Items tagged “rewrite”
135 results found
Article
ISSVA classification of vascular anomalies
The ISSVA classification of vascular anomalies encompasses all vascular malformations and tumors in a framework of internationally consistent nomenclature.
Usage
It is one of the two most widely used classification systems, the other being the Hamburg classification system of vascular malform...
Article
Bone mineral density
Bone mineral density (BMD) is defined as the amount of mineral (calcium hydroxyapatite) per unit of bone and can be used as an indirect indicator of bone strength. The bone mineral density is used to determine if osteopenia or osteoporosis are present.
Radiographic features
Bone mineral densit...
Article
Flare phenomenon (bone scintigraphy)
Flare phenomenon or osteoblastic flare phenomenon refers to interval visualization of lesions with a sclerotic rim around an initially lytic lesion or sclerosis of lesions previously undetected on radiograph or CT in the setting of follow-up of an oncological patient with other signs of partial ...
Article
Non-Hodgkin lymphoma
Non-Hodgkin lymphoma (NHL) is a neoplasm of the lymphoid tissues originating from B cell precursors, mature B cells, T cell precursors, and mature T cells. It includes all types of lymphomas apart from Hodgkin lymphoma.
See the WHO classification of haematolymphoid tumors for further informatio...
Article
Sports injuries - cricket
Cricket is a popular game in Commonwealth countries. Sports injuries in this game can be associated with three positional aspects of the game: bowling, batting or fielding. Radiologists should know the different kinds of injuries related to this game for a better clinical association. Injuries c...
Article
Hip hemiarthroplasty
Hip hemiarthroplasty is an orthopedic procedure for the treatment of certain femoral neck fractures where the femoral head is removed and replaced. The prefix hemi (meaning half) refers to the fact that the prosthetic femoral head articulates with the native acetabulum.
Indications
Hemiarthrop...
Article
Missing IUCD
A missing IUCD is considered when the retrieval strings of certain types of intrauterine contraception devices (IUCD) cannot be seen on physical examination. The possibilities are
expulsion of IUCD
migration of IUCD
detachment of IUCD thread
uterine perforation in IUCD
embedd...
Article
Pseudoenhancement
Pseudoenhancement is an artifact encountered with contrast-enhanced CT, whereby the calculated density of a lesion is inaccurately increased. This phenomenon is most often problematic during evaluation of renal cysts by CT.
On CT, it can be challenging to distinguish cystic versus solid renal l...
Article
Small pulmonary nodules (HRCT chest approach)
Small pulmonary lung nodules refer to an HRCT chest imaging descriptor for 5-10 mm lung nodules and are divided into three main categories based on their distribution pattern:
centrilobular
perilymphatic
random
Terminology
Radiologists often informally refer to indeterminate small pulmonary...
Article
Effect of isolated pronation-supination (lateral wrist radiograph)
The wrist series is comprised of a posteroanterior, oblique, and lateral projection. The series examines the carpal bones (namely, the scaphoid, lunate, triquetrum, pisiform, trapezium, trapezoid, capitate and hamate). It also examines the radiocarpal joint along with the distal radius and ulna....
Article
Flip angle
The flip angle is an MRI phenomenon by which the axis of the hydrogen proton shifts from its longitudinal plane (static magnetic field B0) Z axis to its transverse plane XY axis by excitation with the help of radiofrequency (RF) pulses. A RF pulse is sent in at the precise Larmor frequency in re...
Article
Filtered back projection
Filtered back projection is an analytic reconstruction algorithm designed to overcome the limitations of conventional back projection; it applies a convolution filter to remove blurring. It was, up until recently the primary method in cross-sectional imaging reconstruction.
It utilizes simulta...
Article
Cholescintigraphy
Cholescintigraphy is the use of radiotracers to assess the anatomy and function of the biliary system (and the liver indirectly). Currently, this is most commonly performed with Tc-99m-IDA analogs 1, and "hepatic IDA" imaging gave rise to the more common term "HIDA scan."
Indications
Cholescin...
Article
Nerve injury classification (MRI)
Nerve injury classification describes the various features of nerve injury on MRI with respect to pathological events.
Classification
neuropraxia
grade I:
there is increased T2/STIR signal in the nerve, however, the muscle appears normal
recovery occurs within a few days to 3 months
axono...
Article
Side lobe artifact
Side lobe artifacts occur where side lobes reflect sound from a strong reflector that is outside of the central beam, and where the echoes are displayed as if they originated from within the central beam.
Ultrasound transducer crystals expand and contract to produce primary ultrasound beams in ...
Article
Delayed nephrogram
A delayed nephrogram, commonly described on plain film urography, but also visible on CT urography, is when there is absence or reduction of the normal renal parenchymal enhancement on the nephrographic phase images.
Terminology
A delayed nephrogram is characteristically unilateral and is usua...
Article
Diffuse T1 bone marrow signal loss
Diffuse T1 vertebral bone marrow signal loss is associated with replacement of fatty marrow by edema or cellular tissue.
Radiographic features
MRI
T1-weighted imaging without fat suppression is one of the most important sequences for distinguishing between normal and abnormal bone marrow. Ab...
Article
Stellate ganglion
The stellate ganglion (plural: ganglia), also known as the cervicothoracic ganglion, is formed by the inferior cervical and first thoracic ganglia and is located just anterior to the head of the first rib. It receives input from the paravertebral sympathetic chain and provides sympathetic effere...
Article
Synovial enhancement
Synovial enhancement is an imaging feature typically observed on MRI imaging. It can occur in various forms and can be focal or diffuse.
Pathology
inflammatory
synovitis
transient synovitis of the hip
infective synovitis
inflammatory arthritides
septic arthritis
tuberculous septic arthri...
Article
Hartmann pouch
Hartmann pouches are a technique in colonic surgery. After a segment of colon is resected, there are generally two options with regards to what to do with the two ends of the colon:
both the upstream end of the colon (the end of the colon through which fecal contents would pass) and the downs...