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Articles

Articles are a collaborative effort to provide a single canonical page on all topics relevant to the practice of radiology. As such, articles are written and edited by countless contributing members over a period of time. A global group of dedicated editors oversee accuracy, consulting with expert advisers, and constantly reviewing additions.

782 results found
Article

Pediatric cervical lesions (differential)

The differential diagnosis of pediatric cervical lesions is commonly encountered in practice, unfortunately, the list is long. Differential diagnosis Inflammatory Most lesions tend to be inflammatory 3: non-tuberculous mycobacterial lymphadenitis scrofula sialodochitis abscess infected ...
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Pediatric clavicle abnormalities

The clavicle is a unique bone and as such it often displays unique pathology. The following is an attempt to summarize pediatric clavicle abnormalities. Pediatric bone tumors and tumor-like lesions of the clavicle majority of clavicular tumors are malignant Ewing sarcoma (most common) osteos...
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Pediatric nasal cavity masses

Pediatric nasal cavity masses can occur within the nose or the nasopharynx. These masses are often found incidentally on imaging but can be readily apparent clinically. Clinical presentation The clinical features of these lesions tend to mimic upper respiratory processes and may result in dela...
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Pediatric renal tumors and masses

Pediatric renal tumors and masses are another group of diseases (just like cystic renal diseases in both the adult and child) that are bewildering in their number, nomenclature and overlapping findings. Commoner lesions Wilms tumor: common in older children 1-8 years old nephroblastomatosis: ...
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Pediatric skeletal metastases (differential)

There are a wide range of primary malignancies that result in pediatric skeletal metastases 1: neuroblastoma leukemia: although not truly metastases lymphoma clear cell sarcoma: Wilms’ variant rhabdomyosarcoma retinoblastoma Ewing sarcoma: lung metastases much more common osteosarcoma: l...
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Pancreatic atrophy

Pancreatic atrophy is non-specific and is common in elderly patients, although in younger patients it can be a hallmark of pathology. Most commonly it is associated with aging, obesity and end-stage chronic pancreatitis.  It occurs principally with fatty replacement of the pancreas (pancreatic ...
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Pancreatic calcifications

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...
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Pancreatic neoplasms

There are numerous primary pancreatic neoplasms, in part due to the mixed endocrine and exocrine components. Classification Classification based on function exocrine: ~99% of all primary pancreatic neoplasms pancreatic ductal adenocarcinoma ~90-95% cystic neoplasm intraductal papillary muc...
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Pancreatitis

Pancreatitis (plural: pancreatitides) refers to inflammation involving the pancreas.  It has various forms which can be classified in many, many ways according to time of onset, etiological agent or associated pathology. acute pancreatitis interstitial edematous pancreatitis necrotizing panc...
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Papillary lesions of the breast

Papillary lesions of the breast comprise a wide group and range from benign to malignant. Pathology They develop as tufts of epithelium with a fibrovascular core that arborizes into branching papillae and protrude into the duct lumen. Benign papilloma of breast / intraductal papilloma of the ...
Article

Parasyndesmophytes

Parasyndesmophytes or floating syndesmophytes are, as the name suggests, paravertebral dystrophic soft tissue calcifications or heterotopic ossifications. Pathology Etiology They are known to be seen in 4:  psoriatic arthritis reactive arthritis Radiographic features Initially they begin ...
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Paratesticular lesions

Paratesticular lesions have a long list of differential diagnoses: neoplastic benign epididymal cyst (most common epididymal mass) scrotal tunica cysts tunica vaginalis cyst tunica albuginea cyst spermatic cord lipoma scrotal hemangioma: is often hypervascular on color Doppler, unlike ot...
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Paratesticular tumors

A paratesticular mass may derive from a number of structures that surround the testicle 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 par...
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Parkinson-plus syndrome

