16. Methods for imaging of the heart, coronary vessels, large and peripheral vessels

Cardiac Basics in Modalities:

Non-Invasive methods

1. a. CXR – limited Dx value, used to visualise shadows of heart and great vessels. Cardiothoracic ratio 2:1
2. b. US – echocardiography and doppler US – allows speed and direction of blood flow, assessment of valve function, regurgitation, degree of stenosis and measure of diastolic dysfunction
3. c. CT angiography, w/ or w/o iV contrast (lopadmimol) – great Dx value

• Indications – planned Dx test for stenosis, atherosclerosis or so on or in emergencies such as PE, aneurysms, dissection
• Advantages – Quick and less expensive compared to MRI
• Disadvantages – high dose of radiation and contrast

1. d. MRT – great Dx value, can do angiography w/o contrast

• Disadvantage – expensive, contraindicated with ferromagnetic implants, limited availability

Invasive methods – Dx or Tx

1. a. Transoesophageal echocardiography - TEE placed down oesophagus
2. b. Percutaneous coronary angioplasty
3. c. Digital substruction angiography DSA – Xray imaging method, Tx and Dx value
4. d. Angiography/venography

Cardiac Basic Anatomy

• RA in (AL) and lies inferior the LA
• SVC enters through the roof of RA
• IV enters RA below cardiac septum
• Coronary sinus enters RA to drain venous blood from coronary veins
• RA appendage is trabecular part of RA
• TV is between RA and RV
• PV is RV and pulmonary artery
• MV is between LA and LV
• Aortic valve between LV and aorta

Cardiac blood supply

Coronary artery branches into R and L. L includes LAD and LCX and R includes PDA and right marginal

Cardiac conduction system

SAN which is pacemaker, AVN, BOH, R and L BB, PJ,

Factors affecting normal heart shadow

1. a. Body type – oblique, transverse, vertical
2. b. Age – with age globular – oblique – horizontal
3. c. Respiration: Inspiration – dropping heart, normal shadow but with expiration horizontal shadow
4. d. Px position: Erect – heart shadow elongated, laying – enlarged

Heart diseases and abnormalities:

1. Dextrocardia – heart apex is on right, can be isolated abnormality or with other malformations

2. Acquired heart defects

• Includes Rheumatoid endocarditis, bacterial endocarditis, lues, atherosclerosis – damaged valves results in congestion in lungs and change in shape and size of shadow

• Mitral stenosis: Extension of LA, constriction of retrocardiac space in upper part – contrasted oesophagus passes backwards with an arc and small radium, ↑ bifurcation angle >90degrees, deformation of heart left heart contour, pulmonary stasis and right heart contour