title: Renal contrast microangiography with synchrotron radiation: a novel method for visualizing structures within nephrons in vivo.
abstract: Background No non-invasive method of observing renal microcirculation in vivo has been established as yet. Although angiography is considered to be ideally suited for the purpose, conventional X-rays cannot be used to image structures smaller than 100 µm. Purpose To develop a method for visualizing the renal arterioles, glomeruli, and proximal tubules of rats in vivo making use of synchrotron radiation. Material and Methods Male Wistar rats were anesthetized, and a catheter was inserted via laparotomy into the abdominal aorta with its tip placed above the renal arteries. The rats were paralyzed with a neuromuscular blocking agent and mechanically ventilated. An inorganic iodine contrast medium was injected via the catheter. The SR derived X-rays transmitted through the subjects were recorded with a CCD camera. Two-dimensional images with a pixel size of 9 µm were obtained. The exposure time was fixed at 50 ms, with a maximum acquisition rate of three images/s. Results Renal arterioles as small as 18 µm in diameter, glomeruli with an average diameter of 173 ± 21 µm, as well as proximal tubules, were clearly visualized. In addition, glomerular density at the peripheral renal cortex was measurable. Conclusion Rat renal microcirculation could be successfully observed in real-time, without exteriorization of the kidney in this study.
authors.affiliation: 1 Emergency and Critical Care Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Miya
authors.affiliation: 2 Department of Health, Tsukuba University of Technology, Tsukuba, Ibaraki, Japan.
authors.forename: Shonosuke
authors.initials: S
authors.lastname: Matsushita
authors.affiliation: 3 Photon Factory, High Energy Accelerator Research Organization, Tsukuba, Ibaraki, Japan.
authors.forename: Kazuyuki
authors.initials: K
authors.lastname: Hyodo
authors.affiliation: 4 Cardiovascular Surgery, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Chiho
authors.initials: C
authors.lastname: Tokunaga
authors.affiliation: 4 Cardiovascular Surgery, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Sakamoto
authors.affiliation: 1 Emergency and Critical Care Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Taro
authors.initials: T
authors.lastname: Mizutani
authors.affiliation: 4 Cardiovascular Surgery, University of Tsukuba, Tsukuba, Ibaraki, Japan.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Hiramatsu
mesh_terms: D000792:Angiography / Q000295:instrumentation / Q000379:methods*; D000818:Animals; D001160:Arterioles / Q000000981:diagnostic imaging; D003287:Contrast Media; D007089:Image Enhancement / Q000295:instrumentation / Q000379:methods; D007668:Kidney / Q000098:blood supply / Q000000981:diagnostic imaging; D008297:Male; D008833:Microcirculation; D009399:Nephrons / Q000098:blood supply* / Q000000981:diagnostic imaging*; D011859:Radiography / Q000295:instrumentation / Q000379:methods*; D051381:Rats; D017208:Rats, Wistar; D017356:Synchrotrons
chemical_list: D003287:Contrast Media
keywords: Synchrotron radiation; angiography; kidney