Medical Infrared Imaging

Skin temperature measured by infrared thermography after ultrasound-guided blockade of the sciatic nerve.

van Haren FG¹, Kadic L, Driessen JJ.

Author information 

Abstract

BACKGROUND:

In the present study, we assessed the relationship between subgluteal sciatic nerve blocking and skin temperature by infrared thermography in the lower extremity. We hypothesized that blocking the sciatic nerve will lead to an increase in temperature, and that this will correlate with existing sensory block tests.

METHODS:

We studied 18 healthy individuals undergoing orthopaedic surgery of the foot under ultrasound-guided subgluteal blockade of the sciatic nerve with 30 ml ropivacaine 7.5 mg/ml. Skin temperature was measured on the toes, the dorsal and plantar side of the foot, the malleoli, and the lateral side of the lower leg, just before sciatic nerve blockade and at 10-min intervals thereafter.

RESULTS:

Baseline skin temperatures showed a significant distal-to-proximal gradient. After sciatic block, temperatures on the blocked side increased significantly in the toes and foot. When comparing pinprick to skin temperature in a receiver operating curve, there was an AUC of 85.9% (95% confidence interval = 83.7-88.2%, P < 0.001). The medial malleolus (not being innervated by the sciatic nerve) showed no significant difference to the lateral.

CONCLUSIONS:

After sciatic nerve block, temperatures of the foot increased significantly. There was a good correlation between pinprick testing and infrared temperature measurement. This makes infrared skin temperature measuring a good test in determining block success when sensory testing is impossible.

© 2013 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Medical Infrared Imaging

Does the temperature gradient correlate with the photodynamic diagnosis parameter numerical colour value (NCV)?

Cholewka A, Stanek A, Kwiatek S, Sieroń A, Drzazga Z.

Source

Institute of Physics, Department of Medical Physics, University of Silesia, Uniwersytecka 4, 40-007 Katowice, Poland. armand.cholewka@gmail.com

Abstract

BACKGROUND:

Photodynamic diagnosis (PDD) as well as thermovision belong to the category of non-invasive optical diagnosis techniques. Among many different skin cancer diseases, basal cell carcinoma (BCC) is the most frequently occurring one (almost 95% of all skin tumours). In contrast, seborrhoeic keratosis represents almost 70% of benign skin tumours. In this paper we present infrared thermography as an additional method, combined with PDD, to show the differentiation between these two skin mutations.

METHODS:

The photodynamic diagnosis studies were performed by using the autofluorescence diagnosis system Xillix Onco. As an additional non-invasive diagnosis technique, thermovision studies were performed. Thermal imaging was done by using a Thermovision Camera A40M with a sensitivity of 0.07K. The thermograms of the chosen areas were performed in a special room with a temperature of 22.5±1°C. All patients were treated in the Chair and Clinic of Internal Diseases, Angiology and Physical Medicine in Bytom. Thirteen skin lesions were studied: 9 diagnosed as basal cell carcinoma and 4 as seborrhoeic keratosis. All skin lesions were confirmed in histopathological examinations.

RESULTS AND CONCLUSIONS:

The results of the studies revealed significant differences in skin thermal mapping between patients suffering from basal cell carcinoma and seborrhoeic keratosis. It appears that benign skin lesions are characterised by a lower mean temperature than the surrounding healthy skin. To the contrary, cancerous skin mutations appeared on the thermal map at a higher mean temperature. Thermal images for the chosen skin lesions and temperature parameters derived from the thermograms are contiguous with the photodynamic diagnosis results and may give some additional diagnostic information.

Clinical Application Of Thermography In Dentistry
Thermography measurement in the clinical set up can be done on a given spot or over an extended area of interest. Infrared telethermography of the face in normal subjects have shown that men have higher temperatures than females. The rationale behind this is that men have more basal metabolic than women and his skin dissipates more heat per unit area of body surface. Similarly age and ethnicity variations in facial temperature can also occur. [14-16]

In Chronic Orofacial pain patients 
Gratt and his colleagues in 1996 developed a classification system using telethermographs for patients with chronic pain. [17] They classified them as normal when selected anatomic area (ΔT) values range from 0.0 to +0.250C, hot when it is >0.350C, and cold when it is <0.350C. When a selected anatomic area value is 0.26- 0.350C, the finding is classified as equivocal. Moreover they also found that hot thermographs had the clinical diagnosis of (1) sympathetically maintained pain, (2) peripheral nerve mediated pain, (3) TMJ arthropathy, or (4) maxillary sinusitis. Subjects classified with cold subareas on their thermographs were found to have the clinical diagnosis of (1) peripheral nerve-mediated pain (2) sympathetically independent pain. Subjects classified with normal telethermographs included patients with the clinicaldiagnosis of (1) cracked tooth syndrome (2) trigeminal neuralgia (3) pretrigeminal neuralgia (4) psychogenic facial pain. This system of thermal classification resulted in 92% agreement in classifying pain patients making it as an important diagnostic parameter. [12,17]

