|Because the heart is not just a blob in the middle, as some who shall remain nameless have suggested.|
|Massive cardiomegaly is present. The differential for this appearance is relatively short and includes: |
•Severe univalvular disease
|So the key points are to evaluate the cardiac shape and determine selective chamber enlargement that would suggest valve disease. If there is pulmonary venous congestion this would support valvular disease, cardiomyopathy or endomyocardial fibrosis but not necessarily the latter 3 dianoses.|
|In this case the heart has a water bottle or conical shape. Allowing for the size of the heart the pulmonary vascularity is notably normal.|
Diagnosis: Pericardial Effusion
•Normal pericardial fluid volume 15-30mls
•For CXR changes 250-500mls must be present (far less for CT/MR)
•“Water bottle”, “Conical flask” appearance
•Often little or no pulmonary venous congestion
•No systemic venous obstruction
|History: Chronic Dyspnoea|
|Again marked cardiomegaly is present. The key features of this case are the box-like shape of the heart caused by two features. These are prominence of the right cardiac border due to right atrial enlargement (note that there is no double density to suggest LA enlargement) and the very narrow pulmonary artery region caused by small main pulmonary arteries. The more peripheral pulmonary vascularity is also markedly reduced. The right cardiac border is very sharpely defined.|
|Diagnosis: Ebstein's anomaly of the heart |
(Uhl's anomaly may appear indistinguishable-caused by a parchment thin right ventricle)
|Features of Ebstein's|
• Congenital inferior displacement of the tricuspid valve –(septal and posterior cusps) - the atrialized portion of the right ventricle contracts late against the atrial contraction. In combination with...
• Severe tricuspid regurgitation there is consequent...
• Massive RA dilatation, causing...
•“Box” shaped heart, which has a...
•“Pencil sharp” or “etched” right cardiac border, due to reduced ejection/contraction, resulting in reduced right ventricular blood flow, causing a...
•Narrow vascular pedicle and...
•Pulmonary oligaemia, this may be circumvented by the variable presence of an...
•ASD or other shunt
•Conduction anomalies often associated.
|PA CXR||Lateral CXR |
|There is an unusually bulge to the right cardiac border visualised also on the lateral projection as an increased density overlying the anterior cardiac silhouette. The differential for this appearance could include aetiologies from many different anatomical structures:|
•Cardiac (Right atrial chamber enlargement)
•Pericardial (fat pads, cysts, effusions, rarely tumours)
•Pleural (solitary fibrous tumour of the pleura, thymoma)
Most commonly these abnormalities will be due to pericardial fat pads or hernias. For the former we would really like to appreciate low density and more importantly a triangular shape that gives obtuse angles with the diaphragm at the cardiophrenic angles (on the PA and lateral). In this case these angles are acute ("bulging" apperance). To diagnose a hernia would be more difficult without CT but the presence of herniated air containing bowel would be confirmatory. Again this abnormality may be low density due to herniated fat.
Effusions are usully more diffuse involving both sides of the heart, tumours of the pleura and pericardium might be more lobulated. The list is getting shorter!
Here are some old films:
|6 year earlier: PA||Lateral |
|2 year earlier: PA||Lateral|
|So the appearances wax and wane (no treatment). Most tumours are all realistically out now (solitary fibrous tumours can have different shapes according to position but it is hard to envisage near normal intervening images). We are left with two realistic propostions: |
1.Right atrial dilatation- difficult to justify in the absence of a valve replacement/repair and possibly SVC dilatation and
2.Pericardial cysts which are known to wax and wane.
