Saturday 11 August 2012

Funny.Pho.to - Select a photo to insert into the Golden Fish template.

Funny.Pho.to - Select a photo to insert into the Golden Fish template.

Wednesday 18 July 2012

Radionuclide angiography + +


Coronary Angiography-YouTube Video



Radionuclide angiography

Purpose

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 angioplastycoronary 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
  • Coronary angiography procedure-You Tube

    Procedure

    At a high level, the MUGA test involves the introduction of a radioactive marker into the bloodstream of the patient. The patient is subsequently scanned to determine the circulation dynamics of the marker, and hence the blood.
    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 thein 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 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.

    External links

    • Radionuclide+Angiography at the US National Library of Medicine Medical Subject Headings (MeSH)
    • YouTube - Angiography
    • ACC/AHA Guidelines for Coronary Angiography: Executive Summary and Recommendations

      A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Coronary Angiography) Developed in collaboration with the Society for Cardiac Angiography and Interventions

      Figure 1.
      Nomogram of prognostic relations embodied in the Duke Treadmill Score. Determination of prognosis proceeds in 5 steps: 1. The observed amount of exercise-induced ST-segment deviation (the largest elevation or depression after resting changes have been subtracted) is marked on the line for ST-segment deviation during exercise. 2. The observed degree of angina during exercise is marked on the line for angina. 3. The marks for ST-segment deviation and degree of angina are connected with a straight edge. The point where this line intersects the ischemia reading line is noted. 4. The total number of minutes of exercise in treadmill testing according to the Bruce protocol (or the equivalent in multiples of resting oxygen consumption [METs] from an alternative protocol) is marked on the exercise-duration line. 5. The mark for ischemia is connected with that for exercise duration. The point at which this line intersects the line for prognosis indicates the 5-year survival rate and average annual mortality for patients with these characteristics. Patients with <1 mm of exercise-induced ST-segment depression should be counted as having 0 mm. Angina during exercise refers to typical effort angina or an equivalent exercise-induced symptom that represents the patient’s presenting complaint. This nomogram applies to patients with known or suspected CAD, without prior revascularization or recent MI, who undergo exercise testing before coronary angiography. Modified with permission from Mark DB, Shaw L, Harrell FE Jr, et al. Prognostic value of a treadmill exercise score in outpatients with suspected coronary artery disease. N Engl J Med. 1991;325:849–853. © 1991 Massachusetts Medical Society. All rights reserved.
      Figure 2.
      Clinical context for noninvasive and invasive diagnostic testing of patients with known or suspected ischemic heart disease. *ECG interpretable unless preexcitation, electronically paced rhythm, left BBB, or resting ST-segment depression >1 mm. See text for discussion of use of digoxin, left ventricular hypertrophy, and ST-segment depression <1 mm. **For example, high risk if Duke treadmill score predicts average annual mortality >3%. Modified from Gibbons RJ, Balady GJ, Beasley JW, et al. ACC/AHA guidelines for exercise testing: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Exercise Testing). J Am Coll Cardiol.1997;30:260–311.
      View this table:
      Table 1.
      Noninvasive Test Results Predicting High Risk1 for Adverse Outcome

+ + Angiography or Angiogram


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Angiography or Angiogram

Interventional Radiologists are Vascular Experts

Interventional radiologists use imaging to diagnose, understand and visualize the full scope of the pathology and to map out the procedure tailored to the individual patient. Angiography is an X-ray exam of the arteries and veins to diagnose blockages and other blood vessel problems.
An interventional radiologist performs this X-ray procedure, which is also called an angiogram. During the angiogram, the doctor inserts a thin tube (catheter) into the artery through a small nick in the skin about the size of the tip of a pencil. A substance called a contrast agent (X-ray dye) is injected to make the blood vessels visible on the X-ray.
One of the most common reasons for angiograms is to see if there is a blockage or narrowing in a blood vessel that may interfere with the normal flow of blood through the body. In many cases, the interventional radiologist can treat a blocked blood vessel without surgery at the same time the angiogram is performed. Interventional radiologists treat blockages with techniques called angioplasty andthrombolysis.

Additional Reasons for Performing Angiography or Angiogram

  • aneurysms -- an area of a blood vessel that bulges or balloons out
  • cerebral vascular disease, such as stroke or bleeding in the brain
  • blood vessel malformations
  • Angiography - NHS Choice

    Introduction 

    Areas that can be checked using an angiography

    The heart is one of the most common areas of the body that can be checked using an angiography. A coronary angiographycan check the flow of blood into the heart and help to diagnoseheart disease.
    Other areas of the body that can be examined using an angiography include the:
    • brain (cerebral angiography)
    • lungs (pulmonary angiography)
    • kidneys (renal angiography)
    • arms or legs (extremity angiography)
    For further details about how the procedure is used to check these areas of the body, see Angiography - what is it used for.


CT pulmonary angiogram


CT pulmonary angiogram

CT pulmonary angiogram (CTPA) is a medical diagnostic test that employs computed tomography to obtain an image of the pulmonary arteries. Its main use is to diagnosepulmonary embolism (PE).[1] It is a preferred choice of imaging in the diagnosis of PE due to its minimally invasive nature for the patient, whose only requirement for the scan is an intravenous line.
Modern MDCT (multi-detector CT) scanners are able to deliver images of sufficient resolution within a short time period, that CTPA has now supplanted previous methods of testing, such as isotope scanning or direct pulmonary angiography, as the gold standardfor diagnosis of pulmonary embolism.
The patient receives an intravenous injection of an iodine-containing contrast agent at a high-rate using a injector pump. Images are acquired with the maximum intensity of radio-opaque contrast in the pulmonary arteries. This can be done using bolus tracking.
A normal CTPA scan will show the contrast filling the pulmonary vessels, appearing as bright white. Any mass filling defects, such as an embolus, will appear dark in place of the contrast, filling/blocking the space where blood should be flowing into the lungs.

Contents

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Pulmonary angiography


Pulmonary angiography

Selective pulmonary angiogram revealing significant thrombus (labelled A) causing a central obstruction in the left main pulmonary artery

Pulmonary angiography (or pulmonary arteriography) is a cardiological medicalprocedure. Pulmonary blood vessels are x-rayed to detect arteriovenous malformations.
Direct angiography is the injection of radiocontrast into the circulation with subsequentfluoroscopy (direct X-ray visualisation) of the lungs. A more common form of direct angiography, is the catheterisation of the right atrium of the heart and injection of radiocontrast into the right heart.
A popular form of pulmonary angiography is computed tomography pulmonary angiography(CTPA). This involves venous contrast only.
Invasive pulmonary angiography was first performed in 1931 by Egas Moniz and colleagues.[1] Robb and Steinberg described pulmonary angiography by infusion of peripheral radiocontrast.[2][3]

Computed tomography angiography


Computed tomography angiography

omputed tomography angiography (CTA) is a computed tomography technique used to visualize arterial and venous vessels throughout the body. This ranges from arteries serving the brain to those bringing blood to the lungs, kidneys, arms and legs.

Contents

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Monday 16 July 2012

Digital subtraction angiography


Digital subtraction angiography

From Wikipedia, the free encyclopedia
Digital subtraction angiography (DSA) is a type of fluoroscopy technique used in interventional radiology to clearly visualize blood vessels in a bony or dense soft tissue environment. Images are produced using contrast medium by subtracting a 'pre-contrast image' or the mask from later images, once the contrast medium has been introduced into a structure. Hence the term 'digital subtraction angiography'.

Contents

Digital subtraction angiography
Intervention

Example of iodine-based contrast in cerebral angiography
MeSHD015901