In TMJ disorders 
Normal TMJ examination using thermography had showed symmetrical thermal patterns with a mean ΔT values of 0.10C. [12, 14, 18] On the other hand, patients affected with internal derangement and TMJ osteoarthritis showed ΔT values of +0.40C. [19, 20] Beth and Gratt in 1996 conducted a double-blinded clinical study to compare the ΔT values among active orthodontic patients, TMD patients and symptomatic TMJ controls. The results showed that the average TMJ area ΔT values as +0.20C, +0.40C, and +0.10C in these groups respectively.(21) The above findings suggest that tele-thermography can distinguish between patients undergoing active orthodontic treatment and patients with TMD. [12,21]

In quantification of thermal insult to pulp 
Dental pulpal tissue is exposed to variety of thermal insult during various dental treatment modalities. Of late for debonding of orthodontic brackets Eelectro Thermal Ddebonding (ETD) method is widely used, this technique although has many advantages than the conventional mechanical method can pose serious thermal damage to pulp. Cummings and his colleagues in 1999 performed an in-vitro study on extracted human premolar teeth applying ETD. Thermal imaging analysis was done using mercury cadmium terullide detector showed that the pulpal temperature increased from 16.80C- 45.60C, which can pose serious threat to pulpal vitality. It can be stated from the study that, ETD methods needs intermittent cooling of the teeth with simultaneous thermal imaging to prevent pulpal damage. [22] Similarly the use of ultra high speed air-driven instrumentation during cavity preparation can result in serious thermal insult to the pulp. To overcome this, it is believed that various coolants (air water spray or air/water alone) can be used to reduce the intrapulpal temperature and prevent subsequent damage to the pulp. It was only until 1979, when Carson and his colleagues performed a study employing thermography to determine the pattern of heat distribution and dissipation during ultra-speed cavity preparation using both an air-water spray and air only coolants to determine if a point heat source is generated. This study stated that the mean magnitude of temperature increases with both types of coolant, 2.80C and 3.670C, probably does not exceed the physiologic limits of the pulp. [23]
In assessing inferior alveolar nerve deficit
Over the years numerous studies have shown that thermal imaging technique can play a vital role in effective assessment of inferior alveolar nerve deficit. [12,24] Gratt and his colleagues in 1994 stated that patients with inferior alveolar nerve deficit when examined showed ΔT values of +0.50C on the affected side whereas subjects with no inferior alveolar nerve deficit showed a symmetrical thermal ΔT value of +0.10C. [25] The authors stated that the changes are due to blockage of the vascular neuronal vasoconstriction and this was confirmed by the same colleagues in the same year when similar thermological picture was obtained in normal subjects by temporary blockage of the inferior alveolar nerve using 2% lidocaine. [26]

Qualitative evaluation of N2O concentration
N2O is a highly insoluble gas which is rapidly absorbed and is eliminated swiftly by the lungs, thus it is used widely either alone or in combination with other anesthetic agents. [27] Results of various studies have shown that leakage of N2O into the workplace can lead to adverse health effects such as reproductive, hematologic and nervous dysfunctions. [28] Studies on acute and chronic occupational exposures have shown that N2O air concentration levels as low as 50 parts per million (ppm) can result in bone marrow depression, paresthesias, altered concentration, impaired visual effects, alterations in vitamin B12 and plasma homocysteine concentrations. [29-31]

In response to these findings and in order to effectively control exposures several guidelines have been published that define appropriate use and control criteria for N2O usage. The ADA made 10 recommendations that address the use of appropriate engineering controls for proper scavenging. [32] However, they are proved futile and health hazards secondary to N2O exposure is still on the rise. Rademaker et al in 2009 conducted a study using infrared thermography to determine the effectiveness of two N2O scavenging systems- The Safe Sedate Dental Mask (Airgas, Radnor, Pa.) system (System I) and Porter Nitrous Oxide Sedation System (Porter Instrument, Hatfield, Pa.) (System II). The results suggested that neither of the system was able to control occupational exposure of N2O oxide below the NIOSH REL. [33]

Additional applications of telethermography
- Evaluation of cranio mandibular disorders. [34]
- Detection of carotid occlusal disease. [35]
- Quantification of the effects of post-surgical inflammation. [36]
- Quantification of the effects of analgesics, anti-inflammatory drugs, etc.
- In the diagnosis of myofacial symptoms.

Conclusion
Thermography aids in the assessment and staging of various dysfunctions of the head and neck region. The unique significance of thermography is both qualitative and quantitative assessment which helps in estimation of progression of the disease in a systematic manner. With the innovation of novel equipments and the state of the art facility, thermography in the near future will certainly re-emerge as a unique research tool in dentistry.