Parkinson-plus syndromes are a loose group of neurodegenerative disorders that are characterized by features of Parkinson disease but with other neurological symptoms/signs. They have a poor response to levodopa, and mostly have fairly characteristic neuroimaging features.  Conditions included ...
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Parotid enlargement

Parotid enlargement (also known as parotidomegaly) has a wide differential given the significant breadth of pathology that can affect the parotid gland. These can be separated by the standard surgical sieve approach into infective, inflammatory, immune, neoplastic, infiltrative, and congenital c...
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Patella alta

Patella alta, or a high riding patella, describes a situation where the position of the patella is considered high. It may be idiopathic or may result secondary to a patellar tendon rupture.  Epidemiology Associations Several conditions are known to be associated with patella alta, including:...
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Patella baja

Patella baja (or patella infera) is an abnormally low lying patella, which is associated with restricted range of motion, crepitations, and retropatellar pain. If longstanding, extensor dysfunction may ensue with significant morbidity. Pathology It is seen in a variety of clinical scenarios in...
Article

Patellar tumors

Patellar tumors are extremely rare. They can be either benign or malignant primary bone tumors, or metastases.  Epidemiology Patellar tumors represent just 0.1% of all primary bone tumors 1.  Clinical presentation Patients may present with anterior knee pain and/or a palpable mass 1,3. Path...
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Pathological gas

Some medical conditions are characterized by the presence of pathological gas i.e. gas/air found in a space, tissue, or organ, where it would not normally be expected to be. Terminology prefix 'pneumo' is common, especially when it refers to gas within a body space/cavity e.g. pneumothorax em...
Article

Patterns of bone bruise in knee injury

The pattern of bone bruise in knee injuries (a.k.a. bone contusion) can give clues for the mechanism and associated injuries.  Radiographic features Five classic bone contusion patterns have been described 1-4: pivot-shift injury valgus stress to flexed and externally rotated knee contusion...
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Patterns of neonatal hypoxic–ischemic brain injury

Neonatal hypoxic ischemic brain injuries can manifest in different patterns of involvement depending on the severity and timing of the insult. When considering the perinatal maturation process of the brain and the severity of an insult, it is possible to understand the various manifestations. T...
Article

Pear-shaped bladder

Pear-shaped (or teardrop-shaped) bladder is one whose normal round or ovoid shape has been extrinsically compressed to resemble a pear. The pear may be inverted or upright, depending on how the excess pelvic tissue compresses the bladder. Pathology Etiology Causes of a pear-shaped bladder inc...
Article

Pedunculated intratracheal mass

A pedunculated intratracheal mass has a variety of differential diagnoses: benign tumor, e.g. hamartoma, chondroma, lipoma hemangioma inspissated mucus metastasis to tracheal mucosa, e.g. renal cell carcinoma, melanoma polyp, e.g. inflammatory, antrochoanal papilloma post-intubation trach...
Article

Pelvic masses in females

Pelvic masses in females carry a broad differential diagnosis: benign adnexal cyst leiomyoma pelvic malignancy dermoid endometriosis pelvic inflammatory disease tubo-ovarian abscess hydrosalpinx pregnancy Extragynaecological masses, e.g. colorectal carcinoma, appendicular abscess, lymp...
Article

Pencil-in-cup deformity

Pencil-in-cup deformity is the description given to one of the appearances on plain radiographs classically associated with psoriatic arthritis; however, it is not pathognomonic. Radiographic features The appearance results from periarticular erosions and bone resorption giving the appearance ...
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Periampullary tumors

Periampullary tumors are those that arise within 2 cm of the ampulla of Vater in the duodenum. Tumors that fall under this group include four main types of tumors 1,4 that will be approached in their specific articles: pancreatic head/uncinate process tumors: includes pancreatic ductal adenoca...
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Periapical radiolucency (teeth)

