Lecture 3 (x-ray-chest), Exam 2 Flashcards
Chest
- Plain flim diagnosis of heart disease is limited because why?
- What is the standard set of imaging?
- How should you look at the chest r-xay?
- Plain film diagnosis of heart disease islimited to the determination of cardiacenlargement, pulmonary vascularabnormalities, cardiac calcifications andCHF
- PA and Lateral comprise standard set of imaging
- Start at apices, thencostophrenicangles,cardiophrenicangles, diaphragms, gastric bubbles,pulmvasculature, and then trachea and heart size.
Chest PA vs AP
- How is PA chest radiograph obtained?
- What does AP projection result in?
- What is the x-ray for those that cannot stand?
- Posteroanterior (PA) chest radiograph obtained by placing the x-ray source behind the patient.
- Anteroposterior projection (AP)results in apparent enlargementof the heart, a phenomenonknown as magnification.
- AP Chest reserved for those thatcannot stand
Which one is AP and PA?
The AP shows magnification of the heart and widening of the mediastinum. Whenever possible the patient should be imaged in an upright PA position. AP views are less useful and should be reserved for very ill patients who cannot stand erect.
The Heart – Key Concepts
- Advanced imaging can give detailed information about what?
- Heart size should be no larger than what?
- When can cardiac enlargment be simulated or masked?
- Advanced imaging can give detailedinformation about cardiac thickness andmotion, precise chamber size, the presenceof valvular disease, coronary artery disease,pericardial disease, and cardiac function
- Heart size should be no larger than half ofthe thoracic cage at its widest margin (thisis known as the cardiothoracic ratio)
- Cardiac enlargement may be simulated (ason poor inspiration) or masked (as in apatient with a pleural effusion)
- The cardiac silhouette normally occupies what? What happens if it exceeds that?
- What can the exceed space be the result from?
- What are non-cardiac causes of an enlarged silhouette?
- The cardiac silhouette normally occupies less than 50% of the transverse diameter of the chest on a PA radiograph. If this cardio-thoracic ratio exceeds 50%, the cardiac silhouette may be enlarged.
- This can result from enlargement of the heart or from pericardial fluid.
- Non-cardiac causes of an enlarged silhouette include increased mediastinal fat, thoracic cage deformities such as pectus excavatum, and poor inspiration.
Lateral views
- How is lateral view obtained?
- What ribs are larger?
- What is usually lower than the right?
- What is easy to see?
- The lateral view is obtained with the left chest against the cassette.
- Right ribs are larger (red arrows)
- Left hemidiaphragm (black arrow) and left costophrenic angle (blue) areusually lower than the right
- easy to see posterior fluid collection
On the left lateral chestfilm, the convexposterior heart border does what?
On the left lateral chestfilm, the convexposterior heart border does not extendbeyond the posterior margin of the inferiorvena cava
* (A to B) X2 =C to D
Lateral Decubitus Position:
* Could be helpful in what?
* Not a _ view
* What does the this flim show?
- This could be helpful to assess the volume of pleural effusion and demonstrate whether a pleural effusion is mobile or loculated (look at difference).
- Not a standard view
- Decubitus film in this case showing a mobile pleural effusion (arrows).
Nowadays: order CT +percuss on PE
What are the factors that alter the cardiothoracic ratiomeasurement?
- Factors that alter the cardiothoracic ratiomeasurement:
- Expiratory films
- Whenever any kind of abdominal distension ispresent (pregnancy, ascites, intestinal obstruction),you will not be able to determine heart size
- AP portable chest film will slightly magnify theheart
- A rotated film will change the size of the heartand shape of themediastinum–cannotdetermineheart size
Chest:
* Patient should be examined when? What does this help with?
* What can expiration lead to?
* What level should the diaphragm be found out?
- The patient should be examined in full inspiration. This greatly helps the radiologist to determine if there are intrapulmonary abnormalities.
- Expiration can lead toloss of the right heart border silhouette.
- The diaphragm should be found at about the level of the 8th- 10thposterior rib or 5th- 6thanterior rib on good inspiration.
Which one is underpenetrated and overpenetrated?
What type of film is this?
Right: rotated film skin folds can be mistaken for a tension pneumothorax.
