Cardiac/Vascular Flashcards
Left sided SVC
90% drain into an enlarged coronary sinus
10% drain into left atrium
PDA
10% cases with congenital heart disease
In a normal patient duct will close within hours of birth
In duct dependent circulating it stays open for days
It will classically then close around day 5 and child will deteriorate
Prostaglandins can be given to re open the duct.
Abdominal aorta and branches
Thromboangiitis obliterans
Disease linked to smoking and manifests as small vessel vascularised.
Arterial occlusion and corkscrew shaped collaterals.
Patients are younger than those affected by atherosclerotic problems
Popliteal artery entrapment syndrome (PAES)
Anomalous insertion of medial head of gastrocnemius - compresses popliteal artery leading to exertional claudicant symptoms.
Cystic adventitial degeneration
Mucous cysts in wall of popliteal artery
High T2
Variable T1
Strong male preponderance.
Diaphragmatic openings
Amniotic fluid embolus
Rare serious complication of pregnancy
- amniotic fluid enters the venous system causing an anaphylactic reaction and DIC.
Features of ARDS
- pulmonary oedema
- diffuse ground glass opacification
(Will not be seen as filling defect on CTPA)
IVC filter
IVC tributaries
Pulmonary trunk anatomy
May - Thurner syndrome
- left leg swelling and left DVT secondary to obstruction of left common iliac vein compressed by right common iliac artery
Fibrosis mediastinitis
Most commonly seen as a partially calcified mass in middle mediastinum - subcarinal and right paratracheal regions
- causes vascular compression and leads to right heart strain.
-SVC obstruction is most common complication
Peribronchial cuffing and septal thickening are secondary to pulmonary venous congestion
Wedge shaped infarcts seen as consolidation
Two aetiologies
1) Histoplasma
2) IGG4
VQ imaging
- used in pregnancy, contrast allergy or risk of contrast induced nephrostomy
CXR must be normal
In pregnancy or lactation, VQ has a reduced breast dose to mother, however may be higher to the foetus in uterine secondary to tracer accumulation.
Can perform perfusion only at half mother/foetus dose
Scimitar vein
Partial anomalous pulmonary venous drainage circulation
Anomalous vein drain in from a hypoplastic lung on CXR
Other CXR findings of PAPVC
- right lung drained by the vein is hypoplastic and consequentially heart is malpositioned (dextro position)
Brachial artery anatomy
Continuation of axillary artery beginning at lower margin of teres MAJOR.
Gives off profunda brachii immediately distal to teres major. Supplies deep compartment and run between long and medial head triceps
GIves off superior ulnar collateral artery and then inferior ulnar collateral artery
Post procedure lung biopsy complications
Contraindications to CT guided lung biopsy
Management of Pseudoaneurysm
Risk factors: anticoagulation, haemodialysis, calcified arteries, obesity
Procedural: Low puncture sites SFA / profundus
Sub-optimal post procedural pressure.
<2cm can usually be managed with compression (attempt to occlude neck).
For thrombin injection - average pseudoaneurysm size is approx 3cm.
If not amenable to either then surgical ligation.
Elevated hemi diaphragm
Angiogram
Aortic aneurysm screening
- men >65
- or m+w with family history
Contraindications of thrombolysis
Popliteal stenosis
Aorta and pulmonary trunk run through a common pericardial sheath.
Left aortic sinus - left coronary artery origin.
Right aortic sinus - right coronary artery
Posterior sinus - no coronary artery
Step artefact - misregistragtion of anatomical landmarks worsening by irregular heart rhythm or large field of view with short detector row.
Motion artefact caused by breathing or fast/irregular HR
Patterns of late enhancement in cardiomyopathies.
Adenosine stress MRI > Dobutamine with regard sensitivity and specificity.
1/2 life 10 seconds
Causes vessel vasodilation, and will highlight hypoperfusion.
Contraindications
2nd/3rd degree heart block
Bronchospasm
Hypotension <90
MI within 48 hrs
Uncontrolled arrhythmia
Severe/critical aortic stenosis.
Dobutamine MRI (now superseded)
- increases HR + BP
Stops if;
HR 85% resting
New wall motion abnormality
BP >240/220
Systolic falls by 40
Persistent arrhythmias
Patient too symptomatic
Usual contraindication to performing the MRI
Hypertension >220/110
Unstable angina
Severe aortic stenosis
Uncontrolled AF
HCOM
Congestive cardiac failure
Valvular disease
ARVC
Arrhythmogenic right ventricular cardiomyopathy
Familial 50%
Fibro - fatty degeneration of right ventricular wall.
