Contrast Radiography With Special Reference to

Angiography

Amulya V.R.

Contrast Radiography

• Lack of contrast in soft tissue makes diagnosis by survey radiography

difficult.

• Various applications

Contrast Media

Positive

Contrast

Agents

BaSO4, I2

Negative

Contrast

Agents

Air, O2, CO2

Iodine Preparations

Water-Soluble agents• Triiodinated compounds

• Angiography, angiocardiography

Viscous/oily agents• Lymphography

Dosage

Smaller volume of high concentration rather than larger volumes of lower density.

5 – 10 ml of medium containing 420 mg I per ml or 1 ml/kg.

Considerations

Contrast Medium

Hypersensitivity

Thromboemboli

sm

Technical

feasibility

TechniqueInsert catheter into access vessel of choice

Advance catheter (under fluoroscopic guidance) to desired point

Measure pressures, if applicable

Make and capture injection “sequence”

Treatment manoeuvres if applicable

Flush

Angiography

Radiographic demonstration of portions

of the vascular system by the injection of a water-soluble contrast agent either intra-venously or

intra-arterially.

Angiography contd.

• Single radiograph taken immediately at the termination of the injection

(portal venography)

• Films taken serially at intervals of 0.5 – 2 seconds may be necessary

(angiocardiography).

Angiocardiography

An intravenous radiographic contrast study evaluating the vascular system and

chambers of the heart

Congenital or acquired lesions

Arteriography

• Localised narrowing or obstruction of an artery

• Pathological circulation

• Tumour

• Treatment

• Time consuming : ½ hour – 2 hours

Indications

• Regional morphology

• Chamber size, shape, location, connections

• Vessel size, shape, location, connections

• Flow direction (? normal, ? shunt)

• Pressure evaluation

• Stenosis/valve/shunt

• Vessel invasion by local masses

Contraindications

Coagulopathy or active anticoagulation

Combined renal and hepatic failure

Contrast medium hypersensitivity

Dehydration

Selective Angiography

Arterial & venous

Normal Left and Right Ventricles

VSD

PDA

Aortic Stenosis

Splenoportogram

Non – Selective

AngiographyVenous only

Technique

• 2-5 seconds post injection for right ventricle

• 4-8 seconds post injection for left ventricle

• Technique not good for – L→R shunts– Distal arterial/limb evaluation

• Frequent re-injections

Limitations

Normal Canine Angiocardiogram

Feline Aortic Thromboemboslism

A-V Fistula

Direct Parenchymal

Injection

Indications

• Splenic venous drainage pattern• Trans-hepatic study• Lymph node morphology• Miscellaneous parenchymal organ

drainage• Cavity integrity (cavity injected)

Precautions

Bleeding

Organ injury

Pleurography/peritoneographyRoll patient to assure contrast distribution

Diaphragmatic Hernia

Digital Subtraction Angiography (DSA)

• Specialised electronic equipment, computing and radiographic hardware to

produce rapid sequential images.

• Contrast filled vessels free from the distraction of overlying structures

Lymphatic Imaging

Indications

• Drainage status of regional nodes

• Define internal node anatomy

• Find local lymphatic vessels :

(lymphangectasia/thoracic duct)

Normal Lymphangiogram

Urethral TCC

Sub-lumbar Lymph Nodes

Conclusion

• Limited use

• Much replaced by ultrasound, particularly colour-flow (Doppler imaging)

References• Feeney, D.A., 2003. Special Radiographic Procedures: Practical

Vascular Imaging. Available: www.academic-server.cvm.umn.edu/radiology/student/Student_Sp_09/Feeney/PDF/sp.%20Vascular.09.pdf. [13 Jan. 2015]

• Burke, R.L. and Feeney, D.A, 2003. Small Animal Radiology and Ultrasonography: A Diagnostic Atlas and Text. (3rd Ed.). Saunders Elsevier, Philadelphia, 740p.

• Lavin, L.M., 2005. Radiography in Veterinary Technology. (4th Ed.). Saunders Elsevier, Philadelphia, 400p.

• Trey. 2009. Special Procedures: Radiology. Available: www.kwilkerson.yolasite.com/resources/CH.%2018-Special%20Procedures.ppt. [13 Jan. 2015]

• Kealy, J.K., McAllister, H. and Graham, J.P., 2011. Diagnostic Radiology and Ultrasonography of the Dog and Cat. (5th Ed.). Saunders Elsevier, Philadelphia, 592p.

Thank You!