* Notice the skewed positioning of the heads of the clavicles.
Which views comprise a standard CXR series
* AP and lateral
* PA and lateral
* AP and PA
* PA and decubitus
PA and lateral
What are the lobes and fissures of the lungs?
* What divides lobes? What does it allow?
* On PA chest x-ray, the minor fissure divides what?
* What is really not seen well?
* If there is fluid in the fissure, it is occasionally manifested as what?
- Fissures divide lobes. Knowing them allows localization of lesion.
- On the PA chest xray, the minor fissure divides the right middle lobe from the right upper lobe and is sometimes not well seen. There is no minor fissure on the left.
- The major fissures are usually not well seen on the PA view because you are looking through them obliquely.
- If there is fluid in the fissure, it is occasionally manifested as a density at the lower lateral margin.
What does the x-rays show?
Fill in the lung margins
Fill in
Fill in
Fill in
Great Vessels
- What is indicated of the right aortic arch?
- Where is the descending aorta?
- Presence of a right aortic arch is indicated by a large bulge on the right side of the trachea (arrows) and leftward deviation of the trachea.
- The descending aorta is just to the left of the spine shadow in patients with a left arch and usually to the right of the spine in those with a right arch.
Depending on age, the ascending aorta may not be visible. The aortic arch is on the left in almost all individuals, but is found on the right in a small number (see figure below). Right aortic arch is occasionally associated with other cardiac anomalies or dysphagia.
Great Vessels: what is this?
In the adult, the pulmonary trunk (arrow) is normally concave or straightened.
- The main pulmonary artery (pulmonary trunk) is normally where? Why?
- In adults it should be what?
- In children and young adults it will be what?
- Enlargement of the pulmonary trunk suggests what?
- The main pulmonary artery (pulmonary trunk) is normally present just below the aortic arch. Because it is within the pericardium, its shadow is continuous with the left cardiac border.
- In adults it should be either flat or concave (see figure below).
- In children and some young adults it will be convex.
- Enlargement of the pulmonary trunk suggests increased pulmonary blood flow or increased pressure due to pulmonary valvular stenosis.
What is this?
Enlargement of the azygous vein (arrow) in a patient with right ventricular failure secondary to left ventricular failure or vena cava obstruction.
What is this?
Enlargement of the inferior vena cava is indicated by bulging of the cava at the right cardiophrenic angle (arrow, left) and posteriorly (arrow, right) in this patient with severe tricuspid regurgitation.
- The inferior vena cava (IVC) is usually visible where?
- What does the SVC usually form?
- What may indicate increased right atrial pressure?
- The inferior vena cava (IVC) is usually visible posterior to the posterior border of the heart on the lateral projection.
- The superior vena cava (SVC) usually forms the right border of the upper supracardiac mediastinum.
- Distension of the SVC or posterior bulging (see figure below) or visibility of the IVC in the right cardiophrenic angle may indicate increased right atrial pressure
Pulmonary Vascular Patterns:
* A normal pulmonary vascular pattern in the adult is characterized by what?
* What tapers laterally
* What should happen inferiorly?
* Where should there be no markings?
- A normal pulmonary vascular pattern in the adult is characterized by a concave or straight pulmonary trunk and normal gravitational distribution of the blood flow.
- Blood vessels taper laterally (bolded medially)
- Increase in caliber inferiorly (gravity)
- Outer 1cm should have no markings (becasue distal is the most smallest vessel)
- What are erect individuals, what will the lobes look like?
- What will the lobes look like in a supine patient?
In the erect individual this meansthat the upper lobe vessels will be smaller than the lower lobevessels, and that none of the vessels will be enlarged. In the supinepatient, the upper and lower lobe vessels will be more equal insize.
- What is this?
- What is it usually caused by?
- > _ mmHg
- Redistribution of blood flow to the upper lung zones results in what?
- PVH is usually caused by left atrial hypertension
- > 12-14mmHg (start seeing cephilization)
- Redistribution of blood flow to the upper lung zones results in abnormal enlargement of the upper lobe vessels.
Normal pressure is under 10
Look at picture and like increase pressure
Mild elevation of the PCWP (pulmonary wedge pressure) results in what?
in redistribution of the pulmonary blood flow to the non-dependent lung zones
- What is this?
