Volume 7 - Issue 2, 2012 HIT - Cover Story

Data Ownership & Protection Issues

Technological advances have created great opportunities for society to develop new products and services,  and to communicate and share data. A tremendous amount of ubiquitous computational power  and online services are used every day as a normal commodity. These new facilities allow data storage  and exchange of information anytime and anywhere, at high speed. In recent years, cloud computing is  the new term that has emerged to define these services. The main idea is to merge computational power  and storage in a dynamically scalable infrastructure, i.e. the system capability grows as needed, which  allows decoupling of the business service from infrastructure. This new buzzword is changing the computing  paradigm and has given rise to vendors dedicated to providing this new utility in a pay-as-yougo  business model, offering customers huge computational power and storage. The offer is diversified,  including virtual operating systems and basic services, for instance, storage, database and signaling.

It is evident that the computing-as-utility business model  is becoming prevalent in the electronic world and numerous  industries are adopting it. So this new paradigm ought  be of interest to the healthcare industry in various ways  and may likely be increasingly adopted in the coming  years. The medical imaging sector will not be an exception,  despite its special requirements. The main advantages  of cloud computing are cost savings, wide availability  and high scalability. However, this new technology also  brings new challenges regarding data ownership, trust,  privacy and interoperability with healthcare standards. In  this article, we will stress the applicability of cloud computing  solutions to support medical image repositories,  addressing the existent problems and point out possible  solutions to solve these issues.  

Trust and Data Privacy  

The outsourcing of data records can be a good solution,  depending on the type of information transmitted  to the cloud providers. The privacy of medical information  is a vital requirement and a very sensitive issue,  especially when medical digital images and patient information  are stored in third parties and transmitted  across public networks. Healthcare institutions often  insist on safeguarding the privacy of involved actors to  avoid data being tampered with by provider companies  (i.e. cloud services suppliers).  

Medical image repositories usually deal with outsized  data volumes, regularly including an ever-growing list  of files. Apart from medical exams, PACS also supports  a database with textual information corresponding to  those exams. Both are relevant and only authorised parties  should access them. Thus, a challenge in outsourcing  medical images over the cloud is how to protect the  privacy of patients and physicians, including protection  against misuse of data.  

A possible way to minimise those risks is the use of a  hybrid cloud solution, i.e. a combination of public computing  utility with a local infrastructure retained by institutions.  The idea is to keep critical mechanisms inside institutions  and outsource the heavy computational resources.  The hybrid cloud approach allows outsourcing of medical  records without losing control, which means that only authorised  entities can access the data. The third party entity,  located within the institution’s control, provides the  core element of privacy. This huge amount of medical information  is stored across public cloud providers, granting  patient privacy through data encryption. Possible unauthorised  access to the cloud repository does not jeopardise  data privacy, since access to the repositories requires  the right key to get medical imaging records. Moreover,  an additional strategy of splitting ciphered chunks of the  same image across different storage providers could be  used to provide an even higher level of privacy.  

Data Ownership and Protection  

Data protection in the outsourcing of medical images is  required because these records are important assets for  data holders. Medical institutions need to be aware of  legal aspects when storing data in outsourced repositories.  The first concern should be the SLAs (Service Level  Agreements), giving special attention to the problem of  data locking. Another topic to be considered is the permanence  of patient data. Data protection laws in several  countries, require knowledge of where data is stored. For  this reason, storage of patient data in the cloud will be  very difficult to use in countries like Spain, France or Italy.  However, several cloud providers allow obligatory data storage in a specific geographic location. Thus, the problem  addressed can be minimised and even countries with  higher restriction laws might accept the solution.  

Economic Aspects  

Healthcare institutions need to reap certain benefits in  terms of service quality and financial impact to be motivated  to outsource their medical repositories. To analyse  if cloud computing is economically viable in the imaging  context, the following cost variables of the current solution  are crucial:

  • Server hardware;  
  • Network equipment;  
  • Licenses;  
  • Energy;  
  • Air conditioning;  
  • Maintenance; and  
  • Technological obsolescence.  

A medical image repository based on the cloud does not  require high initial investment compared to traditional archive  solutions, which require purchase and maintenance  of a data centre. It is well suited to a small centre because  it does not require initial investment. However, for  medium-to-large image centres there is a point of operation  where it is economically more rational to have data  centre storage in co-location. It is very difficult to define  this tipping point because it is dependent on department  workload and processes, and the cloud services market is  rapidly changing, providing more resources at lower cost.  

Furthermore, the cloud solution can facilitate multicentre  collaborative environments, including the sharing  of medical records across medical institutions. So it will  reduce duplication of medical exams, on one hand reducing  the costs of patient care, and on the other, reducing  the dose of exposure to radiation.  

Interoperability with Healthcare Standards  

There are many standards in the medical community  (DICOM, XDS-I, IHE, HL7, etc.) that need to be interoperable  with current cloud providers’ interfaces. Historically,  healthcare communications standards were  thought to operate inside an institution’s intranet. However,  new standards are starting to follow a service-oriented  architecture (SOA), which allows inter-institutional  communication. Nevertheless, the compatibility with  cloud services’ interface is not directly supported due  to data privacy and confidentiality.  

For instance, in medical imaging, communication between  medical devices follows the DICOM standard.  However, the cloud data store and database interfaces are  not DICOM compliant. Most public cloud providers supply  access to their services through a proprietary web service  interface. Thus, we need a middleware component to  provide interoperability between DICOM equipment and  cloud repositories solutions compatible both with medical  practice and pre-existing medical information systems  (Bastião et al., 2011). To access cloud medical image repositories  we need a cloud broker (see fig. 1), which will  carry out the communication with healthcare standards  (for instance, DICOM), as well as cloud services.  

Data Availability  

The availability rate of cloud services is very high, which  means that services are always ready and reachable.  However, availability in the medical imaging scenario  is linked to the performance of access to the repository.  Due to latency associated with service access and  communication with public cloud providers, the retrieval  process can be slower. This process is extremely important  for the overall quality of the solution because there  is real-time interaction with end-users, i.e. the professional  is at the computer waiting for images. In order to  reduce latency in data transmission, a caching mechanism  can be placed on the cloud broker inside the medical  institution. This mechanism is a local storage area  that temporarily stores studies that are very likely to be  requested in future operations. Moreover, the usage of  pre-fetching mechanisms associated with the cache is  fundamental to the solution’s viability.  

Conclusion and Future Perspectives  

The use of a cloud computing utility has increased significantly  in recent years and it appears to be a natural  evolution of the data centre to execute computing and  storage in a more scalable way. With such a significant  increase, the market is growing quickly and more companies  are providing new services with better features,  including isolated services. We strongly believe that in  the near future, cloud computing will be widely used  in the healthcare sector. Several companies are already  adopting this kind of solution, offering PACS and RIS  services in private clouds.  

Medical images are very important records, and so  the storage repository needs redundancy to be a reliable  system. Cloud providers offer this data security  and backup system without any worries or additional  charges for customers. Medical institutions can reduce  the costs of local storage maintenance with PACS archive  outsourcing. Moreover, outsourcing is an opportunity  for small image centres that purchase modality  equipment, despite not having the financial resources  to buy software and hardware to keep up a PACS repository  as it grants a redundancy/backup system.


BASTIÃO, L., COSTA, C. & OLIVEIRA, J. L. 2011. A PACS  archive architecture supported on Cloud services. International  Journal of Computer Assisted Radiology and  Surgery. Springer.  

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Technological advances have created great opportunities for society to develop new products and services,  and to communicate and share data. A tremen

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