This document discusses different techniques for angiography of the head and neck, including digital subtraction angiography (DSA), CT angiography (CTA), and MR angiography (MRA). DSA uses image subtraction to visualize contrast-filled blood vessels. CTA uses a CT scan after injection of contrast media. MRA is non-invasive and does not require contrast, using magnetic fields to visualize blood flow. The document provides details on the protocols, advantages, and images produced for each angiography technique of the head and neck vasculature.

1. PERSENTOR
RAJAN KR SHARMA
B.SC. MIT
BPKIHS

2. GENERAL ANATOMY
• Arterial Supply of the Brain
• Blood supply to the brain is derived from two arteries:
(1) The internal carotid artery and
(2) The vertebral artery.
• These arteries and their branches arise in pairs that supply blood to both
sides of the brain.
• The major arteries supplying the cerebrum (basilar artery and internal
carotid) get interconnected to one another at the base of the brain to
form a six-sided polygon of arteries called circular arteriosus.
• It formed around the interpeduncular fossa.

5. INTRODUCTION
 WHAT IS ANGIOGRAPHY ?
 Study of blood vessels in the body by injecting a contrast
media through particular arteries and veins.
 ANGIOGRAPHY OF HEAD
 Done for the study of CIRCLE OF WILLIS
 Also known as CEREBRAL ANGIOGRAPHY
 ANGIOGRAPHY OF NECK
 Done for the study of CAROTID ARTERIES.
 Also known as CAROTID ARANGIOGRAPHY

6. TECHNIQUE FOR ANGIOGRAPHY
 Vascular structures can be imaged by 3 means:
1) SUBSTRACTION ANGIOGRAPHY
 CONVENTIONAL ANGIOGRAPHY (PHOTOGRAPHIC
SUBSTRACTION ANGIOGRAPHY / IMAGE SUBSTRACTION)
 DIGITAL SUBSTRACTION ANGIOGRAPHY (DSA)
2) CT ANGIOGRAPHY (CTA)
3) MR ANGIOGRAPHY (MRA)

7. SUBSTRACTION ANGIOGRAPHY
 It is simply a technique by which bone structures images are
subtracted or canceled out from a film of bones plus opacified
vessels, “leaving an unobscured image of the vessels
 It is used in angiography in which unwanted bony and soft
tissue structure are removed from radiograph leaving behind
contrast filled blood vessel.

8. IMAGE SUBTRACTION
 Also known as PHOTOGRAPHIC SUBTRACTION.
 Image subtraction is necessary to visualize clearly the blood
vessels obscured by bones and soft tissue in the radiograph.
 Image Subtraction technique is done in two steps:
1. Production of mask image
2. Image subtraction

9. TECHNIQUE OF IMAGE
SUBSTRACTION
SUBTRACTED IMAGE
(IMAGING CONTAINING
BLOOD VESSEL ONLY)
CONTROL FILM
(HEAD/NECK)
1ST IMAGE
SUBSTRACTION
FILM
MASK FILM
SUBSTRACTION
FILM
CONTRAST FILLED
RADIOGRAPH
(2ND IMAGE)
MASK FILM
No Movement Of
Head/Neck

10. DIGITAL SUBSTRACTION ANGIOGRAPHY (DSA)
 Acquisition of digital fluoroscopic images combined with
injection of contrast material and real time subtraction of pre-
and post contrast images to perform angiography is referred
to as digital subtraction angiography
 Digital subtraction angiography (DSA) was developed to
improve vessel contrast.
 Anatomical structures that are the same in the two images can
be removed and the resulting image shows the vessels only.

11. Contd…
 Modern DSA systems are based on digital fluoroscopy/
fluorography systems, which are equipped with special software and
display facilities
 DSA is an invasive procedure hence performed in combination with
seldinger technique .
 Catheter is inserted and placed at the site of examination (artery to
be examined) and contrast media is injected.

13. FIG :- PROCESS OF SELDINGER
TECHNIQUE

14. FIG:- DSA IMAGE OF CIRCLE OF
WILLIS

15. FIG:- CEREBRAL ANGIOGRAPHY USING
DSA TECHNIQUE

16. ADVANTAGE OF DSA
 Better visualization of blood vessels and less
radiation exposure
 High spatial resolution
 Wide dynamic range
 Square field of view
 Real-time imaging
 Capabilities with no geometric distortion

17. FIG:-ALLURA XPER FD20/10 BIPLANE FLAT DETECTOR
SYSTEM WITH INTEGRATED 3-D FOR INTRICATE
NEUROVASCULAR PROCEDURES.

18. CT ANGIOGRAPHY (CTA)
 Computerized tomographic angiography is used to visualize
blood vessels that have been opacified by CM.
 This include:
 CIRCLE OF WILLIS.
 CAROTID ARTERIES
 Subclavian arteries
 Thoracic & abdominal aorta
 Renal vasculature
 Abdominal viscera vasculature
 Lower limb arteries

19. • Aneurysm
• Narrowing of arteries in the
brain
• Abnormal blood vessels.
• Narrowing or blockage of
carotid arteries.
• Stenosis
• To determine future risk of
stroke
• Stricture of the Carotid
arteries.
• Pregnancy
• Allergic to Contrast media.
• Weak kidney Function.
• Unstable vital signs
INDICATION CONTRAINDICATION

20. PROTOCOL FOR CT ANGIOGRAPHY OF HEAD & NECK
(CEREBRAL & CAROTID ANGIOGRAPHY)
CEREBRAL ANGIOGRAPHY CAROTID ANGIOGRAPHY
Patient Positioning
Supine with head first arm
beside the trunk
Supine with head first arm
beside the trunk
Topogram Position Lateral Lateral
Topogram
Landmark
Level of vertex Level of forehead
Mode of Scanning Helical
Helical with single breathe
hold
Scan Orientation Caudo-cranial Caudo-cranial
Gantry Tilt Nil Nil
Field of View
Just including the region of
interest
Just fitting the region of
interest
Contrast
Administration
Intravenous Intravenous monophasic
Volume of Contrast 100-150 ml 100-120 ml