Periapical radiolucencies are commonly observed findings on OPG and other dental/head and neck imaging modalities. Differential diagnosis They can represent a number of pathologies: periapical lucency related to apical periodontitis periapical granuloma periapical abscess periapical cyst ...
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Periarticular soft tissue calcification

Common causes of periarticular soft tissue calcification include: myositis ossificans post surgical dystrophic calcification or heterotopic bone formation calcific tendinitis or bursitis gout CPPD HADD calcific periarthritis (fingers and toes) tuberculous arthritis scleroderma hyperpar...
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Peribronchovascular thickening

Peribronchovascular thickening is a broad imaging descriptive term usually used to describe thickening of any or a combination of the below: peribronchovascular interstitial thickening bronchial wall thickening: can be differentiated from true peribronchovascular thickening on cross-sectional ...
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Pericardial fat pads

Pericardial fat pads are normal structures that lie in the cardiophrenic angle. They are adipose tissues surrounding the heart composed of the epicardial fat, which lies between the myocardium and visceral pericardium, and paracardial fat, which is adherent and external to the parietal pericardi...
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Perilymphatic lung nodules

Perilymphatic lung nodules follow perilymphatic channels and on imaging are typically subpleural, occur along fissures (perifissural nodules), interlobular septa and adjacent to the bronchovascular bundles. Differential diagnosis Lung nodules in a perilymphatic distribution can be seen in asso...
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Perinephric fluid collection post renal transplant

Perinephric fluid collections post renal transplant are common. The appearance of a perinephric fluid collection after renal transplantation is often non-specific but may be partially differentiated by how long ago the transplant occurred. Radiographic features Early post-transplant period (<4...
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Periosteal new bone formation in children

Periosteal reaction in the pediatric population, also known as periostitis in children, is relatively common occurrence and can result from many causes. Differential diagnosis The differential diagnosis for multiple bone periostitis include but not limited to the following: physiological peri...
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Periosteal reaction

Periosteal reaction, also known as periostitis or periosteitis, is a nonspecific radiographic finding that indicates periosteal irritation. Periosteal reactions may be broadly characterized as benign or aggressive, or more specifically categorized by pattern. Classification Benign versus aggre...
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Periportal hyperechogenicity

Periportal hyperechogenicity can result from many causes including: pneumobilia cholecystitis schistosomiasis of the portal region recurrent pyogenic cholangitis (oriental) inflammatory bowel disease: has been described to give "echo-rich" periportal cuffing 2​
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Periportal hypoechogenicity

Periportal hypoechogenicity can result from many causes: orthotopic liver transplant rejection congestive hepatopathy malignant lymphatic obstruction cholangitis viral hepatitis See also periportal hyperechogenicity periportal halo
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Peritoneal calcification

Peritoneal calcification is seen in a limited number of conditions that result in calcification of peritoneal structures. Therefore, the differential diagnosis is small: psammoma bodies in malignancy (most frequently cystadenocarcinoma of the ovary): fine sand-like calcification pseudomyxoma p...
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Per vaginal bleeding in the exam

It is important to have a systematic way of approaching a case with per vaginal (PV) bleeding in the exam.  Premenopausal embedded IUCD lost IUCD submucosal fibroid Pregnancy-related perigestational hemorrhage intrauterine fetal demise ectopic pregnancy ruptured ectopic cervical ectopi...
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Petrous apex lesions (differential)

There is a wide differential diagnosis of petrous apex lesions: asymmetrical marrow / asymmetrical pneumatization non-expansile fat signal intensity on all sequences petrous apex cephalocoele 4 CSF signal intensity on all sequences petrous apicitis congenital cholesteatoma  restricted di...
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Pituitary region masses

A simple and popular mnemonic to remember the common suprasellar/parasellar/intrasellar masses is SATCHMO. The more comprehensive list includes: tumors pituitary adenoma (commonest in the adult population) pituitary macroadenoma pituitary microadenoma pituitary carcinoma pituitary lymphoma...
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Pituitary region masses (most common)

