Soenke Heinrich Bartling MD, Presenter: Nothing to Disclose

Omid Majdani MD, Abstract Co-Author: Nothing to Disclose

Arkadius Schlesinger MD, Abstract Co-Author: Nothing to Disclose

Christian Dullin, Abstract Co-Author: Nothing to Disclose

Eckhardt H. Grabbe MD, Abstract Co-Author: Nothing to Disclose

Hartmut G. Becker MD, Abstract Co-Author: Nothing to Disclose

Thomas Lenarz MD,PHD, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

When imaging of small high contrast structures is crucial it has been shown that fpVCT offers an image quality starkly superior to that of current MSCT scanner systems. However, published comparisons were performed by scanning small, exiled specimens such as cut temporal bones. For a more realistic assessment of fpVCT the imaging results of more natural specimens such as the whole human skull (base) should be compared. Big objects challenge CT more then smaller objects, due to beam hardening, scattering, etc.

Three embalmed human cadaver heads were scanned. MSCT scanning was performed to optimize the spatial resolution (120kV, 80 mA, 0,625 mm collimation) as were reconstruction (9,6 cm rFOV, 512*512 matrix, 0,3 mm z-spacing, “boneplus” kernel, “standard” reconstruction). The fpVCT scanner consisted of two flat-panel detectors (10242 elements a 2002µm2) side by side on a standard CT- gantry. Scan parameters were:sFOV 27 cm, z-cov. 3,4 cm, 1000 proj., 8 s rotation, 140kV, 25 mA, FDK recon., high contrast kernel. Appearance of 21 structures of the skull base and maxillo facial region that are known to be challenging for MSCT have been rated on a 4 point scale by two independent raters (S.B., A.S.) for each skull and side. T-test statistic was used.

The comparison revealed a significantly (p=0,02) higher average sum score for fpVCT (28,8) then for MSCT (19,8). Structures such as the stapedial muscle and the bony walls of the facial nerve canal towards the middle ear were much crisper displayed in fpVCT. The amount of pseudo-dehiscences and pseudo-foraminae were starkly reduced in fpVCT. FpVCT showed more streak artifacts.

Using fpVCT imaging of the whole human skull base and maxillo facial region is possible and the image quality is not only sufficient but superior to MSCT when it comes to small high contrast structures. Thus, fpVCT could be highly beneficial for various diagnostic challenges in ENT and maxillo facial surgery e.g. dehiscence diagnostic and certain applications such as surgical planning and intraoperative navigation. C-arm based fpVCT could become available for intra operative imaging during skull base or ENT surgery.

Bartling, S, Majdani, O, Schlesinger, A, Dullin, C, Grabbe, E, Becker, H, Lenarz, T, et al, , First Results of Flat-panel-based Volume-CT (fpVCT) of the WHOLE Human Skull Base and Maxillo Facial Region and Comparison with MSCT.  Radiological Society of North America 2005 Scientific Assembly and Annual Meeting, November 27 - December 2, 2005 ,Chicago IL. http://archive.rsna.org/2005/4410091.html