21. CONTD…
CEREBRAL ANGIOGRAPHY CAROTID ANGIOGRAPHY
Rate of Injection of CM 4-5 ml 4-5 ml
Scan Delay 20-25 sec 10-15 sec
Slice Thickness In
Reconstruction
1-1.5 mm 1-1.5 mm
Slice Interval In
Reconstruction
0.5 - 0.75 mm 0.5 – 0.75 mm
Reconstruction
Algorithm
Smooth smooth
3D Reconstruction MPR, MIP, VRT, SSD MIP, VRT

22. FIG :- AXIAL SLICE CEREBRAL
ANGIOGRAPHY
FIG :-3D-RECONSTRUCTION
CEREBRAL ANGIOGRAPHY

23. FIG :- 3D-RECONSTRUCTION CAROTID ANGIOGRAPHY

24. MR ANGIOGRAPHY (MRA)
 MR ANGIOGRAPHY
 NON INVASIVE
 NO CONTRAST REQUIRED
 NON IONISING
 Preferred for carotids and intracranial vessels as MRI brain
can also be obtained and is widely used in neurological
disorders

25. INDICATION
 Intracranial aneurysm (ICA)
 Arteriovenous malformation (AVM)
 Patients with symptoms highly suggestive of Vertebro-Basilar
Syndrome
 Evaluation of carotid arteries
 F/U case of TIA
 Stroke
 Dissection
 Occlusion

26. PROTOCOL FOR MR ANGIOGRAPHY OF HEAD & NECK
(CEREBRAL & CAROTID ANGIOGRAPHY)
Cerebral Angiography Carotid Angiography
Patient
Positioning
Supine with head first arm
beside the trunk
Supine with head first arm
beside the trunk
Topogram
Position
Centre the field of view in
the midline at nasion
Centre the field of view in the
midline
Type of Coil Head Anterior neck coil
Mode of scanning 2-D / 3-D 2-D / 3-D
Scout Sagittal and Coronal T1
 For non contrast – 6 axial &
1 sagittal with an oblique
sagittal as well
 For contrast enhanced –
sagittal
Pulse sequence
 3-D TOF for circle of
willis in the Axial Plane
 3-D TOF for
vertebrobasilar system
in the Axial Plane
For noncontrast
 2-D TOF with travelling
saturation band or 2-D SGE
in axial plane
 2-D PC for the bifurcation
3-D TOF with TONE

27. Cerebral Angiography Carotid Angiography
Pulse
sequence
 For AVM additional sequence
needed are
 3-D TOF through region of
interest
 2-D PC in the sagittal &
axial plain for draining veins
in the region of interest
 For contrast enhanced
 3-D SGE EPI based in the
coronal plane
Scan range  Region of interest
 In axial plane, cover the neck
from the thoracic inlet to the
base of skull
Slice
Thickness
 3 mm for 2-D series
 1 – 2 mm for 2-D series
 23 or 64 volume partition in 3
D series
Slice interval  0-1 mm for 2 D series  Nil
Contrast
administratio
n
 Nil
 Intravenous (with pressure
injection)
Volume of
contrast
 Nil
 15-20 ml followed by 20 ml
saline flush
Rate of
injection
 Nil  2 ml/ sec

28. FIG:- CEREBRAL & CAROTID MRA

29. FIG :-7T 3D CE-MRA

30. MRA TECHNIQUES
1.TIME OF FLIGHT (TOF)
2.PHASE CONTRAST (PC)
3.CONTRAST ENHANCED MRA (CE MRA)

31. BASIC PRINCIPLES
 TOF MRA- “manipulating magnitude of magnetization”
 Vascular contrast in TOF MRA is due to difference in the
magnitude of the inflowing protons in the blood and the
surrounding stationary protons.
 No contrast agent injected
 Motion artifact
 Difficulty with slow flow

32. CONTD…
 PC MRA- “manipulating phase of magnetization”
 Directional flow encoding magnetic field gradient causing
difference in the phase/orientation
 In PC MRA bipolar gradient is applied and if the proton is
stationary there is no phase shift. However if the protons are
moving, a phase shift occurs. The faster the proton moves
greater the phase shift.
 Phase is proportional to velocity
 Allows quantification of blood flow and velocity
 More time consuming

33. CE MRA
 Uses parameters typical of 3-D TOF MRA but gadolinium contrast is
also given.
 Data are acquired after contrast bolus infusion ( Gad. 0.1-.2 mmol/kg).
 Unlike, time-of-flight (TOF) or phase contrast (PC) imaging, the signals
of the blood in CE-MRA is based on the intrinsic T1 signal of blood
and rather less on flow effects; therefore, this technique is less flow
sensitive.

34. 2D and 3D Fourier transform
 In 2-D FT technique, multiple thin sections of body are studied
individually and even slow flow is identified.
 In 3-D FT technique , a large volume of tissue is studied ,which can
be subsequently partitioned into individual slices, hence high
resolution can be obtained and flow artifacts are minimized, and less
likely to be affected by loops and tortuosity of vessels
 MOTSA(Multiple Overlapping Thin Slab Acquisition): Prevents proton
saturation across the slab. This technique have advantage of both
2D and 3D studies. It is better than 3D TOF MRA in correctly
identifying vascular loops and tortusity, and have lesser chances of
overestimating carotid stenosis.