Teleradiology: A review of growth, challenges, and future potential

INTRODUCTION

The field of radiology began with the discovery of X-rays by Wilhelm Conrad Roentgen in 1895.^[1] From its inception, radiology has served as an important field for physicians to visualize and evaluate the internal structures of the human body, which were till only seen by open surgery. This field has witnessed remarkable technological advancements, evolving from basic radiographic imaging to sophisticated modalities such as computed tomography (CT), magnetic resonance imaging, and several other diagnostic techniques.^[2] Alongside these technological developments, the rise of digital communication has transformed how radiology services are delivered, giving way to models such as teleradiology.^[3] Teleradiology is the transmission of radiological images and related metadata from one location to another for interpretation and consultation from a radiologist. This model has significantly reshaped diagnostic workflows worldwide and is particularly relevant in countries such as India.

India has approximately 63.4% of its population residing in rural areas, where access to healthcare remains critically inadequate. Rural regions continue to experience substantial barriers, including inadequate infrastructure and a pronounced shortage of qualified medical professionals.^[4] The Rural Health Statistics Report 2021–22 indicates that nearly 80% of specialist positions encompassing surgeons, physicians, gynecologists, and pediatricians remain vacant at community health centers in rural areas.^[5,6] The country faces a shortage of medical professionals, with an overall doctor-to-patient ratio of approximately 1:1500, falling short of the World Health Organization’s recommended ratio of 1:1000. With just over 20,000 radiologists for a population exceeding 1.4 billion, the country contends with an alarming ratio of approximately one radiologist for every 100,000 people compared to the United States’ ratio of 1:10,000. This shortage is compounded by the uneven distribution of healthcare resources, with approximately 75% of infrastructure and medical professionals concentrated in urban regions, which account for only 27% of the population.^[7] These disparities highlight the urgent need for scalable, practical solutions to improve healthcare accessibility.

Teleradiology has emerged as one such solution with considerable potential in the field of radiology. It allows patients in remote or underserved regions to receive timely, expert radiological opinions without the need for travel to tertiary care centers. In recent years, the growth of teleradiology in India has been catalyzed by the expansion of internet connectivity, the increasing availability of digital imaging equipment, and government initiatives supporting telemedicine and digital health infrastructure.

The widespread adoption of teleradiology is not without challenges. These include issues related to data privacy, image quality consistency, medico-legal ambiguities, infrastructure disparities, and professional isolation or fatigue among teleradiologists.

In this narrative review, we aim to provide a comprehensive overview of the current landscape of teleradiology in India, including its historical development, implementation models, benefits, limitations, and future directions. Relevant literature was identified through a non-systematic search of databases including PubMed and Google Scholar, using keywords such as “teleradiology,” “India,” “radiology infrastructure,” and “AI in radiology [Figure 1].”

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Figure 1:

A computed tomography scan of a patient’s chest is displayed through teleradiology (Source: Wikimedia Commons, Public Domain).