|Diagnosis: Pericardial Cyst (or diverticulum)|
|Pericardial cysts and diverticula are indistinguishable both arising from the parietal pericardium and drooping down under the weight over their contents. Contents can be confirmed on CT as fluid density although a small subset may be hyperdense. They are usually asymptomatic although 1/3 may have a variety of non-specific symptoms. They occur more frequently in men and usulally on the right side (80%). Their apppearance can be vary variable on plain films depending on position and inspiration.|
|History: Suspected neck tumour. CT of the neck could not distinguish between a node and the azygos arch in this patient. |
|There is a fluid density lesion present in the right paratracheal region. The key feature here is the absence of any peripheral soft tissue to suggest a necrotic node, homgeneous fluid attenuation and the moulding nature of this lesion to the trachea and great vessels. |
|Diagnosis: High riding” or cephalad extension of the superior pericardial recess.|
|Diagnosis may be confirmed on multidetector CT by demonstrating communication to the typically crescentic shaped retroaortic superior pericardial recess on 1mm reconstructed axial images or on coronal imaging (see left). Incidence is unknown, but probably far less than the 2% figure quoted in the only paper to review a series.|
|Case 1: Diagnosis please||Case 2: Diagnosis please|
|Diagnosis: Complete congenital absence of the pericardium.||Diagnosis: Partial congenital absence of the pericardium.|
|Remember that the normal cardiac position is approximately 1/3 to the right of the mediastinum and 2/3 to the left. If no heart projects to the right of the mediastinum, the appearance is abnormal. In the absence of LLL volume loss or right chest displacing pathology, the first consideration should be patient rotation. If the patient is well centred the next point of call is the thoracic shape. If the Lateral CXR demonstrates reduction of the AP dimension (straight spine) or pectus excavatum this may displace the cardiac silhouette to the left. If the chest morphology is generally normal and the heart is significantly displaced to the left and there is left cardiac border straightening consider congenital absence of the pericardium. Additional noted features may be a deep or very well defined aorto-pulmonary window caused by the absence of pleura allowing lung to invaginate into this space. |
Absence of the pericardium is almost invariably on the left and is caused by incomplete formation of the pleuropericardial mebrane due to premature atrophy of the left common cardinal vein (Duct of Cuvier).The abnormality may be complete or incomplete, the latter actually being less frequent but more problematic as the PA or left atrial appendage may herniate and become incarcerated or torsed in the defect. The abnormality is more frequent in males and may be associated with ASD, PDA, Fallots, Bronchogenic Cyst, or Pectus in a third of cases.
|Diagnosis: Mitral Stenosis|
|The cardiac size is normal. There is a prominent left atrial appendage and a double density over the right cardiac border. These are features of left atrial enlargement. When promted by these features you should look for a cause and look for the effect. If you look at the mitral valve there is a calcification present indicating likely rheumatic mitral valve disease. There is mild upper lobe vascular redistribution (poorly projected) indicating elevated pulmonary venous pressure secondary to elevated LA pressure. The diagnosis is mitral stenosis rather than combined MS/MR or MR because the LV is not dilated (see below).|
|Diagnosis: Mitral Regurgitation|
|This case also demonstrates enlargement of the left atrium (left atrial appendage, double density and carinal splaying). There is also overall cardiac enlargement due to LV dilatation. There is upper lobe vascular distribution associated with Kerley B septal lines, indicative of early interstitial oedema changes. These features are all consistent with mitral regurgitation (coexistant mitral stenosis may also be present). |
The left atrium seldom becomes massively enlarged in the absence of MR. This is because excess volume has a greater effect on chamber dilatation than pressure. Unlike isolated MS the LV dilates in MR because the end-diastolic LV volume has to increase to compensate for the loss of blood into the left atrium in order to maintain a constant stroke volume into the aorta.
|History: Malaise, febrile illness|
|Diagnosis: Kawasaki syndrome (LAD aneurysm) |
|The CXR demonstrates a "third mogul"- a bulge below the pulmonary artery. Usually these bulges will be due to enlargement of the left atrial appendage. However, in this case there are no ancillary findings of LA enlargement, which would be unusual in a child anyway. Other aetiologies for a third mogul might include thymic enlargement/adenopathy, pericardial cysts, and aneurysms or fistulas of the coronary arteries. The CT demonstrates an aneurysm of the LAD. The diagnosis in a child with fever is Kawasaki Syndrome.|
The angiogram of this patient is shown below.
|Kawasaki's disease is a mucocutaneous lymph node syndrome, usually presenting with fever,cervical lymphadenopathy and rashes (often palmar and desquamative) in children most commonly under 5 years of age. It is a multisystem vasculitis with a coronary predeliction. Coronary aneurysms, thrombosis or occlusions may occur. The risk of occlusion is 8% for >9mm aneurysms. Myocarditis, pericarditis, valvulitis or AV node conduction anomalies may also occur. Treatment is with gamma globulin and aspirin. Steroids may cause aneurysm rupture.|
|History: Cyanosis and SOB on exertion.|
|Diagnosis: Fallots (Blalock-Taussig repair)|