Hypertrophic cardiomyopathy
- can be associated with autosomal dominant inheritance
Non dilated thickening of the ventricular wall. If associated with left ventricular outflow obstruction can be fatal.
(Due to pulling of the anterior leaflet of the mitral valve into the outflow tract)
- midwall hyperenhancement at the junction of right and left ventricles.
Sarcoidosis
- mid wall high T2 signal, predominately septal base.
- interventricular septum or left ventricle most commonly
- EPICARDIAL or mid wall
- nodular
Amyloidosis
- diffuse sub endocardial gad enhancement.
- causes restrictive cardiomyopathy
- speckled, granular
(Remember if history of myeloma - amyloidosis should be considered).
Cardiac myxoma
Commonly affect left atrium
Most common cardiac primary tumour
Attach to inter-atrial septum
Demonstrate post-gad enhancement
Constrictive pericarditis
Pericardial inflammation leads to fibrous thickening
- usual cause is post - operative / idiopathic / TB
Clinical features:
Malaise, dyspnoea, neck vein distension, paradoxical JVP
Imaging: right ventricle becomes flattened and septum can curve towards the left.
Pericardium fibrotic >2mm
Pleural effusions and ascites
Aberrant left pulmonary artery
This is the only vessel to pass between the trachea and Oesophagus and therefore the only vessel to cause an anterior indentation of the Oesophagus.
Posterior indentation
Right sided arch with aberrant left subclavian
Left sided arch with aberrant right
Double aortic arch (also indents anterior trachea).
Cardiac metastases
More common than cardiac sarcomas
In contrast to myxoma/fibroblastoma - malignant lesions have a broad attachment to heart
(Malignant melanoma is most common to met to heart — but also is not it’s most common met).
Atrial myxoma
-most common benign heart neoplasm
Small mass attached to interatrial septum by a stalk.
ISO/hypointense T1
Cardiac sarcoma
RARE
Malignant
Many types
BROAD based
Alcoholic cardiomyopathy
Dilated cardiomyopathy occurs in patients with alcohol abuse
Thinning of both ventricles which also appear hypokinetic on dynamic studies.
Mid myocardial fibrosis can occur + will delayed enhance
Contra-indications for beta blocker administration
Pericardial layers
- double walled sac
2 layers
+ external fibrous pericardium
+internal serous pericardium
The fibrous pericardium is thicker, tougher and is continuous with the central tendon of the diaphragm.
The serous pericardium
- parietal, fused to and inseparable from fibrous pericardium
- visceral layer contacts the epicardium.
Pericarditis - Constrictive v Restrictive
Both: biatrial dilatation with normal ventricular size
Constrictive:
1) Thickened pericardium
2) Interventricular dependence - diastolic septal bounce or sigmoidisation of septum.
Restrictive: subendocardial late gad enhancement
Ie leading cause is restrictive cardiomyopathy.
Inter-arterial left main coronary artery
- this is very significant and most likely to cause symptoms.
- origin of the left main or LAD from the right coronary sinus and therefore a course between the ascending aorta and pulmonary trunk.
Inter-arterial course of right coronary artery
- aberrant origin from left coronary sinus.
Again passes between ascending aorta and pulmonary trunk.
Coronary fistula
- connection coronary artery and cardiac chamber or great vessels.
- results in large coronary artery aneurysms
Myocardial bridging of left anterior descending artery
- left anterior descending artery dives into myocardium.
Anomalous left coronary artery arising from pulmonary artery
- left coronary artery arises from pulmonary artery and get flow reversal in the left coronary artery - steal syndrome
Left coronary artery (arises ABOVE left cusp) + supplies
- left atrium
-left ventricle
-intraventricular septum
- left branch bundle of His
Right coronary artery (arises ABOVE right cusp)
+ supplies
- right atrium
- SA and AV nodes
- posterior intraventricular septum
Black blood T2 is NOT useful for amyloidosis
Why?
amyloid deposition leads to fibrosis, therefore little water
- also gad washes out faster of myocardium than what normally occurs.
THEREFORE heart is very dark.
Cardiac CT artefacts
Truncus arteriosis
- single trunk rather than aorta and pulmonary trunk separately
Associated with DiGeorge syndrome
Chromosome 22 - elongated face and cleft palate
Also associated with tetralogy of Fallot
Truncus also associated with
CHARGE
C (coloboma) - posterior eye defect
H - congential heart disease
A - Choanal atresia
R - Retardation
G - genital hypoplasia
E - ear abnormality
Also associated with VSD, and right sided arch
Loeffler endocarditis (Eosinophilic cardiomyopathy)
Biventricular thrombus with endocardial fibrosis is classical
Physics - MRI artefacts
