CurrentBlue Cross Blue Shield - IowaPolicy N/A

Thermography and Temperature Gradient Studies

This policy governs the use and coverage stance for all forms of thermography (thermal imaging and temperature gradient studies) for diagnostic and treatment-planning purposes for Blue Cross Blue Shield - Iowa members.

Policy Summary

PayerBlue Cross Blue Shield - Iowa

PolicyThermography and Temperature Gradient Studies

Policy CodePolicy N/A

Change TypeAnnual review (no material changes)

Effective DateN/A

Next Review DateN/A

Key ActionDo not use thermography as a replacement for established diagnostic imaging; obtain conventional imaging (eg, mammography, radiography, MRI) before relying on thermography.

SourceLink

POLICY UPDATE CHANGES

No material clinical or coverage changes in this revision.

investigationalcoverage stance for all indications

insufficient evidenceconclusion on clinical utility

22studies in systematic review

no RCTsno RCTs for most indications

93740CPT listed

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Coverage Determinations and Rationale

inv-01: Not medically necessary / Investigational

Covered when ALL of the following are met

Investigational designation: The use of all forms of thermography (thermal imaging and temperature gradient studies) is considered investigational for all indications because the evidence is insufficient to determine that the technology results in an improvement in net health outcomes.

Applies to screening and diagnostic use across discussed indications (breast cancer, musculoskeletal injuries, TMJ, miscellaneous).

inv-02: Coverage conclusions

Summary coverage logic based on evidence:

Breast cancer screening/diagnosis: Thermography lacks sufficient diagnostic accuracy and there is no evidence that its use improves clinical management or patient outcomes; therefore it is not an acceptable substitute or supplement to mammography for breast cancer screening or diagnosis.

No direct evidence of clinical utility; chain of evidence cannot be constructed.

Musculoskeletal injury evaluation: Evidence from systematic reviews is limited, heterogeneous, and at moderate-to-high risk of bias; reported sensitivities and specificities for stress fractures and other injuries are variable, so clinical validity is uncertain and clinical utility has not been established.

Sanchis-Sanchez et al (2014) identified 6 studies (N=416) with variable accuracy measures.

inv-03: Musculoskeletal Injuries

Musculoskeletal Injuries — evidence summary

Musculoskeletal Injuries: evidence requirements: Systematic reviews and cohort studies report moderate and variable accuracy of thermography for musculoskeletal injuries, but studies lack a consistent reference standard and are heterogeneous; there is insufficient evidence that thermography improves patient management or health outcomes.

No high-quality randomized studies compare management with and without thermography; chain of evidence cannot be constructed.

inv-04: Temporomandibular Joint Disorder

Temporomandibular Joint Disorder — evidence summary

TMJ: evidence requirements: Systematic reviews report wide variation in diagnostic accuracy of thermography for TMJ disorder and high risk of bias across studies; there is no consistent reference standard and no studies evaluating the impact of thermography on patient management or health outcomes.

Reported sensitivity and specificity vary widely across included studies; clinical utility not demonstrated.

inv-05: Miscellaneous Conditions

Miscellaneous Conditions — evidence summary

Miscellaneous indications: evidence requirements: Numerous small diagnostic studies have assessed thermography for varied indications (eg, herpes zoster, pressure ulcers, postoperative wound healing, burn depth, lymph node metastasis, vascular/perforator detection, rheumatologic disease activity); randomized trials evaluating impact on management or health outcomes are lacking for most indications.

One randomized trial for diabetic foot ulcer prevention found no significant difference; other indications have only preliminary studies.

inv-06: Not supported / Not medically necessary

Not supported as a substitute for established diagnostic or screening modalities and lacking demonstrated clinical utility:

General: For breast cancer screening/diagnosis, TMJ disorder, diabetic foot complications, musculoskeletal injuries, and other miscellaneous indications, there is insufficient evidence from randomized trials or high-quality studies showing that thermography improves patient management or health outcomes; diagnostic accuracy is variable and reference standards are inconsistent, so thermography is not supported as a replacement or routine adjunct to established diagnostic modalities.

