A multi-modality medical imaging head and neck phantom: Part 2. Medical imaging. (April 2022)

• Record Type: Journal Article
• Authors: De Deene, Yves; Wheatley, Morgan; Greig, Thomas; Hayes, Daniel; Ryder, William; Loh, Han
• Is Part Of: Physica medica. Volume 96(2022)
• Page Start: 179
• Page End: 197
• Publication Date: 2022-04
• Subjects: Anthropomorphic phantom -- MRI phantom -- 3D radiation dosimetry -- Arterial Spin Labeling -- DCE MRI -- 3D gel dosimetry -- Ultrasound; AIF, cAIF Arterial Input Function, carotid Arterial Input Function -- BW Receive Bandwidth -- Cp Plasma concentration -- DCE Dynamic Contrast Enhanced -- DTI Diffusion Tensor Imaging -- ETM Extended Tofts Model -- FA Flip Angle -- FOV Field-Of-View -- GM Grey (Brain) Matter -- HU Hounsfield Units -- ICA Internal Carotid -- IVIM IntraVoxel Incoherent Motion -- JV Jugular Vein -- Ktrans Volume transfer coefficient -- MIP Maximum Intensity Profile -- MPRAGE Magnetization Prepared RApid Gradient Echo -- MS Matrix Size -- νe, νp extravascular space volume fraction, plasma space volume fraction -- ROI Region Of Interest -- R1, R2 longitudinal NMR relaxation rate (= 1/T1), tranverse relaxation rate (= 1/T2) -- R2f, R2s transverse NMR relaxation rate of the fast relaxing component, transverse NMR relaxation rate of the slow relaxing component -- ρHw proton density relative to that of water -- TSE Turbo Spin Echo (equivalent to Fast Spin Echo (FSE) and RApid Acquisition with Relaxation Enhancement (RARE)) -- ΔTE Echo Time Spacing (time between two successive spin echoes in TSE) -- UTE MRI Ultrashort Echo Time Magnetic Resonance Imaging; Medical physics -- Periodicals; Biophysics -- Periodicals; Biophysics -- Periodicals; Imagerie médicale -- Périodiques; Radiothérapie -- Périodiques; Rayons X -- Sécurité -- Mesures -- Périodiques; Physique -- Périodiques; Médecine -- Périodiques; 610.153
• DOI: 10.1016/j.ejmp.2022.02.009
• Languages: English
• ISSNs: 1120-1797

Abstract

Graphical abstract: Highlights: Multi-modality medical imaging Head & Neck phantom for quality assurance, experimental testing and training. Realistic vasculature and micro-vasculature hardware and software model for flow imaging and perfusion scanning. Physiologically realistic pressure-flow dynamics. Tissue equivalent structures. Demonstration for MRI, X-ray CT, Doppler Ultrasound and Nuclear Medicine. Abstract: The head and neck phantom discussed in an accompanying paper (part 1), is imaged with MRI, X-ray CT, PET and ultrasound. MRI scans show a distinct image contrast between the brain compartment and other anatomical regions of the head. The silicone matrix that was used to create a porous brain compartment has a relatively high proton density and a spin–spin relaxation time (T2 ) that is long enough to provide an MRI signal. While the longitudinal magnetization was found to recover according to a mono-exponential, a bi-exponential decay was observed for the transverse relaxation with a slow T2 relaxation component corresponding to the perfusate and a fast T2 relaxation component corresponding to the silicone. The fraction of the slow T2 relaxation component increases upon perfusion. A dynamic contrast enhanced (DCE) MRI experiment is conducted in which the injection rate of the contrast agent is varied. Parametric DCE maps are created and reveal regional differences in contrast agent kinetics as a result of differences in porosity. The skull, vertebra and the brain compartment are clearly visible on X-ray CT. Dynamic PET scanning has been performed while the carotic arterial input function is monitored by use of a Geiger-Müller counter. Similar regions of perfusion are found in the PET study as in the DCE MRI study. By doping the perfusate with a lipid micelle emulsion, the phantom is applicable for carotic Doppler ultrasound demonstration and validation.