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Results

      All abdominal organs having elastomechanical and visual influences on the surgical area were segmented by using the aforementioned technique. The abdominal cavity to be reconstructed was divided into 11 organ groups. Each organ group was delegated to a medical student, who had completed the educational requirements in anatomy. The work was done as an extracurricular promotional project. The criteria for the group division were as follows:      In addition to the selected organ groups, we also defined a hypothetical border of the abdominal cavity, shown on Figure 2 . This "virtual organ" represents the pneumoperitoneum. Before the start of each laparoscopy, this cavity would be filled with several liters of CO2 gas and would be allowed to expand between the abdominal wall and the intestines. The surgeon would then use an opening in the abdominal wall to insert the endoscope and the instruments. The created borders of the pneumoperitoneum were entirely speculative. They were set as a result of a knowledge based guess, based on information gathered from numerous surgical photographs and anatomical studies. The results will allow to simplify the simulation of the pneumoperitoneum, a significant step in creating an anatomical base for a laparoscopy.

     Due to the selected segmentation technique we experienced two recurring problems during organ definition, which needed to be solved;

     An important technical aid was the possibility for fast comparison between the current slice and the more cranial or caudal situated slices overlayed with the previously defined contours. One could use this option with single images or for quick pass throughs. Another essential help was the comparison of the cryosectional images to cadavers which were still intact, and studying published literature. As a result, we could establish borders in almost every case based on anatomical and topographical information. Although we rarely had to establish arbitrary borders, a detailed account of the encountered problems with the selected solutions and justifications has been compiled.

Esophagus, Stomach, and Duodenum
     There were no noteworthy variations or abnormalities. The Esophagus goes through the diaphragm for a total of 3.7 cm. The resulting pars abdominalis measures 2.3 cm. The stomach which looks flat and elongated is according to a cranio-caudal measurement 24.5 cm long, with an estimated volume of about 1000 cm3. The walls of the stomach have an average thickness of 3 mm, in the pyloric region the thickness increases to 7 mm. The duodenum is estimated to be 23.5 cm with good replications of the pars superior, descendens, horizontalis and ascendens.

Jejunum and Ileum
     There were no noteworthy variations or abnormalities. We estimated this organ to be approximately 9.5 m long. The length, which was on the upper limits (normal 4-10 meters), could be attributed to the postmortal tonus lost of the intestinal walls. We identified 25 coils. The small intestines, to the right of the spine, were very compact and were pushed to the left side of the cecum. As we expected, the ventral intestinal tract was clearly more bloated than the dorsal tract. This was the result of gas collecting in a cadaver lying down. The valvula ileocoecalis ran into the cecum at a right angle. This occurs in 55% of the cases, according to our literature references. Meckel's diverticulum could not be detected.

Colon
     The cecum was enlarged due to stool. The colon transversum ran steeply down from the flexura coli dextra and into the pelvis minor ( Figure 3 ). It took a sharp turn and continued up to the flexura coli sinistra. At the colon descendens and the sigma around 30 diverticula were present ( Figure 4 ). No abscesses were found around these diverticula.

Liver, Gallbladder, and Ductus cysticus
     There were no noteworthy variations or abnormalities. The division of the cadaver into different blocks was quite apparent here. The missing slices could not be segmented. The volume of the liver which was about 2300 cm3 seems to be enlarged, as it would correspond to a body weight of 123-130 kg. The liver carried the impressions of the neighboring organs. As expected, the gallbladder was located in the fossa vesicae felleae, and it did not exceed the caudal edge of the liver. It appeared to be more flabby than firm. The ductus cysticus melted with the d. hepaticus into the d. choledochus. It continued and expanded into the ampulla hepatopancreatica and ran into the duodenum. The segmentation results are illustrated on Figure 5 .

Pancreas, Spleen
     There were no major macroscopic abnormalities. We experienced difficulties in establishing the correct borders for the pancreas and its surroundings. The s-shaped pancreas leaned toward the spleen without making actual contact to it. The ductus choledochus ran into a canal along the rear wall. It was connected to pancreas tissue and joined the approximately 18 cm long ductus pancreaticus major to the ampulla hepatopancreatica which joined the duodenum at the papilla duodeni major. In addition, a ductus pancreaticus accessorius could be segmented. This was situated near the ampulla hepatopancreatica. There were no abnormalities found in the spleen, no double or accessory spleen.

Omentum majus
     The main problem was establishing borders between this fold and the neighboring fatty tissue. The omentum majus of the Visible Woman was very distinct, fatty and had a volume of approximately 625 cm3. It extended into the lower pelvis and covered all of the intestines. It expanded cranially over the lower edge of the liver, the stomach and the spleen. There was also a hole, approximately 15 cm3 and situated directly ventral of the flexura coli dextra ( Figure 6 ). In order to maintain the continuity of this organ, the hole was segmented as a peritoneal duplicate.

Kidneys, Urinary Tract, and Vagina
     All of the organs in this group could be segmented ( Figure 7 ). Aside from a few minor variations, these anatomically and topographically inconspicuous organs exhibited no signs of pathologies. Five simple, subcapular cysts with diameters varying from 3-6 mm were found in the left kidney. A single cyst with 5 mm diameter was found in the right kidney. Both Aa. renales gave off a high polartery which entered the renal hilus from the cranial side. The bladder was pushed in at its facies anterior by a 9 mm long section of bone dorsal, cranial and medial. It ran from the ramus superior ossis pubis down the left side. Caudal to the vagina, a muscular mass was found. It pushed the vaginal lumen dorsal. This structure is most probably the columna rugarum posterior and a section of the m. transversus perinei profundus.

Arteries and Veins of the Pelvis minor
     The effects of arteriolosclerosis were clearly seen. The following anatomical variations have been detected:

Skeleton and Muscle Tissue
     The missing slices between the abdominal and thoracic blocks cuts through the 10th chest vertebra. In the database, the gap should be wide enough in order to prohibit distortions. The height of the thoracic vertebrae from VIII to XI led us to believe that possibly too many slices were added. Vertebra thoracalis VIII: 16 mm, IX: 18 mm, X: 25 mm! (20 mm were expected), XI: 22 mm ( Figure 10 ). As a result, we estimated that the gap was about 5 mm too wide. The dextral costal IV and V exhibited a black-brownish gap. The perifocal zone did not show any virtual reaction whatsoever. It could be the result of a postmortem fracture. The discus intervertebralis between vertebrae lumbales I and II had an osteophytic bridge caudo-ventral to the right of vertebra I, and cranio-ventral to the right of vertebra II ( Figure 11). Another spondylophyte was found caudo-ventral to the right of vertebra lumbalis II. In the iliosacral joint there was a bony projection which came out of the Os sacrum. A connection to the Os coxae sinistrae could not be positively identified.


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