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HISTORY AND GROWTH OF TELERADIOLOGY IN INDIA

The concept of teleradiology can be traced back to the early use of facsimile technology for image transmission. During the 1930s, American engineer Austin G. Cooley introduced a pioneering facsimile system, which was later employed by The New York Times to send photographic images. In the 1940s, hospitals in the United States experimented with sending photographic copies of X-rays over telephone lines and slow-scan television systems. The term “telognosis” was historically used to describe the transmission of roentgenograms (X-ray images) via wire or radio. It is derived from a combination of teleo, roentgen, and diagnosis.^[8] The first experimental teleradiology apparatus, installed in 1947, was in daily operation for 2 years between Chester County Hospital and Philadelphia, Pennsylvania.^[9] Following the initial trial of the first experimental teleradiology system between Chester County Hospital in West Chester, Pennsylvania, and Philadelphia, a new circuit was established using commercial telephone lines between the Ventnor Clinic in Atlantic City, New Jersey, and Philadelphia, a distance of 60 miles (100 km). This circuit was continuously tested over the following year to evaluate the feasibility of providing full-time radiological services remotely and to explore its potential for training radiology residents.^[10] The term “teleradiology” was formally introduced in 1972 by Andrus and Dr Kenneth Bird, marking the beginning of scientific assessments of remote radiological interpretation.^[11,12] The 1970s and 1980s marked significant advancements in radiology, notably with the introduction of CT and magnetic resonance imaging. This period also saw the emergence of “store-and-forward” teleradiology, allowing asynchronous transmission of digitized diagnostic images. The development of Picture Archiving and Communication Systems (PACS) enabled efficient digital storage and retrieval of medical images, replacing traditional film-based methods.^[13] At the same time, efforts were made to standardize digital imaging formats. This led to the introduction of the ACR/NEMA standards, developed by the American College of Radiology and the National Electrical Manufacturers Association.^[14] By 1993, the earlier guidelines had evolved into digital imaging and communications in medicine (DICOM), which became the global standard for handling, storing, and transmitting medical images.^[15] These innovations, combined with the expansion of high-speed internet in the 1990s, allowed teleradiology to become practically viable and scalable.^[16,17] By the late 1990s and early 2000s, teleradiology was increasingly used for after-hours image interpretation, particularly in emergency and remote care settings, giving rise to “nighthawk” services [Figure 2].^[18,19]

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Figure 2:

Sequential workflow of teleradiology. PACS: Picture archiving and communication system.

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Teleradiology began in India in 1996 when Jankharia Imaging in Mumbai initiated the digital transfer of CT scans to radiologists’ homes. In this early practical approach, a Siemens AR.C incremental CT scanner, which lacked DICOM support, was used. To extract images, they connected a video capture card to the CT system’s analog video output. Images were manually captured in JPEG (Joint Photographic Experts Group) format at a resolution of 640 × 480, with each brain CT scan (24–30 images) taking 8–10 minutes. Transfers were done through Windows 95 dial-up networking using 14.4 kbps modems, taking 10–15 minutes per set.^[20] This design was used for 3 years by Jankharia Imaging and was replaced in 1999. In 1997, Siemens and Wipro GE demonstrated the potential of teleradiology at the Indian Radiological and Imaging Association conference.^[21] This resulted in the establishment of Teleradiology Solutions in 2002 by Yale University-trained physicians Dr. Arjun Kalyanpur and Dr. Sunita Maheshwari, the first Indian company based in Bengaluru to offer round-the-clock radiology services with U.S. board-certified radiologists.^[22-25]

After that, there was a significant increase in teleradiology and widespread adoption.^[26,27] Many players joined the teleradiology field in India after 2002, including 5C Network, TeleradTech, Manipal Hospitals Radiology Group, and Wipro, among others [Table 1].^[22]

The global teleradiology market reached $6.6 billion in 2024 and is projected to grow to $20.1 billion by 2033, with a compound annual growth rate (CGAR) of 13.2% between 2025 and 2033, according to International Market Analysis Research and Consulting (IMARC) Group [Figure 3]. This growth is fueled by the increasing need for affordable healthcare solutions.^[28] In India, the teleradiology market was valued at INR (Indian rupee) 3,057.6 Crore in 2024 and is expected to reach INR 27,800.0 Crore by 2033, exhibiting a substantial CAGR of 24.7% during the forecast period (2025–2033).^[29] This significant expansion is driven by the rising demand for remote medical services and increased health awareness.^[30]

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Figure 3:

Teleradiology market size in India and globally (in USD million) in 2024 and 2033, projected growth.

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The COVID-19 pandemic served as a critical inflection point in the adoption and integration of teleradiology across India.^[31,32] The abrupt disruption of conventional clinical workflows, coupled with the necessity for infection control and social distancing, accelerated the transition toward remote diagnostic practices.^[33] Radiologists rapidly adopted decentralized work models to interpret imaging studies from off-site locations, including home-based workstations and distributed reading centers.

