Medical Data Annotation
Done by Clinicians
Every dataset we annotate is handled by a medical professional with expertise in the relevant clinical field, then reviewed by a licensed specialist in that domain. Every annotator is employed with fair pay, proper training, and full transparency, that’s what makes the output reliable
60+
Completed Projects
95%
Accuracy
100%
Data Security
24/7
Real-time Live Monitoring
Medical AI annotation by professionals
Our Doctors in the Loop provide annotation services for medical data, including X-rays, MRI and CT scans, microscopic imagery, ultrasound videos, and other 2D, 3D and video data
Trusted by 100+
leading AI companies
Completed Projects
Annotation Types
Expert Medical Annotation Across Key Clinical Modalities
X-ray, CT, MRI, ultrasound, pathology, each dataset is matched to a specialist in that scan type, not a generalist.
2D Imaging
X-rays, pathology slides, retinal fundus, dermatology, mammography and histology. Annotated across bounding boxes, polygons, semantic segmentation and classification tasks.
3D Volumes
MRI, CT, CBCT dental scans and 3D ultrasound. Annotated with volume segmentation, multi-slice labeling, landmark annotation and 3D bounding volumes.
Video
Surgical footage, colonoscopy, echocardiography and laparoscopic recordings – annotated frame-by-frame with temporal segmentation, keypoints and instance tracking.
Unsure which annotation method fits your dataset? Our team will evaluate your data and provide a tailored recommendation before any commitment.
Our Specialists
We Match Your Dataset to the Right Specialist
Every project is assigned based on scan type, clinical domain, and annotator track record on similar datasets.
Radiology & Imaging
Radiologists
Radiology Technologists
Nuclear Medicine Specialists
Oncology & Pathology
Oncologists
Clinical Pathologists
Hematologists
Cardiology
Cardiologists
Vascular Surgeons
Surgery & Intervention
General Surgeons
Orthopaedic Surgeons
Laparoscopic Specialists
Ophthalmology & Neurology
Ophthalmologists
Neurologists
＋ Further Specialties
Dentists & Oral Surgeons
Gastroenterologists
Pediatricians
Urologists
Pharmacists
Why Doctors in the Loop
Built for Healthcare AI Where Annotation Accuracy Matters Most
01
Clinically Reviewed Annotation
The annotators working on your data follow guidelines built around your specific requirements
95% Precision
Ready for Regulatory Review
02
Unbiased & Diverse Data
Annotator diversity means your model doesn’t overfit to one clinical style or one geography.
Specialists across 6+ countries
03
A Social Mission Behind Every Annotation
Every annotator is a trained medical professional from conflict-affected communities, matched by specialty to your dataset.
Fair Work Conditions
UN SDG recognized
04
Scales With Your Team
Whether you’re piloting with 500 images or running a multi-thousand image production project, the review process and the annotator matching criteria stay the same.
60+ completed projects
Unsure which annotation method fits your dataset? Our team will evaluate your data and provide a tailored recommendation before any commitment.
Our Clients
The teams that built their annotation pipeline with us
“We developed a great partnership with Humans in the loop, and their dedication to our projects is evident in the final results. The communication was convenient and fast, tools were easy to use, and we could monitor the progress of the project and report any issues at any time. We appreciate their attention to details and their creative approach that made our annotation pipeline more productive.”
“I was really impressed by Humans in the Loop's commitment to deliver high-quality annotation. They take care of the details, educate annotators about the importance of details for each specific case, and provide a verification step to ensure precise annotations.”
“We came across Humans in the Loop through personal connections, which was also the primary factor in our decision to collaborate with the company, in addition to its social impact. Throughout the entire process, HITL team proved to be a dependable and consistent partner.”
Our Mission
Through our foundation, we provide accessible remote work opportunities to conflict-affected medical professionals
Most data annotation relies on platforms that hire anyone available, pay the minimum the market allows, and treat accuracy as a post-processing problem. We were built on a different assumption: that the quality of annotation work is a direct function of the conditions under which it’s done.
The people who annotate your data are medical professionals, trained, employed, and paid fairly. Many of them come through our foundation programmes, which provides structured clinical annotation training to conflict-affected people.
Price matters, and we are not the cheapest option. We engage medical professionals, pay them fairly, and structure every project around quality and accountability. Shortcuts save money upfront and cost significantly more when datasets need to be corrected or models retrained. We do not compete on price because our model is built around outcomes, and that is what separates us from other vendors.
Our 2025 impact in numbers
168
active annotators across all locations
113
people graduated from instructor-led courses
45.24%
women annotators (all locations)
364
career counseling sessions in 2025
€238.764 K
total earnings distributed
How It Works
Our structured review process combines medical expertise, QA validation, and consistent delivery standards across every dataset.
FAQ
Questions before starting a project.
Can’t find what you need? Contact us and we’ll get back to you as soon as possible.
Our annotation team is made up of clinically trained professionals with verified medical credentials and direct patient-facing experience. The team includes medical students, nurses, radiology technicians, interventional radiologists, general practitioners, internists, and specialists across cardiology, gastroenterology, ophthalmology, and other disciplines.
Our team has direct experience across major medical imaging modalities:
- X-ray
- Computed Tomography (CT or CAT)
- Magnetic Resonance Imaging (MRI)
- Ultrasound (Sonography)
- Nuclear Medicine (PET/SPECT)
- Fluoroscopy
- Thermograms
If your dataset involves a modality not listed here, contact us, our annotator network spans a wide range of clinical specialties and imaging contexts.
We run a pilot annotation round together to validate guidelines, review quality, and confirm project requirements. This gives you the opportunity to evaluate the experts working on your data, refine the scope of the project, and confirm that the workflow aligns with your objectives before full production begins.
As an EU‑based service provider, we are fully GDPR‑compliant. For HIPAA, it depends on the type of data you provide. We would need to review a sample to confirm whether any PHI is included. If the data is fully anonymized and contains no patient identifiers, then it meets the basic HIPAA‑safe criteria.
We ensure annotation accuracy through detailed project guidelines, trained annotators, and a multi-level quality assurance process. Every dataset undergoes annotation, review, and final QA checks, while we track quality metrics such as accuracy and consistency.
Yes, absolutely. Our team can work with your existing and/or proprietary annotation platform.
We’re highly adaptable and have extensive experience using both commercial and open‑source tools, including V7, Encord, Supervisely, RedBrick AI, CVAT, 3D Slicer, and others.
Because our annotators and QA specialists regularly switch between different tool environments, they’re able to learn new platforms quickly and become proficient in navigating workflows, toolsets, and project configurations.
In addition, the team uses a series of tools specifically for medical annotation of 2D and 3D imagery (such as DICOM, NIfTI, NRRD, TIFF/SVS).
We can typically start very quickly. Once we review your project scope and complete a complimentary 2‑hour trial, we’ll provide a detailed price quote and delivery timeline for your approval. In most cases, we move from scoping to trial, service agreement, and full project kickoff within just a few days.
What Clients Say About Us
We work with academia, large enterprises, and fast growing startups which are all working to advance Artificial Intelligence in the Medical Field
Ethan Shaw
PointLab Expert Team
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Margaret Anderson
Mark Anthony
Senior Pathologist
