Dynamic Infrared Thermography Research Articles

The Precision of Colour Doppler Ultrasonography Combined with Dynamic Infrared Thermography in Perforator Mapping for Deep Inferior Epigastric Perforator Flap Breast Reconstruction.

Background: Perforator mapping is a mandatory tool for the preoperative planning of a microsurgical free flap, especially in breast reconstruction. Numerous methods for mapping have been described. In this study, we investigate the combined use of Dynamic Infrared Thermography (DIRT) and Colour Doppler Ultrasonography (CDUS) only to see whether it can eliminate the need for Computed Tomography Angiography (CTA). Methods: A prospective study was conducted on 33 patients with deep inferior epigastric perforator (DIEP) flaps for breast reconstruction. DIRT, followed by CDUS and CTA, was performed preoperatively and perforators were confirmed intraoperatively. Results: From 135 hot spots found on DIRT, 123 perforators were confirmed by CDUS (91.11%). A total of 86.66% of the perforator vessels detected on CTA have their correspondent on DIRT, while 95.12% have their correspondent on CDUS. No statistically significant difference (p > 0.05) was found comparing DIRT vs. CTA and CDU vs. CTA. The average DIRT time was 121.54 s and CDUS 232.09 s. The mean sensitivity for DIRT was 95.72% and 93.16% for CDUS. Conclusion: DIRT combined with CDUS can precisely and efficiently identify suitable perforators without the need for CTA in DIEP breast reconstruction.

Automated thermographic detection of blood vessels for DIEP flap reconstructive surgery.

Inadequate perfusion is the most common cause of partial flap loss in tissue transfer for post-mastectomy breast reconstruction. The current state-of-the-art uses computed tomography angiography (CTA) to locate the best perforators. Unfortunately, these techniques are expensive and time-consuming and not performed during surgery. Dynamic infrared thermography (DIRT) can offer a solution for these disadvantages. The research presented couples thermographic examination during DIEP flap breast reconstruction with automatic segmentation approach using a convolutional neural network. Traditional segmentation techniques and annotations by surgeons are used to create automatic labels for the training. The network used for image annotation is able to label in real-time on minimal hardware and the labels created can be used to locate and quantify perforator candidates for selection with a dice score accuracy of 0.8 after 2min and 0.9 after 4min. These results allow for a computational system that can be used in place during surgery to improve surgical success. The ability to track and measure perforators and their perfused area allows for less subjective results and helps the surgeon to select the most suitable perforator for DIEP flap breast reconstruction.

Advancing DIEP Flap Monitoring with Optical Imaging Techniques: A Narrative Review.

This review aims to explore recent advancements in optical imaging techniques for monitoring the viability of Deep Inferior Epigastric Perforator (DIEP) flap reconstruction. The objectives include highlighting the principles, applications, and clinical utility of optical imaging modalities such as near-infrared spectroscopy (NIRS), indocyanine green (ICG) fluorescence angiography, laser speckle contrast imaging (LSCI), hyperspectral imaging (HSI), dynamic infrared thermography (DIRT), and short-wave infrared thermography (SWIR) in assessing tissue perfusion and oxygenation. Additionally, this review aims to discuss the potential of these techniques in enhancing surgical outcomes by enabling timely intervention in cases of compromised flap perfusion. A comprehensive literature review was conducted to identify studies focusing on optical imaging techniques for monitoring DIEP flap viability. We searched PubMed, MEDLINE, and relevant databases, including Google Scholar, Web of Science, Scopus, PsycINFO, IEEE Xplore, and ProQuest Dissertations & Theses, among others, using specific keywords related to optical imaging, DIEP flap reconstruction, tissue perfusion, and surgical outcomes. This extensive search ensured we gathered comprehensive data for our analysis. Articles discussing the principles, applications, and clinical use of NIRS, ICG fluorescence angiography, LSCI, HSI, DIRT, and SWIR in DIEP flap monitoring were selected for inclusion. Data regarding the techniques' effectiveness, advantages, limitations, and potential impact on surgical decision-making were extracted and synthesized. Optical imaging modalities, including NIRS, ICG fluorescence angiography, LSCI, HSI, DIRT, and SWIR offer a non- or minimal-invasive, real-time assessment of tissue perfusion and oxygenation in DIEP flap reconstruction. These techniques provide objective and quantitative data, enabling surgeons to monitor flap viability accurately. Studies have demonstrated the effectiveness of optical imaging in detecting compromised perfusion and facilitating timely intervention, thereby reducing the risk of flap complications such as partial or total loss. Furthermore, optical imaging modalities have shown promise in improving surgical outcomes by guiding intraoperative decision-making and optimizing patient care. Recent advancements in optical imaging techniques present valuable tools for monitoring the viability of DIEP flap reconstruction. NIRS, ICG fluorescence angiography, LSCI, HSI, DIRT, and SWIR offer a non- or minimal-invasive, real-time assessment of tissue perfusion and oxygenation, enabling accurate evaluation of flap viability. These modalities have the potential to enhance surgical outcomes by facilitating timely intervention in cases of compromised perfusion, thereby reducing the risk of flap complications. Incorporating optical imaging into clinical practice can provide surgeons with objective and quantitative data, assisting in informed decision-making for optimal patient care in DIEP flap reconstruction surgeries.