- What is present and thickened?
- What is the pressure?
- Pulmonary Venous Hypertension
- Interstitial edema with indistinct vessels and thickened interlobular septa (Kerley B lines)-> CHF, ARDS and pulm edema
- Pressure approaches 20 mmHg
What is this?
* Pressures in the mid 20s typically cause what?
* What do you need to note?
* What are common causes?
- Pulmonary Venous hypertension
- Pressures in the mid 20s typically cause alveolar edema
- Note airspace edema with confluent airspace opacities in both lungs
What is this?
* What is present?
- Pulmonary arterial hypertension results from what?
- What is it characterized? This has been referred to as what?
- Pulmonary arterial hypertension results from elevation of the resistance in the pulmonary arterial bed, usually at the arteriolar level.
- It is characterized radiographically by enlargement of the pulmonary trunk and right and left main pulmonary arteries with disproportionately small peripheral vessels. This has been referred to as “pruning” of the pulmonary arteries.
- What is this?
- What happens to vessels?
Mild pulmonary HTN
- Pulmonary overcirculation, also referred to as shunt vascularity, results from what?
- Radiographically it is characterized by what?
- Pulmonary overcirculation, also referred to as shunt vascularity, results from an absolute increase in blood flow to the lungs and in adults is most often associated with left to right shunts.
- Radiographically it is characterized by proportional enlargement of all of the central and peripheral pulmonary vessels
- What is this?
- Who is this seen in?
Diminished vascularity in a patient with Ebstein’s anomaly. Both the central and peripheral vessels are small. There is also massive right heart enlargement owing to severe tricuspid valve regurgitation.
Water bottle heart
- Diminished pulmonary vascularity is rare in the adult. the most frequently encountered lesion being what?
- What is decreased in size?
Diminished pulmonary vascularity is rare in the adult. the most frequently encountered lesion being Ebstein’s anomaly of the tricuspid valve. Both the central and peripheral vessels are decreased in size.
What is this?
Tetralogy of Fallot. The pulmonary vascularity is markedly diminished and the heart is not enlarged.
PS, VSD, OA, RVH
What are these?
What is this?
Cardiac Enlargement:
* Left atrial enlargement in a patient with chronic mitral regurgitation.
* There is a double density behind the right side of the heart (arrows).
- What is this?
- Who is this seen in?
Right atrial enlargement in a patient with mild Ebstein’s anomaly (normal pulmonary vascularity). The right heart border is prominent (arrows, left) and the retrosternal clear space is filled in by the right heart (arrows, right)
What is this?
Pericardial Effusion
Pericardial Effusion:
* What type of shadow?
* What is a fat pad sign?
* What is the choice to screen for effusions?
* 400-500 ml of fluid must be in the pericardium to lead to what?
- Globular shaped shadow
- A “fat pad” sign, a soft tissue stripe wider than 2mm between the epicardial fat and the anterior mediastinal fat can be seen anterior to the heart on a lateral view.
- Echo is the modality of choice to screen foreffusions
- 400-500 ml of fluid must be in the pericardium to lead to a detectable change of increased heart shadow on CXR
What is this?
Fat Pad Sign
* Indication of percardial effusion so get echo
What is this?
Heart lesions:
* Calcified myocardium (arrows, left) in a patient with previous myocardial infarction. Calcified aortic valve (arrows, right) in a patient with left ventricular failure secondary to critical aortic stenosis.
What is this?
Heart lesions:
* Rheumatic mitral valve stenosis (after strept throat infection without abx). There is enlargement of the left atrium (arrows, left) and left atrial appendage-> cleft formation in a.fib (arrows, right). The latter is relatively specific for rheumatic heart disease and is rarely seen in non-rheumatic mitral disease.
How do we read an x-ray?
Notes from under PP:
* It is best to do a directed search of the chest film rather than simply gazing at the film. An abnormality will not likely hit you over the head.
* Remember that detail vision is only permitted at the fovea centralis of your retina. This area contains only cones and is the part that you use to read. The remainder of the retina helps you to put this detailed portion in context and helps to determine whether this is a saber tooth tiger sneaking up on you. Therefore, it is best to look for abnormalities and to have a planned search in mind.