Supported by systematic reviews and professional society positions discouraging thermography for breast screening.

inv-07: Diabetic foot — clinical utility not demonstrated

Evidence specific to diabetic foot monitoring:

Diabetic foot utility trial: A randomized trial (n=110) comparing monthly thermography versus no thermography found no significant difference in foot ulcer incidence or time to ulcer recurrence after 12 months (ulcer incidence 62% vs 56%; adjusted OR 0.55, 95% CI 0.21–1.40; adjusted HR 0.67, 95% CI 0.34–1.3).

Clinical utility for diabetic foot monitoring was not demonstrated in this trial.

inv-08: TMJ — insufficient evidence

TMJ disorder diagnostic validity:

TMJ: A systematic review found wide variation in diagnostic accuracy of thermography for TMJ disorder, absence of a consistent reference standard, and no studies assessing whether thermography-guided management improves health outcomes.

Insufficient evidence to support replacement or supplementation of standard diagnostic testing for TMJ.

The policy classifies all forms of thermography (including thermal imaging and temperature gradient studies) as investigational for all indications because available evidence is insufficient to show that thermography improves net health outcomes compared with established diagnostic strategies.

Evidence from diagnostic studies and systematic reviews indicates that thermography alone is insufficient to replace conventional breast imaging. Automated and manual thermography studies report variable accuracy, and several studies applied reference testing only to patients with positive thermograms, limiting validity; overall, no data demonstrate thermography can reliably substitute for mammography in diagnostic evaluation.

Thermography is explicitly excluded as a replacement or supplement to mammography for breast cancer screening or diagnosis because systematic reviews show wide ranges of sensitivity and specificity and there are no studies demonstrating that thermography use improves patient management or outcomes compared with standard mammographic techniques.

Where diagnostic accuracy has not been shown to be at least equivalent to standard techniques, clinical usefulness cannot be inferred. The policy therefore does not support using thermography to replace standard diagnostic pathways when evidence of comparable diagnostic performance is lacking.

Major professional organizations and position statements do not endorse thermography for breast cancer screening or diagnosis. For example, the American Cancer Society and the American College of Radiology guidelines do not recommend thermography, and the European Society of Breast Imaging specifically discourages screening with thermography as an alternative to mammography; the NCCN states current evidence does not support routine use.

There is no specific CPT code for skin surface infrared thermography. Temperature gradient studies are listed under CPT 93740, and when a specific thermography procedure is reported using an unlisted code, CPT 93799 (unlisted cardiovascular service) has been cited as an alternate; coding limitations should be considered when submitting claims.

Because evidence across indications is limited, heterogeneous, and lacks randomized trials demonstrating improved patient management or outcomes, the policy concludes thermography is investigational for all indications and therefore not medically necessary for covered benefit determinations.

Systematic reviews and diagnostic studies show high heterogeneity and methodological limitations (selective reference testing, inconsistent blinding, and variable reference standards). This high heterogeneity and study quality concerns undermine confidence in pooled accuracy estimates and preclude recommending thermography as a standalone diagnostic test.

For breast cancer screening and diagnosis, there are no studies demonstrating that thermography improves patient health outcomes; diagnostic accuracy is variable and generally lower than mammography, so thermography is not medically necessary for these indications.

Available evidence does not support using thermography to replace or routinely supplement standard testing for musculoskeletal injuries, temporomandibular joint disorder, or diabetic foot evaluation. Systematic reviews report moderate but inconsistent accuracy for musculoskeletal applications, wide variation for TMJ, and the diabetic foot literature lacks replicated trials showing clinical benefit.

Across a broad set of potential indications (eg, burn depth assessment, wound healing, peripheral vascular assessment, rheumatologic disease activity), studies are small and preliminary. Given the limited and inconsistent clinical validity data and absence of trials demonstrating improved outcomes, thermography is not medically necessary for screening, diagnosis, or routine management of these listed indications.

