Purpose

The purpose of this poster is to present a topographic overview of the undisturbed anatomical interrelationships of the fetal bowhead whale (Balaena mysticetus). Excluding any three-dimensional dissection, multiplanar images, consisting of transverse, sagittal, and dorsal images are presented for each of three general body areas of the bowhead whale fetus. They are, the Head and Neck, the Thorax, and the Abdomen and Tail.

Methods and Specimens

Two fetal bowhead whales, specimen No. 86WW1F (30 cm) and specimen No. 88KKIF (1.5 m), have been imaged using the technique of magnetic resonance imaging. Specimen No. 86WWIF, discovered during routine subsistence slaughter of a mature female bowhead whale, was placed in 4% BNF fixative soon after it was taken from its mother. Specimen No. 88KKIF, along with part of the umbilicus, was fresh-frozen at the time of subsistence slaughter. The latter specimen remained frozen until it was received by the School of Veterinary Medicine at Louisiana State University in Baton Rouge, Louisiana.

Magnetic resonance imaging of both fetal specimens, took place in New Orleans, Louisiana at The Imaging Center in cooperation with Dr. Charles Aprill. For poster presentation, images were selected and photographed to obtain low-contrast, 4" x 5" black & white negatives. Negatives were contact printed on Kodak Velox, F2 photographic paper, trimmed, arranged sequentially according to body areas, and mounted on white foam-core presentation board.

Results

More than one-thousand images have been produced using the technique of magnetic resonance imaging in the two fetal bowhead whale specimens. All images have been read and evaluated. From these, a limited number have been selected to illustrate the undisturbed anatomical overview of the fetal bowhead whale. To facilitate understanding, images have been grouped according to body area and placed in sequential order. Each figure has been labeled and annotated to aid moving forward and backward through the specimen. Follow-up correlation studies have been conducted using 2.5 cm thick transverse sections of specimen No. 88KKIF. The latter studies have permitted confirmation of details found within the magnetic resonance images.

In addition to demonstrating excellent anatomical relationships and detail, these studies have provided technical evidence of image quality regarding the suitability of previously fixed and fresh-frozen specimens. A small problem exists with the interface formed during voluntary thawing of the frozen materials. Immersion-fixed and/or better still, perfusion-fixed materials are quite satisfactory and yield excellent images using magnetic resonance techniques.