CT: a new nondestructive method for visualizing and characterizing ancient Roman glass fragments in situ in blocks of soil.

A rare, complete ancient Roman burial site was discovered near the Dutch village of Bocholtz. In addition to many preserved grave offerings, there were countless fragments of deteriorated glass objects still buried in the ground. This glass was in very poor condition, however, and there was no possibility of excavating it directly. Instead, archeologists working at the site decided to dig up blocks of soil containing the glass fragments. High-resolution spiral computed tomography (CT) with multiplanar reformation, shaded-surface-display rendering, and volume rendering was used to obtain detailed information about the position, number, and form of the deteriorated glass fragments. CT-guided removal of the soil made it possible to restore some of the objects excavated from the blocks. In five of the 14 excavated objects, a correct Isings classification could be made based on the CT findings. In addition, CT was very important for the reconstruction of the layout of the burial chamber, the compilation of a list of grave contents, and the positioning of these contents within the chamber.

CT colonography interpretation times: effect of reader experience, fatigue, and scan findings in a multi-centre setting.

Our purpose was to assess the effect of reader experience, fatigue, and scan findings on interpretation time for CT colonography. Nine radiologists (experienced in CT colonography); nine radiologists and ten technicians (both groups trained using 50 validated examinations) read 40 cases (50% abnormal) under controlled conditions. Individual interpretation times for each case were recorded, and differences between groups determined. Multi-level linear regression was used to investigate effect of scan category (normal or abnormal) and observer fatigue on interpretation times. Experienced radiologists (mean time 10.9 min, SD 5.2) reported significantly faster than less experienced radiologists and technicians; odds ratios of reporting times 1.4 (CI 1.1, 1.8) and 1.6 (1.3, 2.0), respectively (P

Polyp measurement and size categorisation by CT colonography: effect of observer experience in a multi-centre setting.

The extent measurement error on CT colonography influences polyp categorisation according to established management guidelines is studied using twenty-eight observers of varying experience to classify polyps seen at CT colonography as either 'medium' (maximal diameter 6-9 mm) or 'large' (maximal diameter 10 mm or larger). Comparison was then made with the reference diameter obtained in each patient via colonoscopy. The Bland-Altman method was used to assess agreement between observer measurements and colonoscopy, and differences in measurement and categorisation was assessed using Kruskal-Wallis and Chi-squared test statistics respectively. Observer measurements on average underestimated the diameter of polyps when compared to the reference value, by approximately 2-3 mm, irrespective of observer experience. Ninety-five percent limits of agreement were relatively wide for all observer groups, and had sufficient span to encompass different size categories for polyps. There were 167 polyp observations and 135 (81%) were correctly categorised. Of the 32 observations that were miscategorised, 5 (16%) were overestimations and 27 (84%) were underestimations (i.e. large polyps misclassified as medium). Caution should be exercised for polyps whose colonographic diameter is below but close to the 1-cm boundary threshold in order to avoid potential miscategorisation of advanced adenomas.

High-resolution spiral computed tomography with multiplanar reformatting, 3D surface- and volume rendering: a non-destructive method to visualize ancient Egyptian mummification techniques.

Ancient Egyptians used mummification techniques to prevent their deceased from decay. This study evaluates the potential of computed tomography (CT) in determining these techniques in a non-destructive way. Twenty-five mummies were studied by using high-resolution spiral CT, 1mm slice thickness for the head and 3mm slice thickness for the rest of the body. Images were reconstructed with 3D, multiplanar reformatting and volume rendering. In all cases the used mummification techniques could be reconstructed. The way the brain was removed, the presence of chemicals, like resin and natron, could be detected and the way the intestines were handled could be made visible. The use of CT is indispensable as a non-destructive method in the reconstruction of mummification techniques.