The five most common masses in the pituitary region are: pituitary macroadenoma meningioma aneurysm craniopharyngioma suprasellar pilocytic astrocytoma Craniopharyngioma and suprasellar pilocytic astrocytoma are common in children, and pituitary macroadenoma, meningioma, aneurysm are mostl...
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Pituitary region mass with intrinsic high T1 signal

Pituitary region masses with intrinsic high T1 signal, also referred to as suprasellar hotspots, are relatively frequently encountered, and the presence of high T1 signal narrows the differential somewhat.  Differential diagnosis The differential can be divided by the substance causing the T1 ...
Article

Placentomegaly

Placentomegaly is a term applied to an abnormally-enlarged placenta. Epidemiology Associations It can be associated with a number of maternal and fetal disorders which include: maternal maternal anemia(s) maternal diabetes chronic intrauterine infections alpha-thalassemia fetal umbilic...
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Pleural adhesions

Pleural adhesions usually refers to the formation of fibrotic bands that span the pleural space, between the parietal and visceral layers of the pleura.  Pathology They may be local or diffuse. The presence of a pleural adhesion is one of the causes for a pneumothorax not to resolve. Etiology...
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Pleural calcification

Pleural calcification can be the result of a wide range of pathology and can be mimicked by a number of conditions/artifacts. True calcification calcified pleural plaques from asbestos exposure: typically with sparing of the costophrenic angles hemothorax infection involving the pleura: e.g....
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Pleural effusion

Pleural effusions are abnormal accumulations of fluid within the pleural space.  They may result from a variety of pathological processes which overwhelm the pleura's ability to reabsorb fluid. Terminology "Pleural effusion" is commonly used as a catch-all term to describe any abnormal accumul...
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Pleural thickening

Pleural thickening is a descriptive term given to describe any form of thickening involving either the parietal or visceral pleura.  It can occur with both benign and malignant pleural disease. According to etiology it may be classified as: benign pleural thickening following recurrent inflam...
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Pleural tumors

There are several tumors that can involve the pleura which can range from being benign to malignant. The list includes: primary pleural tumors 5 mesothelial tumors pleural malignant mesothelioma well-differentiated papillary mesothelioma adenomatoid tumor mesenchymal tumors solitary fibro...
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Pneumatocele

Pneumatoceles are intrapulmonary gas-filled cystic spaces that can have a variety of sizes and appearances. They may contain gas-fluid levels and are usually the result of ventilator-induced lung injury in neonates or post-infectious. They should not be mistaken for a cavitating lung mass.  Epi...
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Polyarticular arthropathy

Polyarticular arthropathy can arise from a number of causes. The list includes osteoarthritis (OA) erosive osteoarthritis rheumatoid arthritis (RA) psoriatic arthritis Reiter syndrome ankylosing spondylitis gout calcium pyrophosphate dihydrate deposition disease (CPPD) hemochromatosis ...
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Polyhydramnios

Polyhydramnios refers to a situation where the amniotic fluid volume is more than expected for gestational age. It is generally defined as: amniotic fluid index (AFI) >25 cm largest fluid pocket depth (maximal vertical pocket (MVP)) greater than 8 cm 6: although some centers, particularly in ...
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Polyostotic bone lesions in adults

Common causes of polyostotic bone lesions in adults include: inflammatory arthritic or synovial-based lesions neoplastic benign non-ossifying fibromas (fibroxanthomas) polyostotic fibrous dysplasia (McCune-Albright syndrome) malignant multiple myeloma metastases metabolic primary hype...
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Posterior mediastinal mass (differential diagnosis)

The differential diagnosis for a posterior mediastinal mass includes: neoplasm neurogenic tumors: most common  nerve sheath tumors schwannoma neurofibroma malignant peripheral nerve sheath tumor parasympathetic ganglion tumors paraganglioma  chemodectoma pheochromocytoma 3 sympathetic...
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Postobstructive pulmonary edema

