure of the brain to excessive amounts of ammonia.
Contrast-induced nephropathy (CIN) describes an association between intravenous or intraarterial contrast administration and renal impairment, but increasingly the evidence shows that contrast is not the cause of the renal impairment and that confounding factors such as sepsis are likely to be r...
Patella alta, or a high riding patella, describes a situation where the position of the patella is considered high. It may be idiopathic or may result secondary to a patellar tendon rupture.
Several conditions are known to be associated with patella alta, including:...
Blake's pouch cyst is a cystic appearing structure that represents posterior ballooning of the inferior medullary velum into the cisterna magna, below and posterior to the vermis that communicates with an open fourth ventricle. It is caused by a failure of regression of Blake's pouch secondary t...
Senile calcific scleral plaques, also known as senile scleral plaques (SSP), are benign scleral degenerations common in elderly individuals. They are a common incidental finding on CT imaging.
The prevalence of SSP increases with age, from ~2.5% at age 60, to 25% at age 80 years a...
Internal carotid artery dissection, like arterial dissection elsewhere, is a result of blood entering the media through a tear in the intima 1 and is a common cause of stroke in younger patients.
Dissection may occur at any age, but is a common cause of stroke in young patients (2...
This article lists examples of normal imaging of the head and neck and surrounding structures, divided by region and modality.
For normal spinal imaging, please see: normal spinal imaging
soft tissue: example 1
soft tissue: example 2
A Rokitansky nodule or dermoid plug refers to a solid protuberance projecting from an ovarian cyst in the context of a mature cystic teratoma. It often contains calcific, dental, adipose, hair and/or sebaceous components 1.
History and etymology
It is named after Carl von Rokitansky (1804-187...
Transitional cell carcinoma (TCC), also called urothelial cell carcinoma (UCC), is the most common primary malignancy of the urinary tract and may be found along its entire length, from the renal pelvis to the bladder.
As imaging findings and treatment vary according to where along the urinary...
The left superior intercostal vein drains the left posterosuperior hemithorax and is considered to be part of the azygos venous system even though it does not directly drain into the azygos vein.
Origin and course
The left superior intercostal vein forms by the union of the 2nd...
The left anterior descending (LAD) artery, also known as the anterior interventricular branch, is a branch of the left coronary artery.
It descends along the inteventricular groove.
It can be divided into proximal, mid and distal segments and this helps to differentiate the nam...
Trochlear apparatus calcification in the orbit is a common incidental finding on CT of the head, found in ~12.5% of patients. There is no association with diabetes mellitus but an association has been demonstrated with autoimmune disease and elevated ALP 1,2.
Intracranial epidermoid cysts are relatively common congenital lesions which account for about 1% of all intracranial tumours. They result from inclusion of ectodermal elements during neural tube closure, and typically present in middle age due to mass effect on adjacent structures. Their conten...
Adenoid cystic carcinomas of the tracheobronchial tree are a type of low-grade tracheal tumour. They are considered to be the second most common primary tumour of the trachea.
They are usually first recognised in patients in their 4th and 5th decades. There is no recognised gender...
Calcification of the globe has many causes, varying from the benign to malignant. When calcification is seen of the posterior half of the globe, it could relate to any of the layers (scleral, choroidal or retinal), as it is not possible to separate them out on CT.
drusen: 1% population...
Vascular malformations and tumours are a heterogeneous group of lesions that may affect the arterial, capillary, venous or lymphatic system or any combination thereof. They encompass a bewildering range of lesions, syndromes, and masses ranging from the relatively common (e.g. infantile haemang...
A subcapsular perirenal haematoma is a form of perirenal haematoma where blood accumulates beneath the renal capsular margin.
It can arise from a number of causes
trauma, important in assessing renal trauma grading
post procedural, e.g. extracorporeal shock-wave lithotripsy (ESWL) ...
Bronchial carcinoid tumours are carcinoid tumours primarily occurring in relation to a bronchus. They were previously incorrectly termed as bronchial adenomas. They usually occur in association with a segmental or larger bronchus.
Typically affects patients from 3rd to 7th decades...
Aortoiliac occlusive disease refers to complete occlusion of the aorta distal to the renal arteries.
When the clinical triad of impotence, pelvis and thigh claudication, and absence of the femoral pulses are present, it may also be called Leriche syndrome, which usually affects you...
The IASLC (International Association for the Study of Lung Cancer) 8th edition lung cancer staging system was introduced in 2016 and supersedes the IASLC 7th edition.
It is as follows:
T: primary tumour
Tx: primary tumour cannot be assessed or tumour proven by the presence of mal...
Cancer staging using a number of systems to help direct treatment and aid prognosis.
FIGO (in gynaecological cancer)
Dukes staging system
breast cancer staging
lung cancer staging
malignant pleural mesothelioma staging
Intracranial hypotension, also known as craniospinal hypotension is defined as cerebrospinal fluid (CSF) pressure <7 cm H2O in patients with clinical presentation compatible with intracranial hypotension, which are postural headache, nausea, vomiting, neck pain, visual and hearing disturbances, ...
