title: A new magnetic resonance-based technique for high-resolution quantification of amorphous and quasi-amorphous structures.
abstract: We present a novel, high-resolution magnetic resonance technique, fine structure analysis (FSA) for the quantification and analysis of amorphous and quasi-amorphous biological structures. The one-dimensional technique is introduced mathematically and then applied to one simulated phantom, two physical phantoms and a set of ex vivo biological samples, scanned with interpoint spacings of 0.0038-0.195 mm and cross-sectional sizes of 3 × 3 or 5 × 5 mm. The simulated phantom and one of the physical phantoms consists of randomly arranged beads of known size in two and three dimensions, respectively. The second physical phantom was constructed by etching lines on Perspex. The ex vivo samples are human bone specimens. We show that for all three phantoms, the FSA technique is able to elucidate the average spacing of the structures present within each sample using structural spectroscopy, the smallest of which was 180 µm in size. We further show that in samples of trabecular bone, FSA is able to produce comparable results to micro-computed tomography, the current gold standard for measuring bone microstructure, but without the need for ionizing radiation. Many biological structures are too small to be captured by conventional, clinically deployed medical imaging techniques. FSA has the potential for use in the analysis of pathologies where such small-scale repeating structures are disrupted or their size, and spacing is otherwise altered.
authors.affiliation: Acuitas Medical Ltd, 8 Technium 1, Kings Road, Swansea SA1 8PH, UK james.m.rafferty@gmail.com.
authors.forename: James
authors.identifier: 0000-0002-1667-7265
authors.initials: J
authors.lastname: Rafferty
authors.affiliation: Acuitas Medical Ltd, 8 Technium 1, Kings Road, Swansea SA1 8PH, UK.
authors.forename: Lance
authors.initials: L
authors.lastname: Farr
authors.affiliation: Cbrite Inc., 421 Pine Avenue, Goleta, CA 93117, USA.
authors.forename: Tim
authors.initials: T
authors.lastname: James
authors.affiliation: Vareda Engineering Inc., 144 Santa Felicia Drive, Goleta, CA 93117, USA.
authors.forename: David
authors.initials: D
authors.lastname: Chase
authors.affiliation: Acuitas Medical Ltd, 8 Technium 1, Kings Road, Swansea SA1 8PH, UK.
authors.forename: John
authors.initials: J
authors.lastname: Heinrich
authors.affiliation: Department of Oncology, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford OX3 7DQ, UK.
authors.forename: Michael
authors.initials: M
authors.lastname: Brady
mesh_terms: D000818:Animals; D001842:Bone and Bones / Q000000981:diagnostic imaging*; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods; D019047:Phantoms, Imaging
keywords: MRI; bone density; spectroscopy