1. BROOKLYN 3 MRI USER GROUP Anna Marie LYNDON Sat 31 st Aug 2013 Session 2 / Talk 1 10:34 – 10:55 ABSTRACT In this study we assessed a Works-in-Progress sequence developed by Siemens for evaluation of the peripheral arterial tree without contrast agent - Quiescent Interval Single Shot MR Angiography (QISS) sequence. Previously we have evaluated other non-contrast enhanced angiographic techniques (Native Space and Native TrueFisp) which worked well in the majority of regions but still presented some limitations. It was hoped that the new technique using the inflow of non-saturated blood spins & acquiring single-shot 2D TrueFISP readout images might improve detection and accuracy of lesions, particularly in the abdominal and pelvic region. A total of 50 volunteers were recruited between March 1 st 2011 and December 12 th 2011. All studies were acquired on a 1.5T Magnetom Avanto scanner (Siemens, Erlangen, Germany). The first two participants were healthy volunteers, followed by 48 clinical patients. The images were independently reviewed by 3 Vascular Radiologists blinded to patient details. Diseased arterial segments were assessed as normal, stenosed or occluded. Stenosis severity was assessed as mild ( 70% diameter loss). Stenosis and occlusion length were also assessed. These findings were then compared to the “gold standard” CE-MRA to allow assessment of accuracy of the QISS sequence in assessing arterial disease severity and extent. The QISS sequence produced images that corresponded very well with the contrast enhanced images of the same anatomical regions. Stenoses and occlusions were accurately assessed in the majority of cases. We present our findings and show some examples of the strengths and weaknesses of this Works-in-Progress technique.

2. Evaluation of QISS Non-CE MRA technique Anna-Maria Lydon, Andrew Holden Centre for Advanced MRI University of Auckland, New Zealand

3.  Background  Other non CE-MRA techniques  QISS – how it works  Recruitment  Challenges & limitations  Results  Case examples  Conclusion SIEMENS WIP sequence - QISS

4. Conventional CE-MRA sequences  Compares favourably with invasive catheter angiography  Still requires contrast media

5. SIEMENS non-CE MRA sequences  Native SPACE A technique that relies on the inherent difference in signal between fast flowing blood in systole and the slower flowing blood in the diastolic phase of the cardiac cycle  It is a high spatial resolution 3D TSE sequence with contrast optimized variable flip-angle trains and inherent flow sensitivity

6. Cine Scout Mean curve analysis

7. Femoro-popliteal Station CE-MRA NATIVE SPACE DSA

8. Tibial Station CE-MRA NATIVE SPACE

9. Aorto-iliac Station  All 4 cases assessed as poor quality  Poor vessel signal intensity obtained from the aorta and iliac vessels but femoral vessels well seen (S:N issues?) CE-MRA NATIVESPACE

10. SIEMENS WIP sequence - QISS  Quiescent-Interval Single Shot Magnetic Resonance Angiography (QISS)  Rapid, sequential two-dimensional (2D) steady-state free precession acquisition acquired using ECG-gating  Acquires one slice per heartbeat Figure 1. Pulse sequence diagram of the QISS sequence (Edelman et al, MRM 2009).

11. QISS – CAMRI Experience  50 volunteers studied from March 1 st to December 12 th 2011  Of these - 3 normal volunteers - 47 clinical patients  1.5T Magnetom Avanto scanner (Siemens, Erlangen, Germany) using a dedicated peripheral vascular coil and body matrix coils as required  Image quality assessed and graded from non- diagnostic to excellent

12. QISS – CAMRI Experience

13. 3 volunteers 2 Female – all stations 1 Male – foot and ankle 47 clinical patients 21 Female 26 Male Stations – Tibial (Std) - 16 Hi-res trifurcation - 6 Hi-res trifurcation - 6 Fem-pop - 17 Aorto-iliac - 14 Heart rate - Range 50-120bpm QISS – Patient distribution

14.  Claudication – 31  Ulcers – 3  Other - ?PAD (specific level) - pulses (weak/absent) - pulses (weak/absent) - 1 x Type B aortic dissection - 2 x aneurysms (AAA and iliac) - 1 x toe numbness - Previous grafts/ PTA - 1 x amputee with weak pulses remaining limb - 5 x TKJR, 1 x THJR QISS – Clinical Indications

15.  Venous Contamination - Our first clinical patient had the QISS sequence acquired in the abdominal (aorto- iliac) region post contrast. QISS – Limitations & challenges QISS #03 data set MIP

