Articles

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16,905 results found
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V/Q scan

V/Q (ventilation/perfusion) scan is a scintigraphic examination of the lung that evaluates pulmonary vasculature perfusion and segmental bronchoalveolar tree ventilation. Indications diagnosis of suspected pulmonary embolism, particularly in patients with a contraindication to CTPA (e.g. iodin...
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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 ...
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Hydrosalpinx

Hydrosalpinx is a descriptive term and refers to a fluid-filled dilatation of the fallopian tube. If the fluid is infected, i.e. pus, then it is a pyosalpinx; if bloody, then hematosalpinx. Clinical presentation Patients may be asymptomatic or may present with pelvic pain or infertility. Path...
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Mixed germ cell tumor of the mediastinum

Mixed germ cell tumors of the mediastinum or mediastinal mixed germ cell tumors are malignant non-seminomatous germ cell tumors of the mediastinum consisting of more than one type of germ cell tumor. Terminology The term ‘malignant teratoma’ is not recommended. Epidemiology Mixed germ cell t...
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Testicular seminoma

Testicular seminomas are a type of germ cell tumor and the most common testicular tumor, accounting for ~45% of all primary testicular tumors. This article concerns only testicular seminomas; however, seminomas can arise outside of the testis, most often within the anterior mediastinum (see arti...
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Progressive multifocal leukoencephalopathy

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease which results from the reactivation of John Cunningham virus (JC virus) infecting oligodendrocytes in patients with compromised immune systems. It is considered the most common clinical manifestation of JC virus infecti...
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Tubo-ovarian abscess

Tubo-ovarian abscesses are one of the late complications of pelvic inflammatory disease. Epidemiology Risk factors Risk factors for tubo-ovarian abscesses include 15: previous pelvic inflammatory disease 16 intrauterine device multiple sexual partners diabetes mellitus immunosuppression ...
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Focal hepatic hot spot sign

The focal hepatic hot spot sign, also known as the hot quadrate sign can be seen on technetium 99m sulfur colloid scans of the liver and spleen, as well as CT studies. Radiographic features It occurs as a focal area of increased radiopharmaceutical uptake, or iodinated contrast accumulation, i...
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Sinonasal disease

The nasal cavity and paranasal sinuses are host to many diseases and conditions, collectively termed sinonasal disease. Pathology inflammatory and infective conditions sinusitis acute sinusitis Pott puffy tumor chronic sinusitis fungal sinusitis non-invasive: hyphae do not invade mucosa...
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Robust rheumatoid arthritis

Robust rheumatoid arthritis, also known as arthritis robust or rheumatoid robustus, refers to a rare variant of rheumatoid arthritis with marked subchondral cysts (geodes) and preserved bone density 1,2. Patients remain in good health usually with few - or even no - symptoms, hence the epithet "...
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Systemic lupus erythematosus (gastrointestinal manifestations)

Gastrointestinal manifestations in patients with systemic lupus erythematosus (SLE) are common and may involve any region of the gastrointestinal tract or visceral organs. Clinical presentation Patients with abdominal or gastrointestinal involvement by systemic lupus erythematosus may have a v...
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Intercostal catheter

Intercostal catheters (ICC), or informally chest tubes, are inserted into the pleural space to drain fluid and/or air. They typically refer to large-bore (10-14 Fr) drains placed under direct vision rather than percutaneous pigtail catheters (6-8 Fr) placed under image guidance. Indication Th...
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Olfactory neuroblastoma

Olfactory neuroblastomas, also known as esthesioneuroblastomas (the spelling aesthesioneuroblastoma is considered archaic), are tumors arising from the basal layer of the olfactory epithelium in the superior recess of the nasal cavity. They usually present as a soft tissue mass in the superior o...
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Scleroderma

Scleroderma, also known as systemic sclerosis, is an autoimmune connective tissue disorder characterized by multisystem fibrosis and soft tissue calcification. As such, it affects many separate organ systems, which are discussed separately: musculoskeletal manifestations of scleroderma pulmona...
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Fibromuscular dysplasia

Fibromuscular dysplasia (FMD) is a heterogeneous group of vascular lesions characterized by idiopathic, non-inflammatory, and non-atherosclerotic angiopathy of small and medium-sized arteries. Epidemiology The prevalence is unknown 7. It is most common in young women with a female to male rati...
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Osteomyelitis

Osteomyelitis (plural: osteomyelitides) refers to infection, typically bacterial, of bone involving the medullary cavity 21. This article is focused on acute bacterial osteomyelitis. Other types of osteomyelitis are discussed separately: chronic osteomyelitis fungal osteomyelitis skeletal sy...
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Chronic osteomyelitis

Chronic osteomyelitis is a form of osteomyelitis that is defined as a progressive inflammatory process resulting in bone destruction and sequestrum formation. Bacteria and fungi can cause it, and it may present as recurrent or intermittent disease. Terminology Chronic osteomyelitis is where sy...
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Iannetti classification of orbital invasion

The Iannetti classification grades orbital invasion by sinonasal tumors. Usage There is no universally accepted classification system (c.2021) for assessing orbital invasion by sinonasal tumors and other grading systems, including those proposed by McCary et al. and Neel et al. 2. Classificat...
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Liver trauma

The liver is one of the most frequently damaged organs in blunt trauma, and liver trauma is associated with a significant mortality rate. Epidemiology In blunt abdominal trauma, the liver is injured ~5% (range 1-10%) of the time 1,3. Clinical presentation Patients can present with right uppe...
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Varicocele embolization

Varicocele embolization is a minimally invasive method of treating varicoceles by embolizing the testicular vein (internal spermatic veins). Indications symptomatic varicocele infertility/subfertility failed surgical ligation Contraindications Relative contraindications include: intraveno...

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