* Your eye gaze should scan all portions of the film, follow lung/mediastinal interfaces and look again carefully in areas where you know that mistakes are easily made, such as over the spine on the lateral view and in the apex on the PA view.
What is present?
sharp v
Pulmonary arteries and veins
- What is this?
- What are some causes?
What is this?
* Loss of lung/soft tissue interface caused by what?
* What will obscure the border?
* The location of this abnormality can help to determine what?
Silhouette sign
* Loss of lung/soft tissue interface caused by a mass or fluid in the normally air-filled lung
* If an intrathoracic opacity is in anatomic contact with, for example, the heart border, then the opacity will obscure that border.
* The location of this abnormality can help to determine the location anatomically.
What is an air bronchogram?
- An air bronchogram is a tubular outline of an airway made visible by filling of the surrounding alveoli by fluid or inflammatory exudates. In this case patient hasbilateral lower lobe pulmonary edema.
- Air Bronchograms = Alveolar filling
What is this?
Atelectasis:
* What is it? Common or uncommon?
* What is it caused by?
* What is an unusual type of atelectasis?
* Atelectasis is almost always associated with what? What does the apex tend to be?
* The density is associated with what? What are some indirect signs?
* What might there be?
* Most common in who?
- Atelectasis is collapse or incomplete expansion of the lung or part of the lung. This is one of the most common findings on a chest x-ray.
- It is most often caused by an endobronchial lesion, such as mucus plug or tumor. It can also be caused by extrinsic compression centrally by a mass such as lymph nodes or peripheral compression by pleural effusion.
- An unusual type of atelectasis is cicatricial and is secondary to scarring, TB, or status post radiation.
- Atelectasis is almost always associated with a linear increased density on chest x-ray. The apex tends to be at the hilum.
- The density is associated with volume loss. Some indirect signs of volume loss include vascular crowding or fissural, tracheal, or mediastinal shift, towards the collapse.
- There may be compensatory hyperinflation of adjacent lobes, or hilar elevation (upper lobe collapse) or depression (lower lobe collapse). Segmental and subsegmental collapse may show linear, curvilinear, wedge shaped opacities.
- This is most often associated with post-op patients and those with massive hepatosplenomegaly or ascites .
What is this?
What is this?
What is this?
Left Lower Lobe Atelectasis:
* What can be seen on the left?
* It is important to remember that these findings are all nonspecific, often occuring in cases of what?
* A substantially collapsed lower lobe will usually show as what?
- Silhouetting of the corresponding hemidiaphragm, crowding of vessels, and air bronchograms are sometimes seen, and silhouetting of descending aorta is seen on the left.
- It is important to remember that these findings are all nonspecific, often occuring in cases of consolidation, as well.
- A substantially collapsed lower lobe will usually show as a triangular opacity situated posteromedially against the mediastinum.
What is this?
What is this?
What is this?
* What is it a common acuse of?
* What can be done to remove it?
What is cardogenic and noncardogenic pul edema caused from?
What is a helpful mnemonic for noncardiogenic pul edema?
A helpful mnemonic for noncardiogenic pulmonary edema is NOT CARDIAC (near-drowning, oxygen therapy, transfusion or trauma, CNS disorder, ARDS, aspiration, or altitude sickness, renal disorder or resuscitation, drugs, inhaled toxins, allergic alveolitis, contrast or contusion.
- On a CXR, cardiogenic pulmonary edema can show what?
- Unilateral, miliary and lobar or lower zone edema are considered what?
- A unilateral pattern may be caused by what?
- Unusual patterns of edema may be found in patients with what?
- On a CXR, cardiogenic pulmonary edema can show; cephalization of the pulmonary vessels, Kerley B lines or septal lines, peribronchial cuffing, “bat wing” pattern, patchy shadowing with air bronchograms, and increased cardiac size.
- Unilateral, miliary and lobar or lower zone edema are considered atypical patterns of cardiac pulmonary edema.
- A unilateral pattern may be caused by lying preferentially on one side.
- Unusual patterns of edema may be found in patients with COPD who have predominant upper lobe emphysema.