II. Definitions

  1. Single Photon Emission Computed Tomography (SPECT)
    1. Radiolabeled Contrast Material is injected
    2. Emitted radiation from Contrast Material uptake is measured by an external gamma camera
      1. Contrast with CT in which applies x-ray source through a patient to detectors
    3. Other detectors of emitted radiation include scintigraphy and positron emission tomography (PET)
  2. Hybrid CT and SPECT Scanners
    1. CT adds precise anatomic positioning to the SPECT's physiologic data
    2. CT also facilitates correction of attenuation artifacts

III. Medications

  1. Thallium T1 201 chloride
    1. Originally used for imaging
  2. Technetium agents replaced Thallium for higher efficacy
    1. Technetium 99mTc-Sestamibi (Cardiolite)
    2. Technetium Tc-99m-tetrofosmin (Myoview)

IV. Indications

  1. See Exercise Stress Test
  2. Nondiagnostic Stress EKG, Intermediate CAD likelihood
    1. Resting ST-T Wave abnormalities
    2. Left Bundle Branch Block
    3. Ventricular paced rhythm
    4. Left Ventricular Hypertrophy
    5. Digoxin treatment
  3. Suspected Acute Coronary Syndrome, nondiagnostic tests
  4. CAD Diagnosis, risk stratification, and therapy
    1. Assess ventricular function
    2. Identify lesions in planning for PTCA intervention
    3. Risk stratification prior to noncardiac surgery
  5. Specific conditions
    1. Cocaine-associated Chest Pain
    2. Well-controlled Diabetes Mellitus

V. Contraindications

VI. Protocol

  1. Resting Images
    1. Radiotracer is injected with patient at rest
    2. Resting perfusion scan is performed
  2. Exercise Images
    1. Radiotracer is injected at peak Exercise (or 1-2 minutes before end of vasodilator infusion)
    2. Exercise perfusion scan is performed

VII. Advantages

  1. High Test Sensitivity for ischemia (>85%)
  2. Distinguishes baseline wall motion abnormality from CAD
    1. Severe valvular disease
    2. Severe Hypertension
    3. Idiopathic Hypertrophic Subaortic Stenosis (IHSS)
    4. Left Bundle Branch Block
    5. Severe Left Ventricular Hypertrophy
    6. Atrial Fibrillation
  3. In above cases angiography may be needed

VIII. Disadvantages

  1. Test Sensitivity decreases significantly when patient is not actively experiencing Chest Pain

IX. Efficacy: Coronary Ischemia

  1. Overall SPECT
    1. Test Sensitivity: 85-90%
    2. Test Specificity: 80-90%
    3. McArdle (2012) J Am Coll Cardiol 60(18): 1828-37 [PubMed]
  2. Pharmacologic with Dobutamine
    1. Test Sensitivity: 89%
    2. Test Specificity: 75%
    3. Multi-vessel Disease Test Sensitivity: 44%
    4. Geleinjnse (2000) J Am Coll Cardiol 36(7): 2017-27
  3. Symptomatic
    1. Test Sensitivity: >85%
    2. Test Specificity >80%
  4. References
    1. Metz (2007) J Am Coll Cardiol 49(2): 227-37 [PubMed]

X. Prognosis

  1. Normal perfusion scan: Cardiac event rate <1% per year
  2. Factors suggestive of worse prognosis
    1. Increased numbers of involved vascular territories
    2. Increased severity and extent of defect size
    3. Decreased reversibility
    4. Post-stress ejection fraction <45%
    5. End-systolic volume >70 ml
    6. Transient ischemic dilation

XI. References

  1. Broder (2022) Crit Dec Emerg Med 36(6): 20-1
  2. Cayley (2024) Am Fam Physician 110(6): 577-84 [PubMed]

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Related Studies

Ontology: Radionuclide myocardial perfusion study (C0430471)

