Examination of arterial system
Methods:
Invasivity
■ Invasive
■ Non-invasive
Modality used in the metho
■ Physical examination
^ff™nctin---
■ Electromagnetic
■ Magnetic resonance
Most methods try to verificate or visuali< stenosis caused by atherosclerotic lesion
		
Physical examinations		
■ Can be used in the neck or extremities ■ Inspection - trophic changes in ischemia, pale to „marbled" periphery of an extremity ■ Auscultation - stenosis can be manifested by a murmur (turbulent flow) ■ Palpation - pulse can't be palpated distally of obstruction, difference in temperature between	J /	
healthy and ischemized^— extremity	1	
Stress tests
Are used to triggering ischemia during the labour of skeletal or heart muscle, which leads into ischemic pain
Treadmill or exercise bike can be used to provoke ischemia
If there is a suspicion for IHD, 12-lead ECG can be recorded to verificate ischemic changes
UltraSonoGraphy (USG)
I In the diagnostics of atherosclerosis, two dimensional image together with doppler examination is used (duplex USG)
I By common devices, large vessels, vessels of extremities or neck, and renal arteries can be investigated (also the heart) +^^T"
I In bh*in arteries, modified transcranial doppler can be used ■
Doppler effect
blue^hiu
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The principle is different frequency of waves in front of and behind moving source ^^^^
Electromagnetic waves are used e.g. in astronomy or in police radars (speed measuring), acoustic waves e.g. in sonars or in medical applications
In USG, the source and reciever is stationary, but it is reflected by moving particles (blood cells). Frequency is higher when cells move towards the source, lower when they move awap
Duplex USG -
SIEMENS
VF10-5 C-Vascular
5.3 MHz 5580 Hz Filter 1ft7 Hz Update Off DR55dB Map C TintO Sweep 2 Gate 1.0 mm
T/F Res F Angle 60 ° 12fps
combination of 2D image and Doppler USG
12 mm 60
PI = 1.B5 i    I I PS = 92.0cm/s TAmn = 23.5 cm/s
J
Common Carotid Artery
i    i    i R|l= 0.74 i ' ED = 23.5 cm/s
'S/r/=3l91 i ' TAmx - 37.1 cm/s
Color and Pulse Wave Doppler
3 cm Z
\
! The thinner is the stenoSTsTthe faster is the blood flow!
Intravascular Ultrasonography
(IVUS)
Invasive method, used as supplement of angiographic examination
The probe is carried by a catheter directly into the vessel to gain more exact information about the morphology of atherosclerotic lesion
Angiography
In wide sense all methods, where the vessels are visualized using contrast matter
In narrow sense, it is used for skiascopy-based methods ^^^^^
■ Advantages: detailed view of long vessel sections
real-time picture      ^^^^ \
■ Disadvantages: invasive method - risk of an injury (on the other hand, this can be an advantage - angioplast^\^
needs expensive equipment ^f000"^
( radiation load on both patient and staff
Less invasive alternatives are CT and MR angiography
Angiographic picture
mm
ffir
Normal digiM subriadion pulmonary angiogram gt Ihe right Igng
Digital subtraction angiography - th other tissues is digitally removed
Coronary angiography
After cathetrization, the contrast matter (mostly iodine) is injected into left and right coronary artery
The examination of arteries is usually followed by visualization of left ventricle (ventriculography)
In case of need, therapeutic intervention on the artery can be performed
Coronary angiography 2
Anti-radiation measures must be taken during the examination
CathLab - Cathetrization Laboratory
CT and MR angiography
CT and MR AG can display large parts of arterial system
In MR angiography, there is not radiation exposition
As a disadvantage, there is not a possibility of real-time picture and of an intervention
OCT (optical coherent tomography)
Invasive method similar to IVUS
Based on echolocation, instead of ultrasound waves it uses IR electromagnetic radiation (Xj^OOnm) _
More exact than IVUS
The tissue can be "displayed only up to 1-2 mm
after stent implantatio
NIRS
Near infrared spectroscopy
May be combined with IVUS or OCT
Valuable in the detection of necrotic core, especially when hiden behind dense material (calcium deposits)
Combination of imaging methods
NIRS
■ Left Anterior Descending Artery                         |a3 | I	
it 1                       ■ \;. 1 V 1 V	
Q IVUS-NIRS -	OCT Histology
4/ - fibrous cap with calcifications; # - necrotic core; * - other lipid deposit
Blood testing
■ Focused on known risk factors (lipid spectrum, hyperglycemia) ^^^^Br^
■ In familiar atherosclerosis in young age, it is suitable to perform genetic tests with respect to known risky alleles