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.
More than 200 results
Article
Coronary artery disease
Coronary artery disease (CAD) is primarily due to the narrowing of the coronary arteries due to atherosclerosis, which results in myocardial ischemia and is the leading cause of mortality globally.
Diagnosis
The diagnosis of coronary artery disease is based on typical imaging criteria either ...
Article
Low-lying placenta
A low-lying placenta occurs when it extends into the lower uterine segment, and its edge lies close to the internal os of the cervix without covering it.
Terminology
The term should be used when the edge of the placenta is <2 cm from the cervical internal os in pregnancies >16 weeks gestation ...
Article
Myocardial infarction with non-obstructive coronary arteries
Myocardial infarction with non-obstructive coronary arteries (MINOCA) is referred to as a syndrome characterized by the clinical characteristics of myocardial infarction but with normal coronary arteries or no significant coronary stenosis on coronary angiography.
Epidemiology
The suggested pr...
Article
Pulmonary hypoplasia
Pulmonary hypoplasia refers to underdevelopment of one or both lungs. This can be rapidly fatal at birth or mild, escaping detection for decades. It is most often secondary to congenital abnormalities that either restrict intrathoracic space or alter pulmonary fluid dynamics.
Epidemiology
Pulm...
Article
Scatter to primary ratio
The scatter to primary ratio is a ratio of the scattered radiation to the primary unscattered radiation transmitted by the object being imaged. Hence, the scatter to primary ratio provides an indication of the degree of unwanted scattered radiation arising from a particular imaging study.
The s...
Article
CT stair-step artifact
The CT stair-step artifact is found in straight structures which are oriented obliquely with respect to movement of the table and appear around the edges of sagittal and coronal reformatted images when wide collimations and non-overlapping reconstruction intervals are used.
It is also seen in c...
Article
Exudative retinitis
Exudative retinitis, also known as retinal telangiectasis or Coats disease, is a rare congenital disease affecting the eyes and a cause of leukocoria.
Epidemiology
It occurs predominantly in young males, with the onset of symptoms generally appearing in the first decade of life with a peak age...
Article
Acquisition time
The time of acquisition for a conventional spin echo or gradient echo sequence is the product of the repetition time, phase encoding steps, and number of averages (TR x phase steps x NEX).
For example, with a one-second TR, 128 phase steps, and two averages, we would get an acquisition time of ...
Article
Progressive supranuclear palsy
Progressive supranuclear palsy (PSP), also known as the Steele-Richardson-Olszewski syndrome, comprises a group of related tauopathies and is considered a neurodegenerative disease with no efficacious treatment.
Epidemiology
Progressive supranuclear palsy typically becomes clinically apparent...
Article
Herring classification of Perthes disease
The Herring classification, also known as the lateral pillar classification, is one of the many systems used to describe Legg-Calvé-Perthes disease.
Usage
The Herring classification is currently the most recommended system given its higher inter- and intraobserver reliability (c. 2025) 2.
The...
Article
Anterior cruciate ligament reconstruction complications (overview)
Anterior cruciate ligament (ACL) reconstruction complications are common, occurring in 10-25% of patients.
Clinical presentation
Patients with complications of ACL reconstruction can present with decreased range of motion (impingement or arthrofibrosis) and/or laxity (graft rupture or stretchi...
Article
Lipiodol
Lipiodol (also known as ethiodized oil) is an oil-based iodinated contrast medium that was historically used for myelography and hysterosalpingography 1. It was later superseded by newer, less hazardous, agents, and now is used primarily as a therapeutic agent. Guerbet was previously the sole ma...
Article
Selective internal radiation therapy
Selective internal radiation therapy (SIRT), also known as transarterial radioembolization (TARE) or hepatic radioembolization, is a treatment for non-resectable liver tumors. The procedure consists of a transcatheter injection of radioactive particles via the hepatic artery.
It is technically...
Article
Mass attenuation coefficient
The mass attenuation coefficient (MAC) is a quantity used in calculations involving the penetration and energy deposition of photons (such as X-rays and gamma rays) in various materials, including biological tissues and shielding substances.
Definition
The MAC is defined as the linear attenuat...
Article
Anterior cruciate ligament reconstruction
Anterior cruciate ligament (ACL) reconstruction is a common procedure post ACL tear. It 's aim is to rebuild the anatomy and function of the native ACL and reduce knee joint instability, thus it will prevent any further meniscal and/or cartilage damage.
Procedure
There are numerous surgical t...
Article
Radiographic evaluation of anterior cruciate ligament reconstruction
Radiographic evaluation of anterior cruciate ligament (ACL) reconstruction involves:
femoral component
a line is drawn along the posterior cortex of the femur
a second line is drawn along the roof of the intercondylar notch of the femur (Blumensaat line)
the point of intersection of these tw...
Article
CT dose index
CT dose index (CTDI) (measured in mGy) is a standardized measure of radiation dose output of a CT scanner which allows the user to compare radiation output of different CT scanners. It is rather a calculated value, not a directly measureable value. In the past CTDI100 (measured over a 100 mm lon...
Article
Transitional cell carcinoma (urinary tract)
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...
Article
Synostosis
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...
Article
Brachytherapy
Brachytherapy, also known as sealed source radiation therapy or endocurietherapy, is a form of radiation therapy where a radioactive source is placed, under the guidance of imaging, within or next to the area requiring treatment. This provides localized targeted internal radiation.
Brachytherap...
Unable to process the form. Check for errors and try again.