Previously, small cell lung cancer (SCLC) was not staged in the same manner as non-small cell lung cancer (NSCLC), but since 2013 both are staged using the IASLC (International Association for the Study of Lung Cancer) lung cancer staging system (currently in its 8th edition, published in 2016)....
The IASLC (International Association for the Study of Lung Cancer) 7th edition lung cancer staging system was proposed in 2010 and has now been updated and superseded by the 8th edition, published in 2016.
Small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) used to be staged di...
Focal nodular hyperplasia (FNH) is a regenerative mass lesion of the liver and the second most common benign liver lesion (most common is a haemangioma). Many FNHs have characteristic radiographic features in multimodality imaging, but some lesions may be atypical in appearance. FNHs are typical...
The EDiR day 2 exam was part of the European Diploma in Radiology. It was held on the second day of a two-day exam and was divided into two parts. Only candidates that passed day 1 were eligible for the day 2 examination. The examination was oral, and there was one examiner per candidate (30 min...
Until March 2016 the European Diploma in Radiology was a two-day exam.
EDiR day 1 exam was divided into two parts:
short cases (SCs): computer-based (90 minutes)
multiple response questions (MRQs): computer-based (90 minutes)
skills examination: practical-oriented cases, com...
The European Society of Radiology (ESR) was formed in 2005 from the amalgamation of the European Congress of Radiology (ECR) and the European Association of Radiology (EAR).
Chairpersons of the ESR Board of Directors
Bernd Hamm 2018-2019
Paul M Parizel ...
In 2013, the 5th World Symposium on pulmonary hypertension took place in Nice, France and modified the classification system for pulmonary hypertension.
The modified system divides pulmonary hypertension into five groups:
group 1: pulmonary arterial hypertension (disorders of the pulmonary ar...
Phlegmasia cerulea dolens (PCD) is an uncommon complication of deep venous thrombosis, which results from extensive thrombotic occlusion of the major and collateral veins of an extremity (usually the legs).
Left leg is more commonly affected than the right 4.
The International Day of Radiology (IDOR) is an annual celebration held on the anniversary of the date of discovery of x-rays, i.e. November 8th 1895. The sixth annual celebration was held on November 8th 2017.
The day, first commemorated in 2012, started as, and remains, a joint ente...
The differential for tracheal masses can be rather wide.
For a single mass consider:
direct invasion from adjacent organ (lung, thryoid,esophagus)
distant metastsis ( such as melanoma)
squamous cell carcinoma: commonest primary tracheal malignancy 2 ~50 %
This article contains a list of commonly used medical abbreviations and acronyms that start with the letter E and may be encountered in medicine and radiology (please keep in alphabetic order).
A - B - C - D - E - F - G - H - I - J - K - L -M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z ...
This is a basic article for medical students and other non-radiologists
Tuberculosis is a non-bacterial multisystem infection that often affects the lungs. It may be a primary tuberculous infection, secondary infection or appear as chronic scarring. TB may also be seen on a chest x-ray as lymph...
Extraskeletal osteosarcoma (ESOS) is a rare mesenchymal malignant tumour that occurs in the retroperitoneum and soft tissue of extremities without any attachment to bone.
Extraskeletal osteosarcoma in contrast to other subtypes of osteosarcoma occurs infrequently in individuals un...
A slash (the forward slash in English is formally called the solidus) is used mainly as a substitute for the word 'or'. Radiopaedia.org follows standard English style with no space either preceding or following a slash. A slash is often used to avoid indicating a preference for one of the terms ...
In March 2016, the European Diploma in Radiology (EDiR) exam structure was updated from a two-day exam with a viva voce component, to a single day exam 1.
The current exam structure consists of three parts:
multiple response questions (MRQs)
computer-based (90 minutes)
short cases (SCs)
Pulmonary hypertension is defined as a resting mean pulmonary arterial pressure of 25 mmHg or greater at right heart catheterisation, which is a haemodynamic feature that is shared by all types of pulmonary hypertension. A resting mean pulmonary arterial pressure of 20 mmHg or less is considered...
An os peroneum is a small accessory bone located at the lateral plantar aspect of the cuboid within the substance of the peroneus longus tendon as it arches around the cuboid. It is very common, seen in up to 26% of feet 1.
It should not be mistaken for:
The apophysis of the proximal 5th metatarsal lies laterally and is oriented longitudinally parallel to the shaft.
Apophysis of the fifth metatarsal base appears on plain radiographs at age 12 for boys and 10 for girls. Fusion of the apophysis to the metatarsal base usually occurs within the fol...
The proximal 5th metatarsal is the site of a number of fractures and variants which mimic fractures. These include:
stress fracture of the 5th metatarsal
avulsion fracture of the proximal 5th metatarsal
os vesalianum or os peroneum
normal apophysis of the proximal 5th metatar...
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 ...
A Jones fracture is an extra-articular fracture at the base of the fifth metatarsal.
It is a transverse fracture at the base of the fifth metatarsal, 1.5 to 3 cm distal to the proximal tuberosity at the metadiaphyseal junction, without distal extension.
The fracture is ...