IMPLEMENTATION MODELS

Teleradiology practice models have evolved to meet the diverse demands of healthcare systems. Some providers offer comprehensive off-site services, managing the entire diagnostic process from image acquisition to interpretation through centralized reading facilities. Nighthawk or on-call coverage models address after-hours needs by leveraging global time zones. In this model, radiologists provide preliminary reads overnight, with final reports completed locally the next day. The “Indian model,” wherein radiologists based in lower-cost countries deliver diagnostic services often without host-country licensure at reduced costs, exemplifies this approach.^[34] Yale University Medical Center’s partnership with a teleradiology group in Bangalore illustrates such international collaborations.^[35] In parallel, individual radiologists or small groups often contract directly with institutions to provide general or subspecialty interpretations, commonly supplementing in-house teams or serving systems like the military. Expert or second-opinion teleradiology connects remote sites with academic centers for specialized input, though its wider adoption has been limited by integration challenges, workforce shortages, and ambiguous reimbursement structures.^[36] Finally, global virtual radiology networks have emerged within large healthcare systems in facilitating cross-border workload sharing to address radiologist shortages and improve service efficiency, for example, in the army.^[37]

APPLICATIONS OF TELERADIOLOGY

Teleradiology is now applied across every aspect of diagnostic radiology, from X-rays to advanced MRI and PET scans, and spanning both routine and specialized procedures. However, there are particular areas where teleradiology proves especially instrumental and highly beneficial.

FOUNDATIONAL TECHNOLOGIES AND DATA PROTOCOLS IN TELERADIOLOGY

The technological backbone of teleradiology has evolved significantly with the adoption of cloud-based PACS and radiology information systems (RIS). Cloud-based PACS and RIS have transformed the scalability and accessibility of imaging services in teleradiology.^[70] Unlike on-premises solutions, cloud architectures support platform-independent access to imaging data, enabling remote diagnostics across geographical boundaries. Studies report significant gains in operational efficiency, disaster recovery, and cost effectiveness with cloud migration.^[71-73]

Equally important were advances in image compression techniques, such as JPEG2000, which preserved diagnostic quality while reducing bandwidth consumption.^[74] The deployment of dedicated teleradiology workstations and viewing software allowed radiologists to interpret images with high resolution, manipulation tools, and 3D reconstructions from remote locations.

The secure data transfer protocols are fundamental to protecting patient confidentiality during remote transmission of medical images in teleradiology. The DICOM standard, along with its security extensions, provides secure exchange of radiological data. To ensure both privacy and efficiency, various methods have been adopted, including the use of encrypted and compressed image archives, with decoding keys transmitted separately through email or file transfer protocol (FTP).^[75] More advanced solutions, such as the secure file transfer protocol, have proven effective for transmitting images over long distances, particularly in rural and underserved areas.^[47] Some system exemplifies a versatile approach by supporting multiple transfer methods, including DICOM, hypertext transfer protocol (HTTP), hypertext transfer protocol secure (HTTPS), and CD, while maintaining a strong emphasis on data privacy and integrity.^[76]

Bandwidth and network stability are critical determinants of teleradiology efficiency. High-speed internet enables the rapid transmission of large imaging datasets, facilitating timely subspecialist consultations and collaborative diagnosis in emergency care settings. The rollout of 5G and fiber optic networks has markedly improved latency and data throughput, yet digital divide issues persist in rural and underserved regions. Technical factors such as compression algorithms, packet loss, and image degradation must be continually optimized to ensure diagnostic accuracy.^[77]

Interoperability is essential for integrating teleradiology into broader clinical workflows.^[78] Standards such as Health Level Seven and Fast Healthcare Interoperability Resources enable consistent and structured data exchange across various health information systems, including PACS, electronic health records (EHRs), laboratory systems, and hospital information systems.^[79] These standards facilitate the seamless integration of radiology reports and imaging metadata into patient records, thereby enhancing communication among healthcare providers and supporting informed clinical decision-making. Improved interoperability also reduces administrative delays, avoids redundant imaging, and enables efficient auditing, billing, and analytics.^[80]