Сapabilities of Dynamic Infrared Thermography for Planning and Monitoring of Perforating Flaps

Background. Free perforating flaps are the most optimal for reconstruction of both upper and lower extremities. However, along with the obvious advantages of these flaps, there are also a number of difficulties associated with their more complex vascular anatomy and, as a consequence, more time-consuming dissection. This determines the need for a more thorough preoperative planning, including the mapping of perforating vessels and development of flap design. At the same time, the problems with intraoperative assessment of perfusion of perforating flaps and their monitoring in the postoperative period have not been solved. For these purposes, several instrumental methods of examination such as MRI and CT angiography, Doppler sonography, ICG and dynamic infrared thermography are used.
 Aim of the study — to evaluate the capabilities of dynamic infrared thermography (DIT) for mapping of perforating vessels when planning the design of perforating flaps, as well as for assessing their intra- and postoperative perfusion.
 Methods. We have analyzed the results of using DIT along with CT-angiography and Doppler sonography for preliminary mapping of perforating vessels in the design of 18 perforating flaps (ALT flap — 10, SCIP flap — 8) transplanted in 15 patients from 01.01.2022 to 30.07.2022. DIT was also used in all cases for intraoperative instrumental confirmation of flap perfusion and for its monitoring in the postoperative period.
 Results. A total of 39 perforating vessels were detected by CT angiography at the point of origin from the main arteries. DIT was used to detect the distal portions of 37 perforating vessels in 15 patients at the marking of 18 flaps. On average, 2.5 per ALT flap and 1.4 per SCIP flap. Thermographic examination time was approximately 10 minutes. Localization of all perforating vessels detected by DIT were first confirmed by Doppler sonography and then visualized intraoperatively during flap dissection. Intraoperatively, perfusion of all transplanted flaps was clearly confirmed by DIT. In the postoperative period, perfusion problems were clinically detected in 3 (16%) flaps and confirmed by DIT: venous stasis — 2 cases, arterial insufficiency — 1 case. In two patients (13%) with a body mass index of more than 35 (corresponding to class 2–3 obesity), the location of perforating vessels could not be determined by thermography and Doppler sonography. Also, in these patients DIT was ineffective for confirmation of flap perfusion intraoperatively and in the postoperative period.
 Conclusion. This study confirms that CT angiography, Doppler sonography and infrared thermography are complementary methods that allow to detect and visualize perforating arteries from their origin from a main artery to the site of their passage through the deep fascia (CT-angiography), as well as to determine their more accurate projection on the skin surface (DIT and Doppler sonography). DIT is also an auxiliary method for flap monitoring in the intraoperative and postoperative periods, which allows to engage nursing staff in postoperative monitoring.

Mapping of Thoracodorsal Artery Perforators: Accuracy of Thermography and Handheld Doppler.

