Heriot Watt University | September 2019 | Ultrasound breakthrough can pinpoint cancer with precision
Experts at Heriot Watt University have found a new technique which uses super-resolution ultrasound methods that improves resolution of ultrasound images by 5-10 times compared to standard current ultrasound images.
Their innovation allows whole organs to be scanned in super-resolution for the first time which, it is anticipated, will lead to earlier cancer diagnoses and allow medical staff to more effectively target treatments to any malignant tissue. Potentially, it could eventually replace the need for biopsy altogether.
The team behind this innovation the aim is to start human trials using the new technique in three months’ time at the Western General Hospital in Edinburgh. Patients with prostate issues will be the first to benefit from the enhanced imaging.
Professor Alan McNeill, Consultant Urological Surgeon at the Western General Hospital in Edinburgh said: “Prostate cancer is an increasing problem for our society. Whilst we have a number of methods for detecting it, these don’t always provide us with the important information that we need regarding who has cancer that needs to be treated and who doesn’t.
“A method that maps the blood flow of the tumour accurately could well provide new information about the disease state that allows us to better identify those men who need urgent treatment and those who don’t. It is exciting that we will be the first hospital in the world that will assess this method with patients.” (Source: Heriot Watt University)
Read the full, unabridged press release from Heriot Watt University
Objectives The aim of this study was to provide an ultrasound-based super-resolution methodology that can be implemented using clinical 2-dimensional ultrasound equipment and standard contrast-enhanced ultrasound modes. In addition, the aim is to achieve this for true-to-life patient imaging conditions, including realistic examination times of a few minutes and adequate image penetration depths that can be used to scan entire organs without sacrificing current super-resolution ultrasound imaging performance.
Methods Standard contrast-enhanced ultrasound was used along with bolus or infusion injections of SonoVue (Bracco, Geneva, Switzerland) microbubble (MB) suspensions. An image analysis methodology, translated from light microscopy algorithms, was developed for use with ultrasound contrast imaging video data. New features that are tailored for ultrasound contrast image data were developed for MB detection and segmentation, so that the algorithm can deal with single and overlapping MBs. The method was tested initially on synthetic data, then with a simple microvessel phantom, and then with in vivo ultrasound contrast video loops from sheep ovaries. Tracks detailing the vascular structure and corresponding velocity map of the sheep ovary were reconstructed. Images acquired from light microscopy, optical projection tomography, and optical coherence tomography were compared with the vasculature network that was revealed in the ultrasound contrast data. The final method was applied to clinical prostate data as a proof of principle.
Results Features of the ovary identified in optical modalities mentioned previously were also identified in the ultrasound super-resolution density maps. Follicular areas, follicle wall, vessel diameter, and tissue dimensions were very similar. An approximately 8.5-fold resolution gain was demonstrated in vessel width, as vessels of width down to 60 μm were detected and verified (λ = 514 μm). Best agreement was found between ultrasound measurements and optical coherence tomography with 10% difference in the measured vessel widths, whereas ex vivo microscopy measurements were significantly lower by 43% on average. The results were mostly achieved using video loops of under 2-minute duration that included respiratory motion. A feasibility study on a human prostate showed good agreement between density and velocity ultrasound maps with the histological evaluation of the location of a tumor.
Conclusions The feasibility of a 2-dimensional contrast-enhanced ultrasound-based super-resolution method was demonstrated using in vitro, synthetic and in vivo animal data. The method reduces the examination times to a few minutes using state-of-the-art ultrasound equipment and can provide super-resolution maps for an entire prostate with similar resolution to that achieved in other studies.
The original research is available in full from Investigative Radiology
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