Rule in DVT
Introduction
•Background
•Evidence
•System of examination
•Diagnoses & Variants
•Final actions
•Limitation of the examination
BACKGROUND
•Common presentation
•Influence initial management
•NICE Guidelines
EVIDENCE
EXAMINATION, DIAGNOSIS &
LIMITATION
Rule-In DVT Minimum Equipment
•Ultrasound machine• B-mode ultrasound system
• Regularly safety checked and serviced
•Probe• Frequencies of 3MHz and greater
• High frequency = better resolution = use for small legs
• Linear (small legs) and curvilinear (bigger legs) transducers should be available
Anatomy - CFV
CFA
SFA
DFA CFV
SFV
LSV
SFJ
CFV SFJ
LSVSFV
CFA
DFA
SFA
Anatomy - SFV
CFA CFV
SFJ
LSV
DFA
SFA SFV
Anatomy - PV
PAPV
SSV
PV
LSV
SSV
Per. V
PA
ATV
PTV
LSV
Rule-In DVT Pre-scanning preparation
•Introduction
•Set up machine• Confirm patient’s identity e.g. full name and date of birth
•Explanation to patient (if possible)• Why?
• Exam process
• Expected duration
•Verbal consent
•Expose exam area • groin to below knee
•Positioning• Supine position
• Head tilt if possible (encourages leg vein distension)
• Hip: externally rotated
• Knee: slight flexion
First, Find Mickey Mouse
Left Leg
‘Mickey Mouse Sign’
SFVSFV
LSVLSV CFA
CFA
Left Leg
SFJSFJ
Evidence for ‘Mickey Mouse Sign’Anatomical Variation at the Sapheno-Femoral Junction
Kimihiro Igari, Masayuki Hirokawa, Hidetoshi Uchiyama, Takahiro
Toyofuku, Toshifumi Kudo, Masatoshi Jibiki, Nobuhisa Kurihara,
Yoshinori Inoue
Ann Vasc Dis Vol. 6, No. 4; 2013; pp 702–705 ©2013 Annals of
Vascular Diseases. Online November 15, 2013
DOI:10.3400/avd.oa.13-00087
Duplex Ultrasound Investigation of the Veins in Chronic Venous
Disease of the Lower Limbs — UIP Consensus Document. Part I.
Basic Principles
P. Coleridge-Smith, N. Labropoulos, H. Partsch, K. Myers, A.
Nicolaides, A. Cavezzi
European Journal of Vascular and Endovascular Surgery.
Volume 31, Issue 1, Pages 83-92 (January 2006) DOI:
10.1016/j.ejvs.2005.07.019
Transverse view of common femoral vein and artery in the right groin: ‘Mickey Mouse’ view;
CFA, common femoral artery; CFV, common femoral vein; SFJ, sapheno–femoral junction (from the archive of PCS).
Normal anatomy at the sapheno-femoral junction (transverse view).
It is called “Mickey mouse sign”. GSV: great saphenous vein;
CFA: common femoral artery; FV: femoral veinUltrasound-guided central venous
access
Christopher P Gale, Andrew R
Bodenham
The British Journal of Cardiology.
January 2008 Br J Cardiol 2008;15:51-
4Cross-sectional images of the right
common femoral vessels just below the
inguinal ligament, showing the ‘Mickey
Mouse sign’. The femoral artery (FA) is
depicted on the left and the femoral vein
(FV) on the right. The sapheno-femoral
junction (SFJ) comprises the long
saphenous vein (LSV) and the FV
Anatomy Reminder - CFV
CFA
SFA
DFA CFV
SFV
LSV
SFJ
CFV SFJ
LSVSFV
CFA
DFA
SFA
Finding Mickey Mouse
Slide Probe Up
To
From
If this
is your first image...
Zone 1 – CFV
NO COMPRESSION COMPRESSION
Zone 2 – SFV
NO COMPRESSION COMPRESSION
Zone 3 – PV
NO COMPRESSION COMPRESSION
FAMUS: 3 point, Rule-In DVT Scanning
processFind CFV/SFJ
(Mickey Mouse)
CFV/SFJ - Compress (Zone 1)
Move probe down medial thigh to Mid SFV(compress along vessel as you move between zones)
Mid SFV – Compress (Zone 2)
Move probe down medial thigh and posteriorly towards PV
(compress along vessel as you move zones) (often cannot compress vessel as it goes posterior)
Identify PV trification – Just distal to popliteal fossa
Move probe proximally until a single vessel (PV) appears
PV – Compress (Zone 3)
Colour Flow
Colour Flow
Colour Flow
Normal Variant – Bifid venous system
Main diagnosis (DVT Rule IN)
Zone 1
Main diagnosis (DVT Rule IN)
Zone 2
Main diagnosis (DVT Rule IN)
Zone 2
Main diagnosis (DVT Rule IN)
Zone 2
Main diagnosis (DVT Rule IN)
Zone 3
Other pathology of significance –
SFJ Incompetence
Other pathology of significance –
Oedema
Other pathology of significance –
Oedema
Other pathology of significance –
Lymph nodes
Other pathology of significance –
Lymph nodes
Other pathology of significance –
Bakers cyst
Other pathology of significance –
Bakers cyst (?Ruptured)
Other pathology of significance –
Haematoma
Other pathology of significance –
Phlebitis
Other pathology of significance –
Phlebitis
Other pathology of significance –
Aneurysm
Other pathology of significance –
Aneurysm
Final 3 Actions
• Store ALL images
• Ensure good clinical governance
• Formally Report ALL Scans
• Ideal – Local PACS system
• Minimum – Reporting Template
secured in patients notes
• Act on information obtained
•Incorporate scan information into
effective management plan
•Refer for departmental scan as
needed
Limitation of Rule-In study
•Compared to Society of Vascular Technology (SVT) DVT
Professional Performance Guidelines of October 2012
(Our Standard) – FAMUS scans use 1 (main thrombus
detection tool) of the 3 DVT assessment tools• SVT Guidelines suggest
• B-mode should be used to image the vein and its contents; using compression of the vein in
the transverse plane
• Spectral Doppler should be used to determine direction of flow and detect abnormal flow
patterns
• Colour Doppler maybe used to detect thrombus as an aid to the B-mode procedure; it is an
essential requirement for the assessment of the abdominal veins.
•Hence, FAMUS Scans cannot formally rule-out DVT• Provides good sensitivity for rule-in DVT detection
QUESTIONS?