Articles
Articles are a collaborative effort to provide a single canonical page on all topics relevant to the practice of radiology. As such, articles are written and continuously improved upon by countless contributing members. Our dedicated editors oversee each edit for accuracy and style. Find out more about articles.
336 results found
Article
Erythrocyte sedimentation rate
Erythrocyte sedimentation rate (ESR) is a non-specific marker of acute inflammation which is seen in a very wide spectrum of pathologies. It has been sidelined by the use of C-reactive protein and other acute phase markers but it still has an important role to play in the management of some cond...
Article
All-trans-retinoic acid syndrome
All-trans-retinoic acid (ATRA) syndrome, is the more common cause of differentiation syndrome 8. Acute promyelocytic leukemia (APL) cells respond to therapeutic levels of this normal plasma derivative of vitamin A by maturating into normal granulocytes which can cause capillary leakage and organ...
Article
Twin anemia polycythemia sequence
Twin anemia polycythemia sequence (TAPS) is considered a variant of the twin to twin transfusion syndrome (TTTS) occurring in monochorionic twin pregnancies.
Epidemiology
TAPS may occur spontaneously in up to 5% of monochorionic twins and may also develop after incomplete laser treatment in tw...
Article
Paroxysmal nocturnal hemoglobinuria
Paroxysmal nocturnal hemoglobinuria (PNH), also known as Marchiafava-Micheli syndrome or Strübing-Marchiafava anemia, is an acquired hematopoietic stem cell disorder whereby some of the red blood cells produced are defective and are susceptible to premature destruction by the immune system, lead...
Article
Sclerosing angiomatoid nodular transformation of the spleen
Sclerosing angiomatoid nodular transformation (SANT) of the spleen is a rare, non-neoplastic vascular splenic lesion of uncertain etiology.
Terminology
The term SANT first appeared in the literature in a 2004 article by Martel et al. which examined a series of 25 cases 3. This relatively unco...
Article
Ebola virus disease
Ebola virus disease (EVD) (also known as Ebola hemorrhagic fever (EHF) or simply Ebola) is a viral hemorrhagic disease caused by the Ebola filovirus. Ebola is an extremely virulent virus with a case fatality rate of ~70% 1.
Epidemiology
First recognized in 1967 after polio vaccine laboratory w...
Article
Normal hepatobiliary imaging examples
This article lists examples of normal imaging of the liver and biliary tree and surrounding structures, divided by region and modality.
Liver
Plain radiographs
liver silhouette: example
Ultrasound
liver ultrasound
example 1 with shear wave elastography
liver Doppler ultrasound: example ne...
Article
Bone marrow
Bone marrow is ubiquitous throughout the skeleton, primarily composed of hematopoietic cells and fat cells between bony trabeculae and fibrous retinacula. It performs numerous physiological functions and dynamically changes during normal aging and in response to stressors and pathology. Although...
Article
Immune thrombocytopenia
Immune thrombocytopenia (ITP), historically known as idiopathic thrombocytopenic purpura, is an autoimmune disorder characterized by a decrease in platelet numbers to <100 x 109/L. In most cases it is a primary condition, i.e. no underlying cause is found.
Terminology
Historically, immune thro...
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...
Article
Chédiak-Higashi syndrome
Chédiak-Higashi syndrome is a rare, potentially lethal, multisystemic disorder, characterized by congenital immunocompromise with susceptibility to bacterial infections, a bleeding diathesis, partial albinism affecting the skin and eyes, and gradual neurological decline 2,3.
Epidemiology
The e...
Article
Primary myelofibrosis
Primary myelofibrosis is a myeloproliferative neoplasm in which the bone marrow is replaced with collagenous connective tissue resulting in progressive fibrosis. It is characterized by:
extramedullary hematopoiesis
progressive splenomegaly
anemia
variable change in the number of granulocytes...
Article
PET-CT indications
PET-CT is a combination of cross-sectional anatomic information provided by CT and the metabolic information provided by positron emission tomography (PET).
PET is most commonly performed with 2-[F-18]fluoro-2-deoxy-D-glucose (FDG). Fluorine-18 (F-18) is an unstable radioisotope and has a half-...
Article
Labeled imaging anatomy cases
This article lists a series of labeled imaging anatomy cases by body region and modality.
Brain
CT head: non-contrast axial
CT head: non-contrast coronal
CT head: non-contrast sagittal
CT head: non-contrast axial with clinical questions
CT head: angiogram axial
CT head: angiogram coronal
...
Article
Splenic hamartoma
Splenic hamartomas are very rare lesions commonly found incidentally on imaging. They are most often solitary but may be present as multiple nodules in patients with tuberous sclerosis or Wiskott-Aldrich syndrome.
Terminology
Sclerosing angiomatoid nodular transformation (SANT) of the spleen,...
Article
Waldenström macroglobulinemia
Waldenström macroglobulinemia is a subtype of lymphoplasmacytic lymphoma (LPL), a form of B-cell lymphoma.
Terminology
Waldenström macroglobulinemia is classified as a subtype of lymphoplasmacytic lymphoma with any level of an IgM paraprotein; these two conditions are not synonymous 10.
Epide...
Article
Splenic cyst
Splenic epithelial cysts, also known as splenic epidermoid cysts or primary splenic cysts, are unilocular fluid lesions with thin and smooth walls and no enhancement. They represent ~20% of cysts found in the spleen and are usually an innocuous incidental imaging finding.
Note that most (~80%) ...
Article
Neurolymphomatosis
Neurolymphomatosis is a rare cause of neuropathy due to infiltration of the peripheral nervous system by a hematologic malignancy, in the great majority a B-cell non-Hodgkin lymphoma.
It should be differentiated from non-tumor neuropathies associated with lymphoma, such as irradiation, chemothe...
Article
Rheumatoid arthritis
Rheumatoid arthritis (RA) is a chronic autoimmune multisystemic inflammatory disease that affects many organs but predominantly attacks the synovial tissues and joints.
Epidemiology
The overall prevalence is 0.5-1% and the disease is 2-3 times more common in women 1.
Onset is generally in adu...
Article
Bing-Neel syndrome
Bing-Neel syndrome is an extremely rare neurological complication of Waldenström macroglobulinemia where there is malignant lymphocyte infiltration into the central nervous system (CNS).
Epidemiology
The exact incidence is unknown, however, in one study of patients with Waldenström macroglobul...