References
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[13] Ongole R, Praveen BN. Chapter 21- Specialized imaging techniques. In: Clinical manual for Oral Medicine and Radiology. Jaypee Brothers, New Delhi. 2007, pp 439-441.
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[17] Gratt BM, Graff-Radford SB, Shetty V, Solberg WK, Sickles EA. A six-year clinical assessment of electronic facial thermography Dentomaxillofac Radiol. 1996; 25: 247 -255.
[18] Gratt BM, Sickles EA. Thermographic characterization of the asymptomatic TMJ. J Orofacial Pain. 1993; 7: 7-14.
[19] Gratt BM, Sickles EA, Ross JB. Thermographic characterization of an intemal derangement of the temporomandibular joint. J Orofacial Pain. 1994; 8: 197-206.
[20] Gratt BM, Sickles EA, Wexler CA. Thermographic characterization of osteoarthrosis of the temporomandibular joint. J Orofacial Pain. 1993; 7: 345-353.
[21] McBeth SA, Gratt BM. A cross-sectional thermographic assessment of TMJ problems in orthodontic patients. Am J Orthod Dentofac Orthop. 1996; 109: 481-488.
[22] Cummings M, Biagioni P, Lamey PJ, Burden DJ. Thermal image analysis of electrothermal debonding of ceramic brackets: an in vitro study. European Journal of Orthodontics. 1991; 21: 111-118.
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[26] Shetty V, Gratt BM, Flack V. Thermographic assessment of reversible inferior alveolar nerve deficit. J Orofacial Pain. 1994; 8: 375-383.
[27] Emmanouil DE, Quock RM. Advances in understanding the actions of nitrous oxide. Anesth Prog. 2007; 54(1):9-18.
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[29] McGlothlin JD, Crouch KG, Mickelsen RL. Control of nitrous oxide in dental operatories. Cincinnati: National Institute for Occupational Safety and Health; U.S. Department of Health and Human Services (NIOSH) publication.1994; 94-129.
[30] Krajewski W, Kucharska M, Pilacik B, et al. Impaired vitamin B12 metabolic status in healthcare workers occupationally exposed to nitrous oxide. Br J Anaesth. 2007;99(6):812-818.
[31] Myles PS, Chan MT, Leslie K, Peyton P, Paech M, Forbes A. Effect of nitrous oxide on plasma homocysteine and folate in patients undergoing major surgery. Br J Anaesth. 2008; 100(6):780-786.
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[33] Rademaker MA et al. Evaluation of Two Nitrous Oxide Scavenging systems Using Infrared Thermography to Visualize and Control Emissions. J Am Dent Assoc. 2009; 140; 190-199.
[34] Biagioni PA, Longmore RB, McGimpsey JG, Lamey PJ. Infrared thermography. Its role in dental research with particular reference to craniomandibular disorders. Dentomaxillofac Radiol. 1996; 25: 119-124.
[35] Friedlander AH, Gratt BM. Panoramic dental radiography and thermography as an aid in detecting patients at risk for stroke. J Oral Maxillofac Surg. 1994; 52: 1257- 1262.
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Infrared thermography: Experience from a decade of pediatric imaging.

Eur J Pediatr. 2007 Aug 30;
Infrared thermography: Experience from a decade of pediatric imaging.
Saxena AK, Willital GH.

Department of Pediatric Surgery, Medical University of Graz, Auenbruggerplatz 34, Graz, A-8036, Austria

The aim of this study was to evaluate the feasibility of clinical application of infrared thermography (IRT) in the pediatric population and to identify pathological states that can be diagnosed as well as followed up using this non-invasive technique. In real time computer-assisted IRT, 483 examinations were performed over a period of 10 years from 1990-2000 on 285 patients in the pediatric age group (range 1 week-16 years) presenting with a wide range of pathologies. The temperature was measured in centigrade (degrees C), and color images obtained were computer analyzed and stored on floppy discs. IRT was found to be an excellent noninvasive tool in the follow-up of hemangiomas, vascular
malformations and digit amputations related to reimplantation, burns as well as skin and vascular
growth after biomaterial implants in newborns with gastroschisis and giant omphaloceles. In the
emergency room, it was a valuable tool for rapid diagnosis of extremity thrombosis, varicoceles,
inflammation, abscesses, gangrene and wound infections. In conclusion, IRT can be performed in
the pediatric age group, is non-invasive, without any biological side effects, requires no sedation or
anesthesia and can be repeated as desired for follow-ups, with objective results that can demonstrated as colored images. Periodic thermographic studies to follow progression of lesions seem to be a
useful and reproducible method.

Polygraph

Periorbital thermal signal extraction and applications.
Shastri D, Tsiamyrtzis P, Pavlidis I. Computational Physiology Lab, University of Houston, Houston, TX

We propose a novel method that localizes the thermal footprint of the facial and ophthalmic arterial-venous complexes in the periorbital area. This footprint is used to extract the mean thermal signal over time (periorbital signal), which is a correlate of the blood supply to the ocular muscle. Previous work demonstrated that the periorbital signal is associated to autonomic responses and it changes significantly upon the onset of instantaneous stress. The present method enables accurate and consistent extraction of this signal. It aims to replace the heuristic segmentation approach that has been used in stress quantification thus far. Applications in computational psychology and particularly in deception detection are the first to benefit from this new technology. We tested the method on thermal videos of 39 subjects who faced stressful interrogation for a mock crime. The results show that the proposed approach has improved the deception classification success rate to 82%, which is 20% higher compared to the previous approach.

Facial thermography is a sensitive and specific method for assessing food challenge outcome.
Clark AT, Mangat JS, Tay SS, King Y, Monk CJ, White PA, Ewan PW. Department of Allergy, Cambridge University Hospitals NHS Trust, Addenbrookes Hospital, Cambridge, UK.

