SPOTLIGHT ON MEDICAL CONFIRMATION OF THERMAL IMAGING: MEET THERMA-SCAN

DIRECT FROM THE SOURCE-  HealthTech reporter is proud bring you a mini-autobiographical tour of the science of THERMOLOGY.  We introduce Dr. Phil Hoekstra, a medical physiologist specializing in medical-grade thermal imaging. He is the Laboratory Director at Therma-Scan Reference Laboratory in Mesa, Arizona. With decades of experience in thermal imaging, Dr. Hoekstra has contributed extensively to the field, enhancing the clinical application of infrared imaging in medical diagnostics. Therma-Scan Reference Laboratory stands as the premier facility for medical thermal imaging, setting the standard for accuracy and reliability. The laboratory provides advanced thermographic analysis for various clinical applications, ensuring the highest level of diagnostic precision.

Dr. Hoekstra’s expertise extends beyond laboratory operations; he actively contributes to the advancement of thermal imaging technology and its integration into medical practice. His work has helped establish best practices and protocols that elevate diagnostic thermal imaging as a reliable tool in healthcare.

 

DEFINING MEDICAL-GRADE THERMAL IMAGING
Transcribed from an interview with Dr. Phil Hoekstra (from Feb 22, 2025)

MEDICAL-GRADE THERMAL IMAGING is a term I use with a level of precision that differs from many others in the field. Let me clarify what I mean by it. Thermographic instruments were already in use before the FDA gained oversight over medical devices. Initially, they were grandfathered in as medical devices when the FDA assumed regulatory authority, but the standards set at the time were quite limited. Over the years, thermographic technology has advanced at a pace similar to personal computers. Just as we wouldn’t want to rely on a 1980s-era computer today, we shouldn't be using outdated thermal imaging standards for medical applications. Unfortunately, the FDA still maintains the original 1980s standards for medical thermographs. If a camera meets these older benchmarks, it can be FDA-approved—but this does not necessarily mean it is suitable for modern medical diagnostics. The performance of such cameras is inadequate for properly distinguishing breast cancer from benign conditions that may present with similar thermal patterns.

When I refer to a medical-grade thermograph, I mean a state-of-the-art camera with the necessary precision and reliability for accurate medical diagnostics. While thermal cameras vary widely—from basic models used for home insulation inspections to advanced systems on the James Webb Space Telescope—medical thermographs fall somewhere in between. They must be both practically affordable and sufficiently high-performing. Specifically, a true medical-grade thermograph must be capable of resolving at least 0.001 degrees Celsius over a one-square-millimeter area of skin at the working distance of the lens, with repeatable accuracy. 

Beyond the equipment, medical-grade imaging also refers to the methodology applied in thermal imaging, which must align with the principles of medical oncology. Additionally, the laboratory handling these images must adhere to HIPAA regulations and the same rigorous standards and practices found in top-tier medical centers.

Medical-grade imaging starts with the facility performing the scans. The imaging process must follow strict protocols, utilizing high-quality equipment that meets our specifications. At Therma-Scan Reference Laboratory, we prefer to work with FLIR cameras, which are FDA-listed as medical devices. These cameras are radiometric, meaning each pixel functions as a thermometer that provides quantitative temperature data rather than merely producing a colorized image.

Our analysis relies heavily on specialty software, which is also FDA-listed. This software enables precise temperature measurements at various points, allows us to track changes over time, and facilitates diagnostic evaluations through dynamic applications such as a functional challenge procedures. This process involves taking baseline images, subjecting the patient to a controlled cooling stimulus, and capturing post-exposure images to assess physiologic responses. This level of quantification ensures that our results are not just qualitative interpretations but rigorously analyzed data.

(L) Dense Breast mammography
(R) Breast Thermology

THE ROLE OF NEOANGIOGENESIS IN BREAST CANCER DETECTION

One of the core principles of medical thermography is detecting physiologic changes associated with cancer. Neoangiogenesis—the formation of new blood vessels—is critical for tumor growth. Without it, cancerous cells would be unable to obtain the nutrients they need to proliferate. The abnormal structure of these new blood vessels was not well understood until the late 1980s, when studies revealed their unique porous nature.

Unlike normal blood vessels, which have a structured, three-layered composition, neoangiogenic vessels are disorganized and resemble a natural sponge, with an erratic, unregulated flow. Lacking smooth muscle and autonomic nervous system regulation, these vessels exhibit excessive and uncontrolled blood flow. As a result, areas of neoangiogenesis appear as "hot spots" in thermal imaging. Because breast tissue is located in the outer shell of the body, where body heat is regulated to maintain a stable core body temperature, these hot patterns can indicate malignancy, setting medical thermology apart as a functional imaging modality distinct from structural imaging techniques like mammography, ultrasound and MRI.

 

ADVANCING THE FIELD OF MEDICAL THERMOGRAPHY
Therma-Scan Reference Laboratory is at the forefront of innovation in medical thermography. Our approach is defined by strict adherence to quantitative, repeatable standards that ensure reliability. Many of the advances in the field—including the objective analytic standards, the adaptation of the Marseille system (later incorporated into the American College of Radiology’s BI-RADS system) and the high-caliber equipment used—originated with our work.

Unlike traditional thermographic assessments that relied on static images and pattern recognition, the future lies in dynamic thermology. This emerging field involves capturing real-time, streamed thermal images and applying digital subtraction analysis to detect physiological responses to stimuli. At Therma-Scan, we pioneered the adaptive challenge, in which we capture baseline thermal images, expose the patient to a mild cooling stimulus, and then record post-exposure images to assess changes. The next step in our research is refining this process with advanced digital subtraction techniques, enhancing diagnostic precision.

 Unfortunately, medical thermology has not benefited from significant funding or institutional support comparable to what mammography has received through organizations like the American College of Radiology. As a result, progress has been largely self-funded, requiring careful resource allocation to keep services affordable while driving innovation forward. Although medical thermology is recognized with CPT codes, it is not currently covered by insurance, adding another layer of financial challenge.

 

A LEGACY IN MEDICAL SCIENCE
My journey in medical thermology has been shaped by mentorship from pioneering experts in the field. I was fortunate to train under multidisciplinary leaders, including Harold Isard, a student of Jacob Gershon-Cohen, a key figure in early thermographic research. Through four separate fellowships, I gained hands-on experience and contributed to the field's development. To achieve professional certification, I submitted 50 cases to the American Board of Thermology for rigorous review, defending each case before a physician board in a process akin to a dissertation defense. As far as I know, I am the only individual who has pursued this level of certification across four different specializations in medical thermology. This dedication reflects my commitment to ensuring the highest standards in medical thermography and advancing the field through research, innovation and clinical application.

By continuously refining our methodologies, investing in new technologies and upholding the strictest standards, Therma-Scan Reference Laboratory remains the leader in the evolving landscape of medical thermal imaging. The future of thermology lies in dynamic, quantitative analysis—and we are proud to be paving the way.