Items tagged “refs”

A nutmeg liver appearance is due to a perfusion abnormality of the liver usually as result of hepatic venous congestion. When hepatic veins are congested, contrast is prevented from diffusing through the liver in a normal manner. This results in a mottled pattern of contrast enhancement in the a...

Oculomotor nerve palsies, or third nerve palsies, result in weakness of the muscles supplied by the oculomotor nerve, namely the superior rectus, inferior rectus, medial rectus, inferior oblique, and levator palpebrae superioris muscles. Terminology If the pupil is normal-sized and reactive to...

Odontogenic myxomas are rare tumors that involve the mandible or maxilla and account for 3-6% of odontogenic tumors 2. Epidemiology Typically seen in the 2nd to 3rd decades of life (slightly earlier than ameloblastomas). They are usually not painful. Pathology Arises from mesenchymal odontog...

Odontomas are one of the most common mandibular lesions encountered and the most common odontogenic tumors of the mandible. They account for up to two-thirds of all such tumors; the next most common are ameloblastomas, making up the majority of the remaining one-third. Epidemiology They can oc...

The olfactory nerve is the first (CN I) cranial nerve (TA: nervus olfactorius or nervus cranialis I) and is responsible for conveying the sense of smell from the nasal cavity to the brain. Strictly speaking, the term olfactory 'nerve' refers only to the short first order neurons (olfactory filam...

There are three tiny articulating bones in the middle ear known as ossicles (from lateral to medial): malleus incus stapes Their role is to mechanically amplify the vibrations of the tympanic membrane and transmit them to the cochlea where they can be interpreted as sound. They are located i...

Otomastoiditis refers to inflammation of both the middle ear (otitis media) and mastoid (mastoiditis), can be divided into two distinct entities: acute otomastoiditis: usually due to bacterial infection chronic otomastoiditis: usually due to Eustachian tube dysfunction

Posterior cerebral artery (PCA) infarcts arise, as the name says, from occlusion of the posterior cerebral artery. It is a type of posterior circulation infarction. Epidemiology Posterior cerebral artery strokes are believed to comprise approximately 5-10% of ischemic strokes 6. Clinical pres...

Mnemonics for the causes of osteonecrosis (previously known as avascular necrosis): STARS PLASTIC RAGS ASEPTIC Mnemonics STARS Most common causes: S: steroids, SLE T: trauma (e.g. femoral neck fracture, hip dislocation, scaphoid fracture, slipped capital femoral epiphysis 2) A: alcohol ...

Panner disease is osteonecrosis of the capitellum. It should be distinguished from osteochondritis dissecans of the elbow which also affects the capitellum.  Epidemiology Panner disease is typically seen in children (5-10 years of age), although it is also seen in throwers due to repeated trau...

Patellar tendon rupture is one of the extensor mechanism of the knee injuries and occurs almost invariably at either the patellar or tibial insertion of the patellar tendon, when in the setting of trauma, and is often associated with a small avulsion fracture. Most commonly, it is at the superi...

Persistent primitive trigeminal artery (PPTA) is the most common type of the four persistent carotid-vertebrobasilar anastomoses. It is present in 0.1-0.6% of cerebral angiograms and is usually unilateral. In utero, the trigeminal artery supplies the basilar artery before the development of the...

A pine cone bladder or Christmas tree bladder is a cystographic appearance in which the bladder is elongated and pointed with a thickened, trabeculated wall. It is typically seen in severe neurogenic bladder with increased sphincter tone (detrusor sphincter dyssynergia) due to suprasacral lesion...

The pituitary stalk, also known as the infundibulum or infundibular stalk, is largely outside the blood brain barrier like the rest of the pituitary and therefore normally enhances following the administration of gadolinium. It gradually tapers inferiorly, and superiorly is spread by the infundi...

Abnormal nodular enhancement of the pituitary stalk can be seen in a number of entities. Differential diagnosis tumors germinoma craniopharyngioma hypothalamic glioma pituitary lymphoma pituicytoma granular cell tumor of the pituitary (pituitary choristoma) pilocytic astrocytoma of the...

Pneumatization of the dorsum sella is not uncommon, but needs to be remembered as an unusual site of sinus disease, which otherwise may be mistaken for intracranial of pituitary disease.

Portal hypertensive gastroenterocolopathy is a finding in portal hypertension, whereby chronic portal venous congestion leads to dilatation and ectasia of the submucosal vessels of the stomach (portal hypertensive gastropathy), small bowel (portal hypertensive enteropathy) and/or large bowel (po...

Pregnancy-related osteonecrosis, also known as pregnancy-related avascular necrosis, is a common cause of femoral head osteonecrosis. Since the femoral head is relatively deficient in blood supply, it is particularly vulnerable to osteonecrosis. Pathology The pathophysiology is thought to be d...

One pulmonary edema grading based on chest radiograph appearances and pulmonary capillary wedge pressure (PCWP) is as follows: grade 0: normal chest radiograph, PCWP 8-12 mmHg grade 1: shows evidence of upper lobe diversion on a chest radiograph, PCWP 13-18 mmHg grade 2: shows interstitial ed...

The quadriceps tendon is a thick tendon extending to the patella made up of contributions from all four quadriceps muscles. It classically has a trilaminar structure: superficial layer: rectus femoris middle layer: vastus medialis, vastus lateralis deep layer: vastus intermedius It continues...