BACKGROUND: Oral challenge is widely used for diagnosing food allergy but variable interpretation of
subjective symptoms may cause error. Facial thermography was evaluated as a novel, objective and
sensitive indicator of challenge outcome.

METHODS: A total of 24 children with a history of egg allergy underwent oral challenge, which were scored positive when objective symptoms occurred or negative after all doses were consumed without reaction. Facial temperatures were recorded at baseline and 10-min intervals. The difference between mean and baseline temperature (DeltaT), maximum DeltaT during challenge (DeltaT(max)) and area under curve of DeltaT against time (DeltaTAUC) were calculated for predefined nasal, oral and forehead areas, and related to objective challenge outcome.

RESULTS: There were 13 positive and 11 negative challenges. Median nasal DeltaTAUC and DeltaT(max) were greater in positive compared with negative challenges (231- and 5-fold, respectively; P < 0.05). In positive challenges, nasal temperatures showed an early transient rise at 20 min, preceding objective symptoms at median 67 min. There was a sustained temperature increase from 60 min, which was reduced by antihistamines. A cut-off for nasal DeltaT(max) of 0.8 degrees C occurring within 20 min of the start of the challenge predicted outcome with 91% sensitivity (positive predictive value [PPV] 100%) and 100%
specificity (negative predictive value [NPV] 93%). Subjective symptoms occurred in four of 13 positive and
three of 11 negative challenges.

CONCLUSIONS: Facial thermography consistently detects a significant early rise in nasal temperature during positive compared with negative food challenges, which is evident before objective symptoms occur.
Thermography may therefore provide a sensitive method to determine outcome of food challenges and investigate the pathophysiology of food allergic reactions.

Intraoperative application of thermography in extracranial-intracranial bypass surgery.
Okada Y, Kawamata T, Kawashima A, Hori T Department of Neurosurgery, Tokyo Women's Medical University, Tokyo, Japan. yokada@nij.twmu.ac.jp

OBJECTIVE: The extracranial-intracranial bypass may have the potential to improve hemodynamic cerebral ischemia caused by occlusive diseases of the main cerebral arteries. Intraoperative confirmation of effective distribution of blood flow via the donor arteries to the involved region will assure a successful bypass surgery.
METHODS: Infrared thermography was used to measure the temperature of the cortical surface at the operative field. Regional cerebral blood flow (rCBF) was measured with a laser Doppler flow meter. Changes in the cortical surface temperature before and after temporary occlusion of the bypass were compared with changes in rCBF values in the corresponding sites.
RESULTS: Thermographic examination demonstrated a heterogeneous increase of cortical surface temperature caused by the blood flow via the extracranial-intracranial bypass and was closely related to rCBF changes.
CONCLUSION: Thermography is useful not only to demonstrate the distribution of blood flow through the extracranial-intracranial bypass but also to quantitatively evaluate the rCBF changes in the operative field.

Neurophysiological study of thin myelinated and unmyelinated fibers.
Espinosa ML, Santiago S, Guzman JJ, Prieto J, Ferrer T; Laboratorio de SNA, Hospital General
La Paz, Madrid, Espana.

INTRODUCTION: Standard neurophysiological techniques evaluate thick myelinated fibers. Yet,
peripheral nerves are equally composed of thin myelinated and unmyelinated fibers. The latter are
responsible for autonomic function as well as temperature and pain perception.

DEVELOPMENT:
Microneurographic studies are restricted to investigation laboratories. Since the techniques are complex
and invasive, their performance is still poor for clinical purposes and some of the components to be
analyzed, such as cardiovagal, cannot be directly recorded. The clinical need to evaluate the functions
regulated by the autonomic nervous system (ANS) had led to devising a series of tests which, in most
cases, rely on reflex responses evoked by already known standardize stimuli. The battery chosen has to
be non invasive, reproducible, specific, providing relevant data to the investigated function, with a readily
available technology, which has to be managed being aware of the physiological and pathological factors
that might bear an influence on the results. The recent development of heart rate blood pressure power
spectral analysis, provides a new interesting insight for quantification of ANS abnormalities. The study of
thermography and thermometry of body surface brings forward evidence on the activity of other thin and
unmyelinated fibers components of the peripheral nerve spectrum.

CONCLUSION: The adequate
management of the above mentioned tests gives rise to a more extensive and appropriate knowledge of
the whole peripheral nerve fiber spectrum.

The application of infrared thermography in the assessment of patients with coccygodynia before and after manual therapy combined with diathermy.
Wu CL, Yu KL, Chuang HY, Huang MH, Chen TW, Chen CH. Source Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.

Abstract
OBJECTIVE: This study examines the potential usefulness of a novel thermal imaging technique in the assessment of local physiologic responses before and after conservative therapies for coccygodynia.

METHODS: Patients with coccygodynia were selected on the basis of detailed history taking, clinical examination, and dynamic series radiography. They underwent therapeutic modalities consisting of 6 to 8 sessions of manual medicine treatments (massage of the levators followed by Maigne's manipulative technique) and external physiotherapy (short-wave diathermy) 3 times a week for 8 weeks. We performed the assessments with numeric pain rating scale (NPRS) and infrared thermography (IRT) before treatment and at 12 weeks.

