Items tagged “ultrasound”
398 results found
Long head of biceps tendinopathy
Biceps tendon can be examined both with MRI of the shoulder or Ultrasound of the shoulder. Ultrasound findings The findings on ultrasound indicating tendinopathy are the same as with other tendons: fluid in the tendon sheath (note: it communicates with the shoulder joint and is therefore no...
Ultrasound of the hip (adult)
There are several approaches to ultrasound examination of the adult hip. Anterior approach Patient positioning supine with the hip in mild external rotation Planes sagittal oblique plane parallel to the long axis of the femoral neck to assess femoral head and neck and for any joint effusio...
Ultrasound appearances of liver metastases
Ultrasound appearance of liver metastases can have bewildering variation. Patterns do exist between ultrasound appearance of the liver metastases and the likely primary, which is sometimes helpful in directing a search for an unknown primary, as well as helping distinguish between benign lesion...
A pseudodysraphism refers to the splayed appearance of a normal spine created due to excessive craniocaudal angulation during sonographic evaluation. This can erroneously lead to the diagnosis of a spinal neural tube defect.
Subacromial subdeltoid bursa injection - ultrasound guided
Published 08 Nov 2009
Physical principles of ultrasound
Medical ultrasound is based on the use of high-frequency sound to aid in the diagnosis and treatment of patients. Ultrasound frequencies range from 2 to approximately 15 MHz, although even higher frequencies may be used in some situations. The ultrasound beam originates from mechanical oscillat...
Ultrasound frequencies in diagnostic radiology range from 2 MHz to approximately 15 MHz. It is important to remember that higher frequencies of ultrasound have shorter wavelengths and are absorbed/attenuated more easily. Therefore, higher frequencies are not as penetrating. This explains why h...
Piezoelectric effect refers to applying an electric field to a crystal, which causes realignment of the internal dipole structure resulting in the crystal to lengthen or contract. The process converts electrical energy into kinetic or mechanical energy. The reverse of the piezoelectric effect c...
Historical aspects of ultrasound in medicine
The first written document dealing with the use of waves in spatial orientation dates back to 1794, when Lazaro Spallanzani (“Opus coli di fisica”), analyzed the basic mechanisms of spatial orientation of the bats, proposing other mechanisms of spatial orientation than the visual – ophthalmic sy...
Ultrasound evaluation of breast cysts
Ultrasound evaluation of breast cysts is the modality of choice. Obstruction of the ducts, often appearing as the result of epithelial hyperplastic processes or the stromal fibrosis, or both processes lead to the formation of cysts, disabling the drainage of the terminal ducts of the lobules. I...
Reactive vs malignant lymph nodes (ultrasound features)
A number of sonographic features are helpful in distinguishing reactive versus malignant lymph nodes. Grey scale features Features that favour reactive/infective nodes over malignancy include: nodal matting surrounding soft tissue oedema Doppler features Doppler examination is particularly...
Ultrasound assessment of carotid arterial atherosclerotic disease
Ultrasound assessment of carotid arterial atherosclerotic disease has become the first choice for carotid artery stenosis screening, permitting the evaluation of both the macroscopic appearance of plaques as well as flow characteristics in the carotid artery. This article focus on internal caro...
Hepatic arterial resistive index
The resistive index (RI) is the commonest Doppler parameter used for hepatic arterial evaluation. The usual range in normal, as well as post-transplant individuals, is between 0.55 and 0.8. It is measured by: RI = (peak systolic velocity - end diastolic velocity)/peak systolic velocity Hepati...
Colour comet-tail artifact
The colour comet-tail artifact is an ultrasonographic sign seen in a number of situations when colour Doppler scanning is performed. Typically the artifact, which resembles the grey-scale comet-tail artifact, is seen in a situation when a small highly refractive (usually calcific) object is int...
The comet-tail artefact is a grey-scale ultrasound finding seen when small calcific / crystalline / highly reflective objects are interrogated and is believed to be a special form of reverberation artifact. It is similar to the colour comet-tail artefact and is seen in similar situations, altho...
Failed early pregnancy
Published 05 Aug 2010
Generalised reduced hepatic echogenicity
Causes of generalised reduction of liver echogenicity on ultrasound include: acute hepatitis diffuse malignant infiltration See also generalised increase in liver echogenicity hepatic attenuation on CT
Generalised increase in hepatic echogenicity
Causes of generalised increased liver echogenicity include: diffuse fatty infiltration cirrhosis: can be coarsened as well chronic hepatitis 3: can be coarsened as well diffuse infiltration or deposition malignant process granulomata tuberculosis brucellosis sarcoidosis glycogen stora...
Keyhole sign (posterior urethral valves)
The keyhole sign is an ultrasonographic sign seen in boys with posterior urethral valves. It refers to the appearance of the proximal urethra (which is dilated) and associated thick walled distended bladder which on ultrasound may resemble a key hole.
Acute appendicitis - paediatric
Published 15 Jan 2011