New imaging technologies

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Dr Rajeev Boudhankar, CEO, Bhatia Hospital, reviews the latest imaging techniques and cautions that there is a need to balance technology with affordability

While imaging technology has rapidly progressed in the last decade or so, it has had a dual impact on healthcare providers. On one hand, technology has helped to make difficult cases easy to diagnose, thus reduce errors in treatment modalities. It has also helped early detection so that early treatment is initiated, thus saving lives e.g in cancers of lungs, breasts etc. It also enhances accuracy of diagnosis where differential diagnoses has a wide spectrum. It has reduced medical – legal issues due to late/ wrong diagnosis. It has reduced errors in invasive procedures too.

On the other hand, it has made clinical diagnosis based on history and physical examination almost extinct. This has led to poor clinical skills in newly minted doctors from medical schools. Even senior doctors are slowly losing their clinical skills.

The latest imaging techniques that have a potential in the near future would include:

• The hand-held ultrasound which would eventually replace the good old stethoscope for diagnosis in the cardio – respiratory arena.
• Invasive procedures would become safer and more accurate by the introduction of hyper spectral imaging. This would also reduce doctor’s liability and reduce indemnity insurance premiums in the long run. Hyperspectral imaging has been used in defence sector and has now been applied to the healthcare imaging industry. It simply means, it entails use of optical semi conductor technology to an imaging technique.
• The University of Oxford has developed a modality called ‘Electromagnetic Acoustic Imaging.’ This modality makes use of electro – magnetic and acoustic waves to diagnose various types of solid cancers in the early stages of development. The imaging is claimed to be of far superior quality and clarity than conventional modalities.
• The University of Lincoln in the UK has developed a so called wafer scale mega microchip to enhance medical imaging techniques. The University claims that images that are produced by the chip will help doctors to detect accurately the effects of radiation on cancerous tumors, thus help early detection.
• The ‘University of California, Berkeley’ and the ‘Universidad Autonoma de Madrid’ of Spain, have jointly claimed to have made the use of 3D Meta material which enhances ultrasound images by a factor of 50X. If successful commercially, it would aid current ultrasound probes to capture high resolution images for medical imaging for both diagnosis and interventional procedures.
• Scientists at Japan’s Railway Technical Research Institute, Tokyo, have developed a superconducting magnetic system which would be literally ‘palm-size.’ This would convert current MRI System into mobile imaging applications.
• The University of Medicine, Berlin and Max-Delbruck Centre for Molecular Medicine, Berlin, have claimed to have produced a technology for capturing images of the beating heart in its MRI systems. They claim the magnetic field of resolution would be 150,000 times the earth’s magnetic field. It would thus aid in clearly demarcating between blood and heart muscle, enabling early diagnosis of cardiac malfunction.
• Iron oxide nano crystal technology has now been proposed for medical imaging. Super paramagnetic iron oxide particles have a variety of applications in molecular and cellular imaging. Review of the most recent research has concerned cellular imaging with imaging of in vivo macrophage activity. According to the iron oxide nano particle composition and size which influence their bio – distribution, several clinical applications are possible. For example, detection of liver metastases in cancers, metastatic lymph nodes, inflammatory and degenerative diseases. Ultra small super paramagnetic iron oxide particles are being researched as blood pooling agents for angiography, tumour permeability and tumour blood volume or steady-state cerebral blood volume and blood vessel size index measurements. Research is also being conducted for stem cell migration and immune cell trafficking, as well as targeted iron oxide nano particles for molecular imaging studies.
• Bio-printing: 3D bio-printing has undergone significant advancements in the recent times. This technique allows high precision fabrication of biological structures encapsulating cells and bioactive molecules, with applications in areas such as tissue engineering, drug development and bio-sensing. As such, static structures obtained from conventional 3D bio printing may be unable to elute realistic biological responses. What’s needed is a fourth dimension – time. Research is now being conducted at Harvard Medical School’s Biomaterials Innovation Research Centre by Ali Khadem Hosseni et al, for application and development of 4D Bio printing. They proposed 4D bio printing by combining smart, stimuli responsive biomaterials with 3D bio printing techniques, to introduce this fourth dimension into the fabricated system and emulate the dynamic processes seen in Biological tissues. The clinical application which is predicted is 4D printing dysfunction heart imaging and treatments.
• Virtual CT simulating high – dose: Siemens Healthcare has developed a process to synthesise a virtual target medical image based on a source image. The company claims that this method can be used to synthesise a virtual high dose CT image from a low dose CT image, enabling reduction of the radiation dose to which the patient is exposed. Siemens has reportedly applied for a patent.
• PET segmentation scheme offering all-inclusive analysis: Researchers at John Hopkins University have developed a process for accurate characterisation of tumour burden and response to therapy from PET Scans. This new method provides reliable and reproducible PET tumour boundary definition and metabolic tumour volumetric quantification over a wide range of tumour sizes and shapes and for various levels of PET radiotracer uptake. This method will help clinicians in diagnosis, staging and planning of radiotherapy and surgery as well as determining treatment response. It can also help in cancer therapy research. The patent for this method is awaiting approval.
• CT-based elastography for evaluating tissue stiffness: Researchers at the Ohio State University have researched a new method for performing CT-based elastography. This technique estimates local displacement of tissue in response to a mechanical stimulus from high- resolution images. It can also be applied to hard structures in the body like bone, teeth and cartilage as well as soft tissues. It can also be used to scan patients with pace- makers or metal implants that cannot undergo MR scans. The Ohio State University has applied for a patent for this method.
• MRI-enabling PET attenuation correction: GE has reportedly invented a method for joint reconstruction of activity and attenuation in PET images using MR-based priovs and applied for a patent as well.
• Ultrasound in the determination of blood flow velocity: Philips has applied for a patent for a new method in the determination of blood flow velocity. The method uses ultrasound pulse at one location and the pulse is detected at a second location by an ultrasound receiver. The calculation is then done for flow velocity of blood in a blood vessel between the first and second locations.
• Mapping distortion corrects wrap in MR Images: Synaptive Medical Company of Barbados has developed a new technique for correcting warping in MR images caused by non-linearities in gradient field profiles. The patent for this new technique is pending.

Thus, it seems as technology advances, through helping doctors to give better and faster healthcare, it will make healthcare more expensive for the masses. Hence, the need of balancing ‘affordability and technology’ is imperative.