1. The document discusses practical aspects and common pitfalls of transcranial Doppler (TCD) ultrasonography and their troubleshooting. It provides examples of using TCD to monitor intracranial hemodynamics in various acute neurological cases. 2. Examples include using TCD to measure pulsatility index and calculate intracranial pressure in a patient with subarachnoid hemorrhage, detect an arteriovenous malformation, and monitor recanalization during intravenous thrombolysis for stroke. 3. The document also reviews the limitations of TCD but emphasizes its clinical utility for evaluating cerebral ischemia mechanisms, monitoring disease progression and treatment effectiveness, and aiding prognosis determination.

1. Practical aspects of TCD with pitfalls
and troubleshooting
Presented by
Dr Shubham Garg , Dr vaibhav Somvanshi
DM Neurology Resident

4. TCD WINDOWS

31. SUB-MANDIBULAR WINDOW

36. Pitfalls  Troubleshooting
Vessel identification Only 30-50% of the population have a complete Circle of Willis,
whereas the other 50% have anatomic variations.
PCA identification Differentiate PCA from MCA via eye opening closing
manoeuvre or depth change
Vertebral arteries identification Compression of the extracranial VA against the mastoid assist
in identification
Craniotomy sutures/staples Transducer must be placed either in front of, or behind, the
sutures or staples with ALARA principle
Scalp edema/flap/bandage Cut bandage over window area/adjust depth
Unable to get window 10% population may have hyperostosis difficult to get window
so increase the power
Subcutaneous air Either compress with probe to remove subcutaneous air from
window site or wait for 2-3 days for resorption of air
Semi comatose Irritable pt/ Nuchal rigidity Use sedatives/Pain killer/Manual assistance as head holding

37. Exaggerated VMR and Sleep Apnea
Breathing Pattern
Defined as Wide Fluctuation in velocities associated with change in
respiration
30 Sec
Later

38. • VMR= MFV hypercapnea –MFV hypocapnea/MFV at rest × 100
• A value more than 65% indicates normal VMR while the value of
less than 33% reflects an exaggerated VMR.
• VMR between 33% and 65% represents borderline impaired
autonomic control.

39. Solution
Monitor few rounds for 60 seconds and document mean of velocity swing

40. Loss of autoregulation
Passive changes in velocity associated with changes in blood pressure
BP increased 30 Sec Later BP dropped to
baseline

41. Solution
Spectrum saved to reflect the same PI as rest of the segments of the exam with
baseline of ExICA

42. 1. Case Vignette
Case History- 74/M, on dual antiplatelet agents for cardiac stents, fell down 15 stairs, diagnosed
with diffuse sub-SAH and subdural hemorrhage (SDH), with an admission GCS of 14.
Spectral Doppler of MCA, demonstrating
diastolic blunting secondary to raised ICP
(pulsatility index = 4.31, ICP = 46 mmHg).
Following interventions to reduce ICP,
there was normalization of diastolic flow
in the MCA, and resolution of high ICP
(pulsatility index = 1.65, ICP = 17 mmHg)
Intervention

43. 2. Case Vignette
Case History- 58/M, presented with a headache and GCS – 13 , CT head – ICH with IVE
Midline shift (MLS)=(distance A−distance B)/2
Midline shift (MLS)=(7.41−6.11cm)/2=1.3cm/2=0.65cm=6.5mm
7mm MLS

44. 3. Case Vignette
Case History-63/M p/w retro-orbital headaches diagnosed with AComm artery aneurysm underwent a coiling
attempt. During the procedure, patient had ICA dissection, trans-mural perforation and pseudo-aneurysm
formation. CT head revealed diffuse SAH from aneurysmal rupture with IVH. An EVD placed, showed raised ICP
(> 60 mmHg). A poor prognosis was given. The patient subsequently developed dilated pupils bilaterally and
had hemodynamic alterations.
Raised ICP ICP causing reverse flow in
MCA
Biphasic and oscillating
flow as evidenced by net
zero flow

45. 4. Case Vignette
Case history- 45/M p/w recurrent episodes of impaired consciousness followed by a confusional
state lasting for several minutes. MRI showed lesion with numerous flow voids in the left
temporal region
Transtemporal approach left-
sided insonation- AVM nidus in
the left temporal lobe reflected
by the multicolored signals
indicating different flow
directions (arrowhead).
Note the course of the M1-MCA
(arrows) as well as the A1-
ACA (arrow).

