ANATOMICAL STUDIES USING COMPUTED TOMOGRAPHY (CT)

Images are copyright of Alexander M. Costidis. The images are provided with express permission for Dr. Sophie Dennison DACVR to display them on her website (www.marinemammalradiology.com) in connection to the CRC Handbook of Marine Mammal Medicine.

Images MAY NOT be copied, reproduced or shown outside of this website without permission from Dr. Costidis.

Fig 1: Ventral view of a reconstruction from a postmortem arterial angiographic study of a minke whale (Balaenoptera acutorostrata). Threshold segmentation was used to visualize arterial structures in red and bony structures in white/gray. Note the two dentaries of the mandible and the tympanoperiotic bones appear red due to their high density.

Fig 2: Dorsal view of a reconstruction from a postmortem arterial angiographic study of a minke whale (Balaenoptera acutorostrata). Threshold segmentation was used to visualize arterial structures in red. Epidural and carotid retia perfused unilaterally on left side creating the asymmetry seen along the cervical midline. Note the two dentaries of the mandible and the tympanoperiotic bones appear red due to their high density.

Fig 3: Medial view of a mid-sagittally sectioned reconstruction from a postmortem arterial angiographic study of a minke whale (Balaenoptera acutorostrata). Threshold segmentation was used to visualize arterial structures in red. Note the two dentaries of the mandible and the tympanoperiotic bones appear red due to their high density.

Fig 4: Ventral view of a maximum intensity projection from a postmortem arterial angiographic study of a Gervais’ beaked whale (Mesoplodon europaeus) calf. Threshold segmentation was used to visualize arterial structures in black. Note the two tympanoperiotic bones appear dark gray due to their high density. Incomplete arterial contrast perfusion occurred on the right (bottom) side of the head (maxillary artery) and thorax (supreme intercostal artery and thoracic rete) due to postmortem blood clots.

Fig 5: Lateral view of a maximum intensity projection from a postmortem arterial angiographic study of a Gervais’ beaked whale (Mesoplodon europaeus) calf. Threshold segmentation was used to visualize arterial structures in black. Note the tympanoperiotic bone appears dark gray due to itsr high density. The extensive thoracic rete is visible in the thorax dorsal to the heart and aorta. The thoracic rete is seen connecting to the epidural rete to supply blood to the brain.

Fig 6: Lateral view of a reconstruction from a postmortem venous angiographic study of a Florida manatee (Trichechus manatus latirostris). Threshold and manual segmentation were used to visualize venous structures in blue and bony structures in gray. Note the extensive venous investment of the rostrum and lips as well as the masseter muscle.

Fig 7: Dorsal view of a maximum intensity projection from a postmortem venous angiographic study of a Florida manatee (Trichechus manatus latirostris). Threshold segmentation was used to visualize venous structures in black and bony structures in gray. Note the extensive venous investment of the rostrum and lips. The large tight bundle of small caliber veins extending through the rostrum to the lips is an extensive arteriovenous structure consistent with a counter current vascular bundle. The arterial portions of the epidural rete are visible along the cervical midline as a faint network of small caliber veins.

Fig 8: Lateral view of a maximum intensity projection from a postmortem arterial angiographic study of a bottlenose dolphin (Tursiops truncatus). Threshold segmentation was used to visualize arterial structures in black and bony structures in gray. Note the extensive arterial investment of the thoracic and epidural retia seen connecting to the spinal meningeal arteries and supplying blood to the brain. The maxillary artery and its tributaries are seen supplying the mandible, rostrum and melon.