Historically, the Centers for Medicare & Medicaid Services' National Coverage Determination for Thermography (NCD 220.11) has not supported coverage of thermography for breast cancer screening; this policy references that NCD as background to prior noncoverage determinations.

Indications Reviewed and Coverage Stance

inv-59: General indications reviewed in the evidence summary

General indications reviewed in the evidence summary

Indications discussed: Breast cancer screening or diagnosis; musculoskeletal injuries; temporomandibular joint (TMJ) disorder; diabetic foot and other miscellaneous conditions (eg, herpes zoster, pressure ulcers, burn depth assessment, vascular/perforator detection, rheumatologic disease activity).

These indications were assessed in diagnostic accuracy studies and systematic reviews but evidence was insufficient for coverage.

inv-60: Evaluation of breast cancer screening or diagnosis findings

Evaluation of breast cancer screening or diagnosis findings

Breast imaging context: Thermography has been evaluated for breast cancer screening and diagnosis but shows wide ranges of sensitivity and specificity, and no studies have demonstrated improved management or outcomes compared with standard mammography; thermography should not replace mammography.

Conventional breast imaging appears sufficient to manage patients referred after abnormal thermography findings.

Codes and Billing Guidance

Codes table referencedmixed

Covered CPT CodesCPT

93740

Temperature gradient studies; (note; there is no specific code for skin surface infrared thermography )

Unlisted/Alternate CPT CodesCPT

93799

Unlisted cardiovascular service or procedure (when utilized for thermography).

HCPCS/OtherHCPCS

No code(s)

Indicates places where no HCPCS or other codes are provided in this section.

Ancillary coding notes

Coding noteN/A — no additional ancillary coding guidance provided in this policy beyond listed CPT/ unlisted alternatives.

Reporting instructionReport provider services with appropriate CPT, HCPCS, Revenue, and ICD diagnosis codes as applicable.

Claims processing cautionUse of unlisted CPT (93799) when no specific code exists may affect claims processing — include supporting documentation.

93740 — temperature gradient studies

CPT code93740

Description

Prior Authorization, Documentation, and Billing Actions

Prior Authorization

Prior Authorization Guidance

Prior approval is not applicable under this policy; however, prior authorization is recommended when thermography is proposed as the primary diagnostic or screening test because evidence does not support its use as a replacement for standard diagnostic pathways.

Prior authorization recommended when thermography is the primary diagnostic/screening test

Note

Clinical Workflow — Adjunctive Use Only

Thermography should be used as an adjunctive tool only and not as a replacement for conventional imaging or standard diagnostic evaluation. For breast complaints and screening, conventional imaging (mammography and/or ultrasound) and appropriate clinical assessment should be performed before relying on thermography for diagnostic decisions. For musculoskeletal and TMJ indications, follow standard clinical examination and appropriate imaging (radiography, MRI, arthrotomography) prior to approving thermography.

Use conventional imaging (mammography/ultrasound) before thermography for breast evaluation
For musculoskeletal/TMJ, pursue standard imaging and clinical exams before thermography

Key Terms and Concepts

Thermogram — definition

DefinitionThermogram: the visual display of temperature information obtained from thermal imaging or temperature gradient studies.

ModalityIncludes thermal imaging and temperature gradient studies (infrared thermal imaging).

PurposeNoninvasive measurement of cutaneous or tissue temperature distributions proposed for diagnosis, treatment planning, or monitoring.

Thermal score — automated thermography scoring

DefinitionThermal score: sum of the surface temperature difference at the lesion site compared to the contralateral site plus a vascularity score (scale 1–4).

Vascularity scale1 = absence of vascular patterns; 2 = symmetrical or moderate vascular patterns; 3 = significant vascular asymmetry; 4 = vascular asymmetry extended in at least one-third of breast area.

