Items tagged “rewrite”

Breast calcifications are deposits of calcium salts in the breast, which are radio-opaque on mammography. The majority are benign, but they can be associated with cancer. The ability to diagnose and appropriately manage the significant microcalcifications and differentiate them from innocuous fi...

Pregnancy associated breast cancer (PABC) is usually defined as a breast cancer diagnosed during pregnancy or one year following delivery. PABC occurs in one out of every 1500-10,000 pregnancies 5-6 and represents up to 3% of all breast malignancies. The incidence may be increasing due to many w...

Digital breast tomosynthesis (DBT) is an imaging technique that allows a volumetric reconstruction of the whole breast from a finite number of low-dose two-dimensional projections obtained by different X-ray tube angles, with a geometric principle very similar to that applied in stratigraphic te...

A multicentric breast cancer is a term given to a breast cancer where there are two or more breast cancers separated by normal breast tissue (often taken as 5 cm of separation 4). It is related to but distinct from the term multifocal breast cancer. At a pathological level It can also mean 2 t...

A comedo-type ductal carcinoma in situ, also known as comedocarcinoma in situ, is a high grade subtype of ductal carcinoma in situ (DCIS). It is the most aggressive of intraductal carcinomas. In 30% of cases it can be multicentric and/or multifocal. Diagnosis Comedo-type DCIS is diagnosed hist...

Aliasing on MRI, also known as wrap-around, is a frequently encountered MRI artifact that occurs when the field of view (FOV) is smaller than the body part being imaged. The part of the body that lies beyond the edge of the FOV is projected onto the other side of the image 5. This can be correc...

Patellofemoral instability or maltracking is the clinical syndrome due to morphologic abnormalities in the patellofemoral joint where the patella is prone to recurrent lateral dislocation. Epidemiology Most patients with patellar instability are young and active individuals, especially females...

Naturally occurring radioactive nuclei have a physical half life time of ~108 to 1010 years which makes them unsuitable for use in medical imaging. Thus radioactive nuclei used in medical practice are artificially synthesized. Production of these nuclei involve bombarding stable nuclei with pro...

The half-life time is the duration it takes for any physical process to reduce the initial amount to fifty percent of its initial value. Physical half-life time (Tp) The time interval required for an amount of certain radioactive nuclei to decay to half of its original value. Tp is always a co...

Dystrophic soft tissue calcification is a type of soft-tissue calcification, which occurs in damaged or necrotic tissue, while the serum level of calcium and phosphorus are normal. It may progress to ossification, in which case a cortical and trabecular bone pattern is visible. An often cited a...

Pancreatic calcifications can arise from many etiologies. Punctate intraductal calcifications chronic pancreatitis alcoholic pancreatitis (20-40%) 2  intraductal, numerous, small, irregular preponderant cause of diffuse pancreatic intraductal calcification gallstone pancreatitis (2%) 2 ​m...

Splenic calcifications can occur in various shapes and forms and can occur from a myriad of etiological factors. The usual calcification observed in radiographs are the multiple, miliary form presenting numerous small rounded densities averaging from three to five millimeters in diameter where ...

The differential diagnosis for masses of the cauda equina region is often considered separately to the remainder of the spinal cord. It is often difficult to determine whether masses in this region are intramedullary or intradural-extramedullary. Most common tumors myxopapillary ependymoma by...

Unilateral pulmonary edema represents only 2% of cardiogenic pulmonary edema with predilection for the right upper lobe and is strongly associated with severe mitral regurgitation 1,2. It is hypothesized that the regurgitation jet is directed towards the right superior pulmonary vein thus prefer...

Gastric outlet obstruction, also referred to as pyloric obstruction, occurs when a disease or condition blocks the normal emptying of the stomach. Pathology Etiology Gastric outlet obstruction can be due to malignant or benign causes. Malignant adenocarcinoma (second most common 4) GIST ...

MRI scanners, although free from potentially cancer-inducing ionizing radiation found in plain radiography and CT, have a host of safety issues which must be taken very seriously. MRI safety can be divided into: main magnetic field varying magnetic (gradient) fields radiofrequency M...

Adenocarcinoma of the lung is the most common histologic type of lung cancer. Grouped under the non-small cell carcinomas of the lung, it is a malignant tumor with glandular differentiation or mucin production expressing in different patterns and degrees of differentiation.  This article brings...

In fat pad impingement syndromes, the etiologies are different for each knee fat pad. In anterior suprapatellar fat pad impingement syndrome, the cause is usually due to either a developmental cause related to the anatomy of the extensor mechanism or may be related to abnormal mechanics. In thi...

Hydronephrosis (plural: hydronephroses) is defined as dilatation of the urinary collecting system of the kidney (the calyces, the infundibula, and the pelvis) 1. Hydronephrosis in fetuses and newborns has specific causes that are covered in a separate article. Terminology The term hydroureter...

Cytotoxic cerebral edema refers to a type of cerebral edema, most commonly seen in cerebral ischemia, in which extracellular water passes into cells, resulting in their swelling.  The term is frequently used in clinical practice to denote the combination of true cytotoxic edema and ionic cerebr...