Ill-defined solitary osteolytic lesions can be caused by following entities 1:
giant cell tumour
fibrosarcoma of bone
malignant fibrous histiocytoma
Osteogenesis imperfecta (OI) refers to a heterogeneous group of congenital, non-sex-linked, genetic disorders of collagen type I production, involving connective tissues and bones.
The hallmark feature of osteogenesis imperfecta is osteoporosis and fragile bones that fracture easily, as well a...
The several forms of osteogenesis imperfecta (OI) have been classified, representing wide variation in appearance and severity, and clinical features vary widely not only between types but within types.
OI was initially classified by type according to a scheme developed by Dr Da...
Facial fractures are commonly caused by blunt or penetrating trauma sustained during motor vehicle accidents, assaults, and falls. The facial bones are thin and relatively fragile making them susceptible to injury.
Males are affected more commonly than females and facial fractures...
The left lower lobe posterior or posterior basal segment is one of the four bronchopulmonary segments of the left lower lobe. It is the most inferoposterior of the segments in the left lower lobe, below the superior segment.
Due to its low and posterior position, pathology in...
The left lower lobe lateral or lateral basal segment is one of the four bronchopulmonary segments of the left lower lobe. It is the most inferolateral of the segments in the left lower lobe, below the superior segment.
The left lower lobe anteromedial segment (or cardiac segment) is one of the bronchopulmonary segments of the left lower lobe. It is the most anteromedial of the segments within the base of the left upper lobe.
It is the equivalent segment merger of the anterior and medial segments of the right ...
The left upper lobe inferior lingular segment is one of the four bronchopulmonary segments of the left upper lobe. It lies below the superior lingular segment of the left upper lobe.
The left upper lobe superior lingular segment is one of the four bronchopulmonary segments of the left upper lobe. It lies below the apicoposterior and anterior segments of the left upper lobe.
The trachea bifurcates into the right and left main bronchi at the level of the carina, supplying air to the right and left lungs respectively. Each main or primary bronchus enters the hilum of its lung and gives rise to secondary lobar bronchi, which further divide into tertiary segmental bronc...
The tracheobronchial tree is the branching tree of airways beginning at the larynx and extending inferiorly and peripherally into the lungs as bronchioles. The luminal diameter decreases as the branching increases more peripherally into the lungs. The walls of the airway down to the level of the...
The left main bronchus divides into the left upper lobe bronchus and the left lower lobe bronchus. It is one of the secondary lobar bronchi.
The left upper lobe bronchus is very short and divides immediately into the segmental bronchi. There are usually 10 individual segmental b...
The left main bronchus divides into the left lower lobe bronchus and the left upper lobe bronchus. It is one of the secondary lobar bronchi.
The left lower lobe bronchus is very short and divides immediately into the segmental bronchi. There are usually 10 individual segmental b...
The secondary lobar bronchi or just lobar bronchi are the first subdivision of the main (or primary) bronchi. Like the primary and tertiary bronchi, they are conducting airways that are lined by cartilage rings.
The left main bronchus gives rise to 2 secondary bronchi:
left upper lobe bronchus...
The left lower lobe superior or apical segment is one of the four bronchopulmonary segments of the left lower lobe. It is the most apical of the segments in the left lower lobe, posterior to the upper aspect of the oblique fissure and apicoposterior segment of the left upper lobe.
Well defined solitary osteolytic lesions can be seen with following conditions 1-2:
subchondral geodes or cysts
unicameral bone cyst
aneurysmal bone cyst
epidermoid inclusion cyst
An intraosseous ganglion is a benign subchondral radiolucent lesion without degenerative arthritis.
Tends to occur in middle age.
Patients may have mild localised pain.
They are uni-/multilocular cysts surrounded by a fibrous lining, containin...
Benign renal tumours were histologically classified according to the WHO in 2004 as follows 1:
Renal cell tumours
renal papillary adenoma - renal adenoma
metanephric adenoma of kidney
metanephric adenofibroma of kidney
metanephric stromal tumour of kid...
Renal cell carcinoma staging using the TNM staging system for renal cell carcinoma. Older but still widely used system in some practices is the Robson staging system.
TNM staging (7th edition)
T1a: tumour confined to kidney, <4 cm
T1b: ltumour confined to kidney, >4 cm but <7 cm
Lisfranc injuries, also called Lisfranc fracture-dislocations, are the most common type of dislocation involving the foot and correspond to the dislocation of the articulation of the tarsus with the metatarsal bases.
The Lisfranc joint is the articulation of the tarsus with ...
Renal oncocytoma is a relatively benign renal tumour. The main clinical importance of this lesion is the difficulty in pre-operatively distinguishing it from renal cell carcinomas, as epidemiology, presentation, imaging and even histology can be very similar.
Renal oncocytomas ac...
There are a bewildering number of bone tumours with a wide variety of radiological appearances:
bone island / enostosis
Osteosarcomas are malignant bone forming tumours and the second most common primary bone tumour after multiple myeloma. They account for ~20% of all primary bone tumours and occur in primary and secondary forms, each with different epidemiology and distribution. Although plain radiography can pr...