Objective: Our goal was to optimize the efficiency of contrast materia
l (CM) application in routine examinations of the neck by the use of s
piral CT and slow power injection. Materials and Methods: Dynamic stud
ies were performed in 14 patients to establish a set protocol for spir
al CT examinations of the neck. Prospectively, 100 patients were exami
ned either by use of the spiral technique with 100 ml CM (30 g iodine)
injected in two phases or in conventional CT with 150 ml CM (45 g iod
ine). Vascular and parenchymal enhancement was evaluated at three dist
inct levels of the neck. Results: Despite the reduced CM volume in spi
ral CT, vascular enhancement was significantly higher at all three lev
els. Parenchymal enhancement was comparable in both groups. CM exploit
ation in vascular opacification (ratio of mean enhancement to applied
CM volume) was 0.87 in spiral CT compared with 0.43 in conventional CT
. Conclusion: Spiral CT significantly increases the efficiency of CM a
pplication and is well suited for routine examinations of the neck.