Background and Evidence Overview

Thermography is a noninvasive imaging technique that measures the distribution of surface temperature and produces thermograms; it has been proposed for diagnosis, treatment planning, and monitoring across multiple clinical settings but lacks demonstrated clinical utility for covered indications.

inv-16 (supporting): Evidence heterogeneity and methodological limitations undermining standalone use

Evidence heterogeneity and methodological limitations undermining standalone use

Evidence limitations: Diagnostic studies frequently had selective reference testing, incomplete application of reference standards, unclear blinding, and population or spectrum issues that limit generalizability; these methodological limitations contribute to heterogeneity and preclude reliable conclusions that thermography can replace standard imaging.

Examples include studies where only patients with positive index tests received reference standard evaluation.

Explicit Non-Covered Uses

The use of thermography is considered investigational for all indications and therefore is not covered as medically necessary based on current evidence.

Thermography is classified as investigational and not covered; requests for thermography may be denied as not medically necessary.

Thermography is not covered as a substitute for or supplement to mammography; conventional breast imaging remains the accepted standard for diagnostic evaluation and management.

Thermography is not covered as a replacement for standard imaging in the evaluation of temporomandibular joint disorder, musculoskeletal injuries, or diabetic foot complications due to insufficient evidence of diagnostic accuracy and lack of demonstrated impact on patient outcomes.

All uses of thermography across modality and indication combinations are considered investigational and not supported for coverage in the absence of stronger evidence.

CMS NCD 220.11 (Thermography) is cited in the references and historically indicates noncoverage for thermography as a breast cancer screening test.

Service Frequency and Limits

Thermography/Temperature gradient studies — frequency/limits

Frequency/limitNo specific frequency limits or repeat-usage restrictions are provided for thermography/temperature gradient studies in this policy (N/A).

Documentation for repeat useWhen thermography or unlisted codes are reported repeatedly, include clinical rationale and documentation supporting medical necessity due to potential coverage restrictions.

Prior authorization notePrior authorization may be required when thermography is proposed as a primary diagnostic modality instead of standard imaging.

Prior Authorization Considerations

Prior Authorization

Prior auth when thermography replaces standard imaging

Prior authorization may be required when thermography is proposed as the primary diagnostic modality instead of standard imaging; document justification for departure from standard pathways.

Prior Authorization

Prior authorization callout for thermography/temperature gradient studies

Temperature gradient studies and thermography services may be subject to prior authorization; verify requirements when submitting requests.

Contrast and Technical Notes

Billing Rule

Contrast rules: no explicit contrast-specific guidance

Multiple references describe varied applications of thermography across body regions, but the policy provides no explicit contrast-specific rules for thermography.

Policy Revision History

November 2025Annual review / RenewalLatest

Policy underwent annual review and was renewed.

November 2024Annual review / Renewal

Policy underwent annual review and was renewed.

November 2023Annual review / Revision

Policy Summary

PayerBlue Cross Blue Shield - Iowa

PolicyThermography and Temperature Gradient Studies

Policy CodePolicy N/A

Change TypeAnnual review (no material changes)

Effective DateN/A

Next Review DateN/A

Key ActionDo not use thermography as a replacement for established diagnostic imaging; obtain conventional imaging (eg, mammography, radiography, MRI) before relying on thermography.

SourceLink

On This Page

inv-61: Evaluation of musculoskeletal injury (diagnostic adjunct)

Evaluation of musculoskeletal injury (diagnostic adjunct)

Musculoskeletal diagnostic intent: Thermography has been studied as an adjunct to inform decisions after musculoskeletal injury, with outcomes focused on diagnostic accuracy (sensitivity, specificity) and clinical outcomes such as pain and function; available systematic reviews report moderate and inconsistent accuracy and lack of consistent reference standards.

