Transcranial Doppler (TCD) ultrasonography is a noninvasive technique used to evaluate cerebral blood flow velocities. It was originally introduced in 1982 to detect vasospasm in subarachnoid hemorrhage. TCD is now used for a variety of purposes including detection of stenosis, occlusion, emboli, shunts, and vasospasm. It provides diagnostic information for conditions such as stroke, sickle cell disease, brain death, and arteriovenous malformations. TCD utilizes Doppler effect to measure blood flow velocities in basal cerebral arteries which provides data to assess hemodynamics and diagnose various cerebrovascular diseases.

1. Dr ASHISH SHARMA
SR 1 NEUROLOGY
GMC KOTA

2.  Stethoscope of neurologist
 Introduced in year 1982 by rune aaslid
 Initially introduced for detecton of vasospasm of
SAH.
 cheaper,noninvasive,bed side
 Mark Mohering 2002 M mode doppler
Purkayastha S, Sorond F. Transcranial Doppler ultrasound: technique and
application. Semin Neurol. 2012 Sep;32(4):411-20. doi: 10.1055/s-0032-
1331812

4. American academy of neurology guidelines

5. Bathala L, Mehndiratta MM, Sharma VK. Transcranial doppler: Technique and
common findings (Part 1). Annals of Indian Academy of Neurology. 2013
Apr;16(2):174.

7. TERMS IN TCD
 PULSALITY INDEX---The difference between PSV and EDV divided by
the mean flow velocity (MFV). PI values greater than 1.2 represent high
resistance blood flow.
 PEAK SYSTOLIC VELOCITY --This is the initial peak on each cardiac
cycle’s TCD waveform
 END DIASTOLIC VELOCITY---indicates a low resistance cerebral
artery flow pattern in all main intracranial arteries, ranging from 20 to
50% of the PSV
 MEAN FLOW VELOCITY --calculated as EDV plus one-third of the
difference between PSV and EDV
 RESISTANCE INDEX--The RI is determined by subtracting EDV from
PSV and dividing the value by PSV. If the RI value is less than 0.75, it
is considered normal.
Alexandrov AV, Demchuk AM, Wein TH, Grotta JC. Yield of transcranial Doppler in
acute cerebral ischemia. Stroke. 1999 Aug;30(8):1604-9.

8. FREQUENTLY USED TERMINOLOGY IN
TCD

9. PRINCIPALS OF TCD
 The insonation is performed from the
proximal to the distal artery.
 start closest to the heart and proceed
distally
 located, find and record the best signal
 inspect at least two locations for each
artery
 Find location where the waveforms
exhibit the greatest abnormalities

10. USES OF TCD
 Ischaemic cerebrovascular disease
 Sickle cell disease
 Right to left cardiac shunts
 Intra and extra-cranial arterial steno-
occlusive disease
 Arterio venous malformations and fistulas

11.  Periprocedural/operative
1. Cerebral thrombolysis in acute stroke
2. Carotid end arterectomy
3. Carotid angioplasty and stenting
4. Post thrombolysis monitoring

12.  Neurological/Neurosurgical intensive care
1. Vasospasm after SAH
2. Raised ICP
3. Head injury
4. Cerebral circulatory arrest and brain death
5. Intracerebral aneurysm and parenchymal
hematoma detection
Akif Topcuoglu M. Transcranial Doppler ultrasound in
neurovascular diseases: Diagnostic and therapeutic aspects.
Journal of neurochemistry. 2012 Nov;123:39-51.

13. Intracranial arterial stenosis
 DX on basis of MFV
 50% stenosis ---MCA MFV of >100 and BA
MFV of >80 cm/sec
 70% stenosis-- >120 and >110cm/sec
 sensitivity and specificity of TCD for
diagnosing stenosis are both around 90%.
 Sensitivity 74% and specificity 94% when
compared to CT Angio.

14. Intracranial arterial
occlusion
 No blood flow detectable on direct in
sonating the occlusion.
 The systolic acceleration -lower and
diastolic blood flow observed at more-
distal sites.
 waveform is normal at sites that are
even more distal
 the flow velocity is low, at ≤30 cm/sec

16. TCD MONITORING SPONTANEOUS EMBOLI
 Microembollic signals—distal to Large
artery occlusion---headframe of TCD.
 Single MES after 40 min monitoring
significant,
 Characteristic—random during c.s,brief,
 High intensity ,unidirectional, audible
component.
 Presence of MES on TCD distal to high
grade stenosis has higher risk of stroke.

18. R------L SHUNT REVERSAL
 TCD bubble test can detect CV ischemia
due to R--L (paradoxical emboli)
 Technique– 9ml saline plus 1 ml air plus
few drops blood—10-15 shakes—
injected-----monitoring mca---valsalva for
4 to 6 sec--- RA pressure increased –
emboli to LA
 TCD monitoring is performed for
another 16-20 s.

