New insights from microCT: MILabs’ first-in-class 4D-CT and Molecular CT imaging system
MicroCT imaging has shown its utility over the last decade in many preclinical 3D in-vivo imaging applications. Nevertheless, for in-vivo preclinical applications, biology rarely happens in three dimensions only. The addition of a fourth dimension – time – and early detection of disease onset, are two must-have capabilities of a state-of-the-art in-vivo microCT system.
Here we document user applications of MILabs’ formidable U-CT modality. Worldwide users illustrate that high-resolution anatomical images and functional information can be acquired by microCT from a wide range of subjects at extremely low radiation doses and with high throughputs:
Image-gated dynamic microCT of four mice simultaneously:
Intrinsic or image-based list mode sorting assigns projection images to cyclical intervals by image analysis. No physiological time signal is needed making simultaneous gated acquisitions of up to four mice possible.
Images courtesy of UMC-Utrecht
Time-gated dynamic microCT for ultra-high resolution cardiac and lung imaging:
U-CT enables ultra-high resolution dynamic microCT by combining dual time-gated cardiac and respiratory acquisitions with fast CMOS detection. Unlike conventional CCD detectors, CMOS ensures on-the-fly readout without detector blooming and image smearing, thus ensuring the acquisition of clinically translatable CT images using both preclinical and clinical contrast agents.
Bone remodeling with kinetic and longitudinal 4D microCT:
Ultra-high resolution in-vivo rather than ex-vivo bone CT enables to study bone (re)modeling by assessing bone vascularization and tracking of spatially correlated formation and resorption sites over time.
By adding the element of time to 3D bone imaging, the U-CT system enables studying bone vascularization to visualize and quantify bone turnover in-living animals.
Images courtesy UMC Utrecht
Peeking into the brain of living animals, from small to large:
The U-CT system can image both small and large animals at commensurate ultra-high in-vivo resolution for studying the brain in ways not considered previously. Brain vasculature and BBB integrity can be studied in mouse models (upper), while the lower images show the intricate 3-D wiring of a pig brain.
Dynamic contrast enhanced (DCE) CT with single- or dual-energy acquisitions:
Fast scans, including on-the-fly acquisitions, enable DCE-CT imaging of perfusion in organs and target tissues such as tumors, as well as the functional status of the vascular system within the total body of mice.
Images courtesy of V. Kersemans, Oxford University
Flying through airway lumen, from mice to ferrets:
The unique capabilities of MILabs adaptive U-CT system allow to perform virtual endoscopy (including virtual colonoscopy and bronchoscopy) on both small and medium sized animals, such as rabbits and ferrets.
Especially the bronchoscopy of ferrets (lower images) is well suited for the investigation of the significance of respiratory diseases, given similarities to human airway physiology.
Visualizing bone fracture healing with Molecular microCT
Unlike any other stan-alone CT, MILabs U-CT can be upgraded with molecular imaging using PET, SPECT and /or Optical detection. As illustrated on the left (healing of a fractured left “A” femur), these Molecular CT imaging capabilities are being exploited to develop a targeted, injectable bone-healing drug.
Detecting early onset of bone disease with Exirad CT:
While many promising clinical results have emerged over the last few years highlighting the potential of bone CT combined with SPECT, a number of diagnostic and prognostic issues require further preclinical research. By combining the ultra-high resolution of Exirad-SPECT with U-CT, it is now possible to determine in mouse models if SPECT/CT can be used earlier in the diagnostic work-up of bone and joint conditions.
While dynamic 4D-CT and Molecular CT have specifically been developed for biomedical research applications, the high precision, resolution and ability of U-CT to accommodate a wide range of objects, make the stand-alone system very well suited for many other, non-destructive applications. Besides analyzing archeological and paleontological samples as illustrated here, there are numerous other application fields for MILabs’ U-CT.
Images courtesy of TU Delft & Naturalis in Research Insitute