46. 5. Case Vignette
Case history- 48/F FUC T2DM,Htn p/w sudden onset left hemiparesis NIHSS - 3. A similar transient event with
complete remission had occurred 1 week prior to presentation.
Transtemporal approach right-sided
insonation- Right M1-MCA with
intrastenotic flow velocity of 322/202
cm/s in a depth of 58mm. Note the
turbulent flow pattern.
MRA- clear visibility of
the distal M1-MCA and
M2-MCA segments, a
high-grade stenosis was
assumed
M1 MCA-R M2 MCA-R
Transtemporal approach right-sided
insonation- Right M2-MCA with flow
velocity of 52/35 cm/s in a depth of
44mm.

47. 6. Case Vignette
Case history- 50/M admitted with a mild left-sided weakness which had developed just 40 minutes prior to
presentation. Initial neurologic examination revealed only a left-sided pronator drift during the arm pronation
test with NIHSS – 9 CT head WNL
After 24 hours
L MCA M1
L MCA M1
R MCA M1
MFV – 95
MFV – 20
After thrombolysis MFV – 55 TIBI grade II
R MCA M1

50. • The beginning, speed, timing, and amount of recanalization represent important
parameters of thrombolytic therapy for stroke and measured by following five
parameters:
1. Waveform change by > 1 TIBI residual flow grade
2. Appearance of embolic signals (transient high intensity signals of variable duration)
3. Flow velocity improvement by > 30% at a constant angle of insonation
4. Signal intensity and velocity improvement of variable duration at constant skull/probe
interface and gain/ sample volume/scale settings.
5. Appearance of flow signals with variable (> 30%) pulsatility indexes and amplitude of
systolic peaks .
TCD monitoring during Intravenous
thrombolysis

51. 7. Case Vignette
Case history- 83/M with diffuse SAH from a right anterior-communicating (AComm) artery aneurysm secured
by coiling. Despite prophylactic nimodipine to improve outcomes in vasospasm patients, 5 days later, patient
again had decreased LOC and required intubation.
TCD left MCA flows- mean MCA velocity of
123 cm/s
Measurement of ipsilateral left ICA flows for
calculation of Lindegaard ratio of 3.8 (Mean MCA/ICA
velocity = 123/32.5 cm/s)

54. Spectrum with irregular rhythm
• Identify cardiac rhythm
abnormalities like atrial
fibrillation by TCD as
variable Doppler spectra and
velocities.
• The cardiac cycle with the
highest flow velocities is
used for measurement of
various parameters .

55. TCD monitoring for spontaneous
emboli
• Detection of even a single MES during 40 min of monitoring is
considered as clinically significant
The International Cerebral Hemodynamics Society describes MES as:
a. Random occurrence during the cardiac cycle.
b. Brief duration (usually <0.1 s).
c. High intensity (>3 dB over background).
d. Primarily unidirectional signal.
e. Audible component (chirp, whistle, or pop).

56. Video Demonstration of MES

57. • Operator-dependent technique requiring detailed three dimensional
knowledge of the intracranial arterial anatomy.
• Secondly, TCD is hampered by the 10-15% rate of inadequate temporal
windows most commonly seen in Blacks, Asians and elderly female
patients.
• However, the temporal resolution and convenience of TCD make it a
vital asset to observing the evolution of blood flow changes in the
critically ill patient.
LIMITATIONS

58. • TCD provides real-time information about cerebral hemodynamics and
permits extended monitoring with excellent temporal resolution.
• Advanced applications of TCD are integral parts of the armamentarium
of neurologists for evaluating various mechanisms of cerebral
ischemia.
• Furthermore, TCD helps in planning and monitoring the disease
process, effectiveness of treatment as well as aids in establishing the
prognosis .
SUMMARY

59. • Transcranial doppler: Technique and common findings(Part 1).
• Bathala et al. Ann Indian Acad Neurol 2013;16:174-9.
• Transcranial Doppler: Techniques and advanced applications:
• Part 2. Sharma et al. Ann Indian Acad Neurol 2016;19:102- 107.
• Role of transcranial Doppler ultrasonography in acute stroke.
• Sharma et al. Ann Indian Acad Neurol 2008;11:S39-S51.
• AIUM Practice parameter—Transcranial Doppler Ultrasound for Adults and Children. 2012
• Stroke Prevention Trial in Sickle Cell Anemia (STOP): extended follow-up and final results. Lee et al. Blood,
1 august 2006 volume 108, number 3.
References

60. THANK YOU