Yard.Doç. Dr. Nalan Alan Selçuk Nuclear Cardiology Yard.Doç. Dr. Nalan Alan Selçuk 12.11.2018

Nuclear Cardiology In recent years, radionuclide imaging technologies have evolved rapidly (with the development of new instrumentation and new agents), and both the number and the complexity of choices for the clinician have increased 12.11.2018

Nuclear Cardiology Myocardial perfusion imaging Evaluated myocardial functions Acut myocardial infarction scintigraphy Myocardial viability study (PET) 12.11.2018

Nuclear Cardiology Myocardial perfusion imaging (MPI) is the foremost nuclear cardiology procedure For perfusion imaging with SPECT, thallium-201 (201Tl) and two technetium-99m (99mTc) labelled radiopharmaceuticals (sestamibi and tetrofosmin) are available commercially 12.11.2018

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Nuclear Cardiology Tl 201 Half-life: 73 hours (ca. 3 days) Radiation: 68-80 keV photons ("mercury xrays") 135 + 167 keV gamma rays Cyclotron produced 12.11.2018

Nuclear Cardiology Thallium (Tl) 201 Acts as potassium analog Dose 3.0 - 5.0 mCi at peak exercise 4% of injected dose --> myocardium Imaging: "exercise" (5-10 min), "redistribution" (3-4 hrs) Views: anterior, LAO 45', left lateral 12.11.2018

Nuclear Cardiology interpretation: normal reversible abnl ==> exercise-induced ischemia nonreversible abnl ==> prior MI reverse redistribution ==> normal areas wash out faster lung activity ==> LV failure during exercise 12.11.2018

Nuclear Cardiology Tc-99m Half-life: 6.03 hr Decay: isomeric transition Radiation: gamma, 140 keV (98%) 12.11.2018

Nuclear Cardiology Tc 99–m sestamibi Myocardial uptake proportional to perfusion No redistribution Dose 25mCi Imaging: optimal at 1hr but may be satisfactory out to three hours 12.11.2018

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İmaj kaydı 12.11.2018

İnterpretasyon 12.11.2018

İnterpretasyon 12.11.2018

Treadmil exercise test or bicycle stress Nuclear Cardiology Stress applications Treadmil exercise test or bicycle stress -Bruce or modifiye Bruce protochol -Target max rate:220-age -β-Blockers : before 48-72 h, -Calcium antagonists: before 48 hr 12.11.2018

Pharmacological stress test -Adenosine is a direct coronary arteriolar dilator and in a normal coronary artery results in a three- to fourfold increase in myocardial blood flow. -Dipyridamole is an indirect coronary arteriolar dilator that increases the tissue levels of adenosine by preventing the intracellular reuptake and deamination of adenosine. Adenosine and dipyridamole result in a modest increase in heart rate and a modest decrease in both systolic and diastolic blood pressures. 12.11.2018

Nuclear Cardiology Dipyridamole dose. Dipyridamole should be given as a continuous infusion intravenously at 140 μg/kg/min over 4 min. The tracer is injected 3–5 min after the completion of dipyridamole infusion. 12.11.2018

Nuclear Cardiology Dobutamine results in a dose-related increase in myocardial oxygen demand due to increase in heart rate and blood pressure and usually also in myocardial contractility 12.11.2018

Nuclear Cardiology 12.11.2018

Nuclear Cardiology Exercise stress Bicycle stress Treadmill stress Pharmacological stress Vasodilator agents Adenosine Dipyridamole “Hybrid tests”: both can be combined with low-level exercise Sympathomimetic agent Dobutamine + atropine if necessary 12.11.2018

Myocardial Perfusion Imaging Diagnosis of coronary artery disease Evaluation of prognosis Coronary artery disease After myocardial infarction In patients with unsuitable angina Before other surgery Assessment myocardial viability 12.11.2018

