Effect of volume and rate of contrast medium injection on intravenous digital subtraction angiographic contrast medium curves

The image quality of temporal (mask mode) intravenous digital subtraction angiography is directly dependent on the shape of arterial time-concentration curves produced by the intravenous injection of contrast medium. Curves that are narrow and tall minimize motion artifact (misregistration) and maximize contrast enhancement (pre-and postcontrast differences). To determine the effects of rate and volume of injection of contrast medium on intravenous digital subtraction angiographic curves, ioxaglate (Hexabrix), a mono-acidic ionic dimer, was injected into large mongrel dogs. Quantitative measurements of opacification were made over time in the femoral arteries using a modified General Electric CT/T scanner. Peak opacification was directly proportional to the volume of contrast medium injected. Curve width was not affected by increasing volume of injection. At rates below a critical point, slower injection rates produced progressively shorter and wider arterial time-concentration curves. Above that critical point, increasing the rate of injection did not affect either curve width or curve peak.