Page 516 - Atlas of Small Animal CT and MRI

(<10 kg) and multislice scanners. Timing is determined from the dynamic CT scan by creating a graph with regions of interest, or by counting the number of images (at 1 slice/second)
Protocols for CT angiography. Choose whether to perform a single‐phase or dual‐phase protocol. The most thinly collimated images are appropriate for very small dogs
0 (start scan and injection (TA) Peak arrival in aorta (TA + TAPS + Delay) Plateau of portal (from dynamic) 60–180 s post injection (TP) Plateau of portal (from dynamic). Estimate method 20–30 s post injection, increasing with body weight.
Pre‐delay (TA) and interscan delay (Delay) are programmed into the dual‐phase scan at setup. The portal phase scan should begin at plateau of portal enhancement, which can be
until peak vessel enhancement. TA = time to peak contrast in aorta (s), TAPS = total time of arterial phase scan (s), Delay = time delay between arterial and portal phase scans.

estimated at 20–30 seconds depending on body weight, with moderate individual variability. Contrast medium used should be non‐ionic and high concentration.
Delay 0 simultaneously) (from dynamic)

Contrast medium none 0.25 ml/kg, 5 ml/s, 1 s rotation, 60 s duration 2 ml/kg, 3–5 ml/s 2 ml/kg, 3–5 ml/s

Algorithm Soft tissue Soft tissue Soft tissue Soft tissue Soft tissue Soft tissue

Collimation 0.5–2.5 mm 2–5 mm 0.5–2.5 mm 0.5–2.5 mm 0.5–2.5 mm

Direction Cr–Cd Stationary Cd–Cr Cr–Cd Cr–Cd Cr–Cd

Pelvic inlet Diaphragm Pelvic inlet Pelvic inlet Pelvic inlet

End n/a

Start Diaphragm Porta hepatis Porta hepatis Diaphragm Diaphragm Diaphragm

Phase Precontrast Timing Arterial Portal Delayed Portal

Table 5.2.1 Series Survey abdomen Dynamic Dual‐phase Multiphase Single‐phase

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