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.

47 results found
Article

Aortic pseudoaneurysm versus ductus diverticulum

Differentiation of aortic pseudoaneurysm from ductus diverticulum is critical, particularly in the trauma setting. A traumatic aortic pseudoaneurysm is a surgical emergency whereas a ductus diverticulum is a normal anatomic variant. The following are differentiating features: Aortic pseudoaneu...
Article

Approach to shock (echocardiography)

The presence of shock implies inadequate tissue perfusion, the end-point of which is multisystem organ failure and death. Echocardiography at the point-of-care is fast, non-invasive, and often pivotal in the diagnosis, resuscitation, and management of the patient with an undifferentiated shock s...
Article

Calcium volume score

The calcium volume score is referred to as a measure to quantify coronary artery calcium and is a variant to calculate coronary artery calcium 1-3. Its calculation includes all voxels with a Hounsfield attenuation > 130 and this is done by multiplying the volume of each voxel, determined by the...
Article

Cardiac CT

Computed tomography of the heart or cardiac CT is routinely performed to gain knowledge about cardiac or coronary anatomy, to detect or diagnose coronary artery disease (CAD), to evaluate patency of coronary artery bypass grafts or implanted coronary stents or to evaluate volumetry and cardiac f...
Article

Cardiac CT (an approach)

Cardiac CT can be a more or less frequent examination faced in daily practice also depending on the institution and the CT scanner technology available. With technological advances and improved dose reduction techniques in the last decade, cardiac CT has become increasingly popular. What is pre...
Article

Cardiac CT (prospective acquisition)

A prospective ECG gated cardiac CT angiogram also known as the step and shoot method is considered the default or ‘bread and butter’ protocol for coronary CTA  and combines a reasonably low radiation dose with diagnostic results in most situations. Nowadays, this protocol is available on most CT...
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Cardiac CT (retrospective acquisition)

A retrospective ECG-gated cardiac CT is usually conducted in cases in which adequate control of heart rate cannot be achieved or in which additional information on ventricular or valvular function is required. Indications Please refer to our coronary CT angiography article for general indicati...
Article

Cardiac MRI

Cardiac MRI consists of using MRI to study heart anatomy, physiology, and pathology. Advantages In comparison to other techniques, cardiac MRI offers: improved soft tissue definition protocol can be tailored to likely differential diagnoses a large number of sequences are available dynamic...
Article

Cardiac MRI (an approach)

A cardiac MRI can be a more or less frequent examination faced in daily practice also depending on the institution. In general radiological practices and institutions other than cardiac imaging centers, cardiac MRI examinations are not necessarily gladly enlisted into the appointment schedule pa...
Article

Cardiac segmentation model

The American Heart Association (AHA) has published the nomenclature and segmentation of the left ventricular myocardium (the cardiac segmentation model), now widely used for the description of disease-affected myocardial territories and wall function. There are 17 segments that have a reasonabl...
Article

Cardiac silhouette

Cardiac silhouette refers to the outline of the heart as seen on frontal and lateral chest radiographs and forms part of the cardiomediastinal contour. The size and shape of the cardiac silhouette provide useful clues for underlying disease. Radiographic features From the frontal projection, t...
Article

Cardiac strain imaging

Strain imaging is a cardiac imaging technique which detects ventricular deformation patterns and functional abnormalities before they become obvious as regional wall motion abnormalities on conventional cine imaging or echo. It has become more popular lately due to several technological improvem...
Article

Cardiac tissue characterization

Cardiac tissue characterization is a term for an approach in cardiac imaging used for the evaluation of the myocardial tissue in respect to its inherent properties as opposed to cardiac function e.g. in cine or strain imaging. In cardiac magnetic resonance imaging it typically comprises the use...
Article

Chest x-ray: circulation (summary)

This is a basic article for medical students and other non-radiologists Chest x-ray review is a key competency for medical students, junior doctors and other allied health professionals. Using A, B, C, D, E is a helpful and systematic method for chest x-ray review where C refers to circulation ...
Article

Congenital heart disease chest x-ray (an approach)

With the advent of echocardiography, and cardiac CT and MRI, the role of chest x-rays in evaluating congenital heart disease has been largely been relegated to one of historical and academic interest, although they continue to crop up in radiology exams. In most instances a definite diagnosis ca...
Article

Congenital heart disease in echocardiography (an approach)

The diagnosis of congenital heart disease in echocardiography is outside the scope of basic echocardiography, however, several common features may be recognized at the point of care which allow for initial stablization and management before a complete echocardiography exam may be performed. In ...
Article