Tl-201 Myocardial Perfusion İmaging 12.11.2018

İnterpretasyon 12.11.2018

Myocardial Perfusion Imaging İschemia=reduction in perfusion with stress compared to normal perfusion at rest Myocardial infarction: reduction in both stress and rest images Partial increased uptake (partial reversiblity, partial redistribution) scar + ischemia 12.11.2018

Myocardial Perfusion Imaging Advantages and disadvantages of using Tc-99m sestamibi/tetrofosmin rather than Tl-201 Advantage Higher count rates Higher energy photons (gated SPECT) First-pass assesment of perfusion and function Disadvantage No redistribution Lung uptake not diagnostic Less extraction at hyperemic flows Less sensitive than Tl-201 for viability assessment 12.11.2018

Myocardial Perfusion Imaging AÇ 40 yaş, bayan. Anteroseptal iskemi şüphesi Miyokard perfüzyon testi sırasındaki eforlu EKG normal. 12.11.2018

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Myocardial Perfusion Imaging MP. 56 yaşında bayan hasta. İnferior MI öyküsü olan hastada iskemi şüphesi Miyokard perfüzyon testi sırasındaki eforlu EKG’de inferior derivasyonlarda belirgin Q dalgası. 12.11.2018

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Myocardial Perfusion Imaging MPS has a higher sensitive than stress EKG, MPS shows degree and localization of ischemia In clinical application of MPS Bayes teorisi. 12.11.2018

Indication-CAD Moderate CAD: Asymptomatic, positive ECG Chest pain without angina or suspected stress ECG Atypical angina and negative stress ECG or uncomment ECG (LBBB, left ventricular hypertrophy) 12.11.2018

Miyokard Perfüzyon Sintigrafisi Ş A. 58 yaşında bayan EKG’de anterior derivasyonlarda T(-), angiyografide LAD’de %67 darlık 12.11.2018

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Miyokard Perfüzyon Sintigrafisi KY, 66 yaşında erkek İnferior MI öyküsü olan hastada EKG’de V3-V6’da T(-)’liği mevcut 12.11.2018

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Miyokard Perfüzyon Sintigrafisi TÖ, 65 yaşında erkek EKG’de V1-V5’de ST elevasyonu ve T(-)’liği mevcut 12.11.2018

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Gated Myocardial Perfusion Imaging Two advantages may be accrue when perfusion SPECT studies are acquired in an ECG-triggered, “gated” mode: 1. Evaluation of LV ejection fraction (EF) and volumes, and evaluation of LV regional wall motion 2. Improvement of the diagnostic accuracy of perfusion imaging in the event of attenuation problems (apparently irreversible perfusion defects due to attenuation artefacts may be wrongly interpreted as scar tissue, though function is maintained). 12.11.2018

Gated Myocardial Perfusion Imaging Wall motion is classified as: – Normal – Hypokinetic – Akinetic – Dyskinetic (paradoxical) 12.11.2018

Positron Emission Tomography Clinical cardiac PET imaging is performed for the assessment of myocardial perfusion and/or viability. The PET tracers used in clinical cardiac studies; -13N-ammonia (half life 10 min) -15O-water (half life 2 min) -82Rb (half life 1.23 min) -18F-FDG (half life 110 min) 12.11.2018

Myocardial Functinal Imaging First-pass radionuclide angiography (RNA) RNV evaluate more accuracy than MUGA technique in right ventricule functions 12.11.2018

Myocardial Functinal Imaging Multigated equilibrium (MUGA) The advantages of a MUGA Scan over an Echocardiography are: Ejection fraction calculation by MUGA is volume dependent, which is more accurate than Echo imaging where the dependence is on the area of cardiac chambers It is operator independent and therefore reproducible. This is essential in prognostication or the follow-up of certain cardiac conditions like CCF, etc. A MUGA Scan can be easily performed in patients with a poor Echo window as encountered in patients with COPD, obesity or a thick chest wall. 12.11.2018

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