Postobstructive pulmonary edema is a type of non-cardiogenic pulmonary edema and is an uncommon but well-described complication of upper airway obstruction. Clinical presentation It occurs in three clinical settings 6: acute airway obstruction chronic upper airway obstruction immediately af...
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Premature closure of a growth plate (differential)

Premature closure of a growth plate subsequently results in a shortened bone, which can occur in a number of situations.  Pathology Etiology Common local hyperemia infection: osteomyelitis juvenile chronic arthritis juvenile rheumatoid arthritis hemophilia arteriovenous malformation tr...
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Proptosis

Proptosis (rare plural: proptoses) refers to forward protrusion of the globe with respect to the orbit. There are many causes of proptosis which can be divided according to location and it is worth remembering that it is not just orbital disease processes that cause proptosis. Terminology Exop...
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Prostate cystic disease

Prostate cystic disease encompasses a wide variety of pathologies that all result in cyst formation within the prostate. Epidemiology Prostatic cysts are common, and ~5-8% men will develop one 4,7. However they are much more common in patients being investigated for infertility, with one study...
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Prostate peripheral zone T2 hypointensity

Prostate peripheral zone T2 hypointensity is a common finding in pelvic MRIs that needs to be evaluated. A prostate MRI is usually performed with a multiparametric technique (mpMRI) to differentiate prostate cancer from more benign pathologies. mpMRI includes T2 weighted images, dynamic contrast...
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Prostatomegaly

Prostatomegaly is a term used to generally describe enlargement of the prostate gland from whatever cause. Usually, the prostate is considered enlarged on imaging when its volume measures beyond 30 cc (mL).  Terminology The term prostatomegaly is often used interchangeably with benign prostati...
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Pseudoarthrosis (differential)

A pseudoarthrosis (plural: pseudoarthroses) (a.k.a. false joint) is a mobile fracture non-union. Pathology A fibrous, pseudosynovial capsule forms around the non-union and viscous fluid fills the site that may simulate synovial fluid. Etiology fracture non-union failed bone graft neurofibr...
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Pseudobladder

Pseudobladder refers to a pelvic cystic mass that simulates the urinary bladder. The location of the lesion should allow differentiation from the bladder but if doubt exists and clinical necessity arises, a delayed phase CT/MRI with excreted contrast or Foley catheter-administered retrograde co...
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Pseudocirrhosis

Pseudocirrhosis is a radiological term used to convey the imaging findings of cirrhosis, but emphasize that it occurs in the setting of hepatic metastases. It is most commonly reported following chemotherapeutic treatment of breast cancer metastases, although has also been reported before treatm...
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Pseudohydronephrosis

Pseudohydronephrosis (plural: pseudohydronephroses) refers to normal anatomy or non-significant pathologies that may mimic hydronephrosis. There is usually fluid-density material within a dilated part of the urinary tract, but without other signs of obstruction such as retroperitoneal fat strand...
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Pseudopermeative process in bone

A pseudopermeative process in bone has multiple small cortical holes that are then superimposed over the marrow, giving a similar appearance to a permeative process. Pathology Etiology The most common pathologies that manifest with pseudopermeative appearance (and mimic permeative lesions) ar...
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Pulmonary arterial calcification

Pulmonary arterial calcification is a phenomenon which is usually seen in the setting of advanced pulmonary hypertension. It can however be uncommonly present in those without pulmonary hypertension. Pathology The general mechanism in the vast majority is thought to be from high end pulmonary ...
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Pulmonary bleb

Pulmonary blebs are small subpleural thin-walled air-containing spaces, not larger than 1 or 2 cm in diameter (with the precise limit varying by source). Their walls are less than 1 mm thick. If they rupture, they allow air to escape into the pleural space resulting in a spontaneous pneumothorax...
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Pulmonary calcification

