Figure 1.
State-of-the-art tri-modality fusion systems.
(a) The AnyScan system for clinical PET-SPECT-CT, and (b) the Albira system for preclinical PET-SPECT-CT ((a) and (b) from http://www.mediso.de/anyscan-sc.html and http://www.cmi-marketing.com/7modalities respectively, with the legends added by the authors of this article).
Figure 2.
Advanced Multimodality Image Guided Operating (AMIGO) Suite unveiled on May 4, 2011.
It is an integrated surgical and interventional environment as the translational test bed of the National Center for Image-Guided Therapy (NCIGT) at the Brigham and Women’s Hospital (BWH) and Harvard Medical School (from http://www.ncigt.org/pages/AMIGO, with the legends added by the authors of this paper).
Figure 3.
Ring-shaped design for omni-tomography.
(a) A 3D rendering of the top-level design, (b) a partial rendering, (c) an in-plane view, and (d) a through-plane view. There are two static rings and one rotating ring for omni-tomography. While the red C-arm is a permanent magnet and the yellow outer ring contains PET crystals, the blue ring supports a CT tube, a CT detector and a pair of SPECT camera. The blue CT-SPECT ring is on a green slip ring (like a large ball bearing) as the interface for power and data. The CT-SPECT ring, the slip-ring, and the PET ring all go through the magnetic poles.
Figure 4.
Generation of a locally homogeneous magnetic field.
(a) The magnetic flux from four permanent blocks. The square area (20×20 cm2) represents a region of interest (ROI) where the magnetic flux ranges from 0.208 to 0.211Tesla; (b) and (c) the magnetic flux plots along the x- and y-axes respectively. Each magnetic block is of 40×40×20 cm3, with a gap of 2 cm between two parts of each magnetic pole.
Figure 5.
Double-magnetic-donut-based design for omni-tomography.
The pair of green magnetic rings is arranged similar to that in the Fonar UPRIGHT Multi-Position MRI (http://www.fonar.com/standup.htm) but with a decreased spatial extent of a homogeneous magnetic background field and thus an increased gantry room for interior CT, interior SPECT, and other modalities. This design is scalable according to preferred sizes of animals or humans.
Figure 6.
Interior CT reconstruction of a cardiac region from a clinical patient dataset collected on a GE Discovery CT750 HD scanner.
(a) The reference image reconstructed from global projections using the conventional filtered backprojection (FBP) method, (b) a magnified interior cardiac region, (c) and (d) the interior reconstructions from truncated local projections after 10 and 20 iterations, respectively. (e) and (f) The profiles along the horizontal and vertical white lines respectively in (b)–(d), where the thick lines on the horizontal axes indicate the ROI. The display window for (a)–(d) is [−1000, 1000] HU.
Figure 7.
Interior SPECT reconstruction of a cardiac phantom.
(a) An original SPECT ROI image of 128×128 pixels covering an area of 12.8×12.8 cm2, (b) an interior reconstruction using the HOT minimization algorithm with the attenuation background µ0 = 0.15 after 40 iterations, (c) and (d) the pseudo-color counterparts of (a) and (b) respectively. (e) and (f) The profiles along the horizontal and vertical white lines respectively in (a) and (b), where the thick lines on the horizontal axes indicate the ROI. The display window for (a) and (b) is [0, 1.0] in a normalized unit.
Figure 8.
Interior MRI reconstruction of a cardiac image phantom.
The top row (a)–(c) is from fully sampled data (100%), and the bottom row (d)–(f) is from randomly under-sampled data (25%) along the phase-encoding direction. The first column (a) and (d) is by the inverse fast Fourier transform (IFFT), the second column (b) and (e) by the TV minimization from global MR data, and the third column (c) and (f) by the TV minimization from interior MRI data.
Figure 9.
Unified CT-MRI reconstruction using inter-modality coherence.
An MRI-CT head scan consisted of MR T1 (the 1st column), T2 (the 2nd column), proton density images (the 3rd column), and a CT image (the 4th column). The top row shows the phantom images, the middle row the images separately reconstructed using the conventional FFT or FBP method, and the bottom row the images simultaneously reconstructed in the unified rank-sparsity decomposition framework.