Co-registration of nuclear scintigraphic and magnetic resonance data of the equine foot: A multi-modality imaging ‘proof of principle’ study

Abstract

SummaryThree-dimensional (3D) multi-modality imaging (MMI) is frequently used in human medicine but its use in equine diagnostic imaging has yet to be validated. In a proof of principle manner, this study aimed to evaluate 3D MMI co-registration of magnetic resonance (MR) and scintigraphic data for the assessment of equine foot injury. A multi-compartment equine foot phantom was designed and constructed using the Stereolithography Additive Manufacturing process. Images were obtained by MR imaging and by scintigraphy using different copper sulphate concentrations (CuSO 4 ) (for MR imaging) or radiopharmaceutical concentrations (for scintigraphy) respectively, which were introduced into the compartments of the foot phantom to mimic the normal limb appearance for each image modality. Lesions at specific locations were simulated by introducing increased concentrations of CuSO 4 or radiopharmaceutical into the appropriate compartments. 3D scintigraphic data was obtained by rotating the phantom through 360° with dynamic acquisitions performed every 3°. The MR and scintigraphy data were co-registered using proprietary software. MR image assessment showed the individual compartments of the phantom, and the location of a simulated lesion. The presence of increased radiopharmaceutical concentration was clear on scintigraphic images, but anatomical resolution was less clear than MR images. Accurate detection and localisation of simulated lesions were best with 3D coregisteration of the MR and scintigraphic images. In the future, 3D co-registration of scintigraphic and MR images may prove clinically useful to localise and differentiate between active and inactive injury. Issues relating to the practical implementation of 3D MMI in the standing sedated horse are discussed.Keywords: horse / multi-modality imaging / scintigraphy / magnetic resonance imaging / diagnostic imaging Bildregistrierung von Daten aus der nuklearen Szintigraphie und Magnetresonanztomographie des Perdefußes: Eine multimodale bildgebende 'proof of principle' Studie Die drei-dimensionale (3D) multi-modale Bildgebung wird in der Humanmedizin häufig angewandt, ihre Bedeutung in der equinen Bildgebung muss jedoch erst evaluiert werden. Ziel der Studie ist die Untersuchung der 3D multimodalen diagnostischen Bildregistrierung von Daten aus Szintigraphie und Magnetresonanztomographie (MRT) für die Beurteilung von Verletzungen der Pferdezehe. Mit Hilfe des stereolithographischen Manufakturprozesses wurde ein Multikompartment-Modell der Pferdezehe entworfen und hergestellt. Bildgebende Untersuchungen wurde mittels MRT und Szintigraphie durchgeführt. Um ein physiologisches Erscheinungsbild der Zehe für die jeweilige bildgebende Methode zu gewinnen wurden verschiedene Kupfersulfat-(CuSO 4 ) (für MRT) und radiopharmazeutische Konzentrationen (für Szintigraphie) in das Modell injiziert. Läsionen an spezifischen Lokalisationen wurden durch Injektion größerer Konzentrationen von CuSO 4 oder Radiopharmazeutika in den verschiedenen Departments simuliert. Die 3D-Szintigra...