Mobile & Point-of-Care CT: A Radiologist’s Perspective
Author:
Dr. Shailendra Katwal, from Beth Israel Deaconess Medical Center
The Paradigm Shift: Scanner Goes to the Patient
The conventional model of CT imaging has always demanded that the patient travel to the scanner. For the majority of patients, this is unremarkable. For the critically ill — the ventilator-dependent ICU patient, the hemodynamically unstable trauma case, the acute stroke in the ambulance bay — this journey carries real clinical risk. Mobile and point-of-care (POC) CT inverts this model entirely, and as radiologists, it is essential we understand both its diagnostic capabilities and its limitations.
Diagnostic Performance: What the Evidence Tells Us
The most rigorously studied application of mobile CT remains neuroimaging. Non-contrast head CT is the gatekeeper investigation in acute intracranial pathology — hemorrhage, hydrocephalus, herniation — where time to diagnosis directly influences management.
Comparative studies evaluating mobile CT against fixed scanners in neurosurgical ICU settings have demonstrated that while portable systems show statistically greater image noise — particularly in the posterior fossa — their diagnostic yield for the clinical questions being asked remains clinically acceptable. The critical distinction is this: a slightly noisier image acquired safely at the bedside is frequently superior in clinical value to a technically perfect scan that carries prohibitive transport risk for a specific patient.
For the radiologist, this demands a calibrated approach to reporting: understanding the technical constraints of the device in use, adjusting interpretive thresholds accordingly, and communicating image quality limitations clearly in the report when clinically relevant.
Mobile Stroke Units: When the Ambulance Becomes the Scanner Room
Perhaps the most striking clinical deployment of mobile CT is in the Mobile Stroke Unit (MSU) — a specialized ambulance equipped with a CT scanner, point-of-care laboratory, and teleradiological support. The concept, pioneered in Germany, has demonstrated the ability to perform non-contrast CT within 5 minutes of ambulance admission, delivering intravenous thrombolytics approximately 30–40 minutes faster than conventional in-hospital workflows.
Recent programmes in the United States have deployed the Siemens SOMATOM On.site system offering hospital-grade head CT in the field — as part of MSU fleets. Onboard CT angiography capability is also being developed, enabling early detection of large vessel occlusions and facilitating direct triage to thrombectomy-capable centers before hospital arrival.
For the teleradiologist interpreting these studies, the clinical context is acute and the turnaround expectation is immediate. This is a different interpretive environment from routine reporting, requiring dedicated workflows and escalation protocols.
Photon-Counting Comes to the Bedside
A particularly exciting development is the emergence of portable photon-counting detector CT (PCCT). Massachusetts General Hospital is currently evaluating a portable head-only PCCT system in the Neuro ICU for patients deemed too high-risk for transport to the fixed scanner. Early data suggest that PCCT’s inherent advantages — improved spatial resolution, reduced noise, lower radiation dose, and multi-energy capability — may substantially narrow the image quality gap between portable and fixed systems, potentially redefining what is diagnostically achievable at the point of care.
Workflow & Reporting Considerations for Radiologists
The expansion of POC CT creates several practical responsibilities for the reporting radiologist:
Image quality awareness: Always review the device type and acquisition parameters. Portable systems have known limitations in posterior fossa and skull base imaging; account for this in your interpretation and documentation.
Teleradiology integration: POC CT is inseparable from teleradiology infrastructure. Robust PACS connectivity, remote access protocols, and rapid reporting pathways must be established before clinical deployment.
Dose governance: Compact systems require the same rigorous dose audit processes as fixed scanners. Establish diagnostic reference levels appropriate to the device and clinical indication.
Clinical communication: POC CT reports should explicitly state the imaging context — bedside ICU, MSU, intraoperative — so that referring clinicians and future interpreters understand the diagnostic environment.
Conclusion
Mobile and point-of-care CT is not a compromise — it is a clinically appropriate solution for a specific and important patient cohort for whom conventional imaging carries disproportionate risk. As the technology matures, with improving detector performance, AI-assisted reconstruction, and now portable PCCT on the horizon, the diagnostic gap with fixed systems continues to narrow. For radiologists, engaging with this technology — understanding its evidence base, its limitations, and the reporting standards it demands — is no longer optional. It is part of delivering equitable, timely, and safe diagnostic care.
References
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Goertz L, et al. Portable CT scanners in neurosurgical ICU: image quality comparison with fixed systems. Neuroradiology. [cited 2026 Apr 12].
Grotta JC, et al. Mobile stroke unit deployment and clinical outcomes: BEST-MSU trial. N Engl J Med. 2021.
Siemens Healthineers. SOMATOM On.site: critical care imaging at the point of care https://www.siemens-healthineers.com/en-us/computed-tomography/somatom/somatom-on-site
Mass General Brigham. Emerging CT technology to advance clinical care at MGB https://advances.massgeneral.org/radiology/article.aspx?id=1573
Canadian Agency for Drugs and Technologies in Health (CADTH). Portable CT for use in the hospital. https://www.ncbi.nlm.nih.gov/books/NBK618427/
Radiological Emergencies: Mobile Stroke Rescue Program — When minutes matter. J Vasc Interv Neurol. 2025 .https://www.sciencedirect.com/science/article/abs/pii/S1546084325002263