RESULTS: A total of 53 patients (6 males and 47 females) ranging from 18 to 71 years of age and clinically diagnosed with coccygodynia received the full course of therapy and assessments. There were significant differences in both NPRS and surface temperature obtained by IRT in the 12-week follow-up (P < .05). The correlation between NPRS improvement and temperature decrement was significantly high (r = 0.67, P < .01).

CONCLUSIONS: The study shows that IRT can objectively show the decrement of surface temperatures correlating with changes in subjective pain intensity after treatment of coccygodynia. With the advantages of being painless, noninvasive, and easy to repeat, IRT appears to be useful as a quantifiable tool for monitoring the dynamics of the disease activity in coccygodynia.

Images in plastic surgery: digital thermographic photography ("thermal imaging") for preoperative perforator mapping.
Chubb D, Rozen WM, Whitaker IS, Ashton MW.
 The Taylor Laboratory, Jack Brockhoff Reconstructive Plastic Surgery Research Unit, Department of Anatomy and Cell Biology, The University of Melbourne, Parkville, Victoria 3050, Australia.

Preoperative imaging to identify the location of individual perforators has been shown to improve operative outcomes, and while computed tomographic angiography (CTA) and magnetic resonance angiography are currently the most widely used modalities, these have substantial limitations. Such limitations include the need for intravenous access, the need for iodinated contrast media, radiation exposure with CTA, and long scanning times with magnetic resonance angiography. Complications from the use of contrast media are also noteworthy, and can include anaphylactoid reactions and renal toxicity. In a move to avoid these problems, we have recently introduced a technique that is readily available and easy to implement for preoperative imaging, and may show an accuracy that matches the more advanced imaging modalities. Thermal imaging is a readily performed technique, and can be undertaken by the reconstructive surgeon themselves at the initial consultation, enabling prompt operative planning, and avoiding the need for delays in imaging, confusion in the interpretation of a radiologist report, and the need for an intermediary radiologist altogether. In our experience thus far, the technique matches the accuracy for location of CTA, and a larger clinical trial of the technique is underway.

Evaluation of provocation test monitoring palmoplantar temperature with the use of thermography for diagnosis of focal tonsillar infection in palmoplantar pustulosis.

Asada H, Miyagawa S, Tamura M, Azukizawa H, Tanemura A, Yamaguchi Y, Sumikawa Y, Itami S, Kubo T,Yoshikawa K.

Source

Department of Dermatology, Nara Medical University, 840 Shijo-cho Kashihara, 634-8522, Nara, Japan. asadah@naramed-u.ac.jp

Abstract

BACKGROUND:

Since focal tonsillar infections are often associated with palmoplantar pustulosis (PPP), provocation tests have been performed for preoperative evaluation of tonsillectomy. However, these tests have not been fully established.

OBJECTIVES:

To introduce a more sensitive operative indication for tonsillectomy to the patients with PPP, we have monitored the temperature after provocation tests at palmoplantar sites, as measured by thermography, and we hypothesized that this methodology may lead to a more sensitive marker for tonsillectomy.

METHODS:

Twenty-two PPP patients with/without clinical tonsillitis were included in this study. After mechanical tonsillar massage, using infrared thermography, we have monitored the surface temperature at palmoplantar sites of 22 patients with PPP, five chronic tonsillitis patients without PPP, and four healthy controls, to compare the findings with the skin lesional outcome after tonsillectomy.

RESULTS:

There was a significant relationship between the effects of tonsillectomy and the results of provocation tests assessed by thermography. The sensitivity, specificity, and efficiency of the provocation tests with thermography of detecting a favorable outcome of tonsillectomy were 75.0, 83.3, and 77.3%, respectively, while those of the provocation tests as estimated with the conventional criteria were 37.5, 83.3, and 50.0%, respectively.

CONCLUSION:

Our results suggest that a new indicator using non-invasive thermography for the provocation tests is useful in predicting the effects of tonsillectomy for PPP.

Imaging of the vulnerable plaque: new modalities.
Bhatia V, Bhatia R, Dhindsa S, Dhindsa M.; Department of Internal Medicine, State University of New
York at Buffalo, Buffalo, NY, USA.

Atherosclerosis is currently considered to be an inflammatory and thus a systemic disease affecting
multiple arterial beds. Recent advances in intravascular imaging have shown multiple sites of
atherosclerotic changes in coronary arterial wall. Traditionally, angiography has been used to detect and
characterize atherosclerotic plaque in coronary arteries, but recently it has been found that plaques that
are not significantly stenotic on angiography cause acute myocardial infarction. As a result, newer
imaging and diagnostic modalities are required to predict which of the atherosclerotic plaque are prone to
rupture and hence distinguish "stable" and "vulnerable" plaques. Intravascular ultrasound can identify
multiple plaques that are not seen on coronary angiography. Thermography has shown much promise
and is based on the concept that the inflammatory plaques are associated with increased
temperature and can also identify "vulnerable patients." Of all these newer modalities, magnetic
resonance imaging has shown the most promise in identification and characterization of vulnerable
plaques. In this article, we review the newer coronary artery imaging modalities and discuss the
limitations of traditional coronary angiography.

