Inside Out: Modern Imaging Techniques to Reveal Animal Anatomy

Abstract

Animal anatomy has traditionally relied on detailed dissections to produce anatomical illustrations, but modern imaging modalities, such as MRI and CT, now represent an enormous resource that allows for fast non-invasive visualizations of animal anatomy in living animals. These modalities also allow for creation of three-dimensional representations that can be of considerable value in the dissemination of anatomical studies. In this methodological review, we present our experiences using MRI, CT and μCT to create advanced representation of animal anatomy, including bones, inner organs and blood vessels in a variety of animals, including fish, amphibians, reptiles, mammals, and spiders. The images have a similar quality to most traditional anatomical drawings and are presented together with interactive movies of the anatomical structures, where the object can be viewed from different angles. Given that clinical scanners found in the majority of larger hospitals are fully suitable for these purposes, we encourage biologists to take advantage of these imaging techniques in creation of three-dimensional graphical representations of internal structures.

A novel, non-invasive and in vivo approach to determine morphometric data in starfish

“…For instance, Ruffins et al (2007) produced a 3D atlas for quail development at an isotropic voxel resolution of 40-70 μm 3 using an 11.7 T pre-clinical MRI system. In contrast, Lauridsen et al (2011) demonstrated that for the imaging of larger species clinical MRI at 1.5 T with 0.125 mm 3 spatial resolution is sufficient to display internal organs. Here, we present a non-invasive method to image and determine morphometric data on starfish in vivo using clinical MRI and subsequent 3D modeling.…”

Application of magnetic resonance imaging in zoology

“…Such approaches have been successfully applied to the study of anuran (Rubinsky et al 1994a), chelonian (Rubinsky et al 1994b;Stecyk et al 2009), hexapod (Hart et al 2003), and aranean (Pohlmann et al 2007;Lauridsen et al 2011) species. For example, the following morphological features could be depicted in the case of chelonians: carapace, gall bladder, gut, lungs, liver, plastron, and ventricle (Stecyk et al 2009).…”

Pulmonary compliance and lung volume varies with ecomorphology in anuran amphibians: implications for ventilatory-assisted lymph flux

“…In the present study, we found that the more terrestrial species (Bufonidae) have relatively larger lungs (cf. Lauridsen et al, 2011) than either Ranidae or Pipidae, and are likely to be more effective at transmitting pressure to the surrounding lymph sacs during lung inflation. Inflation of the lungs in anesthetized animals causes increases in pressure of the lymph sacs surrounding the lungs , thus lung inflation would facilitate movement of lymph toward the lymph hearts by 'squeezing' lymph sacs against the body wall.…”

“…Breviceps spp.) (see Hillman et al, 2009), and their lungs occupy a large fraction of the pleuroperitoneal space (Lauridsen et al, 2011). Thus, lung volume relative to body mass should be largest for globose anurans, but nevertheless large for other amphibians, although this has not been systematically examined.…”