chapter3

13

Angiography

Quality Control• 99mTcO−

4: Moly-Al breakthrough, chromatography.

• 99mTc-DTPA: chromatography: > 90%, use within 1 hour.

Adult Dose Range• 8–25 mCi (296–925 MBq)

Method of Administration• Intravenous injection, good bolus for flow.

Radionuclide• 99mTc t1/2: 6 hours

Energies: 140 keVType: IT, γ, generator

Radiopharmaceutical• Na99mTcO−

4 (pertechnetate). 99mTc-DTPA(diethylenetriaminepentaacetic acid). Taggedred blood cells by pyrophosphate or stannouschloride to 99mTcO−

4 by in vivo, in vitro, or kit,e.g., UltraTag®.

Localization• Compartmental to blood supply.

RADIOPHARMACY

INDICATIONS

• Evaluation of blood flow through major vessels as with arteriograms and venograms (more venousthan arterial because contrast radiography is now largely used for arterial flow).

• Evaluation of regional perfusion in organs and extremities.• Evaluation of penetrating wounds to thorax, abdomen, or extremities.• Detection and localization of known or suspected hematoma or bleeding from large vessel.• Detection and localization of vessel obstruction (e.g., deep venous thrombosis).• Detection and evaluation of vessel abnormalities.• Detection and evaluation of vascularized tumors.• Evaluation of vessel location and/or anatomic position.• Evaluation of vessels because of abnormal results on related studies.

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CONTRAINDICATIONS

• None

PATIENT PREPARATION

• Identify the patient. Verify doctor’s order. Explain the procedure.• For 99mTcO−

4: administer 200–400 mg perchlorate PO 30 minutes before imaging to block thyroiduptake if that area is within the region of interest (ROI). Lemon can be used to stimulate andreduce uptake in salivary glands.

EQUIPMENT

14

NUCLEAR MEDICINE TECHNOLOGY: Procedures and Quick Reference

longer times for structures with smaller ves-sels and less blood flow. Suggested times:• 1 sec/image for heart• 2 sec/image for brain• 3 sec/image for kidneys• 5 sec/image for extremities

• Length of flow: 30–60 seconds.

Statics• 300,000–750,000 counts or set for time, e.g.,

180 seconds.• Acquire anterior or posterior images (accord-

ing to ROI).• Acquire added views (laterals, etc.) if needed

for visualization.

Camera• Large field of view.

Collimator• Low energy, all purpose, or low energy, high

resolution.

Computer Set-upFlow• 1–5 sec/image for 30–60 seconds.• Time for flow is according to size of vessels of

interest. Choose shorter times for structureswith large vessels and quick blood flows,

PROCEDURE (TIME: ~20 MINUTES)

• Position patient on table if torso is to be imaged, such that the entire area of interest (suspectedside and normal side) is completely in camera view.

• Position extremities (left and right) in field of view if one or both are the areas of interest.• Position camera as close as possible to area or organ of interest.• Consider a foot injection if the arterial or venous flow to arms is the area of interest.• Inject patient and start camera at appropriate time to catch flow.• Optional quantitative analysis can be done with computer software.

• Acquire flow at 1 image/sec.• Draw ROIs on desired structures.• Generate time-activity curves with computer software.• Calculate quantitative analysis of transit time, blood volume, and flow by this method.

• Optional blood tagging:• In vitro method: Extract ∼2–2.5 mL of blood into heparinized syringe from patient and tag with

UltraTag®• In vivo method: Inject cold pyrophosphate, then 20 minutes later, inject radiotracer under

camera for flow• Modified in vivo method: Inject cold pyrophosphate and wait 20 minutes; then extract

∼2–2.5 mL of blood into a heparinized, shielded syringe containing ∼30 mCi 99mTc-O4

and mix for 5–10 minutes

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• Inject patient (or reinject blood) under camera to image flow to ROI.• Obtain static images of ROI at 5- to 10-minute intervals as per physician’s request.

NORMAL RESULTS

• Depending on the position of the camera and the injection site, veins appear first, leading to theright heart, then out to the lungs, back to the left heart, then out the aorta to the body.

• Large vessels appear prominently and subsequently show branching. With extremities, approximatebilateral symmetry should be present.

• Organs present shortly after aorta, then vascularization of general body tissue.

ABNORMAL RESULTS

• Punctures to a vessel will present with diffuse radiotracer collecting outside the vessel in that area.

• Obstruction presents as vessel to point of obstruction and no vessel appearing distal to theobstruction.

• Obstruction to organs presents as partial or complete lack of perfusion.• Vascularized tumors and cysts will present as localized areas of increased uptake.• Nonvascularized tumors and cysts will present as localized areas of decreased or no uptake.

ARTIFACTS

• Attenuating articles obscuring ROI.• Patient movement blurs image.• Causes of a poor tag:

• Drug interactions e.g., heparin, methyldopa, hydralazine, quinidine, digoxin, prazosin, propranolol,doxorubicin, iodinated contrast agents

• Cold pyrophosphate not injected soon enough after mixing• Antibodies: transfusions, transplantation• Short incubation time• Too much or too little stannous ion

15

Chapter 3 — Angiography

PATIENT HISTORY The patient should answer the following questions.

Do you have a history or family history of cancer? Y N

If so, what type and for how long?

Do you have any pain and if so, where and for how long?

Do you have a history of aneurysm, blood clots, Y Nperipheral vascular disease, or any vessel abnormalities?

If so, explain.

(continued)

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StudentsExplain the relevancy of each of the above patient history questions to this particular scan.

Can you think of others that would be helpful for the interpretation of this type of study?

Suggested Readings

Alazraki NP, Mishkin FS, eds. Fundamentals of Nuclear Medicine, 2nd ed. New York: Society ofNuclear Medicine, 1988.

Datz FL. Handbook of Nuclear Medicine, 2nd ed. St. Louis: Mosby, 1993.Early PJ, Sodee DB. Principles and Practice of Nuclear Medicine, 2nd ed. St. Louis: Mosby, 1995.Klingensmith W, Eshima D, Goddard J. Nuclear Medicine Procedure Manual 1997–98. Englewood,

CO: Wick, 1998.Murray IPC, Ell PJ, eds. Nuclear Medicine in Clinical Diagnosis and Treatment, vols. 1 and 2. New York:

Churchill Livingstone, 1994.Wilson MA. Textbook of Nuclear Medicine. Philadelphia: Lippincott-Raven, 1998.

Notes

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NUCLEAR MEDICINE TECHNOLOGY: Procedures and Quick Reference

Have you been diagnosed with any major organ disorders? Y N

If so, which one(s) and for how long?

Do you have any discolored skin? Y N

Do you have any tingling in the extremities? Y N

Do you have any blood in your stool or urine? Y N

Do you have any unusual lumps or swelling? Y N

Have you had any recent or planned related studies? Y N

Do you have the results of any recent laboratory tests? Y N

Female: Are you pregnant or nursing? Y N

Other department-specific questions.

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