Dynamic infrared imaging of cutaneous melanoma and normal skin in patients treated with BNCT.
Santa Cruz GA, Bertotti J, Marín J, González SJ, Gossio S, Alvarez D, Roth BM, Menéndez P, Pereira MD, Albero M, Cubau L, Orellano P, Liberman SJ. Dpto. de Instrumentación y Control, Comisión Nacional de Energía Atómica, Av. del Libertador 8250 (1429), Buenos Aires, Argentina. santacr@cnea.gov.ar

We recently initiated a program aimed to investigate the suitability of dynamic infrared imaging for following-up nodular melanoma patients treated with BNCT. The reason that makes infrared imaging attractive is the fact that it constitutes a functional and non-invasive imaging method, providing information on the normal
and abnormal physiologic response of the nervous and vascular systems, as well as the local metabolic rate and inflammatory processes that ultimately appear as differences in the skin temperature. An infrared camera, with a focal plane array of 320 x 240 uncooled ferroelectric detectors is employed, which provides a video
stream of the infrared emission in the 7-14 microm wavelength band. A double blackbody is used as reference for absolute temperature calibration. After following a protocol for patient preparation and acclimatization, a basal study is performed. Subsequently, the anatomic region of interest is subjected to a provocation test (a cold stimulus), which induces an autonomic vasoconstriction reflex in normal structures, thus enhancing the thermal contrast due to the differences in the vasculature of the different skin regions. Radiation erythema reactions and melanoma nodules possess typically a faster temperature recovery than healthy, non-irradiated skin. However, some other non-pathological structures are also detectable by infrared imaging, (e.g. scars, vessels, arteriovenous anastomoses and injuries), thus requiring a multi-study comparison in order to discriminate the tumor signal. Besides the superficial nodules, which are readily noticeable by infrared imaging, we have detected thermal signals that are coincident with the location of
non-palpable nodules, which are observable by CT and ultrasound. Diffuse regions of fast temperature recovery after a cold stimulus were observed between the third and sixth weeks post-BNCT, concurrent with the clinical manifestation of radiation erythema. The location of the erythematous visible and infrared regions is consistent with the 3D dosimetry calculations.

Spectron IR Medical Infrared Imaging System
FDA 510(k) Indications for Use


FDA 510(k) #KO32471


Spectron IR is exclusive manufacturer of the TyTron C-500 IR Clinical Infrared Imaging System. The following is the FDA Premarket Notification 510(k) which is applicable to this system.

Indications for use: The TyTron C-500 IR Clinical Infrared Imaging System is intended for adjunctive diagnostic screening for the detection of breast cancer and other uses such as: peripheral vascular disease, neuromusculoskeletal disorders, extracranial cerebral and facial vascular disease, thyroid gland abnormalities, and various other neoplastic, metabolic and inflammatory conditions. Use of the TyTron C-500 is not intended to be a sole diagnostic procedure for these diseases and conditions.

Cancer Detect Prev.
2009;32(5-6):431-6. Epub 2009 Feb 20.

Specific thermographic changes during Walker 256 carcinoma development: differential infrared imaging of tumor  inflammation and haematoma.

Poljak-Blazi M, Kolaric D, Jaganjac M, Zarkovic K, Skala K, Zarkovic N. Division of Molecular Medicine, Rudjer Boskovic Institute, Zagreb, Croatia.

BACKGROUND: Infrared imaging measures spatial variations in the skin temperature aiming to determine pathological processes; hence possible use of this non-invasive analytical method in cancer detection is emerging.

METHODS: Infrared thermal imaging was used to detect changes in rat skin surface temperature
associated with experimental cancer development (Walker 256 carcinoma), inflammation (upon s.c. Sephadex injection) and haematoma (provoked by s.c. blood coagulate injection). Infrared camera with a geometric resolution of 76,800 pixels, spectral range of 8-14 microns and the minimal detectable temperature resolution of 0.07 degrees C with spatial resolution of 0.48 mm at measuring distance of 30 cm was used to obtain computerized thermal scans.

RESULTS: The raise of peripheral temperature was observed after induction of local inflammation or haematoma. Opposite to that, transient decrease of the skin surface temperature was observed after tumor
transplantation. Progressive growth of tumor was associated with the raise of the skin surface temperature from the 10th day after tumor inoculation, when the tumors developed supportive neoangiogenic blood supply, as verified by histology.

CONCLUSION: While the raise of peripheral temperature in advanced tumor was caused by neoangiogenesis, the reduction in skin surface temperature in an early period after tumor cell inoculation indicated a decay of transplanted tumor cells due to the immune response and the lack of blood supply. Thus, infrared thermal imaging may have considerable value in evaluation of the tumor development and
discrimination of cancer from inflammation and haematoma.

Circadian rhythm chaos: a new breast cancer marker.

Keith LG, Oleszczuk JJ, Laguens M.; Department of Obstetrics and Gynecology,
Northwestern University Medical School, Chicago, Illinois, USA.