Evidence does not permit conclusions that thermography can replace or reliably supplement standard imaging modalities.

inv-62: Breast cancer screening or diagnosis

Breast cancer screening or diagnosis

Breast cancer screening/diagnosis: Thermography is not supported as a replacement or routine supplement to mammography due to variable diagnostic accuracy across studies, methodological limitations, and absence of evidence showing improved patient outcomes.

No chain of evidence linking thermography accuracy to clinical utility exists.

inv-63: Musculoskeletal injury monitoring; TMJ assessment; diabetic foot screening; miscellaneous uses

Musculoskeletal injury monitoring; TMJ assessment; diabetic foot screening; miscellaneous uses

Aggregated indications: Thermography has been studied for monitoring musculoskeletal injuries, assessing TMJ disorder, screening and risk assessment for diabetic foot complications, and diverse miscellaneous dermatologic, vascular, and surgical applications; however, studies are small and heterogeneous and clinical utility has not been established for these indications.

One diabetic foot RCT exists with null findings; other indications lack randomized trials of clinical utility.

inv-64: Miscellaneous clinical indications — not supported

Miscellaneous clinical indications — not supported

Miscellaneous not supported: Most miscellaneous clinical indications have only preliminary studies (often 1–2 per indication) and lack sufficient data to evaluate diagnostic accuracy or clinical utility; therefore thermography is not supported for routine use in these indications.

Examples include post-herpetic neuralgia, pressure ulcer prediction, wound healing, burn assessment, and various dermatologic and vascular uses.

inv-65: Breast cancer screening — explicit non-support

Breast cancer screening — explicit non-support

Breast screening non-support: Major professional societies and position papers do not endorse thermography as an alternative to mammography for breast cancer screening and discourage its use as a substitute.

References include ACS guidelines, ACR statements, EUSOBI position paper, and NCCN guidance.

inv-66: Diabetic foot monitoring — not supported

Diabetic foot monitoring — not supported

Diabetic foot not supported: Randomized evidence (single RCT, n=110) did not demonstrate that monthly thermography reduced foot ulcer incidence or time to recurrence; clinical utility for diabetic foot monitoring is not established.

Adjusted OR and HR estimates were not significant at 12 months.

inv-67: Temporomandibular joint disorder — not supported

Temporomandibular joint disorder — not supported

TMJ not supported: Systematic review data show heterogeneous and inconsistent diagnostic accuracy for thermography in TMJ disorder, and no studies have evaluated whether thermography-guided care improves management or outcomes; thermography is not supported as a diagnostic replacement or supplement for TMJ.

High or unclear risk of bias reported across included studies.

inv-68: Document cites multiple diagnostic and investigational uses across conditions without establishing coverage criteria in these chunks

Document cites multiple diagnostic and investigational uses across conditions without establishing coverage criteria in these chunks

Referenced applications: The literature includes studies of thermography for detection of perforator vessels, cellulitis vs other diagnoses, post-operative bypass monitoring, melanoma detection, contact dermatitis assessment, appendicitis diagnosis, inflammatory arthritis evaluation, diabetic foot risk assessment, and breast cancer research, but these references do not provide sufficient evidence to establish coverage criteria for these uses.

References are diverse and primarily provide preliminary or diagnostic accuracy data without clinical utility evidence.

Temperature gradient studies; (note: there is no specific code for skin surface infrared thermography).

Use caseReport temperature gradient studies using CPT 93740 when appropriate per service documentation.

Skin surface infrared thermography — coding

Specific CPTNo specific CPT code for skin surface infrared thermography

Alternate codeUnlisted cardiovascular service/procedure, CPT 93799, may be used when thermography is reported using an unlisted code.

DocumentationWhen using an unlisted code (93799), submit detailed clinical documentation to support the service and facilitate claims processing.

Thermography records cutaneous temperature patterns and produces a visual thermogram; it is noninvasive and has been evaluated using both dedicated and smartphone-compatible devices, but coding and reporting should follow available CPT guidance where applicable.

