Intravenous angiography using scanned projection radiography: preliminary investigation of a new method.
The use of digital subtraction techniques combined with fluoroscopy has rekindled interest in arteriography using intranvenous injections of contrast media. A new method is proposed for intravenous angiography in which an x-ray source and xenon detector array from a computed tomographic (CT) scanner are used to scan a region of interest to produce projection image. In order to provide adequate visualization of small concentrations of iodine in blood vessels, a subtraction scheme is used to remove the contribution from overlapping soft tissue and bone. Initial experiments with a temporal subtraction algorithm on phantoms have demonstrated the ability to image simulated blood vessels of 1.7-mm diameter containing dilute diatrizoate with an iodine concentration of 3.7 mg/cc, at an exposure of less than 100 mR. Vascular structures 5-8 mm in diameter have been imaged in dogs with iodine concentrations of less than 37 mg/cc using temporal subtraction. Principal advantages of the method over other film or fluoroscopic subtraction techniques are: 1) wide dynamic range an low noise of the (CT) detectors, providing excellent iodine sensitivity; 2) high scatter rejection; and 3) efficient utilization of x-ray dose.
D000792:Angiography / Q000379:methods*; D000818:Animals; D003287:Contrast Media / Q000008:administration & dosage; D003973:Diatrizoate / Q000008:administration & dosage; D004285:Dogs; D006801:Humans; D007275:Injections, Intravenous; D008953:Models, Anatomic; D013382:Subtraction Technique; D014057:Tomography, X-Ray Computed
D003287:Contrast Media; D003973:Diatrizoate