Helmut R. Ringl MD, Presenter: Nothing to Disclose

Ruediger Egbert Schernthaner MD, Abstract Co-Author: Nothing to Disclose

Marcel O. Philipp MD, Abstract Co-Author: Nothing to Disclose

Sylvia Metz-Schimmerl MD, Abstract Co-Author: Nothing to Disclose

Christian J. Herold MD, Abstract Co-Author: Nothing to Disclose

Wolfgang Schima MD, Abstract Co-Author: Nothing to Disclose

Christian Czerny MD, Abstract Co-Author: Nothing to Disclose

Michael Weber PhD, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

To assess retrospectively the detection rate of skull base fractures of three different three dimensional reconstruction methods of cranial CT examinations of trauma patients

132 emergency cranial CT scans of patients with severe head trauma were subjected to three dimensional reconstruction of the skullbase, using Maximum Intensity Projection (MIP) , Solid (sVRT) and Transparent Volume Rendering (tVRT). For each patient a series of 60 thick slab paraxial 3D- reconstructed images rotating around the medial-lateral axis and another series rotating around the anterior-posterior axis was rendered. Images were obtained with a 4 row multidetector CT (Siemens Somatom Plus 4; slice-thickness 1.25 mm). Three radiologists independently evaluated all cases in three different sessions separated at least one month from each other. The patient name was blinded, patient order and reconstruction mode was randomized. Three month later one of the readers evaluated all cases on high resolution multiplanar reformats (MPR) in three dimensions. The results were compared to a gold standard built by two experts from all prior reading results, all reconstructions and high resolution MPRs in three dimensions. They found a total of 189 fractures.    

Solid VRTs showed a detection rate of 38% (72), 42% (80) and 34% (65) for reader a, b, and c respectively; 33% (63), 38% (71) and 34% (64) for transparent VRTs and 54% (102), 61% (116) and 59% (111) for MIPs. Reading MPRs only, the detection rate was 69 % (130). Interestingly, MIP visualized 39 different fractures (21%) compared to MPR.

For the detection of skull base fractures, MIP reconstruction outperforms solid and semitransparent VRT by far. It reveals 21% fractures that are not seen if MPRs are viewed alone. Thus, additionally to the obligatory MPRs, we recommend to read MIP reconstruction to improve the fracture detection rate of the skull base.

Association of skull base fractures with the sinuses, nerval and vascular foramina of skull base require adequate therapy.  Additional MIP recontructions significantly improve fracture detection. 

Ringl, H, Schernthaner, R, Philipp, M, Metz-Schimmerl, S, Herold, C, Schima, W, Czerny, C, Weber, M, et al, , Three-dimensional Rendering of Multidetector-row CT Data of the Skull Base of Trauma Patients: Maximum Intensity Projection (MIP) versus Solid and Transparent Volume Rendering (VRT).  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6010954.html