Articles

Likelihood ratios are an alternative to positive and negative predictive values for estimating the likelihood of disease after diagnostic testing. The general formula for a likelihood ratio is the probability that someone with a disease will have a particular test result divided by the probabili...

Myocardial infarction (MI), colloquially known as a heart attack, an acute coronary syndrome, results from interruption of myocardial blood flow and resultant ischemia and is a leading cause of death worldwide.  Epidemiology Risk factors male > females age >45 years for males >55 years for...

Microvascular obstruction (MVO), also known as no-reflow phenomenon, is an established complication encountered in coronary angioplasty for prolonged acute myocardial infarction.  Pathology The phenomenon results from obstruction of the myocardial microcirculation, which is composed of vessel...

Myocardial edema refers to an increased water content of the myocardium particularly within the extracellular interstitium 1. Clinical presentation Myocardial edema often reflects an acute or subacute cardiac event, most often either ischemic or inflammatory and thus can be associated with che...

Coronary stents or coronary artery stents are expandable tubular medical meshwork devices used for interventional treatment of coronary artery disease and prevention of negative remodeling and vascular recoil, restenosis as well as abrupt vessel occlusion from local coronary artery dissection af...

Flocculation refers to the breakdown of a barium suspension during a fluoroscopic study. The small bowel environment eventually separates out a barium suspension, and this can occur during the normal course of a barium study (15 minutes to three hours) or as a feature of certain pathological en...

Epilepsy is a common neurological disorder that is characterized by a predisposition to having epileptic seizures and can take many clinical forms and have a veritable Augean stable of etiologies. Epilepsy is defined by the International League Against Epilepsy (ILAE) as 1: at least two or mor...

Hounsfield units (HU) are a dimensionless unit universally used in computed tomography (CT) scanning to express CT numbers in a standardized and convenient form. Hounsfield units are obtained from a linear transformation of the measured attenuation coefficients 1. This transformation (figure 1) ...

Esophageal-pleural stripe is a soft tissue interface formed between the right wall of the esophagus and the medial wall of the right pleura, projecting from the level of clavicles downwards until the gastro-esophageal junction 1. Although the esophageal-pleural stripe can be used in most patien...

Probability is the likelihood of a random outcome (called an “event”) and is written as P(event)= x, where x is a number ≥0 and ≤1. Using this notation, the probability of rolling a 2 with a fair 6-sided die is written as P(2)=1/6. A probability of 0 means that an event is impossible while a pro...

Buckle rib fractures are incomplete fractures involving only the inner cortex. They typically occur due to an anterior compressive force to the chest, most commonly during external cardiac massage, but can be seen following any such traumatic injury. Pathology Buckle rib fractures occur in all...

The thyroid gland is a single midline endocrine organ in the anterior neck responsible for thyroid hormone production which lies in the visceral space completely enveloped by pretracheal fascia (middle layer of the deep cervical fascia). Gross anatomy The thyroid extends from C5 to T1 and lies...

Unclassified cerebellar dysplasia is defined as focal or diffuse dysplasia of cerebellar hemispheres or vermis not associated with other known malformations or syndromes. Clinical presentation Can present with hypotonia, microcephaly or speech delay. Radiographic features MRI asymmetry or f...

This article contains a list of commonly used medical abbreviations and acronyms that start with the letter L and may be encountered in medicine and radiology (please keep the main list and any sublists in alphabetic order). A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R ...

External auditory canal exostoses, also known as surfer's ear, are benign bony overgrowths of the bony external auditory canal brought about by exposure to cold wind and water combined. Epidemiology The estimated prevalence in cold-water surfers is thought to range between 70-80% 5,6,8. Clini...

This is a basic article for medical students and other non-radiologists Chest x-ray lines and tubes can be easily assessed and should be the first thing that you look at when reviewing a chest x-ray. Assessment of their position is important, but they also give you an idea about how sick the pa...

Heel fat pad syndrome, also known as plantar fat pad syndrome or heel fat pad atrophy is a common but not well-known cause of heel pain in the adult population. Epidemiology Heel fat pad syndrome is common. It is the second most common cause of plantar heel pain after plantar fasciitis. It is ...

Portal venous flow is normally towards the liver (hepatopetal), with the normal main portal vein peak systolic velocities usually measuring 20-40 cm/s. In pathological situations, the flow velocity may decrease or even invert resulting in hepatofugal flow. The flow waveform is usually smooth b...

The basilar transverse fissure, also known as Saucer's fissure, is a potential channel through the clivus in the basilar part of the occipital bone. It is considered a normal anatomical variant and should not be confused with clival clefts that can be seen with certain syndromes such CHARGE synd...

Splenic epithelial cysts, also known as splenic epidermoid cysts or primary splenic cysts, are unilocular fluid lesions with thin and smooth walls and no enhancement. They represent ~20% of cysts found in the spleen, and are usually an innocuous incidental imaging finding. Note that most (~80%)...