Coronary Artery Disease - Reporting and Data System

The Coronary Artery Disease - Reporting and Data System (CAD-RADS) is a standardized findings communication method and clinical decision aid relevant to coronary CT angiography. The system was created by a collaboration of the Society for Cardiovascular Computed Tomography (SCCT), American Colle...
Article

Coronary CT angiography (CT protocol)

The coronary CT angiography or cardiac CT angiogram protocol is the most common dedicated cardiac CT examination and is a non-invasive tool for the evaluation of the coronary arteries. Note: This article is intended to outline some general principles. Protocol specifics especially medications, ...
Article

Deductive echocardiography

Deductive echocardiography is a step-by-step approach in diagnosing and differentiating congenital heart disease. Parameters assessed position of heart  levocardia dextrocardia visceroatrial situs solitus inversus ambiguus ventricular loop D-loop L-loop conotruncus normal transpose...
Article

Determination of atrial situs

Atrial situs refers to the relative position of the cardiac atria in relation to abdominal viscera and the midline. Pathology Identification of atrial situs is an important initial step in the antenatal and postnatal diagnosis of cardiac structural and situs anomalies. Radiographic features ...
Article

Diastolic dysfunction assessment (echocardiography)

According to the American Society of Echocardiography and the European Association of Cardiovascular Imaging, diastolic dysfunction assessment on echocardiography is divided into two different groups based on left ventricular systolic function.  Normal left ventricular systolic function There ...
Article

Diastolic dysfunction (point of care ultrasound)

Assessment for diastolic dysfunction is an advanced application of point-of-care ultrasonography, most commonly used as a supplemental non-invasive estimate of left atrial pressure in hemodynamically complex patients 1. Of note, this article will discuss the simplified, binary approach used in c...
Article

Extracellular volume (ECV) - myocardium

Extracellular volume (ECV) refers to the space or volume of a tissue, which is not occupied by cells. Apart from the usual extracellular space, which surrounds the cells of a specific tissue it also includes the intracapillary plasma volume 1,2. It measures the space, which is occupied by the ex...
Article

Fetal cardiothoracic circumference ratio

Fetal cardiothoracic (C/T) circumference ratio is a parameter than can be used in assessment of fetal cardiac and thoracic/chest wall anomalies. It is the ratio of the cardiac circumference to the thoracic circumference and may be easily measured on fetal ultrasound/echocardiography.  Radiograp...
Article

Focus‐assessed transthoracic echocardiography

FATE (focus‐assessed transthoracic echocardiography) is a goal-directed protocol used in critical care for indications such as hemodynamic instability, shock, and pulseless electrical activity (PEA) arrest 1. The protocol is designed as a series of questions as follows: does the left ventricle...
Article

Four chamber cardiac view (fetal)

The four chamber cardiac view is an important and routinely performed view in both fetal echocardiography as well as on a standard second trimester anatomy scan. Detectable pathology The four chamber view can only detect some of the congenital cardiac anomalies (~64% according to one study 2) ...
Article

Isomerism

Isomerism is a term which in general means 'mirror-image' and refers to finding normally-asymmetric bilateral structures to be similar. It is used in the context of heterotaxy and is of two types: left isomerism right isomerism Left isomerism Mirror image of the structures on the left side o...
Article

Left atrial enlargement

Left atrial enlargement (LAE) may result from many conditions, either congenital or acquired. It has some characteristic findings on a frontal chest radiograph. CT or MRI may also be used for diagnosis. Clinical presentation An enlarged left atrium can have many clinical implications, such as:...
Article

Left ventricular ejection fraction (echocardiography)

Left ventricular ejection fraction (LVEF) is a surrogate for left ventricular global systolic function, defined as the left ventricular stroke volume divided by the end-diastolic volume. Terminology Point-of-care echocardiography protocols typically use a semi-quantitative approach in defining...
Article

Left ventricular outflow tract obstruction in echocardiography (differential)

Left ventricular outflow tract (LVOT) obstruction describes a state in which the egress of blood from the left ventricle to the systemic circulation is impeded as it traverses the anatomic LVOT to the aortic arch. Echocardiography, particularly with the use of spectral Doppler, may be used to de...
Article

Mitral annular plane systolic excursion

Mitral annular plane systolic excursion (MAPSE) refers to the displacement of the mitral valvular plane in the z-direction and reflects left ventricular longitudinal contraction or shortening, which has been attributed to account for about 60% of the stroke volume 1. Terminology Mitral annular...
Article

Myocardial area at risk

Myocardial area at risk (AAR) is defined by the ischemic proportion of the myocardium after coronary occlusion and reflects the potential size of the myocardial infarction 1-9. Usage The assessment of myocardial area at risk is an important measure in the evaluation of the potentially salvagea...
Article

