Radiology procedures such as ultrasound, MRI or CT scans are very useful in detecting and diagnosing cardiovascular anomalies. Fluoroscopy is mostly used in cardiac intervention.

1. Radiodiagnosis of the Cardiovascular
system
ROLE OF ULTRASOUND
SCAN,CT,MRI, &
FLUOROSCOPY
Author:Mkhululi Ndlovu
Researcher in Radiology and Oncology

2. ULTRASOUND SCAN
Provides a real-time view as
either 2D slices or 3D
reconstructions,with no
radiation,making it the
investigation of choice
for a number of conditions.

3. ULTRASOUND SCAN
Uses high-frequency sound waves to view
soft tissues such as muscles and internal
organs. Because ultrasound images are
captured in real-time, they can show
movement of the body's internal organs as
well as blood flowing through blood vessels.

4. ULTRASOUND SCAN
In an ultrasound exam, a hand-held
transducer is placed against the skin. The
transducer sends out high frequency sound
waves that reflect off of body structures. The
returning sound waves, or echoes, are
displayed as an image on a monitor.

5. ULTRASOUND SCAN
The image is based on the frequency and
strength (amplitude) of the sound signal and
the time it takes to return from the patient
to the transducer.

6. ULTRASOUND SCAN
Its applications include
echocardiography,with special applications
such as transesophageal
echocardiography[TEE],and Doppler
ultrasound.

7. ULTRASOUND SCAN
Another special feature is Doppler fetal
heart rate monitor,which is a hand held
transducer used to listen to the fetal heart
beat.

8. ULTRASOUND SCAN
Echo is a non-invasive and more accurate
method for the quantification of left ventricular
ejection fraction[ie,measurement of the amount
of blood ejected from the left ventricle with
systolic contraction].

9. ULTRASOUND SCAN
This helps in ruling out systolic dysfunction.It
may be used to calculate cardiac chamber size
and wall thickness,and to diagnose the
presence of valvular dysfunction and
pericardial effusion.

10. ULTRASOUND SCAN
Other measurements such as stroke volume
and cardiac output may be calculated with
Echo.Echo will also diagnose complications of
myocardial infarction[MI] such as papillary
muscle rupture,ventricular septal defect,left-
ventricular aneurysm and pericardial effusion.

11. ULTRASOUND SCAN
It is the usual imaging test,together with chest
x-ray,in the assessment of congestive heart
failure.Echo also allows direct visualisation of
cardiac anatomy accompanied by Doppler
analysis of flow rates through valves and septal
defects.

12. ULTRASOUND SCAN
In special cases,ultrasound contrast agents may
be injected to enhance the Echo.This may be
mainly applied to visualise small intracardiac
shunts such as atrial septal defect. Colour
Doppler helps in the identification of septal
defects and quantification of gradients across
stenotic valves.

13. ULTRASOUND SCAN
Doppler US also helps in differentiating focal
stenosis from diffuse disease and occlusion.
Aneurysms, pseudoaneurysms and
arteriovenous malformations[AVM] are well
seen in Doppler US ,and is also useful for post
operative graft surveillance.

14. ULTRASOUND SCAN
In the case of abdominal aortic aneurysm,USS
may be useful where CT is unaccessible or for
follow-up measurement of a known
asymptomatic aneurysm.USS provides the
advantages of no ionising radiation, non-
invasiveness,quick,and relatively
cheap.However,it is operator dependent.

15. CT SCAN
Uses conventional X-ray beams
emanating from different
directions through the patient,
then reconstructed into a
single image with the use of a
computer.

16. CT SCAN
The resulting image(axial cut) shows cross-
sectional views free from superposition.

17. CT SCAN
Cardiac CT(Contrast enhanced or non-
contrast enhanced) is useful to diagnose
heart disease.It helps to visualise heart
anatomy,coronary circulation,and great
vessels(i.e aorta,pulmonary arteries and
veins).

18. CT SCAN
Several types are used that include total
body heart scans(TBCT),calcium-score
screening heart scans,and coronary CT
angiography(CTA).

19. CT SCAN
The screening(non-contrast enhanced) is
done to detect calcium deposits found in
atherosclerotic plaque in the coronary
arteries,before symptoms develop.This helps
in preventing future heart
problems,coronary artery disease and in
reducing their risk.

20. CT SCAN
CTA is a non-invasive and contrast
enhanced(iodine is used) heart imaging
test,useful to determine if either fatty or
calcium deposits(plaques) have built up in
the coronary arteries

21. CT SCAN
CTA can determine coronary artery
stenosis. It can non-invasively detect the soft
plaque or fatty matter in the coronary artery
walls that has not yet hardened but may lead
to future heart problems without lifestyle
changes or medical treatment.