20. VASOSPASM
 occurs 3-12 days after SAH --- delayed
ischemic neurological deficits(25%)
 Performed soon and repeatdely
 diagnosed when the ratio of the fv between
the ICA and MCA (the Lindegaard ratio) is
≥3 and the MCA MFV is >200 cm/sec.
 diagnosed when the ratio of the VA and BA
 flow velocities (the modified Lindegaard
ratio) is ≥3 and the BA MFV is >85 cm/sec

21.  MFV <120 cm/s(absent) and >200
cm/s(present) accurate MCA vasospasm
 systematic review of 26 studies comparing TCD
with angiography
 MFV >120 cm/s was 99% specific and 67%
sensitive to angiographic vasospasm of ≥25%.
 MFV >200 cm/s was 98% specific and 27%
sensitive with a positive predictive value (PPV)
of 87% for angiographic vasospasm of ≥33%
(101 studies review)
B. Schatlo and R. M. Pluta, “Clinical applications of
transcranial Doppler sonography,” Reviews on Recent Clinical
Trials, vol. 2, no. 1, pp. 49–57, 2007.

22. TCD IN ACUTE STROKE
 Prognostication value in acute stroke.
 Sensitivity 90% in MCA acute occlusion
detection
 Occlusion –6 hrs – in M1 segment detected---
high chance of hemorrhagic transformation
 Effectiveness ,duration, dose of re canalisation

23.  TCD sensitivity for ICA and MCA (94 and
93%) terminal VA and BA(56 and 60%).
 an abrupt increase in TIBI grade or stepwise
increase over 30 minutes indicates more
complete re canalisation
A. M. Demchuk, I. Christou, T. H. Wein et al., “Accuracy and criteria for
localizing arterial occlusion with transcranial Doppler,” Journal of
Neuroimaging, vol. 10, no. 1, pp. 1–12, 2000

24. TCD IN SICKEL CELL DISEASE
 Stroke mainly occurs in Intracranial ICA
proximal MCA.
 Maximum MFV >200 –requirement for blood
transfusion –risk of first ever stroke.
 Normal: TAMM velocity <170 cm/s — a repeat
assessment is indicated ---(conditional)170-
200 repeat TCD in 2 wks--- (Abnormal) 200.

25. TCD IN AVM
 AVM –supplied by high flow shunts with absent
vasomotor reactivity easily detected by TCD
 Sensitivity in detecting middle and large AVM>
small (2.5 cm)
 2 parameters –velocity and PI
 AVM (high velocity and low PI) as size increases

26.  normalization of PI in first few days after
intervention while normalization of mean
velocity takes 1–3 weeks.
Sharma VK, Wong KS. Alexandrov AV. Transcranial Doppler.
Front Neurol Neurosci.. 2016;40:124-40.

27. TCD IN BRAIN STEM DEATH
 Criteria for the diagnosis on TCD state
that
 one of the following waveforms must be
observed in the BA, B/L ICA, and B/L
MCA on two examinations at least 30
minutes apart
 an oscillating waveform

28.  small systolic spikes of <200ms duration
and <50 cm/s PSV with no diastolic flow
 Disappearance of intracranial flow with
typical signals observed in the extra
cranial circulation.
J. A. Llompart-Pou, J. M. Abadal, A. Güenther et al.,
“Transcranial sonography and cerebral circulatory arrest in
adults: a comprehensive review,” ISRN Critical Care, vol. 2013,

29. J. A. Llompart-Pou, J. M. Abadal, A. Güenther et al., “Transcranial
sonography and cerebral circulatory arrest in adults: a comprehensive
review,” ISRN Critical Care, vol. 2013, Article ID 167468, 6 pages, 2013.

32. REFERENCES
 Pan Y, Wan W, Xiang M and Guan Y (2022) Transcranial Doppler
ultrasonography as a Diagnostic Tool for Cerebrovascular Disorders
Front. Hum. Neurosci. 16:841809
 Transcranial Doppler Ultrasound: A Review of the Physical Principles
and Major Applications in Critical Care (Review Article)
 Transcranial Doppler: examination techniques and interpretation
Youngrok Do1, Yong-Jae Kim2, and Jun Hong Lee3
 Role of Transcranial Doppler Ultrasonography in Evaluation of Patients
with Cerebrovascular Disease Vijay K. Sharma, MD, Georgios
Tsivgoulis, MD, Annabelle Y. Lao, MD, and Andrei V. Alexandrov, MD

33.  Transcranial doppler: Technique and common findings (Part
1) Lokesh Bathala, Man Mohan Mehndiratta1, Vijay K.
Sharma2
 Transcranial Doppler Ultrasound: Technique and
Application Sushmita Purkayastha, Farzaneh Sorond, MD
 Role of transcranial Doppler ultrasonography in stroke
Sanjukta Sarkar, Sujoy Ghosh, Sandip Kumar Ghosh,
Andrew Collier
 Transcranial Doppler: Techniques and advanced
applications: Part 2 Arvind K. Sharma, Lokesh Bathala1,
Amit Batra2, Man Mohan Mehndiratta3, Vijay K. Sharma4