right lower zone - the veins clearly lie in a more - what direction
horizontal orientation
upper lobe vessels are substantially smaller than their lower lobe counterparts, rarely measuring greater than whst in the first interspace
3mm
descending portion of the right lower lobe artery should measure less than WHAT wide
16mm
Pulmonary capillary wedge pressure grading (PCWP)
Mild Redistribution PCWP 13-18 mmHg Moderate Interstitial oedema PCWP 18-25 mmHg Severe Alveolar oedema PCWP >25-30 mmHg
PCWP relates to pulmonary venous hypertension how
Graded I - III cooresponds to mild to severe
Grade I features of PVH
Upper lobe redistribution
Hilar blurring
Effacement of hilar angle
Grade II of PVH features
Interstitial pulmonary oedema
Pleural effusion
Grade III of PVH features
Alveolar oedema
Perihilar/lower zone
Often asymmetrical: right greater than left (R>L)
Acinar shadowing
How can emphysema affect the vascular pattern of lungs?
If lower lobe is affected - can cause upper lobe diversion
if upper lobes affected - cause lower zone crowding
how does the hilar angle relate to PVH
if the veins expand they can obliterate the hilar angle
Kerley lines are named after who?
Peter James Kerley - Irish radiologist died in 1978, worked at westminster hospital.
lamellar effusion
accumulation of fluid in the loose subpleural interstitium (i.e. not in the true pleural space)
two types of pulmonary oedema
hydrostatic - cardiogenic
increased permeability - ARDS
Features of ARDS pulomnary oedema
Changes that may be delayed Uniform distribution Septal lines (rare) Air bronchograms (common) Vascular pattern usually normal Effusions less common and small
absence of septal lines and effusions
pulmonary vascular bed normally has much WHAT resistance than the systemic capillary bed.
Lower
Pulmonary hypertension two types?
Primary
Secondary
Primary PHT tpyes
Familial
Secondary PHT types -
Thromboembolic Chronic obstructive pulmonary disease (COPD) Pulmonary fibrosis Sarcoidosis Intracardiac shunts: Ventricular septal defect (VSD) Atrial septal defect (ASD) Patent ductus arteriosus (PDA) Pulmonary veno-occlusive disease
do chest xr signs correlate to severirty of PHT disease?
no
what size of main pulmonary artery is concerning
> 3.3cm
What syndrome occurs in large untreated left to right shunts
Eisenmenger
Eisenmenger syndrome is seen in what conditions?
ASD, VSD, and PDA
pulomonary oligaemia can be causes by what?
Massive PE in adults
Right to left shunt in paeds
Pulmonary venous hypertension is characterised
a distinct vascular redistribution from the lower lung zones to the upper zones and there may be additional features of interstitial oedema and frank alveolar oedema