Denial Risk

Evidence Limitations — Selective Reference Testing and Bias

Evidence for thermography has important limitations that increase the risk of biased or misleading results. Several studies used selective reference testing (reference standards applied only to patients with positive index tests), had unclear or absent blinding of assessors, and had variable timing between index and reference tests. These design limitations reduce confidence in reported diagnostic accuracy and should be considered when evaluating medical necessity.

Selective reference testing and incomplete blinding were common limitations in diagnostic studies
Timing between index test and reference standard was often inadequate or inconsistently reported

Denial Risk

Denial Risk — Evidence Insufficiency

Requests for thermography may be denied due to insufficient evidence of diagnostic accuracy and lack of demonstrated clinical utility. No randomized trials have shown that thermography improves patient management or health outcomes; absent convincing diagnostic performance compared with standard tests, authorization may be declined.

Lack of RCTs showing improved management or outcomes may trigger denial
Insufficient diagnostic accuracy versus standard modalities is a denial risk

Documentation Required

Documentation Expectations

When thermography is requested, submit documentation that clearly justifies its use and supports clinical decision-making. Required documentation includes the clinical rationale for testing, details of prior conventional evaluations (e.g., exams, imaging, and results), and the specific thermography technology/version to be used. Provide study/reporting details when available (index test thresholds, timing relative to reference tests, and blinding procedures). Absent or inadequate documentation increases the likelihood of denial.

Document clinical rationale and why conventional testing is insufficient or already performed
Provide the marketed technology/version and any algorithm or scoring method
Include prior imaging results, clinical exam findings, and planned use of thermography results in management

Billing Rule

Billing and Coding Guidance

Billing: there is no dedicated CPT for skin surface infrared thermography. Use CPT 93740 for temperature gradient studies where appropriate; when a specific thermography code is not applicable, report the service with unlisted CPT 93799 and include supporting documentation describing the procedure and clinical indication. Report services with appropriate ICD diagnosis codes and place-of-service information as usual.

Preferred code for temperature gradient studies: CPT 93740
If no specific CPT applies for thermography, report with 93799 (Unlisted cardiovascular service or procedure) and attach detailed documentation
Include ICD diagnosis codes and provider/service details on claims

UseUsed in automated thermography scoring to classify findings in breast studies.

\u0394T (temperature gradient) — threshold definition

TermΔT (temperature gradient)

DefinitionIndicates the temperature difference used as a threshold to classify thermography results (examples reported include ΔT ≥ 3 or ΔT > 2.5).

Role in studiesΔT thresholds are applied to distinguish abnormal from normal thermographic findings in diagnostic accuracy analyses.

Clinically Useful — definition

DefinitionClinically useful: a test whose results inform management decisions that improve net health outcomes (eg, enabling correct or more effective therapy, or avoidance of unnecessary therapy/testing).

Net health outcomeImprovement may occur if patients receive correct therapy, more effective therapy, or avoid unnecessary interventions.

Relation to utilityClinical usefulness requires that changes in management based on test results lead to better patient outcomes, not just diagnostic accuracy alone.

Clinically Useful / Clinically Valid — definitions

Clinically validA test must detect presence or absence of a condition, risk of developing a condition, or treatment response (beneficial or adverse).

Clinically useful vs validClinically valid refers to test accuracy; clinically useful requires that use of the test leads to management changes that improve net health outcomes.

Evidence requirementDemonstration of clinical validity is necessary but not sufficient; evidence must show improved management or outcomes to be clinically useful.

Thermography — infrared thermal imaging definition

DefinitionThermography (infrared thermal imaging): a noninvasive imaging technique that records cutaneous temperature patterns to infer underlying pathology.

ApplicationsProposed uses include diagnosis, treatment planning, and evaluation of treatment effects across various conditions (breast, musculoskeletal, TMJ, diabetic foot, burns, vascular/dermatologic).

Limitations notedEvidence on clinical utility across indications is limited and largely preliminary; no RCTs demonstrate improved patient outcomes for most indications.