The versatile musculocutaneous latissimus dorsi flap and the thoracodorsal artery (TDA) perforator flap have developed into indispensable approaches in reconstructive surgery. While the anatomy of the TDA is consistent, the skin perforators vary in location and course. Dynamic infrared thermography (DIRT) recently gained popularity for perforator identification; however, its use and accuracy in thoracodorsal artery perforator (TDAP) mapping is yet to be determined. TDAPs were visualized in 50 cases by DIRT. Based on the thermographic hotspots, the corresponding perforators were then identified by color duplex ultrasound (CDU) and handheld Doppler in a blinded fashion by two separate examiners. The midpoint of all perforator fascia passages was localized 99.7 mm caudal and 13.5 mm medial of the posterior axillary fold. The positive predictive value of perforator identification by dynamic infrared thermography was 86.5% and the correlating perforator fascia passage was 9.9 ± 5.8 mm from the hotspot midpoint, with a maximum of 29 mm. The positive predictive value of perforator identification by handheld Doppler was 95% and the signal was 7.2 ± 5.1 mm from the perforator fascia passage. DIRT precisely localizes TDAPs. The fusion with CDU combines both modalities' advantages. The combination with handheld Doppler is a fast way of perforator imaging, decreasing the handheld Dopplers' high false positive rate.

Finite element skin models as additional data for dynamic infrared thermography on skin lesions

ABSTRACT Skin cancer is a significant global health concern, with increasing incidence rates and a high number of deaths each year. Early detection plays a crucial role in improving survival rates, but current screening methods, such as total body skin examination, often lead to unnecessary invasive excisions. This research aims to explore the use of dynamic infrared thermography (DIRT) in combination with other technologies to potentially eliminate the need for biopsies in the future and gather information about the stage or depth of malignant skin lesions. The study involves data acquisition using a thermal camera and a finite element skin model. The FEM skin model employed in this research follows the commonly used five-layer model and is constructed in Siemens Simcenter 3D to be able to simulate the cryogenic cooling on the skin. It is possible to improve the thermal images by choosing an appropriate cooling method, cooling sequence and optimised measurement setup. While the FEM skin model shares certain similarities with the measurement data, there is room for further enhancements to optimise its performance. The acquired data is analysed to assess the effectiveness of the combined technique compared to existing clinical and diagnostic methods.

Comparative Analysis of Cooling Methods for Dynamic Infrared Thermography (DIRT)-Based Skin Cancer Diagnosis

Skin cancer is a significant global health issue, placing a growing burden on individuals and society. Conventional diagnostic methods like visual examination and biopsy have limitations in invasiveness and accuracy. As a result, alternative tools such as infrared thermography have gained attention in skin cancer diagnosis. Tissue-mimicking phantoms have been instrumental in facilitating research in this field, offering controlled environments. While they do not fully replicate human skin complexity, physical skin models provide stability, ease of fabrication, and control over properties. Agarose phantoms are employed in this study. This research focused on testing and comparing cooling techniques for human skin in the context of skin cancer diagnosis using dynamic infrared thermography. Six cooling methods were investigated: a cool pack, an aluminum medal, ice, alcohol, a vortex cooler and a Zimmer Cryo 6 cooler. The experimental setup involved an infrared camera (Optris Xi400) with microscope optics positioned above an agar phantom mimicking flat skin and an ulcerating skin lesion. Based on experiments conducted on the skin phantom, it was observed that convective cooling methods offered more consistent and uniform cooling. Conversely, conductive methods proved effective for flat objects but posed challenges in achieving uniform cooling for bulging skin or ulcerated lesions. Ice or alcohol were deemed unsuitable due to artifacts influencing the infrared radiation and thermal camera view. A decision matrix assessed cooling techniques based on criteria such as uniformity, repeatability, view obstruction, efficiency, workload, patient comfort, clinical suitability, noise exposure, consumables, additional equipment, and price. The Zimmer Cryo 6 cooler emerged as the most suitable cooling method after evaluating various factors.

Smartphone Dynamic Infrared Thermography for Harvesting AICAP Flap in a Large Breast-conservative Surgery

Flaps based on perforators of the intercostal arteries have been described for the reconstruction of defects resulting from partial mastectomies. Dynamic infrared thermography (DIRT) identifies hot spots that accurately correspond to and evaluate perforator vessels toward the skin. The new generation of portable thermal cameras has become smaller, less expensive, more sensitive, and compatible with common smartphones. One option is the FLIR ONE system (FLIR Systems, Inc., Wilsonville, OR), a smartphone-compatible thermal camera. Despite its lower resolution, compared with the larger infrared camera models, it represents a viable option for thermal skin mapping, and its compact nature allows for easy portable use. The purpose of this article is to report a case of a preoperative study with smartphone DIRT used in the preparation of an anterior intercostal artery perforator-based flap for breast reconstruction after a wide resection at the level of the right infer-internal breast region, including a skin excision. Our study documents how smartphone DIRT is a rapid, sensitive, easily accessible and cost-effective diagnostic method for the topographical identification of intercostal artery perforators. It can be used as a rescue method at any stage of the intervention if it differs from the preoperative planning. It also confirms the proven usefulness of this flap for the reconstruction of partial defects in the breast and thoracic region.

