Iodine-enhanced micro-CT imaging: Methodological refinements for the study of the soft-tissue anatomy of post-embryonic vertebrates
Article first published online: 30 JAN 2014
© 2014 Wiley Periodicals, Inc.
Journal of Experimental Zoology Part B: Molecular and Developmental Evolution
Volume 322, Issue 3, pages 166–176, May 2014
How to Cite
2014. Iodine-enhanced micro-CT imaging: Methodological refinements for the study of the soft-tissue anatomy of post-embryonic vertebrates. J. Exp. Zool. (Mol. Dev. Evol.) 322B:166–176., .
- Issue published online: 8 APR 2014
- Article first published online: 30 JAN 2014
- Manuscript Accepted: 6 JAN 2014
- Manuscript Revised: 29 OCT 2013
- Manuscript Received: 21 MAY 2013
- National Science Foundation. Grant Number: NSF IOS-0749750
- Stony Brook University Department of Anatomical Sciences
The now widespread use of non-destructive X-ray computed tomography (CT) and micro-CT (µCT) has greatly augmented our ability to comprehensively detail and quantify the internal hard-tissue anatomy of vertebrates. However, the utility of X-ray imaging for gaining similar insights into vertebrate soft-tissue anatomy has yet to be fully realized due to the naturally low X-ray absorption of non-mineralized tissues. In this study, we show how a wide diversity of soft-tissue structures within the vertebrate head—including muscles, glands, fat deposits, perichondria, dural venous sinuses, white and gray matter of the brain, as well as cranial nerves and associated ganglia—can be rapidly visualized in their natural relationships with extraordinary levels of detail using iodine-enhanced (i-e) µCT imaging. To date, Lugol's iodine solution (I2KI) has been used as a contrast agent for µCT imaging of small invertebrates, vertebrate embryos, and certain isolated parts of larger, post-embryonic vertebrates. These previous studies have all yielded promising results, but visualization of soft tissues in smaller invertebrate and embryonic vertebrate specimens has generally been more complete than that for larger, post-embryonic vertebrates. Our research builds on these previous studies by using high-energy µCT together with more highly concentrated I2KI solutions and longer staining times to optimize the imaging and differentiation of soft tissues within the heads of post-embryonic archosaurs (Alligator mississippiensis and Dromaius novaehollandiae). We systematically quantify the intensities of tissue staining, demonstrate the range of anatomical structures that can be visualized, and generate a partial three-dimensional reconstruction of alligator cephalic soft-tissue anatomy. J. Exp. Zool. (Mol. Dev. Evol.) 322B: 166–176, 2014. © 2014 Wiley Periodicals, Inc.