Blockchain technology introduces a decentralized and immutable ledger system for recording access to medical data.^[81,82] In the context of teleradiology, blockchain can be used to track when, how, and by whom imaging studies or reports are accessed and modified. This provides a verifiable chain of custody for sensitive patient data, ensuring transparency and accountability in multi-institutional or cross-border collaborations. Blockchain also prevents unauthorized alterations of reports and enhances the legal defensibility of diagnostic interpretations. These capabilities are especially valuable in medico-legal cases, second opinion consultations, and health data research, where data authenticity and auditability are important.^[83,84]

CHALLENGES

Despite the rapid growth of teleradiology, legal and ethical frameworks remain poorly defined, especially when services cross state or national borders.^[85] Issues around licensure, liability, duty of care, data security, and patient confidentiality remain unresolved, particularly due to the lack of direct doctor-patient interaction.^[86] In India, the regulatory landscape is especially ambiguous. Although the Telemedicine Practice Guidelines (2020) exist, they lack specific provisions for teleradiology.^[87] This legal vacuum, combined with the absence of comprehensive health data protection laws, creates serious medico-legal challenges.^[88] Cross-border teleradiology faces significant legal ambiguity, particularly around licensure, liability, and jurisdiction, which hinders its broader adoption.^[89]

Beyond regulatory ambiguities, significant infrastructural and technological limitations impede teleradiology’s widespread adoption, especially in rural areas.^[90] Reliable, high-speed internet connectivity remains a major challenge, hindering the seamless transmission of large imaging data. Furthermore, erratic electricity supply in many healthcare facilities disrupts operations and compromises the quality of care.^[91] The high cost of advanced diagnostic equipment also limits hardware availability and proper utilization. These fundamental infrastructural deficits create a substantial barrier to delivering consistent and high-quality teleradiology services across diverse geographical settings.

Maintaining consistent quality and standardization across various regions proves difficult due to disparities in imaging protocols, radiologist training, and the absence of uniform reporting guidelines.^[79] Significant communication gaps often exist between remote radiologists and on-site clinicians, limiting access to comprehensive patient histories and hindering real-time dialogue, which can impact diagnostic accuracy and patient care.^[92] This remote work, particularly in high-volume settings, also contributes to radiologist burnout, professional dissatisfaction, and a sense of isolation.^[93,94]

Medical data holds high black market value, often fetching more than financial information.^[95] The U.S. Department of Health and Human Services Office for Civil Rights had recorded 725 healthcare data breaches involving 500 or more records for the year 2024.^[96] In 2020, a ransomware attack on a major medical center in Vermont caused a complete shutdown of its electronic medical record system for 28 days.^[97] In 2022 alone, the Indian healthcare sector faced over 1.9 million cyberattacks.^[98] Among the most severe incidents were the ransomware attack on AIIMS Delhi, which compromised more than 40 million patient records and severely disrupted hospital operations.^[99] Platforms that store and transmit sensitive patient data across networks are attractive targets for cyberattacks. Without strong cybersecurity protocols, these platforms risk becoming easy entry points for hackers. Such unauthorized access can result in data deletion or manipulation, thereby compromising patient confidentiality, interrupting clinical operations, and adversely impacting the integrity and efficiency of the healthcare system.^[100]

THE INTEGRATION OF ARTIFICIAL INTELLIGENCE (AI)