Securing perforator flap perfusion by using dynamic infrared thermography (DIRT) in complex traumatic hand surgery – A case report

A complex traumatic hand injury may pose a challenge for the reconstructive surgeon. Perforator flaps provide the surgeon with an option in managing such injuries. Securing perfusion of the perforator flap is essential, as partial, or total flap loss yield poor functional and cosmetic outcome, often requiring reoperation. We report a case of a 28-year -old male suffering a mutilating hand injury after a car accident. Reconstruction was performed with a free microvascular lateral arm flap, and perfusion of the flap was monitored pre-, intra-, and postoperatively with dynamic infrared thermography (DIRT).The purpose of this report is to highlight the usefulness of DIRT as a novel perfusion imaging modality in the management of complex traumatic hand injury. • Dynamic infrared thermography (DIRT) can be used in complex traumatic hand surgery for perforator mapping. • DIRT can be used to evaluate flap perfusion intra- and postoperatively. • DIRT can be used to evaluate patency of the microvascular anastomose. • DIRT is a non-invasive, non-contact imaging modality that provides reliable information on skin perfusion.

Dynamic infrared thermography aiding in flaps

Background: The selection of the best vessels is of utmost importance in reconstruction surgeries. This will reduce operative time, decrease complication rates, and ensure a better overall result. It is observed that dynamic infrared thermography (DIRT) has been increasingly used in reconstructive microsurgery to evaluate flap viability and locate perforators. DIRT measures the rate and patterns of rewarming after cooling. The sensor detects heat irradiation and forms a thermogram where the temperature of each spot can be recognized. This article aims to conduct a systematic review of the clinical applications of DIRT imaging in plastic surgery. Methods: The search was performed in MEDLINE, LILACS, Cochrane, and Scielo databases using the following terms: "thermography", "thermometry", "surgical flaps", "reconstructive surgical procedures" and "microsurgery". Articles published from January 2006 to October 2021 were included. The primary search provided 115 matches in MEDLINE, 0 in LILACS, 6 in Cochrane, and 0 in Scielo. After removing duplicates, 115 articles were considered. Results: After reading the titles and abstracts and removing duplicates, a total of 38 publications were found. These were read in full and evaluated against the inclusion and exclusion criteria. After full reading and analysis, a total of 25 publications met the inclusion criteria. Conclusion: The use of DIRT shows promise for flap monitoring in reconstructions in Plastic Surgery.

Deep inferior epigastric perforator flap preoperative planning: A comparative analysis between dynamic infrared thermography, computerized tomography angiography, and hand-held Doppler.

Hand-held Doppler (HHD) sonography and computerized tomography angiography (CTA) are the common assessment tools for deep inferior epigastric perforator (DIEP) flap preoperative planning. CTA is considered the gold standard method for preoperative perforator mapping but necessitates contrast medium and X-ray exposure. Dynamic infrared thermography (DIRT) does not have these drawbacks and allows the detection of hot and cold spots on a given body area. Our study aimed to compare DIRT, HHD, and CTA in perforator mapping for breast reconstruction using DIEP flap. From March to September 2020, 12 consecutive patients scheduled for DIEP flap breast reconstruction were preoperatively investigated with HHD, CTA, and DIRT. The patients' mean age was 53 and the mean BMI was 29.23 kg/m2 . All the reconstructions were due to breast cancer. The results of preoperative perforator mapping on the lower abdomen were compared among the three techniques. All the evidence was compared to the intraoperative findings, during flap harvesting, to establish if the techniques were able to correctly locate the perforator. We detected 178 perforators intraoperatively, 178 with CTA, 178 with DIRT, and 125 with HHD. The latter revealed a lower number of perforator vessels for each patient (10.42 ± 3.58), compared with CTA (14.83 ± 3.04) and DIRT (14.83 ± 4.76). DIRT resulted superior to HHD (p < .05), while no statistically significant difference (p > .05) was found between DIRT and CTA. We calculated a mean sensitivity of 93.87% for CTA, 69.02% for HHD, and 92.06% for DIRT. DIRT is a useful tool in the preoperative planning of DIEP flaps, as it provides information about the location of perforators and the hemodynamic properties of angiosomes. It is easy to use, and it does not involve ionizing radiation. DIRT could represent an innovative and promising implementation of CTA and HHD techniques for preoperative perforator mapping in DIEP breast reconstruction.

