Articles
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16,854 results found
Article
Focal nodular hyperplasia
Focal nodular hyperplasia (FNH) is a regenerative mass lesion of the liver and the second most common benign liver lesion (the most common is a hemangioma). Many focal nodular hyperplasias have characteristic radiographic features on multimodality imaging, but some lesions may be atypical in app...
Article
Blake's pouch cyst
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 the regression of Blake's pouch second...
Article
Long COVID-19
Long COVID-19 also known as post-acute sequelae of SARS-CoV-2 infection (PASC) or post COVID-19 condition, is a post-viral syndrome affecting people who have recovered from COVID-19 infection. Symptoms are similar to those experienced by patients with chronic inflammatory response syndrome (CIRS...
Article
Löffler syndrome
Simple pulmonary eosinophilia (also known as Löffler syndrome) is a type of pulmonary eosinophilia that typically presents with transient radiographic infiltrates, minimal constitutional upset, and an elevated eosinophil count in peripheral blood.
Pathology
Etiology
The cause is not usually i...
Article
Coarctation of the aorta
Coarctation of the aorta (CoA) refers to a narrowing of the aortic lumen.
Epidemiology
Coarctations account for between 5-8% of all congenital heart defects. They are more frequent in males, M:F ratio of ~2-3:1.
Associations
As with many congenital abnormalities, coarctation of the aorta is ...
Article
Interrupted aortic arch
Interrupted aortic arch (IAA) is an uncommon congenital cardiovascular anomaly where there is a separation between the ascending and descending aorta. It can either be complete or connected by a remnant fibrous band. An accompanying large ventricular septal defect (VSD) and/or patent ductus arte...
Article
Photon-counting computed tomography
Photon-counting computed tomography (PCCT) is a new technology in CT that could represent the next major technological milestone in the field. Briefly, photon-counting CT uses energy-resolving detectors, thereby enabling scanning at multiple energies.
Technique
Physical principles
Current cli...
Article
Reflection
Reflection of a sound wave occurs when the wave passes between two tissues of different acoustic impedances and a fraction of the wave 'bounces' back. This forms one of the major principles of ultrasound imaging as the ultrasound probe detects these reflected waves to form the desired image.
An...
Article
Bosniak classification system of renal cystic masses (version 2005)
The Bosniak classification system of renal cystic masses, now known as Bosniak v2005, divides renal cystic masses into five categories based on imaging characteristics on contrast-enhanced CT, and helps predict a risk of malignancy and suggests either follow-up or treatment. An updated classific...
Article
Mandibular fracture
Mandibular fractures are relatively common especially among young men. Although traditionally the mandible and base of skull are thought to form a complete bony ring, interrupted only by the TMJs. This should mean that the mandible should fracture in two places (akin to the bony pelvis) making s...
Article
Intraosseous lipoma
Intraosseous lipomas are rare benign lesions that account for about 0.1-2.5% of all bone tumors. They are, however, the most common lipogenic tumors in bone 6.
Intraosseous lipomas account for one of the 'I's in the popular mnemonic for lucent bone lesions FEGNOMASHIC.
Epidemiology
Intraosseo...
Article
Langerhans cell histiocytosis (skeletal manifestations)
The skeleton is the most commonly involved organ system in Langerhans cell histiocytosis (LCH) and is by far the most common location for single-lesion LCH, often referred to as eosinophilic granuloma (EG) (the terms are used interchangeably in this article). For a general discussion of this dis...
Article
Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL)
Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an autosomal dominant microvasculopathy characterized by recurrent lacunar and subcortical white matter ischemic strokes and vascular dementia in young and middle age patients without known va...
Article
Neonatal pneumothorax
Neonatal pneumothorax describes pneumothoraces occurring in neonates. It is a life-threatening condition, associated with high morbidity and mortality. The diagnosis is a challenge especially when the amount of air is small and may accumulate along the anterior or medial pleural space.
Epidemio...
Article
Chest (lateral decubitus view)
The lateral decubitus view of the chest is a specialized projection that is now rarely used due to the ubiquity of CT. It is chiefly used in the pediatric population.
Indication
Undertaken to demonstrate small pleural effusions, or for the investigation of pneumothorax and air trapping due to...
Article
Spinnaker sign (mediastinum)
The spinnaker sign (also known as the angel wing sign) is a sign of pneumomediastinum seen on neonatal chest radiographs. It refers to the thymus being outlined by air with each lobe displaced laterally and appearing like spinnaker sails. This is distinct from the sail sign appearance of the nor...
Article
Prostatic abscess
Prostatic abscesses are a rare complication of prostatitis.
Epidemiology
Prostatic abscesses have become relatively uncommon due to the increased use of antibiotic therapy in patients with prostatitis. It tends to affect diabetic and immunosuppressed patients. Most patients affected are aroun...
Article
Mitral annular calcification
Mitral annular calcification refers to the deposition of calcium (along with lipid) in the annular fibrosa of the mitral valve.
Epidemiology
Annular calcification is seen in up to 35% of elderly patients. It is common in females over 65 years, in those with myxomatous degeneration of the mitra...
Article
Lucent/lytic bone lesion - differential diagnosis (mnemonic)
Mnemonics for the differential diagnosis of lucent/lytic bone lesions include:
FEGNOMASHIC
FOG MACHINES
They are anagrams of each other and therefore include the same components. They are by no means exhaustive lists, but are a good start for remembering a differential for a lucent/lytic bone...
Article
Dengue fever
Dengue fever is a mosquito-borne acute systemic viral infection caused by any of the four serotypes of the dengue virus.
Epidemiology
Dengue virus infections occur predominately in tropical and subtropical regions 3.
Clinical presentation
The infection can lead to a broad spectrum of sympto...