16.  In-Plane Signal Loss - be seen when the vessel orientation runs in-plane with the slice orientation. CE-MRA MIP QISS MIP QISS angled slab showing signal loss QISS – Limitations & challenges

17.  Abdominal (aortio-iliac) region – - The initial healthy volunteers struggled with the breath-holds - By adapting the abdominal (aorto-iliac) regions to a single concatenation with 2-3 averages this sequence could be acquired with free breathing QISS – Limitations & challenges MIP QISS data set MIP QISS data set Ce-MRA MIP

18. Patient movement Patient movement  MIP’s often showed small steps between the stations. This was due to slight patient movement between slabs QISS – Limitations & challenges

19. QISS MIP Ce-MRA MIP  Metal Artifact – 5 of the clinical volunteers had a total knee joint replacements and 1 had a total hip joint replacement. QISS – Limitations & challenges

20. Fast AF - QISS MIP Fast AF - QISS MIP  Arrhythmia & poor ECG - 6 patients presented with arrhythmia, eg, atrial fibrillation and bigeminy.  In addition, 2 patients had poor ECG traces  1x patient had tachycardia (HR 115bpm) QISS – Limitations & challenges Fast AF - CE-MRA MIP Slow AF - QISS MIP Slow AF CE-MRA MIP

21. Images independently reviewed by 3 vascular radiologists Images independently reviewed by 3 vascular radiologists Imaged are segments graded for image quality: Imaged are segments graded for image quality: Grade 1: non-diagnostic Grade 1: non-diagnostic Grade 2: poor quality Grade 2: poor quality Grade 3: diagnostic Grade 3: diagnostic Grade 4: excellent quality Grade 4: excellent quality Stenoses were colour coded as according to assessed severity Stenoses were colour coded as according to assessed severity QISS – Image Assessment

22. Grade 1: non-diagnostic Grade 1: non-diagnostic Grade 2: poor quality Grade 2: poor quality Grade 3: diagnostic Grade 3: diagnostic Grade 4: excellent quality Grade 4: excellent quality QISS – Image Quality Grade Number N=14 12 22 34 46 Grade Number N=17 11 23 36 47 Grade Number N=16 10 22 34 410 Aorto-iliacFemoro-poplitealTibial

23. QISS – Stenosis Severity Correlation with CE-MRA Poor Excellent Image qualityNumber Non-diagnostic3 Poor7 Diagnostic14 Excellent23 QISS sequences compared to “gold standard” CE-MRA by 1 reviewer QISS sequences compared to “gold standard” CE-MRA by 1 reviewer QISS images of excellent and diagnostic quality compared well with CE-MRA, independent of site QISS images of excellent and diagnostic quality compared well with CE-MRA, independent of site

24. Case #38 Aorto-iliac station (stations 6-8) 73yo Male Claudication both calves Fast AF – HR 115bpm QISS MIP CE-MRA QISS MIP CE-MRA QISS – Case examples

25. QISS MIP CE-MRA MIP QISS MIP CE-MRA MIP Case #09 Femoro-popliteal stations Male ? SFA occlusion HR 62bpm

26. 56yo Male Severe left leg claudication AF 90 -120 bpm Hi-res trifurcation tibial station QISS – Case examples Case #46 QISS MIP CE-MRA QISS MIP CE-MRA

27. Case #47 Male volunteer Researcher High-res foot & ankle station QISS – Case examples

28.  In our experience the QISS sequence has been a robust and relatively easy sequence to run  We have found it quick and easy to use  Potentially is of great use in cases where patients are unable to have Gadolinium contrast agent.  However – there are pitfalls to be aware of. Conclusion

29. References  Bi, X & Glielmi, C (2010), ‘Non contrast-enhanced, Quiescent Interval Single Shot (QISS) MR Angiography of the Peripheral Arteries’, Siemens Applications Guide (Works-in-Progress # 592).  Eldelman RR, Sheehan JJ, Dunkle E, Schindler N, Carr J, Koktzoglou I (2010), ‘Quiescent-Interval Single-Shot Unenhanced Magnetic Resonance Angiography of Peripheral Vascular Disease: Technical Considerations and Clinical Feasibility’, Magnetic Resonance in Medicine, vol. 63, pp. 951-8.

30. Acknowledgements  Dr Andrew Holden, Dr Brett Cowan, Kate Handley, Hilary McIntyre, Rachel Heron and all the team at CAMRI  Dr Peter Schmitt, Dr Andreas Greiser & the CV development team at Siemens, Erlangen  All our patients who volunteered