A Comparison of Accuracy between Dynamic Infrared Thermography (DIRT) and Handheld Doppler Ultrasonography in Free Flap Reconstruction Perforator Mapping: A Prospective Study

Background: Preoperative perforator mapping is one of fundamental steps for successful surgery in microsurgical perforator free flap. Currently, there is still no gold standard for preoperative perforator mapping. Objective: The present study aims to compare accuracy in perforator mapping between dynamic infrared thermography (DIRT) and handheld doppler which is the main method we used in our hospital. Materials and Methods: Twenty patients scheduled for microsurgical free flap reconstruction between October 2018 to December 2020 was enrolled. Preoperative perforator mapping was performed by both handheld doppler and smartphone dynamic infrared thermography (DIRT). During rewarming period, &ldquo;Hot spots&rdquo; were marked. Then flaps were raised intraoperatively, numbers, diameter and location of each perforators were recorded. Location of perforators at its piercing fascia were reflected to skin. Distance from actual perforators to the nearest preoperative perforator marking point by each method were measured. Results: There were 9 male and 11 female patients enrolled in the present study with mean age of 54.30 years. The average body mass index was 23.85 kg/m2. Hand-held doppler and DIRT images were obtained for 20 flaps, including 15 anterolateral thigh flaps (75%), 1 anteromedial thigh flap (5%) and 4 fibular free flaps (20%). The mean caliber of selected perforators was 2.62 mm at point of their emergence through fascia. All the flap survived without postoperative major complication. The mean distance from actual perforator to the nearest perforator from handheld doppler was 11.88+7.51 mm, and to the nearest perforator from thermal images was 12.68+8.96 mm. The mean distance difference of both methods was 0.80 mm. Perforators were usually within a 20 mm radius of preoperative marking both handheld doppler and DIRT. Conclusion: Dynamic infrared thermography is low cost, non-invasive and reliable methods for preoperative perforator mapping. Keywords: Dynamic infrared thermography; Handheld doppler ultrasonography; Perforator mapping; DIRT; Perforator free flap

A hybrid methodology for breast screening and cancer diagnosis using thermography

Breast cancer is the second most common cancer in the world. Early diagnosis and treatment increase the patient's chances of healing. The temperature of cancerous tissues is generally different from that of healthy neighboring tissues, making thermography an option to be considered in the fight against cancer because it does not use ionizing radiation, venous access, or any other invasive process, presenting no damage or risk to the patient. In this paper, we propose a hybrid computational method using the Dynamic Infrared Thermography (DIT) and Static Infrared Thermography (SIT) for abnormality screening and diagnosis of malignant tumor (cancer), applying supervised and unsupervised machine learning techniques. We use the area under receiver operating characteristic curve, sensitivity, specificity, and accuracy as performance measures to compare the hybrid methodology with previous work in the literature. The K-Star classifier achieved accuracy of 99% in the screening phase using DIT images. The Support Vector Machines (SVM) classifier applied on SIT images yielded accuracy of 95% in the diagnosis of cancer. The results confirm the potential of the proposed approaches for screening and diagnosis of breast cancer.

Impact on Abdominal Skin Perfusion following Abdominoplasty.

Background:Wound healing problems following abdominoplasty may be a result of impaired tissue perfusion. This study evaluated the impact a standard abdominoplasty may have on abdominal skin perfusion.Methods:A standard abdominoplasty was performed in 16 patients. Dynamic infrared thermography (DIRT) using a mild and a stronger cold challenge was performed pre-, intra-, and postoperatively on day 1, 2, and in week 6. The abdomen was divided into Huger’s vascular zones. A two-tailed t test was used to evaluate differences in mean temperature between zones. Statistical significance was defined as P < 0.05.Results:Two patients suffered wound healing problems. Abdominal skin perfusion showed a hyperaemic state on day 1, day 2, and week 6, postoperatively. Hotspots in zones I and II had all disappeared at the end of surgery and on day 1, except in the cranial part of zone I. Hotspots reappeared in zones I and II during day 2. A statistically significant difference between zones I and II was seen on day 1 and 2, with zone II being cooler. This difference had disappeared in week 6 for the mild cold challenge but not for the stronger cold challenge.Conclusions:A standard abdominoplasty has a significant impact on abdominal skin perfusion. The skin perfusion is a dynamic process with a gradual improvement over time. The strongest effect was seen in zone II near the lower transverse incision line, where skin perfusion was the least. Such may contribute to impaired wound healing at this site.