The convergence of AI and teleradiology represents a paradigm shift in Indian healthcare, poised to address the persistent challenges of radiologist shortages and immense diagnostic workloads. This integration acts as a crucial force multiplier, moving beyond simply bridging geographical gaps to actively enhancing the efficiency and accuracy of radiological services.^[101] In the Indian context, AI’s primary applications include the automated triage and prioritization of critical cases, such as strokes or pulmonary embolisms, directly from the teleradiology worklist, which significantly reduces turnaround times for life-threatening conditions.^[102,103] AI algorithms function as a powerful “second reader” to augment diagnostic accuracy and reduce errors, proving particularly effective for detecting highly prevalent diseases like tuberculosis from chest radiographs and quantifying oncological findings.^[104] A study by Chu et al. in 2023 found that radiologists are open to integrating AI tools into their practice, provided that these tools meet high performance thresholds.^[105] Careful implementation, ethical oversight, and continuous validation are essential to realizing the full potential of AI in teleradiology without compromising patient safety.

FUTURE DIRECTIONS

While current applications have successfully bridged geographical and accessibility gaps, the next decade is expected to witness a qualitative transformation driven by deep technological integration, policy maturation, and a redefined role for radiologists.

A pivotal future direction is the integration of teleradiology services with the Ayushman Bharat Digital Mission (ABDM). This will involve moving beyond standalone PACS/RIS systems to platforms that are fully interoperable with the ABDM framework. In this vision, a patient’s imaging data and the corresponding teleradiology report will be seamlessly linked to their unique Ayushman Bharat Health Account. This will create a longitudinal imaging history for every citizen, accessible to authorized healthcare providers nationwide, thus eliminating redundant scans and providing a holistic view of a patient’s health journey. This integration will also be crucial for strengthening public health initiatives, allowing for real-time epidemiological analysis and resource allocation based on anonymised, large-scale imaging data.

The role of AI will mature from detection and classification to prediction and generation. The next wave of AI tools will focus on predictive analytics, using imaging data combined with clinical and genomic information to forecast disease progression, treatment response, and patient risk profiles. For instance, AI could predict the likelihood of malignant transformation in a pulmonary nodule or estimate the response of a brain tumor to a specific chemotherapy regimen based on its radiomic signature.^[106]

Generative AI is poised to revolutionize the reporting process.^[107] Advanced Large Language Models trained on vast radiological datasets could generate high-quality, structured draft reports from imaging findings in seconds.^[108] The teleradiologist’s role would then evolve from primary interpretation and dictation to one of expert oversight, verification, and clinical correlation, a model often referred to as “human-in-the-loop.”^[108]

Teleradiology will drive national “Telesubspecialization,” enabling remote district hospitals to access specialist expertise, such as pediatric neuroradiology or cardiac imaging, from metropolitan centers.^[109] This equalizes access to advanced care and necessitates radiology postgraduate curricula updates to include health informatics, AI ethics and principles, and teleradiology practice for technology-enhanced roles.^[110]

GAPS IN LITERATURE

While teleradiology has grown rapidly in India, the existing literature leaves several important questions unanswered. Much of the available research is limited to pilot projects or small-scale studies, with little information on the broader reach, quality, and effectiveness of teleradiology networks across the country. Similarly, critical aspects such as data security practices, quality assurance, and medico-legal responsibilities are either briefly mentioned or entirely absent from published studies. Despite the increasing use of public-private partnerships, there is minimal evidence evaluating their performance or sustainability in real-world healthcare settings. In addition, the role of frontline workers, technicians, general physicians, and teleradiologists has not been sufficiently studied, particularly regarding training gaps and the operational pressures they face. These gaps highlight the urgent need for more comprehensive, context-specific research to guide the equitable and effective expansion of teleradiology in India.

CONCLUSION

Teleradiology has clearly helped address some of the deep gaps in diagnostic access across India, especially in rural areas. However, despite its growth, it still operates in a space where rules are unclear, infrastructure is uneven, and radiologists often work in isolation. For teleradiology to truly strengthen the healthcare system, policies need to be more specific, practical, and supportive of both patients and professionals. The focus should not be only on expanding technology but also on ensuring that systems are ethical, reliable, and well-connected to real-world clinical care. With the right support, teleradiology can move from being just a useful tool to becoming an essential part of equitable and quality healthcare in India.