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| Radionuclide angiography |
| Intervention |
| MeSH |
D011875 |
| OPS-301 code: |
3-704, 3-708 |
A MUGA scan (Multi Gated Acquisition Scan) is a time-proven nuclear medicine test designed to evaluate the function of the right and left ventricles of the heart, thus allowing informed diagnostic intervention in heart failure. It is also called radionuclide angiography, radionuclide ventriculography, or gated blood pool imaging, as well as SYMA (SYnchronized Multigated Acquisition) scan. This modality uniquely provides a cine image of the beating heart, and allows the interpreter to determine the efficiency of the individual heart valves and chambers. MUGA/Cine scanning represents a robust adjunct to the now more common echocardiogram. Mathematics regarding acquisition of Q is well served by both of these methods as well as other inexpensive models supporting ejection fraction as a product of the heart/myocardium in systole.
Contents
- 1 History
- 2 Purpose
- 3 Procedure
- 4 Results
- 4.1 Normal results
- 4.2 Abnormal results
- 5 References
- 6 External links
History[edit]
The MUGA scan was first introduced in the early 1970s and quickly became accepted as the preferred technique for measurement of left ventricular ejection fraction (LVEF) with a high degree of accuracy. Several early studies demonstrated an excellent correlation of MUGA-derived LVEF with values obtained by cardiac catheterization contrast ventriculography.[1]
Purpose[edit]
MUGA is typically ordered for the following patients:
- With known or suspected coronary artery disease, to diagnose the disease and predict outcomes
- With lesions in their heart valves
- With congestive heart failure
- Who have undergone percutaneous transluminal coronary angioplasty, coronary artery bypass graft surgery, or medical therapy, to assess the efficacy of the treatment
- With low cardiac output after open-heart surgery
- Who are undergoing cardiotoxic drug agents such as in chemotherapy e.g., with doxorubicin or immunotherapy (herceptin)
- Who have had a cardiac transplant
Procedure[edit]
The MUGA scan is performed by labeling the patient's red blood pool with a radioactive tracer, technetium-99m-pertechnetate (Tc-99m), and measuring radioactivity over the anterior chest as the radioactive blood flows through the large vessels and the heart chambers.
The introduction of the radioactive marker can either take place in vivo or in vitro. In the in vivo method, stannous (tin) ions are injected into the patient's bloodstream. A subsequent intravenous injection of the radioactive substance, technetium-99m-pertechnetate, labels the red blood cells in vivo. With an administered activity of about 800 MBq, the effective radiation dose is about 8 mSv to 12 mSv. In the in vitro method, some of the patient's blood is drawn and the stannous ions (in the form of stannous chloride) are injected into the drawn blood. The technetium is subsequently added to the mixture as in the in vivo method. In both cases, the stannous chloride reduces the technetium ion and prevents it from leaking out of the red blood cells during the procedure. The in vivo technique is more convenient for the majority of patients since it is less time-consuming and less costly and more than 80 percent of the injected radionuclide usually binds to red blood cells with this approach. Red blood cell binding of the radioactive tracer is generally more efficient with the in vitro labeling, and it is preferred in patients with indwelling intravenous catheters to decrease the adherence of Tc-99m to the catheter wall and increase the efficiency of blood pool labeling.
The patient is placed under a gamma camera, which detects the low-level 140keV gamma radiation being given off by technetium-99m. As the gamma camera images are acquired, the patient's heart beat is used to 'gate' the acquisition. The final result is a series of images of the heart (usually sixteen), one at each stage of the cardiac cycle.
Depending on the objectives of the test, the doctor may decide to perform either a resting or a stress MUGA. During the resting MUGA, the patient lies stationary, whereas during a stress MUGA, the patient is asked to exercise during the scan. The stress MUGA measures the heart performance during exercise and is usually performed to assess the impact of a suspected coronary artery disease. In some rare cases, a nitroglycerin MUGA may be performed, where nitroglycerin (a vasodilator) is administered prior to the scan.
The resulting images show that the volumetrically derived blood pools in the chambers of the heart and timed images may be computationally interpreted to calculate the ejection fraction and injection fraction of the heart. This nuclear medicine scan yields an accurate, inexpensive and easily reproducible means of measuring and monitoring the ejection and injection fractions of the ventricles, which are one of many of the important clinical metrics in assessing global heart performance.
Results[edit]
Normal results[edit]
In normal subjects, the left ventricular ejection fraction (LVEF) should be about 60% (range, 50-80%). There should be no area of abnormal wall motion (hypokinesis, akinesis or dyskinesis). Abnormalities in cardiac function may be manifested as a decrease in LVEF and/or the presence of abnormalities in global and regional wall motion. For normal subjects, peak filling rates should be between 2.4 and 3.6 end diastolic volume (EDV) per second, and the time to peak filling rate should be 135-212 ms. (source?)
Abnormal results[edit]
An uneven distribution of technetium in the heart indicates that the patient has coronary artery disease, a cardiomyopathy, or blood shunting within the heart. Abnormalities in a resting MUGA usually indicate a heart attack, while those that occur during exercise usually indicate ischemia. In a stress MUGA, patients with coronary artery disease may exhibit a decrease in ejection fraction. For a patient that has had a heart attack, or is suspected of having another disease that affects the heart muscle, this scan can help pinpoint the position in the heart that has sustained damage as well as assess the degree of damage. MUGA scans are also used to evaluate heart function prior to and while receiving certain chemotherapies (e.g. doxorubicin (Adriamycin)) or immunotherapy (specifically, herceptin) that have a known effect on heart function.