A Computational Method to Assist the Diagnosis of Breast Disease Using Dynamic Thermography.

Breast cancer has been the second leading cause of cancer death among women. New techniques to enhance early diagnosis are very important to improve cure rates. This paper proposes and evaluates an image analysis method to automatically detect patients with breast benign and malignant changes (tumors). Such method explores the difference of Dynamic Infrared Thermography (DIT) patterns observed in patients’ skin. After obtaining the sequential DIT images of each patient, their temperature arrays are computed and new images in gray scale are generated. Then the regions of interest (ROIs) of those images are segmented and, from them, arrays of the ROI temperature are computed. Features are extracted from the arrays, such as the ones based on statistical, clustering, histogram comparison, fractal geometry, diversity indices and spatial statistics. Time series that are broken down into subsets of different cardinalities are generated from such features. Automatic feature selection methods are applied and used in the Support Vector Machine (SVM) classifier. In our tests, using a dataset of 68 images, 100% accuracy was achieved.

The Value of Dynamic Infrared Thermography in Pedicled Thoracodorsal Artery Perforator Flap Surgery.

Background:Dynamic infrared thermography (DIRT) is a noninvasive imaging technique that can provide indirect and real-time information on skin perfusion by measuring skin temperature. Although used in flap surgery, there are no reports on its value in procedures using a pedicled thoracodorsal artery perforator (TDAP) flap. The aim of this study was to assess the usefulness of DIRT in preoperative perforator mapping and in monitoring intra- and postoperative flap perfusion of pedicled TDAP flaps.Methods:This prospective study comprised 21 patients (21 flaps) scheduled for reconstructive surgery with a TDAP flap. Perforator mapping was done by DIRT, handheld unidirectional Doppler ultrasound, and computer tomography angiography. Intra- and postoperative flap perfusion was assessed by clinical signs and with the use of DIRT and handheld unidirectional Doppler ultrasound.Results:Perforator mapping with DIRT showed that first-appearing bright hotspots were always associated with arterial Doppler sounds and suitable perforators intraoperatively. Computer tomography angiography presented useful information on the thoracodorsal artery branching pattern but was less beneficial for perforator mapping. Intra- and postoperative flap monitoring with DIRT was more useful than handheld unidirectional Doppler ultrasound and clinical signs to detect early arterial and venous perfusion problems. DIRT demonstrated that TDAP flap perfusion is a dynamic process with an increase in perfusion during the first operative days. Nineteen flaps survived, of which 3 sustained distal necrosis. Two flaps were lost due to inadequate blood perfusion.Conclusion:DIRT provides valuable real-time information for perforator mapping and for monitoring TDAP flap perfusion intra- and postoperatively.

Study of hot stress dynamic IR thermography for detecting surface cancerous tissue

The early diagnosis of cancer at any location of the human body can help in enhancing the survival rate and in reducing the cost of the treatment. Among the several techniques, the conventional infra-red (IR) thermography suffers from several limitations, including higher patient discomfort and longer time for tumour detection based on the temperature difference between tumour and adjacent healthy tissues. Hence, in this work, a novel non-invasive hot stress dynamic IR thermography system is proposed to detect surface tumour without severe discomfort to the patient. The system is designed to detect the surface tumour under 3 min within a temperature range of 42 and 37 °C. A two-dimensional numerical model based on the bio-heat transfer of tissue consists of cancerous and healthy cells is developed and validated to analysis the thermal contrast arises due to the presence of cancerous and healthy cells while cooling naturally. A light source is introduced with appropriate intensity to achieve a suitable temperature contrast. Moreover, the effects of natural convective heat loss from the tissue to the ambient and the scanning speed of IR Thermography on the tissue are investigated. A temperature difference of about 1.5 °C is found after cooling of tissues for 140 s, which can be detected using a thermographic camera. Finally, a sensitivity study is conducted to access the importance of the individual parameter over the final temperature field. The results predict the blood perfusion rate as the most significant parameter that significantly influences the temperature distribution in the considered domain.

