PET: quantification of perfusion and beyond

Transcription

1 PET: quantification of perfusion and beyond Juhani Knuuti Turku PET Centre University of Turku Turku, Finland

2 Disclosure: Juhani Knuuti, M.D. Juhani Knuuti, M.D. has financial interests to disclose. Potential conflicts of interest have been resolved. Research Support / Grants Stock/Equity (any amount) Consulting Employment Speakers Bureau / Honoraria None None Lantheus None Philips Research contracts (institutional): Orion Pharma, Turku Imanet Ltd, GE Healthcare, GSK, Merck, Bayer-Schering, Novartis, Lundbeck, Roche; Lantheus 2

3 Quantification of perfusion? Quantification perfusion defect score Quantification = Measurement of myocardial perfusion in absolute terms (ml/g/min)

4 Quantification of perfusion? Tracer Imaging protocol Data analysis Implementation of quantitative results into clinical reading Understanding the limitations Convince the clinician that quantitative results are useful and reliable

5 Joutsiniemi et al (submitted) Absolute flow or flow reserve?

6 Quantification of perfusion? Tracer Imaging protocol Data analysis Implementation of quantitative results into clinical reading Understanding the limitations Convince the clinician that quantitative results are useful and reliable

7 Absolute myocardial blood flow: Interpretation criteria need to be revised Stress 6 5 Range in absolute flow image Range in tracer uptake Measured/modelled flow Abnormal Absolute flow Normal Tracer uptake Absolute flow (ml/g/min)

8 Implementation into clinical decision-making Global flow value/reserve in addition to standard reading of relative images Cutoff values for normal and abnormal global flow/reserve Scaling the images into absolute scale regional/vessel based use of quantitative values Cutoff values for normal and abnormal flow

9 The estimated probability of significant CAD (stenosis+reduced FFR) by O-15 water PET stress flow

10 Quantification of myocardial perfusion Which patients will benefit? Balanced 3 vessel or multivessel disease Culprit lesion vs. non-culprit lesion in multi vessel disease Early changes in coronary dysfunction

11 Challenges and solutions of perfusion imaging Challenge Solution LM disease? Balanced 3 vessel disease? Multivessel disease? Anatomical location? Non-ischemic CAD? Microvascular disease?

12 Challenges and solutions of perfusion imaging Challenge LM disease Balanced 3 vessel disease Multivessel disease Anatomical location Non-ischemic CAD Microvascular disease Solution Hybrid imaging Quantitation Quantitation Hybrid imaging Hybrid imaging Quantitation/ hybrid imaging

13 The effect of absolute quantification on clinical interpretation of perfusion images No major difference in clinical interpretation: n=54 (51%) More severe multivessel disease with absolute analysis: n=10 (9%) Heterogenous relative perfusion but normal absolute perfusion: n=36 (34%) Balanced 3-vessel disease with preserved relative perfusion: n=6 (6%)

14 Absolute quantification in patients with multi-vessel disease 100 % 90 % 80 % 70 % 60 % 50 % 40 % 30 % 20 % 10 % 0 % PPV NPV acc absolute relative 106 patients with 30-70% pretest likelihood of CAD Quantitative hybrid PET/CT imaging vs. invasive angiography with FFR Kajander S, et al

15 Quantification of perfusion? Tracer Imaging protocol Data analysis Implementation of quantitative results into clinical reading Understanding the limitations Convince the clinician that quantitative results are useful and reliable

16 Problematic patient groups If no anatomical information is available Patients with heart failure Patients with advanced atherosclerosis but no epicardial obstructive disease Microvascular disease

17 Limitations If no anatomical information is available Patients with heart failure Patients with advanced atherosclerosis but no epicardial obstructive disease Microvascular disease

18 Quantification of perfusion? Tracer Imaging protocol Data analysis Implementation of quantitative results into clinical reading Understanding the limitations Convince the clinician that quantitative results are useful and reliable

19 Case Case LeRe Clinical History - 67-year old male - 3 mo stable exercise associated angina that got more severe - Exercise test Normal exercise capacity ECG normal during stress No symptoms After the test chest pain with st-depressions Turku PET Centre, Finland

20 CTA+ Adenosine stress perfusion Turku PET Centre, Finland Case LeRe Clinical Application of PET/CT O 15 -water parametric PET/CT hybrid images Relative scale image

21 Case Case LeRe RCA LAD CTA Findings Left main severe stenosis Distally in LAD and LCX calcified plaques but not clear stenosis. In RCA distally significant stenosis LCX CTA Turku PET Centre, Finland

22 CTA+ Adenosine stress perfusion Turku PET Centre, Finland Case LeRe Clinical Application of PET/CT O 15 -water parametric PET/CT hybrid images 3.5 ml/g/min MBF 1.3 ml/g/min 0.0 ml/g/min

23 Case 2 LCX CT angiography RCA LAD Case:NYM

24 Case 2 Case:NYM Anterior view Posterior view Hybrid PET/CT imaging (adenosine stress)

25 Case 2 Case:NYM Anterior view Scale ml/min/g Posterior view Hybrid PET/CT imaging (adenosine stress)

26 Ziadi MC, et al J Nucl Cardiol

27 12 unselected examples of relative vs quantitative analysis Relative Absolute Relative Absolute Relative Absolute

28 Quantitation vs relative analysis of perfusion A Saraste and J Knuuti JNC

29 Labeled Stem Cell Stem Cell Engraftment Labeled ATR Ligand Labeled ACE Inhibitor ACE Matrix- Metalloproteina se Labeled MMP Ligand Presynaptic Sympathetic Innervation Nerve Terminal Labeled Adrenocept or Ligand Labeled Catecholamin e Analogue Glucose Postsynaptic Adrenergic Receptors ATR Renin- Angiotensin System (RAS) Cardiac Molecular Imaging Targets Mitochondrium Nucleus Reporter Gene Product MMP v 3 Integrin Reporter Gene v 3 Integrin Expression Vector Labeled Integrin Ligand Gene Expression / Reporter Gene Imaging FFA TCA Flux Labeled Reporter Probe Bengel, F. In: Braunwald s eart Disease, 8th Ed. Labeled Glucose Labeled Analogue Fatty Acid Labeled 29 Analogue Acetate Labeled Membrane Integrity / Metabolism Annexin Apoptosis / Cell Labeled Antimyosin