Pulmonary calcification has many causes and varying morphology: calcific pulmonary nodules or masses micronodules ​healed varicella pneumonia occupational disease/pneumoconioses silicosis coal worker's pneumoconiosis stannosis baritosis pulmonary hemosiderosis mitral stenosis pulmonar...
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Pulmonary cavities

Pulmonary cavities are thick-walled abnormal gas-filled spaces within the lung. They are usually associated with a nodule, mass, or area of consolidation. A fluid level within the space may be present. Plain radiography and CT form the mainstay of imaging. Terminology According to the Fleischn...
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Pulmonary fibrosis

Pulmonary or interstitial fibrosis is a descriptive term given when there is an excess of fibrotic tissue in the lung. It can occur in a wide range of clinical settings and can be precipitated by a multitude of causes. Terminology The term should not be confused with idiopathic pulmonary fibro...
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Pulmonary fungal disease

Pulmonary fungal disease encompasses a broad spectrum of infections related to fungal sources. They can particularly affect immunocompromised individuals. These include: pulmonary aspergillosis: pulmonary aspergillus infection considered the most important in immunocompromised individuals 5 a...
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Pulmonary hemorrhage

Pulmonary hemorrhage is a rather broad term given to describe any form of bleeding into the lung and can arise from a myriad of causes. In a very traditional sense it is described when the following constellation of clinicoradiological features occurs simultaneously 2 (although this is never an ...
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Pulmonary hypertension (differential)

Pulmonary hypertension has many causes, and these can be divided in many ways. A simple and systematic approach is to proceed along the cardiopulmonary pulmonary circulation, as causes are found at each site (for a more official classification system see 2003 third world symposium on pulmonary a...
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Pulmonary infection

Pulmonary infections are common and are caused by a wide range of organisms. Pathology Micro-organisms responsible may enter the lung by three potential routes: via the tracheobronchial tree most commonly due to inhalation of droplets of secretions from another infected human environmental ...
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Pulmonary metastases

Pulmonary metastases are common and the result of metastatic spread from a variety of primary tumors via blood or lymphatics. This article describes hematogenous pulmonary metastases with lymphangitis carcinomatosis discussed separately. Epidemiology The epidemiology will match that of the un...
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Pulmonary necrosis

Pulmonary necrosis is seen in a variety of conditions, including 1:  pulmonary infections  Klebsiella pneumoniae - Klebsiella pneumonia Streptococcus pneumoniae Haemophilus influenzae - pulmonary haemophilus influenzae infection Pseudomonas aeruginosa - pulmonary pseudomonas aeruginosa infe...
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Pulmonary nodule

Pulmonary nodules are small, rounded opacities within the pulmonary interstitium. Pulmonary nodules are common and, as the spatial resolution of CT scanners has increased, detection of smaller and smaller nodules has occurred, which are more often an incidental finding. Classification Pulmonar...
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Pulmonary ossification

Pulmonary ossification is a rare finding and is characterized by the presence of mature bone in alveolar or interstitial spaces, either localized or disseminated throughout the lung parenchyma. It can be idiopathic (idiopathic pulmonary ossification) or secondary to chronic lung, cardiac or sys...
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Pulmonary vasculitis

Pulmonary vasculitis refers to vasculitides that affect the lung or pulmonary vessels. If this definition is used, a large group of conditions can fall into this category. The respiratory system may be potentially involved in all systemic vasculitides, although to a variable degree. Pathology ...
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Pulsatile exophthalmos

Pulsatile exophthalmos, a.k.a. pulsatile proptosis, is a clinical symptom characterized by protrusion - i.e. exophthalmos (proptosis) - and pulsation of the eyeball that can occur due to various causes: caroticocavernous fistulas neurofibromatosis type 1 (with sphenoid wing dysplasia) 2 arter...
Article