The most disappointing aspect of breast cancer treatment as a public health issue has
been the failure of screening to improve mortality figures. Since treatment of latestage
cancer has indeed advanced, mortality can only be decreased by improving the rate of
early diagnosis. From the mid-1950s to the mid-1970s, it was expected that
thermography would hold the key to breast cancer detection, as surface temperature
increases overlying malignant tumors had been demonstrated by thermographic
imaging. Unfortunately, detection of the 1-3 degrees C thermal differences failed to bear
out its promise in early identification of cancer. In the intervening two-and-a-half
decades, three new factors have emerged: it is now apparent that breast cancer has a
lengthy genesis; a long-established tumor-even one of a certain minimum size-induces
increased arterial/capillary vascularity in its vicinity; and thermal variations that
characterize tissue metabolism are circadian ("about 24 hours") in periodicity. This
paper reviews the evidence for a connection between disturbances of circadian rhythms
and breast cancer. Furthermore, a scheme is proposed in which circadian rhythm
"chaos" is taken as a signal of high risk for breast cancer even in the absence of
mammographic evidence of neoplasm or a palpable tumor. Recent studies along this
line suggest that an abnormal thermal sign, in the light of our present knowledge
of breast cancer, is ten times as important an indication as is family history data.

Effectiveness of a noninvasive digital infrared thermal
imaging system in the detection of breast cancer.
Arora N, Martins D, Ruggerio D, Tousimis E, Swistel AJ, Osborne MP, Simmons
RM.
Department of Surgery, New York Presbyterian Hospital-Cornell, New York, NY, USA.

BACKGROUND: Digital infrared thermal imaging (DITI) has resurfaced in this era of
modernized computer technology. Its role in the detection of breast cancer is evaluated.

METHODS: In this prospective clinical trial, 92 patients for whom a breast biopsy was
recommended based on prior mammogram or ultrasound underwent DITI. Three scores
were generated: an overall risk score in the screening mode, a clinical score based on
patient information, and a third assessment by artificial neural network. 

RESULTS: Sixty of 94 biopsies were malignant and 34 were benign. DITI identified 58 of 60
malignancies, with 97% sensitivity, 44% specificity, and 82% negative predictive value
depending on the mode used. Compared to an overall risk score of 0, a score of 3 or
greater was significantly more likely to be associated with malignancy (30% vs 90%, P <
.03). 

CONCLUSION: DITI is a valuable adjunct to mammography and ultrasound,
especially in women with dense breast parenchyma.

Infrared thermography as an access pathway for individuals with severe motor impairments.


Memarian N, Venetsanopoulos AN, Chau T.
Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Canada.

BACKGROUND:
People with severe motor impairments often require an alternative access pathway, such as a binary switch, to communicate and to interact with their environment. A wide range of access pathways have been developed from simple mechanical switches to sophisticated physiological ones. In this manuscript we report the inaugural investigation of infrared thermography as a non-invasive and non-contact access pathway by which individuals with disabilities can interact and perhaps eventually communicate.


METHODS:
Our method exploits the local temperature changes associated with mouth opening/closing to enable a highly sensitive and specific binary switch. Ten participants (two with severe disabilities) provided examples of mouth opening and closing. Thermographic videos of each participant were recorded with an infrared thermal camera and processed using a computerized algorithm. The algorithm detected a mouth open-close pattern using a combination of adaptive thermal intensity filtering, motion tracking and morphological analysis.


RESULTS:
High detection sensitivity and low error rate were achieved for the majority of the participants (mean sensitivity of all participants: 88.5% +/- 11.3; mean specificity of all participants: 99.4% +/- 0.7). The algorithm performance was robust against participant motion and changes in the background scene.


CONCLUSION:
Our findings suggest that further research on the infrared thermographic access pathway is warranted. Flexible camera location, convenience of use and robustness to ambient lighting levels, changes in background scene and extraneous body movements make this a potential new access modality that can be used night or day in unconstrained environments.

Dynamic infrared thermography of the nasal vestibules: a new method.

Kastl KG, Wiesmiller KM, Lindemann J.
Department of Otorhinolaryngology, University of Ulm, Ulm, Germany. 

OBJECTIVE: The surface temperature distribution within the nasal vestibule and the nasal cavity strongly depends on the exact intranasal detection site and point of time during the respiratory cycle. Therefore, conventional temperature measurements e.g. with thermocouples only provide selective measurements. The use of infrared thermography cameras could present a new contactless method with a high spatiotemporal resolution. The aim of the present study was to evaluate the use of infrared thermography camera systems for measurements of the nasal surface temperature during respiration.

METHODS: The surface temperature profiles within the nasal vestibules of healthy volunteers were recorded with infrared thermography cameras during several breathing cycles. Two different types of infrared thermography standard systems were used.

RESULTS: The recordings allowed a display of temperature alterations within the nasal vestibules in a high spatiotemporal resolution synchronous to the breathing cycle. During inspiration, the vestibular surface cooled down presenting a non-homogenous distribution (range, 24.7 to 30.2 degrees C). During expiration, the vestibular surface was warmed again with a non-homogenous distribution (range, 33.1 to 36.2 degrees C). The results of both camera systems were comparable.

CONCLUSION: Infrared thermography cameras allow the exact mapping of nasal surface temperature within the nasal vestibules with a high spatiotemporal resolution without surface contact.

Burn depths evaluation based on active dynamic IR thermal imaging--a preliminary study.

Renkielska A, Nowakowski A, Kaczmarek M, Ruminski J.

