Items tagged “rewrite”

119 results found
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...
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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...
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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, and "hepatic "IDA" imaging gave rise to the more common term "HIDA scan." Indications Cholescint...
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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...
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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 ...
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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...
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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...
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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...
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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...
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Hartmann pouch

​Hartmann pouches​ are a technique in colon 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 downstr...
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Spinal stenosis

Spinal stenosis is a condition in which a portion of the spinal canal narrows to the point at which it can exert pressure on the nerves that travel through the spine. Spinal stenosis is not to be confused with foraminal stenosis, which is the narrowing of the foramina with subsequent compressio...
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Radionuclide cisternography

Radionuclide cisternography is a nuclear medicine imaging technique that uses intrathecal 111In-DTPA (diethyletriaminepentaacetic acid; pentetate) to visualize the flow of cerebrospinal fluid (CSF). There are a few indications 1: localization of CSF leak, such as in spontaneous intracranial hy...
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Abusive head trauma

Abusive head trauma is a term that is used for inflicted head injury that has occurred by either shaking, impact head trauma, or both, as part of the spectrum of non-accidental injury (NAI). Pathology Intracranial injuries Subdural hemorrhage in a child should be viewed with suspicion. Most o...
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Haemodialysis vascular access

Vascular access for haemodialysis is used for end-stage renal failure that requires renal replacement therapy. Options include temporary/permanent and non-surgical vs surgical methods. This article will focus on surgical arteriovenous fistulae. Types of vascular access Temporary temporary vas...
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Harris classification of acetabular fractures

The Harris classification of acetabular fractures is based on definitions of acetabular walls and columns that differ from the Judet and Letournel classification 1. Usage The Judet and Letournel classification is more widely used and is applicable to both CT and plain radiographs, whereas, the...
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Medial collateral ligament bursa

The medial collateral ligament bursa is one of the bursae of the knee with the shape of a vertically expanding compartment located between the superficial and deep portions of the medial collateral ligament 1-5. The bursa is usually located at the middle third of the knee, with the anterior marg...
Article

Acinar cell carcinoma of the pancreas

Pancreatic acinar cell carcinoma is a rare exocrine neoplasm that comprises ~1% of all pancreatic tumors. This tumor shows more aggressive behavior than the far more common adenocarcinoma 1,3,4. Clinical presentation High levels of serum lipase, due to hypersecretion syndrome, resulting in sub...
Article

Solid variant of aneurysmal bone cyst

The solid variant of the aneurysmal bone cyst (ABC) is a rare non-neoplastic and reactive bone lesion. It differs from the classical type of ABC in certain aspects. Epidemiology The solid variant of ABC has an incidence of ~5% (range 3.4-7.5%) and is found to have slight female predilection (1...
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Perivascular adductor longus muscle injury

A perivascular adductor longus muscle injury is an infrequent type of trauma to the adductor longus muscle, which is poorly and infrequently reported in the literature 1-3, and may as a result remain underdiagnosed and undertreated. Pathology The adductor longus muscle originates from the exte...

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