Pure ground glass nodules

Pure ground glass lung nodules are a subtype of ground glass lung nodules where there is no associated solid component. Pathology Etiology They have been shown to represent various pathologies such as 1,3 adenocarcinoma in situ of lung minimally-invasive adenocarcinoma of lung invasive ad...
Article

Purely intrasellar pituitary mass

Purely intrasellar pituitary masses have a similar differential as the more generic pituitary region mass gamut, or the mnemonic SATCHMO, although some entities are far more common than others. Differential diagnosis pituitary hyperplasia pituitary microadenoma Rathke cleft cyst intracrania...
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Pyelonephritis

Pyelonephritis (plural: pyelonephritides) refers to an upper urinary (renal) tract infection with associated renal pelvis, renal calyceal and renal parenchymal inflammation, and comprises a heterogeneous group of conditions. bacterial pyelonephritis chronic pyelonephritis renal tuberculosis ...
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Pyometrium

Pyometrium refers to infection of the endometrial cavity with resulting expansion due to accumulated pus (pyometra). The postmenopausal demographic are most commonly affected due to the association with uterine malignancy. Pathology Causes endometritis / pelvic inflammatory disease uterine ...
Article

Rachitic rosary

Rachitic rosary refers to expansion of the anterior rib ends at the costochondral junctions and is most frequently seen in rickets as nodularity at the costochondral junctions. Differential diagnosis Other causes of this appearance include:  scurvy the costochondral junction is more angular ...
Article

Red marrow depletion (differential)

Complete fatty replacement of red marrow with fat on MRI can occur in a number of situations which includes: aplastic anemia chemotherapy regional radiation therapy See also bone marrow
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Reeder and Felson's Gamuts in Radiology

Reeder and Felson's Gamuts in Radiology, first published in 1975, provided comprehensive lists of radiological differential diagnoses, or gamuts, and was a bestseller for many years. The current publisher is Springer. The first edition was edited and, primarily, written by Ben Felson and Mauric...
Article

Regional osteopenia

Regional osteopenia describes a localized or regional decrease in bone mineral density.   Pathology Etiology disuse osteopenia (usually aggressive osteoporosis with pseudopermeative pattern) immobilization of fractures paralyzed segments bone and joint infections complex regional pain syn...
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Renal artery stenosis

Renal artery stenosis (RAS) (plural: stenoses) refers to a narrowing of a renal artery. When the process occurs slowly, it leads to secondary hypertension. Acute renal artery stenosis does not lead to hypersecretion of renin. Pathology When the stenosis occurs slowly, collateral vessels form a...
Article

Renal cortical defect

Renal cortical defects have a variety of causes, and present on imaging as an area of focal cortical thinning or absence of renal cortex, sometimes accompanied by focal caliectasis.  Differential diagnosis The differential diagnosis for a renal cortical defect includes 1,2: renal scarring re...
Article

Renal emphysema

Renal emphysema, or intrarenal gas, refers to the presence of gas within the kidney, with or without extension to the urinary tract.It is a rare finding and only a few differentials need to be considered 1: infections  emphysematous pyelonephritis 1 iatrogenic instrumentation biopsy surger...
Article

Renal pseudotumor

A renal pseudotumor is a mass that will simulate a tumor on imaging but is composed of non-neoplastic tissue. There are many examples 1: Developmental prominent column of Bertin persistent fetal lobulation dromedary hump splenorenal fusion cross-fused renal ectopia renal hilar lip Infect...
Article

Renal transplant

Renal transplantation is one, if not the most, common transplant procedures undertaken worldwide. Consequently, purposeful and incidental imaging of renal transplants and renal transplant-related complications are increasingly common. These include acute renal transplant rejection and chronic re...
Article

Renal vein varices

Renal vein varices develop for various reasons and are usually asymptomatic. Clinical presentation Renal vein varices are usually asymptomatic. Some patients may present with flank pain and/or hematuria. Pathology Etiology chronic renal vein thrombosis nutcracker syndrome posterior nutc...

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