*Review* **Cyclodextrin-Based Contrast Agents for Medical Imaging**

#### **Yurii Shepelytskyi 1,2 , Camryn J. Newman <sup>3</sup> , Vira Grynko 1,2 , Lauren E. Seveney <sup>4</sup> , Brenton DeBoef <sup>4</sup> , Francis T. Hane 2,5 and Mitchell S. Albert 2,5,6,\***


Academic Editors: Marina Isidori, Margherita Lavorgna and Rosa Iacovino Received: 30 October 2020; Accepted: 26 November 2020; Published: 27 November 2020

**Abstract:** Cyclodextrins (CDs) are naturally occurring cyclic oligosaccharides consisting of multiple glucose subunits. CDs are widely used in host–guest chemistry and biochemistry due to their structural advantages, biocompatibility, and ability to form inclusion complexes. Recently, CDs have become of high interest in the field of medical imaging as a potential scaffold for the development of a large variety of the contrast agents suitable for magnetic resonance imaging, ultrasound imaging, photoacoustic imaging, positron emission tomography, single photon emission computed tomography, and computed tomography. The aim of this review is to summarize and highlight the achievements in the field of cyclodextrin-based contrast agents for medical imaging.

**Keywords:** medical imaging; contrast agents; α-cyclodextrin; β-cyclodextrin; γ-cyclodextrin; MRI; PET; CT; SPECT; PAI
