Protocols and Standards for Thermography Imaging -- Part I

Infrared thermography is a valuable diagnostic imaging modality available to the practicing chiropractor. Thermography is a test of neurophysiology. Cutaneous infrared heat emission is a function of the underlying sympathetic control and local chemical mediators. Thermal imaging is sensitive to detecting abnormalities due to myofascial disorders, spinal nerve dysfunction, peripheral nerve dysfunction, and scleratogenous dysfunction. It is an excellent tool to help the clinician differentially diagnose myofascial, neurologic, and articular sources of pain, as well as temporomandibular joint (TMJ) syndrome and reflex sympathetic dystrophy.

The literature is replete with scientific studies documenting the sensitivity, specificity, predictive value, interexaminer reliability, and clinical efficacy of thermography in clinical practice. Thermography has been considered a favorable technique and diagnostic imaging tool by such groups as the AMA Council on Scientific Affairs, ACA Council on Diagnostic Imaging, ICA Council on Diagnostic Imaging, American Academy of Pain Management, American Academy of Physical Medicine and Rehabilitation, Congress of Neurological Surgeons, and the American Academy of Head, Neck, Facial Pain, and TMJ Orthopedics.

However, infrared thermography is not without controversy. There has been a handful of papers that have criticized thermography's role in neuromusculoskeletal medicine, due to what the authors describe as poor specificity and lack of many controlled double-blinded studies. These authors who, in my opinion, were on a mission to discredit thermography, improperly defined their definition of specificity and ignored the 6,000-7,000 articles published in the world scientific literature that included many blinded studies, specificity/sensitivity studies, and good statistically significant articles published in well-respected peer reviewed journals.

Despite the detractors, thermography is still a helpful, useful tool to the practicing clinician. It stands alone in the diagnosis of Reflex Sympathetic Dystrophy Syndrome and is much more sensitive than bone scan. Thermography is useful in the sports injury practice, as well as for personal injury assessment in practices where soft-tissue injuries are common and need to be documented. It is useful in the orthopedic/neurological specialty practices as a differential diagnostic tool and it is useful in the subluxation-based practice since it documents pathoneurophysiology.

Standards and protocols of infrared imaging have been previously published by the American Chiropractic College of Thermography (ACA), the International Thermographic Society (ITS), the American Academy of Thermology (AAT) and the American Academy of Medical Infrared Imaging (AAMII), (formerly the American Herschel Society). The purpose of this paper is to familiarize the chiropractic profession with the many academies and colleges of thermography in the profession and the protocols and standards associated with infrared imaging. This is just a review paper and should not be construed as a "standards" document, in and of itself.

The following is a 1991 policy statement on thermography from the ACA and the Council on Diagnostic Imaging.

"High resolution infrared (HRI) imaging (electronic infrared thermography) is a diagnostic procedure which measures skin surface temperature. It is germane to chiropractic practice in cases where a physiologic test is required for the diagnosis of selected neurological and musculoskeletal conditions.

"High resolution infrared imaging requires a high level of operator and interpreter competency and an adherence to established and consistent protocol.

"The results of high resolution infrared imaging must be properly correlated with a thorough history; an appropriate clinical examination and other diagnostic studies/tests as may be indicted by clinical necessity. In this setting, high resolution infrared imaging may be an aid in establishing a differentiated diagnosis and in determining a prognosis.

"This policy statement, approved by the ACA House of Delegates on June 13, 1991, supersedes all previous thermography policy statements from the American Chiropractic College of Thermology and ACA Council on Diagnostic Imaging."

Guidelines for Thermography in Chiropractic Practice

Thermographic Description

"Thermography is a diagnostic procedure which measures skin surface temperature distribution."

Thermographic Policy

"This diagnostic imaging procedure is germane to chiropractic practice in cases where a physiologic test is required. High resolution infrared (HRI) imaging is a useful procedure for the diagnosis of selected neurological and musculoskeletal conditions."

Guidelines for Determining Medical Necessity

"The treating doctor shall certify as to the medical necessity of the thermographic study based upon a diagnostic clinical question and the effect of the results on case management decisions. The referring doctor shall certify to the medical necessity by prescription.