Concepts Diagnostic Procedure (T060)
SnomedCT 252432008, 702759004
Italian Diagnostica per imagini perfusionale miocardica, Scansione perfusionale miocardica NAS, Scansione miocardica perfusionale
English Radionuc myocard perfusn study, Scan NOS myocardial perfusion, myocardial perfusion scans, myocardial perfusion scan, myocardial perfusion scanning, Scan myocardial perfusion, Radionuclide imaging of heart for assessment of myocardial viability (procedure), Radionuclide imaging of heart for assessment of myocardial viability, Radionuclide myocardial perfusion study, Radionuclide myocardial perfusion study (procedure), Myocardial perfusion scan
Dutch scan myocardperfusie, myocardperfusiescan NAO, myocardperfusiescan
French Scintigraphie myocardique de perfusion SAI, Scan myocardique de perfusion, Examen de perfusion myocardiaque
German Scan NNB Myokardperfusion, Myokardperfusionsscan
Portuguese Scan NE da perfusão miocárdica, Cintigrafia de perfusão do miocárdio, Scan de perfusão do miocárdio
Spanish Tomografía NEOM con perfusión miocárdica, Prueba de perfusión miocárdica, estudio de perfusión miocárdica con radioisótopos (procedimiento), estudio de perfusión miocárdica con radioisótopos, Gammagrafía de perfusión miocárdica
Japanese 心筋血流スキャンNOS, 心筋血流スキャン, シンキンケツリュウスキャンNOS, シンキンケツリュウスキャン
Czech Sken myokardiální perfuze NOS, Sken myokardiální perfuze
Hungarian Szívizom perfúziós scan k.m.n., Szívizom perfúziós scan

Ontology: Myocardial perfusion stress imaging using Thallium 201 (C2316301)

Concepts Diagnostic Procedure (T060)
SnomedCT 431511008
English Myocardial perfusion stress imaging using Thallium 201 (procedure), Myocardial perfusion stress imaging using Thallium 201
Spanish estudio de perfusión miocárdica de esfuerzo con talio 201, estudio de perfusión miocárdica de esfuerzo con talio 201 (procedimiento)

Ontology: Myocardial Perfusion Imaging (C2350390)

Definition (MSH) The creation and display of functional images showing where the blood is flowing into the MYOCARDIUM by following over time the distribution of tracers injected into the blood stream.
Definition (NCI_CDISC) A procedure that obtains pictures that reflect blood flow in the heart muscle.
Definition (NCI) A procedure that captures pictures of blood flow throughout the heart muscle.
Concepts Diagnostic Procedure (T060)
MSH D055414
English Myocardial Perfusion Imaging, Imaging, Myocardial Perfusion, Perfusion Imaging, Myocardial
Spanish Imagen de Perfusión Miocárdica
French Imagerie de perfusion du myocarde, Imagerie de perfusion myocardique
Italian Scintigrafia miocardica di perfusione, Imaging di perfusione miocardia
Russian MIOKARDA PERFUZII IZOBRAZHENIE, MIOKARDIOSTSINTIGRAFIIA, MIOKARDA STINTIGRAFIIA, МИОКАРДА СТИНТИГРАФИЯ, МИОКАРДА ПЕРФУЗИИ ИЗОБРАЖЕНИЕ, МИОКАРДА КРОВОСНАБЖЕНИЯ ВИЗУАЛИЗАЦИЯ, МИОКАРДИОСЦИНТИГРАФИЯ, MIOKARDA KROVOSNABZHENIIA VIZUALIZATSIIA
Portuguese Imagem de Perfusão do Miocárdio
Swedish Myokardskintigrafi
German Myokardperfusionsszintigraphie, Myokardperfusionsszintigrafie
Czech myokard - zobrazení perfúze, myokardiální perfúze - zobrazování, myokardiální perfúze - zobrazení
Polish Obrazowanie perfuzji mięśnia sercowego, Badanie obrazowe perfuzji mięśnia sercowego, Scyntygrafia perfuzyjna mięśnia sercowego, Badanie scyntygraficzne perfuzji mięśnia sercowego
Japanese 心筋血流画像, 心筋血流撮像法, 心筋血流シンチグラフィ, 心筋シンチグラフィー, シンチグラフィー-心筋, 心筋血流イメージング, 心筋血流撮像, 心筋血流像
Norwegian Myokard perfusjonsscintigrafi, Myokard perfusjonsavbildning

Ontology: Myocardial Scintigraphy (C2350391)

Definition (MSH) Imaging blood flow to the MYOCARDIUM by following the distribution of radioactively labeled tracers injected into the blood stream.
Concepts Diagnostic Procedure (T060)
MSH D055414
English Scintigraphy, Myocardial, Myocardial Scintigraphy, Myocardial scintigraphy
French Scintigraphie du myocarde, Scintigraphie myocardique
German Myokardszintigrafie, Myokardszintigraphie, Myokard-Szintigraphie
Czech myokardiální perfúzní scintigrafie, Scintigrafie myokardu, perfúzní scintigrafie myokardu, scintigrafie myokardiální perfúze
Spanish Cintigrafía miocárdica
Portuguese Cintigrafia miocárdica
Italian Scintigrafia miocardica
Dutch myocardiale scintigrafie
Japanese シンキンシンチグラフィ, 心筋シンチグラフィ
Hungarian Myocardialis izotópos vizsgálata
Norwegian Myokardscintigrafi