22. CT SCAN
CTA can determine whether symptoms of
chest pain may be caused by coronary
blockage,esp in persons that may be at
risk;with a family history of cardiac events,
diabetes, high BP, smokers,and those with
elevated cholesterol

23. CT SCAN
CTA can also be used for assessment of
coronary artery bypass grafts and stent
patency.

24. CT SCAN
CT scan also plays a crucial role in mapping
of the anatomy of the left atrium and
pulmonary veins prior to radiofrequency
catheter ablation for atrial fibrilllation.

25. MRI SCAN
Uses strong magnetic
fields and radiofrequency
waves to produce a signal
that can be reconstructed
into an image slice.

26. MRI SCAN
It results in production of cross-sectional
images of organs and internal structures in
the body.
It does not use ionising radiation.
However,the strong magnetic field used is
unsafe for metal substances such as
pacemakers.

27. MRI SCAN
Because the signal detected by an MRI
machine varies depending on the water
content and local magnetic properties of a
particular area of the body, different tissues
or substances can be distinguished from one
another in the study image.

28. MRI SCAN
The term cardiac MR(CMR) is used because
of its application in investigation of cardiac
disease,described below.CMR is useful in
evaluation of cardiac function.

29. MRI SCAN
In this case,it enables calculation of ejection
fraction,assessment of myocardial mass ,and
regional wall motion where
echocardiography may be equivocal.

30. MRI SCAN
It also helps in determination of congenital
heart disease, complementary to
echocardiography

31. MRI SCAN
CMR is especially useful in assessing cardiac
anatomy,to help rule out
cardiomyopathy,left ventricular
aneurysm,where echo is
difficult/equivocal.Its increasing role is now
ruling out myocardial viability(weakened
myocardium).

32. MRI SCAN
An infarct scan may be performed and the
contrast media accumulates in the infarcted
myocardium,allowing direct visualisation on
a delayed scan.

33. MRI SCAN
CMR is also useful in ruling out great vessel
disease,such as aortic dissection and
coarctation.It can also assess cardiac masses
and rule out pericardial disease.

34. MRI SCAN
MRI provides the advantages of no ionising
radiation,no iodinated contrast media,good
soft tissue differentiation,multiplanar
imaging,and no interference from bone or
air.

35. MRI SCAN
However,its drawbacks include relatively
long scan times,general anaesthetic required
for infants and young children,other
contraindications including cardiac
pacemakers.

36. FLOUROSCOPY
Provides real time
X-ray imaging,useful for
guiding
a variety of diagnostic and
interventional procedures.

37. FLOUROSCOPY
In angiography(procedure that uses
catheterisation),contrast media is injected
through the catheter and images are
obtained using the digital fluoroscopy.

38. FLOUROSCOPY
The entire coronary and artery system is
visualized. Stenosis (blockages/narrowing)
inside blood vessels which inhibits blood
flow and causing pain can be assessed.

39. FLOUROSCOPY
For all structures,except the heart,images
are taken using the technique,Digital
Subtraction Angiography(DSA).

40. FLOUROSCOPY
DSA is achieved through obtaining a pre-
contrast image and then subtracting the
background after injection of a contrast
media.This allows the column of contrast in
the angiogram to be displayed without
interference of the background.

41. FLOUROSCOPY
Thus fluoroscopy is useful in “road
mapping” through real-time catheter
guidance with a contrast background.

42. FLOUROSCOPY
This is achieved through digitally subtracting
the initial non-contrast background, then
contrast is injected into the vessel of interest
and a new combined image of the contrast
injection is superimposed on the real-time
fluoroscopic image.

43. FLOUROSCOPY
Besides cardiac catheterisation[which helps to
evaluate the presence of coronary blockages
though assessment of blood flow through the
conorary arteries],fluoroscopy is also useful in
pacemaker Insertion.In this case,a central vein
(ie subclavian, internal jugular, or axillary vein)
is accessed via a percutaneous approach.

44. FLOUROSCOPY
A pacemaker can
be implanted into
the chambers of
the heart under
flouroscopic guidance.

45. FLOUROSCOPY
During the procedure,it helps in guiding the
passage for guidewires,leads and sheaths.This
is done under pulsed fluoroscopy.However,in
some patients this may be technically difficult
because skeletal landmarks are deviated.
Hence,in this case,an initial brief fluoroscopic
examination will be required.

46. FLOUROSCOPY
This will greatly reduce the time and complications
associated with obtaining the access.Preoperative
fluoroscopy may also be necessary for the arteriography of
the aorta and great vessels to determine precise anatomical
relations when proximal landing zone of the stent graft
cannot be determined by non-invasive imaging.The major
drawback of fluoroscopy is the high radiation dose to the
patient.

47. DETAILS:
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Email : mkhulul.ndlovu@gmail.com
Twitter : @ndlovumkhue
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