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
Raccoon eyes sign (base of skull fracture)
Raccoon eyes sign (or panda eyes in the UK and Ireland) refers to periorbital ecchymosis with sparing of the tarsal plate 3 and is a physical examination finding indicative of a base of skull fracture of the anterior cranial fossa.
However it is not pathognomonic for trauma, and there are sever...
Article
Thoracic lymph node stations
Thoracic lymph nodes are divided into 14 stations as defined by the International Association for the Study of Lung Cancer (IASLC) 1, principally in the context of oncologic staging. For the purpose of prognostication, the stations may be grouped into seven zones. The IASLC definitions leave so...
Article
DNA
DNA (deoxyribonucleic acid) is a nucleic acid that encodes the genetic information (genome) necessary for RNA (ribonucleic acid) transcription (transcriptome) and protein synthesis (proteome) 1. It is contained in the nucleus of eukaryotic cells in the form of chromatin or chromosomes 7,8.
Mole...
Article
Lytic bone metastases
Lytic bone (osteolytic) metastases are distant tumor deposits of a primary tumor within bone characterized by a loss of bone with the destruction of the bone matrix.
Epidemiology
Lytic bone metastases are more common than sclerotic bone metastases.
Diagnosis
The diagnosis is usually establis...
Article
Trousseau syndrome
Trousseau syndrome is an inconsistently defined entity which broadly represents the association between thromboembolism and malignancy, often prior to or concomitantly with the diagnosis of the underlying malignancy 1.
The syndrome has been variably defined to include entities such as migratory...
Article
Bone tumors (overview)
There are a bewildering number of bone tumors with a wide variety of radiological appearances. For a formal and updated classification of bone tumors, see WHO classification of tumors of bone.
bone-forming tumors
osteoma
osteoid osteoma
osteoblastoma
osteosarcoma
cartilage-forming tumors
...
Article
CIC-rearranged sarcoma
CIC-rearranged sarcomas or CIC-DUX4 sarcomas are aggressive undifferentiated small round cell sarcomas with CIC-gene fusions most frequently CIC-DUX4. It is an ultra-rare high grade undifferentiated sarcoma, distinct in terms of clinical presentations and molecular characteristics 6.
Epidemiolo...
Article
Kaposiform hemangioendothelioma
Kaposiform hemangioendotheliomas are rare, locally invasive vascular tumors that often present in infancy, most commonly as an enlarging cutaneous mass 1,2. They are classified as distinct from tufted angiomas in the ISSVA classification of vascular anomalies. However, some consider it to be on ...
Article
Benign and malignant characteristics of breast lesions at ultrasound
Benign and malignant characteristics of breast lesions at ultrasound allow the classification as either malignant, intermediate or benign based on work published by Stavros et al. in 1995.
Radiographic features
Ultrasound
Malignant characteristics (with positive predictive values)
sonographi...
Article
Ischemic colitis
Ischemic colitis refers to inflammation of the colon secondary to vascular insufficiency and ischemia. It is sometimes considered under the same spectrum as intestinal ischemia. The severity and consequences of the disease are highly variable.
Epidemiology
Ischemic bowel is typically a disease...
Article
Neuroblastoma
Neuroblastomas are tumors of neuroblastic origin. Although they may occur anywhere along the sympathetic chain, the vast majority arise from the adrenal gland.
They represent the most common extracranial solid childhood malignancy and are the third most common childhood tumor after leukemia and...
Article
Chordoma
Chordomas are uncommon malignant tumors of the axial skeleton that account for 1% of intracranial tumors and 4% of all primary bone tumors.
They originate from embryonic remnants of the primitive notochord (earliest fetal axial skeleton, extending from the Rathke's pouch to the tip of the cocc...
Article
Meningeal hemangiopericytoma (historical)
Hemangiopericytomas of the meninges are rare tumors of the meninges, now considered to be an aggressive form of solitary fibrous tumors of the dura. They often present as large and locally aggressive dural masses, frequently extending through the skull vault. They are difficult to distinguish on...
Article
Malignant transformation
Malignant transformation is the term given to the process whereby either normal, metaplastic, or benign neoplastic tissue, becomes a cancer. The process usually occurs in a series of steps and the affected tissue gradually accumulates the genetic mutations that express a malignant phenotype. The...
Article
Adrenal metastasis
Adrenal metastases are the most common malignant lesions involving the adrenal gland. Metastases are usually bilateral but may also be unilateral. Unilateral involvement is more prevalent on the left side (ratio of 1.5:1).
Epidemiology
They are present at autopsy in up to 27% of patients with ...
Article
Ovarian-Adnexal Reporting and Data System Ultrasound (O-RADS US)
The Ovarian-Adnexal Reporting and Data System Ultrasound (O-RADS US) forms the ultrasound component of the Ovarian-Adnexal Reporting and Data System (O-RADS). This system aims to ensure that there are uniform unambiguous sonographic evaluations of ovarian or other adnexal lesions, accurately ass...
Article
Neoplasm
Neoplasms, also known as tumors, are pathological masses, caused by cells abnormally proliferating and/or not appropriately dying. Neoplasms may be either benign or malignant. Malignant neoplasms are synonymous with cancers.
Benign neoplasms
clear origin (unless very large)
slow growth
usua...
Article
Basal cell carcinoma
A basal cell carcinoma (BCC) is one of the commonest non-melanocytic types of skin cancer.
Epidemiology
Typically present in elderly fair-skinned patients in the 7th to 8th decades of life. There may be an increased male predilection.
Associations
Multiple basal cell carcinomas may be prese...
Article
Retiform hemangioendothelioma
Retiform hemangioendotheliomas or hobnail hemangioendotheliomas are intermediate locally aggressive and rarely metastasizing vascular neoplasms with a distinctive hobnail endothelial cell morphology.
Epidemiology
Retiform hemangioendotheliomas are rare with <100 cases reported in the literatur...
Article
Kimura disease
Kimura disease, also known historically as eosinophilic hyperplastic lymphogranuloma, is a rare benign inflammatory disease that characteristically manifests as enlargement of cervical lymph nodes and salivary glands.
Epidemiology
Kimura disease typically affects males (80%) between 20-40 year...