Myocardial mapping

Myocardial mapping or parametric mapping of the heart is one of various magnetic resonance imaging techniques, which has evolved and been increasingly used in the last decade for non-invasive tissue characterization of the myocardium 1-5. Unlike normal T1-, T2- or T2*- images, parametric mapping...
Article

Myocardial salvage

Myocardial salvage is referred to as the reversibly injured myocardium in a setting of myocardial ischemia and/or myocardial infarction, which remains non-infarcted after reperfusion 1-7. Usage The assessment of myocardial salvage is an important measure in the evaluation of the efficacy of th...
Article

Normal pulmonary venous Doppler

Normal pulmonary venous blood flow in the pulmonary veins may be investigated during echocardiography with spectral Doppler analysis. Perturbations in the normal pulmonary venous waveform may indicate the presence of diastolic dysfunction and elevated filling pressures in the left atrium and ven...
Article

Point-of-care ultrasound (curriculum)

The point-of-care ultrasound (PoCUS) curriculum is one of our curriculum articles and aims to be a collection of articles that represent the core applications of ultrasonography in a point-of-care setting. Point-of-care ultrasound refers to ultrasonography which may be simultaneously performed,...
Article

Prosthetic cardiac valves on chest x-ray (an approach)

Prosthetic cardiac valves are a routine finding on chest X-ray. The frequency and degree of exposure is greatest in larger hospitals with cardiothoracic centers; however, prosthetic valves are commonplace universally. Recognition of which valve has been replaced, any other related cardiothoraci...
Article

Rapid ultrasound in shock

The rapid ultrasound in shock (RUSH) protocol is a structured point-of-care ultrasound (POCUS) examination performed at the time of presentation of a shocked patient. It is a more detailed and longer exam than the FAST scan, with the aim to differentiate between hypovolemic, cardiogenic, obstruc...
Article

Situs inversus

Situs inversus, (rare plural: sitūs inversi) short form of the Latin “situs inversus viscerum”, is a term used to describe the inverted position of chest and abdominal organs. It is called situs inversus totalis when there is a total transposition of abdominal and thoracic viscera (mirror image ...
Article

Sonographic approach to dyspnea (mnemonic)

This mnemonic will help with the sonographic approach to the critically ill patient with dyspnea: CHEST Mnemonic C: collapsed lung (pneumothorax)  absence of anterior lung sliding, lung pulse, B-lines, or z-lines these artifacts arise from the pleural interface; their presence would rule ou...
Article

T1 mapping - myocardium

T1 mapping is a magnetic resonance imaging technique used to calculate the T1 time of a certain tissue and display them voxel-vice on a parametric map. It has been used for myocardial tissue characterization 1-6 and has been investigated for other tissues 5. T1 is the spin-lattice or longitudin...
Article

T2 mapping - myocardium

T2 mapping is a magnetic resonance imaging technique used to calculate the T2 times of a certain tissue and display them voxel-vice on a parametric map. It has been used for tissue characterization of the myocardium 1-5 and has been investigated for cartilage 6,7 and other tissues 4. The T2 tim...
Article

Transcatheter aortic valve implantation (TAVI)

Transcatheter aortic valve implantation or replacement (TAVI/TAVR) is a technique to replace the aortic valve through a transvascular or transapical approach. Compared to traditional open aortic valve replacement with sternotomy and a heart-lung bypass machine, the TAVI technique is less invasiv...
Article

Transthoracic echocardiography views

A standard transthoracic echocardiogram consists of five standardized windows which are obtained in a standardized sequence 1. Obtaining views from the left parasternal, apical, subcostal, and suprasternal notch windows is mandatory for a complete echocardiography protocol. The right parasternal...
Article

Traumatic aortic injury in the exam

Getting a film with traumatic aortic injury in the exam is one of the many exam set-pieces that can be prepared for.  This is one of the cases you should look and not speak for 10 seconds as there tends to be a lot of findings on the film of patients with a traumatic aortic injury. Description...
Article

Triple rule out

A triple rule out (TRO) protocol is a cardiac CT protocol that aims to assess for different problems at the same time in one single examination: obstructive coronary artery disease, aortic dissection or pulmonary embolism. The approach itself has been continuously under discussion due to diffic...
Article

Years criteria for pulmonary embolism

The YEARS criteria is a diagnostic algorithm that determines the risk of pulmonary embolism (PE) derived from three items in the Wells score that are most predictive of PE1. Unlike the Wells score, it uses a variable D-dimer threshold based off clinical pre-test probability. The YEARS criteria i...

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