Source

Department of Plastic Surgery and Burns, Medical University of Gdansk, il. Debinki 7, 80-211 Gdansk, Poland. aren@mlyniec.gda.pl

Abstract

Proper diagnostic assessment of burn wound depth is of the highest importance in selecting the mode of burn wound treatment. Several diagnostic methods--clinical and histopathological evaluation, as well as methods employing IR imaging--static thermography and active dynamic thermography (ADT)--are compared on the basis of in vivo experiments conducted on three domestic pigs (23 burn wounds). ADT is presented here as a new, reliable and quantitative method of assessing burn wound depth on the basis of discrimination of the thermal properties of burnt tissue. In the case of ADT registration of thermal images was performed following thermal pulse excitation. A series of captured infrared images was used as the basis for calculating the thermal time constant tau for each pixel. The parameter values were compared with histopathological and clinical assessments of burn depth. The mean value of tau was found for burns, which heal within 3 weeks (tau=12.08+/-1.94s) and for burns, which did not heal during this period (tau=9.07+/-0.68s), p<0.05. The accuracy, sensitivity and specificity of all the methods tested were compared, the best results coming from ADT. The ADT method is fast, non-invasive and relatively inexpensive, although it still requires further animal experimentation as well as clinical study to confirm the results.

[Study on technique of thermal imaging and soft-sensing].

[Article in Chinese]

Qu J, Liao Q, Zhang X.

Source

Faculty of Biomedical Engineering, The Fourth Military Medical University, Xi'an 710033, China.

Abstract

The differences of body surface temperature reflect the changes of the status of body tissues. In this regard, detecting and forecasting the changes of the surface temperature is the objective of the technique of medical thermal diagnosis, and how to diagnose the disease earlier with the use of thermal images is a common problem in the field of medical diagnostics and biological engineering. The authors put forward that utilizing the soft-sensing techniques in the field of engineering will be a good solution.

[Thermal imaging properties of toes after walking stress test in diabetic patients].

[Article in Japanese]

Minamishima C, Kuwaki K, Shirota E, Matsuzaki M, Yamashita K, Kamatani M, Maeda K, Yano F.

Source

Department of Clinical Physiological Laboratory, Nishitokyo Metropolitan Police Hospital, Kokubunji.

Abstract

In consecutive 50 diabetic patients hospitalized for medical education, without subjective symptoms of autonomic neuropathy (DM group), performed treadmill walking stress test and thermography, for clarify the feature of the pattern typical of diabetic autonomic neuropathy. Thermal images were collected, before, immediately after, 3, 6, 12 minutes after walking. The mean temperature of toes fell more than 1 degree C than that of baseline level and returned within 0.5 degrees C of baseline level within 6 minutes (N type) in 66% of 30 normal subjects (C group) and 24% of DM group. In 10% of C and 24% of DM, the temperature fell but not returned within 0.5 degrees C of baseline level in 6 minutes (D type). In 17% of C and 38% of DM, the temperature changed within 0.5 degrees C (F type), or rose more than 0.5 degrees C after exercise (U type) in 7% in C and 14% in DM groups. Pts D, F group, have more complications (HbA1c, nephropathy, retinopathy or somatic neuropathy), but not so in C, U type. We concluded D, F types were the typical thermographic features of the toes of pts with diabetic autonomic neuropathy.

FPA-based infrared thermography as applied to the study of cutaneous perspiration and stimulated vascular response in humans.

Vainer BG.

Source

Institute of Semiconductor Physics, Russian Academy of Sciences, Siberian Branch, Novosibirsk. bgv@isp.nsc.ru

Abstract

This review gives an overview of focal plane array (FPA)-based infrared (IR) thermography as a powerful research method in the field of physiology and medicine. Comparison of the gained results with the data previously obtained by other authors with other research tools is given. Outer thermoregulatory manifestations displayed by the human organism subjected to whole-body heating (sauna bath) and physical loads (exercise bicycling) are quantitatively analysed. Some details of human body emotional sweating (psycho-physiological effect) are reported. Particular attention is paid to studying active sweat glands as individual objects. All experimental data were obtained with the help of a high-sensitivity (0.03 degrees C) fast 128 x 128 InAs IR detector-based thermal imaging system operating in the short-wave spectral region (2.5 to 3 microm) and perfectly suiting medical purposes. It is shown that IR thermography makes it possible to overcome limitations inherent to contact measuring means that were traditionally used before in thermal studies. It is also shown that heterogeneous thermograms displayed by organisms with disturbed inner equilibrium can be quantitatively analysed in terms of statistical parameters of related surface-temperature histograms, such as the mean temperature and the standard deviation of temperature (SDT). The increase and the decrease in SDT turned out to be typical of prolonged physical load and subsequent relaxation, and of external whole-body heating, respectively. Explanation of this result based on a hypothesis advanced within the context of the doctrine of human-organism evolution is given. Skin-temperature distribution function accompanying the relaxed organism in normality was found to closely resemble normal-distribution function. Symmetry break down and variation of the shape of this characteristic may serve as an indicator of homeostasis shift and can be used as a quantitative criterion for the latter. A new phenomenon, stable punctate hidrosis, is discovered and described. The term sweatology is introduced to refer to the discussed specific research area in biomedical science.