Download - Shoulder MRI for Surgeons

AMSTERDAM / THE NETHERLANDS

www.esska-congress.org

Lennard Funk

1

[email protected]

mailto:[email protected]



• Prof. Waqar Bhatti

2

• Dr. Jonathan Harris

• Dr. Sarah Jackson



QUIZ

3


www.esska-congress.org4

QUESTION A

My IDEAL investigation for cuff pathology

is:

a. Ultrasound

b. MRI

c. MR Arthrogram

d. CT Arthrogram



QUESTION B

My IDEAL investigation for Instability is:

a. Ultrasound

b. MRI

c. MR Arthrogram

d. CT Arthrogram



QUESTION 1

Radiologists are better at interpreting MRI scans than surgeons:

a. True

!b. False

6



QUESTION 2

MRI Sequences:

a. T1 is best for pathology

b. In T2 fat tissue is bright

c. A long TR is shows inflammation

b. STIR is a Fat Suppression sequence



QUESTION 3

MR Arthrogram:

a. ABER improves accuracy

b. Cannot show Bony lesions

c. Is not ideal for fatty infiltration

d. Is 100% accurate for labral tears



MRI



AMBIGUOUS REPORTS

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“Full width tear”

“Advanced muscle atrophy along with Infraspinatus”

“mild atrophy supraspinatus”



CONFUSING REPORTS

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There is a partial full tear of the supraspinatus tendon.

There is a complete partial tear of the supraspinatus tendon.



INADEQUATE SCANS

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Grainy Shadows

Movement



CUFF PATHOLOGY IN ASYMPTOMATIC

• 96 MRI’s viewed by 2 radiologists

• 20% PTT; 15% FTT

– Increased with age:

• >60yrs = 55% PTT; 30% FTT

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Sher et al. JBJS. 1995



MR ARTHROGRAM V. SCOPE

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Sensitivity Specificity Accuracy

SLAP 0.42 0.92 77%

Rotator Cuff Tear 0.50 0.86 83%

Hill Sachs 0.91 0.78 90%

Bankart 0.85 0.83 86%

N Karlson, J Geoghan, L Funk; 2008



RADIOLOGIST LOCALITY

• Nine radiologists - regional & secondary care

• MR diagnostic accuracy is better when surgeon and radiologist work in the same institution.

• Differences between local- and non-local MRA data suggest that diagnostic accuracy is better in the local secondary referral centre.

18

N Karlson, J Geoghan, L Funk; SECEC 2011



DO NOT RELY ON THE SCAN REPORT

An experienced Shoulder Surgeon better Can correlate with clinical context Experience of reviewing Scopes & Scans

19



MRI BASICS

• T1 - Fat Bright - Anatomy

• T2 - Water Bright - Pathology

• Standard 3mm thick slices

• Thick slices = more signal & less grainy, but lower spatial resolution (due to volume averaging)

20



MRI BASICS

• PD = Long TR & Short TE

• T1 = Short TR & Short TE

• T2 = Long TR & Long TE

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• TE is always < TR

• Short TR < 500ms

• Long TR > 1500ms

• Short TE < 30ms

• Long TE > 90ms

http://www.imaios.com/en/e-Courses/e-MRI/MRI-signal-contrast/Signal-weighting



MRI BASICS

• Fat Suppression

• PDFS

• T2 Gradient Echo

• STIR

• SPIR

• SPAIR

25

• Labral Tears

• Bankart

• Perthes

• ALPSA

• SLAP

• GLAD

• GLOM



T1 WI T2 FS

INFLAMMATION



MUSCLE OEDEMA

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T1 FS T2 FS



LABRAL TEARS

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T1 WI T1 FS



PLAIN MRI SEQUENCES

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• Hospital 1:

• Hospital 2:



MRI SEQUENCES

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• No universal standards

• Each Hospital has different MRI Protocols

• Each Radiologist has different experience

• Each clinical question demands different approach



PLAIN MRI - PREFERENCES

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1. Full Series

!!2. T1 Axial - Bony Bankarts

3. T1 Sag - Bony Bankarts

4. T1 Sag - extend medial to scapula ‘Y’

5. T2 FS Cor - Cuff, ACJ, Bursa



T1 WITH FS SAGITTAL IN GLENOID PLANE

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SCAPULA ‘Y’ ON T1WI

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ARTEFACT

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ARTEFACT

• Rotator cuff repair

36



ARTEFACT

• ACJ Metalwork

• Deodorant spray in axilla

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MR ARTHROGRAM

• Direct / Indirect

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INDIRECT ARTHROGRAM

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INDIRECT ARTHROGRAM



ABER

43



ABER



MR ARTHROGRAM

• Direct / Indirect

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SUMMARY

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• Beware / Be aware of Reports • Full 6 series • T1 FS Axial - Instability • T2 FS Cor - Rotator Cuff • T1 Sag to Scapula ‘Y’ • MRA:

– Direct – T1 FS in 2 planes (axial; sagittal) – ABER (if able)



RELATIONSHIPS

• Clinical Imaging is a ‘request for consultation to clarify a clinical query’

• NOT ‘ordering’ an investigation

!• Vetting of request should be an MSK Radiologist

• Provide clear clinical info and query

47



I can see it now !



QUIZ

49



QUESTION 1

Radiologists are better at interpreting MRI scans than surgeons:

a. True

!b. False

50



QUESTION 2

MRI Sequences:

a. T1 is best for pathology

b. In T2 fat tissue is bright

c. A long TR is shows inflammation

b. STIR is a Fat Suppression sequence



QUESTION 3

MR Arthrogram:

a. ABER improves accuracy

b. Cannot show Bony lesions

c. Is not ideal for fatty infiltration

d. Is 100% accurate for labral tears



WWW.SHOULDERDOC.CO.UK

53

Full Time / Part Time

http://www.shoulderdoc.co.uk

Download - Shoulder MRI for Surgeons

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