"HRI imaging is a value in the diagnostic evaluation of patients when the clinical history suggests the presence of one of the following situations:

1. "Early diagnosis and monitoring of reflex sympathetic dystrophy syndromes.

    

2. "Evaluation of spinal nerve root/fiber irritation and distal peripheral nerve fiber pathology for detection of sensory autonomic dysfunction.

    

3. "To evaluate and monitor soft tissue injuries, including segmental dysfunction/subluxation, sprain, and myofascial conditions (strains and myofascial pain syndromes) not responding to clinical treatment.

    

4. "To evaluate for the physiological significance of equivocal or minor anatomical findings seen on myelograms, CT and/or MRI.

    

5. "To evaluate for feigned disorders (symptom magnification)."

Utilization Review

"Because of the detailed knowledge, training, and skill level required, thermographic studies ordered, produced, or interpreted by chiropractic physicians must be reviewed only by a licensed chiropractor who holds appropriate** credentials with regard to knowledge, skill, and experience in thermography. Only licensed chiropractors holding such credentials can claim sufficient competence to make valid judgments or comments regarding appropriateness, necessity or accuracy of thermographic studies, and their relevance in chiropractic case management.

• "Board certified status with the American Board of Thermography or other national thermographic certifying board which restricts its examination to candidates who have completed a prescribed postgraduate syllabus program offered by a chiropractic college having status with a national chiropractic accrediting agency approved by the United States Department of Education (USDE)."

II American Academy of Medical Infrared Imaging

Considerations Must Be Given to the Following:

1. "Environmental Room Factors: Temperature and humidity should be maintained during the procedure. Ideally a 69^oF, (Ring, et al.) low humidity, minimal draft, non-reflective walls room is needed. The instrument being used should be capable of compensating for temperature fluctuations in the examining room on line. No heat source other than the patient should be in the optical path of the imaging instrument.

    

2. "Mechanical Stimulation of the patient's nervous system must be minimized. No physiotherapy, TENS or testing such as EMG/nerve conduction that day. No braces, splints or use of powder, creams or lotions applied. No sunburn.

    

3. "Medications: Care must be taken to avoid the influence of vasoactive substances in amounts sufficient to curb autonomic skin responses. No nicotine or coffee in large quantities.

    

4. "Skin Equilibration: The rate of change of skin temperature to the examining room temperature should come to a relative steady state prior to final imaging.

"(Suggested: The patient should disrobe and remain in the controlled (20^oC) examining room for approximately 15-20 minutes prior to the thermogram being made.

5. "Instrumentation: Used for medical diagnostic thermography should, as a minimum, be able to detect and measure temperature differences of 0.1^oC over the temperature ranges of the human body. Accuracy, stability, and repeatability of the instrument is a must.

6. "A minimum of one set of entire skin surface images shall be accomplished."

 

III. International Thermographic Society

Definition "Clinical thermography is a non-invasive, diagnostic imaging procedure involving the detection and recording of a patient's skin surface thermal patterns, using instruments which can provide visual and quantitative documentation of these temperature measurements. The interpretation of these temperatures and thermal patterns can be important in the development of diagnostic impression.

"Thermography is appropriate and germane to any health care practice whenever the treating physician feels a physiological imaging test is needed for diagnosis or case management. It provides information about acute as well as chronic conditions and can be useful in distinguishing aggravated from residual tissue injury. Thermography is an imaging technology which provides information on the normal and abnormal functioning of the sensory and sympathetic nervous systems, vascular dysfunction, myofascial trauma, and local inflammatory processes. It may contribute to a diagnosis and patient management by aiding in the determination of the site and degree of lesion, the type of functional disorder, and the prognosis for treatment outcomes, as well as assisting in the determination of the most effective course of treatment through continual case evaluation.

"Thermography is an acceptable analytical procedure which may be performed by a licensed or certified professional or under their supervision, in specific cases which demonstrate adequate clinical justification. However, only a certified professional, holding appropriate credentials with regard to knowledge, skill, and exercise in thermography may interpret the results."

David J. BenEliyahu, D.C., DABCT
Selden, New York