System performance of multislice spiral computed tomography.

Multislice spiral CT offers many new possibilities for clinical CT imaging. Drastically increased scan speeds and z-resolution, respectively, as well as applications such as cardiac CT that have become feasible for the first time in routine clinical use. The concept of multiple simultaneously acquired slices yields image quality equivalent or better than single-slice spiral CT. Especially, there is no dependence on spiral pitch, neither with regard to noise nor to slice sensitivity. The reconstructed slice width can be chosen freely and retrospectively, which offers additional flexibility when evaluating optimal protocols for various kinds of examinations. Three-dimensional isotropic resolution can be achieved routinely with examinations fast enough to scan in a single breath hold (Fig. 9). Without any drawbacks in image quality, MSCT in combination with online tube current modulation can reduce patient dose. In some body regions, dose is decreased to 50% compared to a scan with constant tube current. One of the most promising new applications is the dedicated ECG-gated cardiac interpolation 180 degrees MCI, which allows four-dimensional (4-D) imaging of the heart. The complete beating heart can be reconstructed in well-defined phases of the heart cycle, thereby adding high temporal resolution to isotropic 3-D spatial resolution (for more examples refer to http://www.imp.uni-erlangen.de/e/research/cardio/).