- Open Access
Magnetic resonance imaging (MRI) has failed to distinguish between smaller gut regions and larger haemal sinuses in sea urchins (Echinodermata: Echinoidea)
© Holland and Ghiselin; licensee BioMed Central Ltd. 2009
- Received: 17 February 2009
- Accepted: 13 July 2009
- Published: 13 July 2009
A response to Ziegler A, Faber C, Mueller S, Bartolomaeus T: Systematic comparison and reconstruction of sea urchin (Echinoidea) internal anatomy: a novel approach using magnetic resonance imaging. BMC Biol 2008, 6: 33.
- Internal Anatomy
- Modern Imaging Technique
- Marginal Sinus
- Comparative Morphological Analysis
- Magnetic Resonance Imaging Section
Magnetic resonance imaging: a powerful tool in comparative morphology despite initial interpretative difficulties
Alexander Ziegler* 1, Thomas Bartolomaeus2
1Institut für Immungenetik, Charité-Universitätsmedizin Berlin, Berlin, Germany
2Institut für Evolutionsbiologie und Zooökologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
Drs. Holland and Ghiselin have convincingly pointed out, initially as a direct response to Drs. Campos and Moura , and now in the correspondence above, that Pedinidae and Diadematidae are indeed characterized by the presence of a siphonal groove rather than a siphon. Their data effectively challenge our interpretation of these structures in Caenopedina mirabilis (Pedinidae) and Diadema savignyi (Diadematidae), as presented in our BMC Biology paper [, Fig. 3]. The images of 3D models depicted in this article were based exclusively on datasets generated using magnetic resonance imaging (MRI). We are happy to see these points of interpretation corrected and this issue of minor controversy resolved.
For some analyses, however, invasive techniques are not appropriate. Possibly, the most important attribute of modern imaging techniques is their non-invasive nature, which permits the study of rare specimens and the elucidation of the original topography of organ systems. This is of particular importance in organisms whose soft tissue structures are enclosed by skeletal elements, as is the case in sea urchins.
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