References[edit]
- ^ Folland, ED; Hamilton GW, Larson SM, Kennedy JW, Williams DL, Ritchie JL (1977). "The radionuclide ejection fraction: a comparison of three radionuclide techniques with contrast angiography". J Nucl Med 18 (12): 1159.
External links[edit]
- Radionuclide Angiography at the US National Library of Medicine Medical Subject Headings (MeSH)
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Health science – Medicine · Surgery · Vascular surgery and other vascular procedures (ICD-9-CM V3 38–39, ICD-10-PCS 03–6)
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Incision, excision,
and occlusion
of vessels |
Peripheral arterial occlusive disease: Balloon embolectomy · Thrombectomy
Carotid stenosis: Endarterectomy (Carotid endarterectomy)
Varicose veins: Ambulatory phlebectomy · Laser ablation · Sclerotherapy · Vein stripping
Venous cutdown
Temporal artery biopsy
Arteriotomy · Phlebotomy
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Other operations
on vessels |
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Shunt/bypass
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Peripheral arterial occlusive disease: Peripheral arterial bypass surgery
Portal hypertension: Transjugular intrahepatic portosystemic shunt (TIPS) · Distal splenorenal shunt procedure
Vascular grafting (Human umbilical vein graft)
Blalock–Taussig shunt
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Repair
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Aortic aneurysm / dissection: Open AAA repair · Endoluminal AAA repair (EVAR)
Peripheral arterial occlusive disease: Angioplasty with/out Stenting
Atherectomy
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Auxiliary to
heart surgery
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Cardiopulmonary bypass · Cardioplegia · Extracorporeal membrane oxygenation
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Other
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Carotid stenosis: Carotid stenting
Hemodialysis/Hemofiltration · Revascularization
Glomectomy
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| Medical imaging |
Angiography (Digital subtraction angiography, Cerebral angiography, Aortography, Fluorescein angiography, Radionuclide angiography, Magnetic resonance angiography)
Venography (Portography) · Impedance phlebography
Intravascular ultrasound · Carotid ultrasonography
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| Other diagnostic |
Angioscopy · Ankle brachial pressure index · Tilt table test
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anat (a:h/u/t/a/l,v:h/u/t/a/l)/phys/devp/cell/prot
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noco/syva/cong/lyvd/tumr, sysi/epon, injr
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proc, drug (C2s+n/3/4/5/7/8/9)
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Medical testing : Medical imaging · Radiology · (ICD-9-CM V3 87–88, ICD-10-PCS B, CPT 70010–79999)
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X-ray/
medical radiography/
Industrial radiography |
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2D
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Medical: Pneumoencephalography · Dental radiography · Sialography · Myelography · CXR (Bronchography) · AXR / KUB · DXA/DXR · Upper gastrointestinal series/Small bowel follow-through/Lower gastrointestinal series · Cholangiography/Cholecystography · Mammography · Pyelogram · Cystography · Arthrogram · Hysterosalpingography · Skeletal survey · Angiography (Angiocardiography, Aortography) · Venography · Lymphogram
Industrial: Radiographic testing
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3D / XCT
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Medical: CT pulmonary angiogram · Cardiac CT · Abdominal and pelvic CT (Virtual colonoscopy) · CT angiography · CT head · pQCT · Spiral computed tomography · High resolution CT · Whole body imaging (Full-body CT scan) · Electron beam tomography
Industrial: Industrial CT Scanning
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Other
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Fluoroscopy
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| MRI |
MRI of brain and brain stem · MR neurography · Cardiac MRI/Cardiac MRI perfusion · MR angiography · MR cholangiopancreatography · Breast MRI
Functional MRI · Diffusion MRI
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| Ultrasound |
Echocardiography / Doppler echocardiography (TTE · TEE) · Intravascular · Gynecologic · Obstetric · Echoencephalography · Transcranial doppler · Abdominal ultrasonography · Transrectal · Breast ultrasound · Transscrotal ultrasound · Carotid ultrasonography
Contrast-enhanced · 3D ultrasound · Endoscopic ultrasound · Emergency ultrasound (FAST · Pre-hospital ultrasound) · Duplex
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| Radionuclide |
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2D / scintigraphy
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Cholescintigraphy · Scintimammography · Ventilation/perfusion scan · Radionuclide ventriculography · Radionuclide angiography · Radioisotope renography · Sestamibi parathyroid scintigraphy · Radioactive iodine uptake test · Bone scintigraphy · Immunoscintigraphy
full body: Octreotide scan · Gallium 67 scan · Indium 111 WBC scan
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3D / ECT
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SPECT (gamma ray): Myocardial perfusion imaging
PET (positron): Brain PET, Cardiac PET, PET mammography, PET-CT
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| Optical laser |
Optical tomography (Optical coherence tomography) · Confocal microscopy · Endomicroscopy
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| Thermography |
Breast thermography
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