Moving and fusion of the pancreatic buds in the rat embryos during the embryonic period (carnegie stages 13-17) by a three-dimensional computer-assisted reconstruction.

AIM: The purpose of the present study was to illustrate the modality of rotation of ventral and dorsal pancreatic buds by three-dimensional (3D) reconstructions in the rat embryos, during the Carnegie stages 13-17. MATERIALS AND METHODS: Serial sections of thirty rat embryos stages 13-17, were observed. The embryos were fixed in Bouin's solution, dehydrated, and paraffin embedded. The sections, 7 µm thick, were cut in longitudinal or transverse planes and were stained alternately by hematoxylin-eosin or Heindenhain' azan. The images were digitalized by Canon Camera 350 EOS D. The 3D reconstruction was performed by computer using Cell Image Analyser software. RESULTS: The two pancreatic buds ventral and dorsal, were clearly identified at stage 13, in anterior and posterior position, respectively, in relation to the duodenum. In stage 15, the duodenum started its rotation of 90° clockwise. The ventral bud moved 90° from the midline to the right. In stage 16, the ventral pancreas continued its rotation until 180° in posterior position behind the duodenum. In stage 17, the two pancreatic buds were related closely to the ventral part of the portal vein. The two buds began to merge. The anterior face of the pancreas's head was arising from the dorsal pancreatic bud. The rest of the head including the omental tuberosity and the uncinate process emanated from the ventral pancreatic bud. CONCLUSION: The use of 3D reconstruction of the pancreas of rat embryos illustrates the modality of the two pancreatic buds rotation and fusion. This method explains the final position of the pancreas.

[Polysplenia syndrome: two cases in adults revealed by biliary and pancreatic malformations]. / Syndrome de polysplénie: à propos de deux cas révélés chez l'adulte par des malformations biliaires et pancréatiques.

Polysplenia Syndrome (PS) associates multiple spleens with other malformations usually cardiac, vascular, visceral and biliary. The diversity of these malformations and their embryological mechanisms are described in relation to two cases of PS that were diagnosed in adults.

MRI thermodosimetry in laser-induced interstitial thermotherapy.

BACKGROUND AND OBJECTIVES: The aim of this study was to establish a correlation between a thermal measurement and a magnetic resonance imaging (MRI) signal during laser-induced interstitial thermotherapy (LITT) in liver. STUDY DESIGN/MATERIALS AND METHODS: Pig liver was irradiated for 15 minutes with a diode laser at two different powers, 0.5 W (450 J) and 1.5 W (1,350 J). Tissue temperature was monitored every 20 seconds using thermocouples. Thermosensitive MRI sequences (T(1)-weighted Turbo-Flash) were acquired with the same irradiation parameters. Correlation between MRI signals (SI) and temperature measures was defined at two different distances from the fiber (5 and 10 mm). RESULTS: At 0.5 W, temperatures rose progressively up to a maximum increase of 9.5 degrees C at 5 mm and 4 degrees C at 10 mm after 15 minutes. The corresponding MRI signal decreased progressively to -27.6 SI at 5 mm and -18.5 SI at 10 mm. At 1.5 W, temperatures rose dramatically at 5 mm, reaching a plateau. The temperature elevation measured at the end of the irradiation was of 30 degrees C whereas at 10 mm it was only 14.5 degrees C. The MRI signal varied accordingly, remaining inversely proportional to temperature (-76 SI at 5 mm and -35.5 SI at 10 mm). CONCLUSIONS: An inversely proportional relationship was observed between MRI signal in sequential Turbo-Flash and temperature. MRI should allow to analyze heat diffusion in the liver, and thus to monitor real-time LITT treatments.