Items tagged “ultrasound”
506 results found
Case
Subacromial subdeltoid bursa injection - ultrasound guided
Published
08 Nov 2009
16% complete
Ultrasound
Article
Hepatic hemangioma
Hepatic hemangiomas or hepatic venous malformations are the most common benign vascular liver lesions. They are frequently diagnosed as an incidental finding on imaging, and most patients are asymptomatic. From a radiologic perspective, it is important to differentiate hemangiomas from hepatic m...
Article
Gallbladder polyp
Gallbladder polyps are commonly occurring elevated lesions on the mucosal surface of the gallbladder. The vast majority are benign. They are best characterized on ultrasound as a non-shadowing endophytic growth into the gallbladder lumen.
Epidemiology
Gallbladder polyps are relatively frequen...
Article
Medullary thyroid carcinoma
Medullary thyroid carcinoma is a subtype of thyroid cancer that accounts for 5-10% of all thyroid malignancies. It occurs both sporadically (80%) and as a familial form.
Epidemiology
In non-familial cases, it typically peaks in the 3rd to 4th decades.
Associations
When familial, it is seen a...
Article
Choledocholithiasis
Choledocholithiasis denotes the presence of gallstones within the bile ducts (including the common hepatic duct/common bile duct).
Epidemiology
Choledocholithiasis is relatively common, seen in up to 20% of patients undergoing cholecystectomy for gallstone-related complaints 2.
Clinical prese...
Article
Endometrial thickness
Endometrial thickness is a commonly measured parameter on routine gynecological ultrasound and MRI. The appearance, as well as the thickness of the endometrium, will depend on whether the patient is of reproductive age or postmenopausal and, if of reproductive age, at what point in the menstrual...
Article
History of ultrasound in medicine
The first written document dealing with the use of waves in spatial orientation dates back to 1794, when an Italian physicist Lazzaro Spallanzani (“Opus coli di fisica”), analyzed the basic mechanisms of the navigation of flying bats in the dark, and rightly deduced that bats employed sound rath...
Article
Piezoelectric effect
The piezoelectric effect converts kinetic or mechanical energy, due to crystal deformation, into electrical energy. This is how ultrasound transducers receive the sound waves.
The same effect can be used in reverse – inverse piezoelectric effect – whereby the application of an electric field to...
Article
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...
Article
Ultrasound frequencies
Ultrasound frequencies in diagnostic radiology range from 2 MHz to approximately 15 MHz.
Higher ultrasound frequencies have shorter wavelengths and provide better detail and spatial resolution (recall that Axial resolution (ultrasound) = ½ ⨉ spatial pulse length). However, shorter wavelengths...
Article
Primary cardiac tumors
Primary cardiac tumors are uncommon and comprise only a small minority of all tumors that involve the heart: most are mediastinal or lung tumors that extend through the pericardium and into the heart, or metastases 1.
Epidemiology
Primary cardiac tumors have an estimated autopsy prevalence of ...
Article
Testicular microlithiasis
Testicular microlithiasis is a relatively uncommon condition that represents the deposition of multiple tiny calcifications throughout both testes.
Diagnosis
The most common criterion for diagnosis on ultrasound is that of at least five microcalcifications in one testis although the European ...
Article
Testicular cancer
Testicular cancers are the most common malignancy in men between the ages of 20 and 34 years.
Epidemiology
Testicular cancer is uncommon, accounting for less than 1% of all internal organ malignancies 2.
The commonest histology of the tumor varies with the age of affected individuals. Over 90...
Article
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 stromal fibrosis, or both processes lead to the formation of cysts, disabling the drainage of the terminal ducts of the lobules.
In al...
Article
Paratesticular tumors
A paratesticular mass may derive from a number of structures that surround the testis within the scrotum; most commonly, they derive from the spermatic cord.
Pathology
The masses can be categorized as benign (70%) or malignant (30%).
Etiology
Benign
spermatic cord lipoma (most common parat...
Article
Anaplastic thyroid carcinoma
Anaplastic thyroid carcinoma is a highly aggressive form of thyroid cancer and accounts for ~1-2% of primary thyroid malignancies. Of all the subtypes, this carries the worst prognosis.
Epidemiology
Typically occurs in the elderly with the peak incidence in the 6th and 7th decades. A significa...
Article
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 and flow characteristics in the carotid artery.
This article focuses on internal carotid a...
Article
Ovarian torsion
Ovarian torsion occurs when the ovary rotates around its supporting ligaments, twisting and squashing the accompanying blood vessels and lymphatics. The term adnexal torsion is preferred because a portion of the fallopian tube is commonly torsed along with the ovary. The term adnexal torsion als...
Article
Circumvallate placenta
Circumvallate placenta refers to a variation in placental morphology in which, as a result of a small chorionic plate, the amnion and chorion fetal membranes ‘double back’ around the edge of the placenta.
Epidemiology
The prevalence is estimated to be around 1-7% 3.
Pathology
There is an inw...
Article
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 favor reactive/infective nodes over malignancy include:
nodal matting
surrounding soft tissue edema
Doppler features
Doppler examination is particu...
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