[anatomy&imaging][module A] Flashcards
Discuss anatomy (can ask them to point out the following structures): Trachea centrally Aortic arch next to this Ribs laterally Both oblique fissures (more inferior of the 2 on the right) Normal lung with small vessels Emphysematous areas of lung e.g. right apex More defined bulla e.g. right lower lobe, lateral left midzone.
Normal lung parenchyma and small lung vessels (esp on right) well seen on this. o Can see ascending (anterior) and descending (posterior) aorta, as well as bifurcation of pulmonary artery. o Bulla on left.
Compare with CT o The emphysematous changes are less well seen. o Best visualised lesion is left midzone bulla o Note how there are possible masses in the left midzone (point out the hila bilaterally, and masses next to the left hilum). o Note how you see the whole heart here as on the CT, you don’t see the heart (as you have sliced through an area without the heart in it).
CXR:
- Consolidation – right lower zone
- Bulky right hilum
- In normal practice, even if the patient came in with signs of a chest infection, you would always do a repeat CXR. Why?
To rule out an underlying mass (as in this case)
Axial CT 1:
• Right hilar mass, just anterolateral to the right main bronchus, lateral to the right pulmonary artery and posterior to SVC. o The anatomical relations of the mass determine how easy it is to remove o The more difficult to remove, the higher the “stage” of the tumour.
Axial CT2: • This image is inferior to the previous one. • The mass is better seen, abutting the right atrium (the atrium is very bright on this picture as it is full of contrast). A left pulmonary vein can be seen joining the right atrium.
Coronal CT 1: • Note the slightly different appearance of the CT on this scan. o This image has different CT “windows” – which shows the bronchi better. • The mass abuts the inferior aspect of the right main bronchus a few cm from the carina.
Axial CT liver:
• Small low density (dark) lesion in the liver (near the edge). o Metastasis – therefore higher stage tumour o The most common system of staging involves the TNM classification: T – characteristics of primary tumour (e.g. size + anatomical relations / involvement of neighbouring structures) N – involvement of lymph nodes M – other distant metastases • Other common sites of lung mets: o Bones o Adrenals
Right-sided pneumothorax o Lung edge visible No lung markings seen lateral to this. o The medistinum has shifted to the left (hence the vertebrae are well seen) This is a medical emergency (tension pneumothorax) Needs urgent decompression (chest drain or cannula) – otherwise the increase in pressure stops venous return to heart causing cardiac arrest.
Right-sided pneumothorax o Lung edge visible No lung markings seen lateral to this. o The medistinum has shifted to the left (hence the vertebrae are well seen) This is a medical emergency (tension pneumothorax) Needs urgent decompression (chest drain or cannula) – otherwise the increase in pressure stops venous return to heart causing cardiac arrest.
Chest drain inserted • Residual small right pneumothorax • New surgical emphysema in chest wall and neck (air leaking around drain into skin)!
Pneumothorax with lung edge visible on right • Surgical emphysema within skin and between muscles • Pneumomediastinum – anterior to the heart and medial to left lung (note, there is no left pneumothorax, this is the pneumomediastinum).
PE: can look normal. Specific signs outside remit of syllabus.
Bifurcation of the pulmonary artery has a dark linear filling defect (migrated clot from a vein in the leg) o This is known as a “saddle embolus” as it bridges the bifurcation. As it is so central and both lungs are affected, can be life-threatening.
• Clot seen within the right main pulmonary artery going into its branches (rim of contrast seen around the clot in one branch).
Consilidation: • This term just means that the lung is in essence more solid • Consolidation can be due to many things: o Bacteria o Pus cells o Blood o Proteinaceous fluid • However, in most cases the term is used interchangeably with infection. • Here we have left lower lobe consolidation and a bulky left hilum o Note we usually do a follow up x-ray in patients with consolidation to make sure it resolves (i.e. no underlying mass)
Miliary deposits: • Multiple small nodules thoughout the lungs o Compare against normal CXR • Can be difficult to differentiate from the normal lung vessels when the nodules are more subtle.
Consolidation CT: • Similar to appearances on CT. • The vessels disappear into the consolidation • An air bronchiole is seen (bronchus full of air)
Miliary CT: • Multiple added nodules between the vessels (subtle but best seen laterally on both sides).
Right coronary artery • Point out posterior descending artery (the more inferior terminal branch on this picture)
Left coronary angiogram: • Point out: o Left main stem o Circumflex + obtuse marginals o Left anterior descending + diagonal branches
Pre circumflex angioplasty: • Circumflex narrowing • The 2 dots are either ends of an angioplasty balloon that is about to be inflated to open the narrowing. ANd post.
Left anterior descending artery on CT.
Normal echocardiogram (movie provided): • 4 chamber view o Note, unlike most other imaging the left side of the patient is on the left side of the image: RV LV RA LA o Point out position of mitral and tricuspid valves on movie o The image is taken from the front of the chest, and the closest structures lie at the top of the image. i.e. the ventricles which lie more anteriorly in the chest, are at the top of the screen.
Mitral valve prosthesis on CXR: • Prosthesis = ring structure in middle of heart • Point out this relates to normal mitral valve position on CXR • Multiple other lines (NG tube, tracheostomy, right CVP line, sternotomy wires, cardiac monitoring leads). • Multiple rings lateral to left chest wall is part of ventilation system.
Prosthesis on echo (movie provided): • Very bright line in region of mitral valve. o Compare with normal echo.
Cardiothoracic ratio (ratio of “width of heart : internal diameter of chest wall”). Ratio > 0.5 = cardiomegaly.
Cardiomegaly • Upper lobe blood diversion o Best seen on the right on this film o Usually the lower lobe vessels are more prominent (due to gravity), but in pulmonary oedema this is reversed • Kerley B lines o These are very subtle o Multiple horizontal lines at the lung edge, best seen near the right costophrenic angle on this film o Due to fluid (from the pulmonary oedema) collecting in the interlobular septa of the lungs
CT axial 1: • Point out ascending and descending aorta • Widened ascending aorta o Dissection flap seen medially • Dissection flap seen in descending aorta
Widened mediastinum on CXR:
More inferiorly in aorta • Dissection flap at level of renal arteries o Note different opacities of left and right arteries (they are on different sides of the flap) o Please note the large transverse vessel is the left renal vein.
More inferiorly in aorta • Dissection flap at level of renal arteries o Note different opacities of left and right arteries (they are on different sides of the flap) o Please note the large transverse vessel is the left renal vein.
Flap involving the brachiocephalic vessels and also the aortic root.
Outline the normal paths for NG, left/right jugular lines and ET (3)
Discuss normal path of: • NG tube o Oesophagus in midline to diaphragmatic hiatus, and then to left into stomach.
- Left and right jugular lines o Jugular to brachiocephalic vein, to SVC, then right atrium Ideal placement at cavoatrial junction (roughly level of carina) Bad placement • Right ventricle, pulm arteries, • IVC
- ET tube o Trachea, above carina o Ideally not into bronchi Usually goes into R main bronchus preferentially as • Wider • Shorter • More vertical
Enlarged lymph node.