Dynamic Infrared Thermography (DIRT) in DIEP flap breast reconstruction: A clinical study with a standardized measurement setup

ObjectiveBreast reconstructions with perforator flaps from the lower abdomen, commonly known as Deep Inferior Epigastric artery Perforator flap (DIEP-flap), have become the golden standard for autologous breast reconstruction after breast amputation. During this surgical procedure multiple challenging steps are encountered such as the selection of a suitable perforator that provides sufficient blood supply for the flap, surgical dissection of the chosen perforator, determination of perfusion area of the chosen perforator, microsurgical anastomosis, flap inset and shaping the flap into a breast.The current gold standard for perforator mapping is Computed Tomography Angiography (CTA). However, this is a relatively expensive imaging modality that requires intravenous contrast injection and exposes patients to ionizing radiation. More recently, Dynamic Infrared Thermography (DIRT) has been proposed as an alternative imaging modality for perforator identification. DIRT appears to be an ideal alternative technique not only for the identification of the dominant perforators, but also for the mapping of the individual influence of each perforator on the flap perfusion, to monitor integrity of the perforator after dissection and to monitor the patency of the pedicle of the free flap after the anastomosis, during flap inset and flap shaping. Study designIn this clinical study we present the results of the use of DIRT in 33 DIEP-flaps in 21 patients after mastectomy. The same standardized measurement set-up was used for all the flaps in the pre-, intra- and postoperative period. ResultsIn the pre-operative period DIRT confirmed the location of the 69 perforators shown on the CTA. In the intra-operative period the rate and pattern of rewarming was successfully observed. One perforator was severely damaged during dissection and the DIEP flap was converted to a Muscle Sparing free Transverse Rectus Abdominis Muscle (TRAM) flap, after viability check of the flap by DIRT. DIRT diagnosed one kinking of the pedicle after microsurgical anastomosis. Two flaps were monitored successfully post-operatively. All 33 breast reconstructions were with good outcome. ConclusionThe use of DIRT with our standardized measurement setup is a useful, non-invasive tool during breast reconstructions with free DIEP-flaps in all the phases of the reconstruction (pre-, intra- and post-operative). This study confirms that DIRT with the standardized measurement setup provides information on perforator location, blood supply and patency of the anastomosis without interference with the operating surgeon.

DIEP flap breast reconstructions: thermographic assistance as a possibility for perforator mapping and improvement of DIEP flap quality.

In the modern world, one-third or more of breast cancer patients still undergo uni- or bilateral mastectomy. Breast cancer patients, in general, have a good prognosis and long-term survival. Therefore, the treatment must not only focus on survival but also on the quality of life. Breast reconstruction with an autologous free deep inferior epigastric artery perforator (DIEP) flap is one of the preferred options after mastectomy. A challenging step in this procedure is the selection of a suitable perforator that provides sufficient blood supply for the flap to prevent necrosis after anastomosis. In this pilot study, the possibilities for dynamic infrared thermography (DIRT) are investigated to select the best suitable perforator. The measurements are done with external cooling in the preoperative stage to accurately predict the location of the dominant perforators. During the surgery, in the peroperative stage, measurements are done for mapping the influence of a specific perforator on the perfused areas of the abdominal flap. Perforators are sequentially closed and opened again to map the influence of that perforator on the vascularization of the flap, visualized with the help of the thermographic camera. The acquired steady-state thermal images could help decide which parts of the abdominal flap to use for the reconstruction so that the chance of (partial) necrosis is reduced. In the postoperative stage, DIRT could visualize the arterial and or venous thrombosis before they become clinically obvious as (partial) necrosis. At present DIRT seems to be a valuable investigation for the pre-, per-, and postoperative phases of DIEP-flap reconstructions. Large, high-quality clinical studies are needed to determine its definitive role.

Dynamic infrared thermography (DIRT) in Deep Inferior Epigastric Perforator (DIEP) flap breast reconstruction: standardization of the measurement set-up.

Breast reconstruction with an autologous free Deep Inferior Epigastric Perforator (DIEP) flap is one of the preferred options following mastectomy. A challenging step in this procedure is the selection of a suitable perforator that provides sufficient blood supply for the flap. The current golden standard for perforator mapping is computed tomography angiography (CTA). However, this is a relatively expensive imaging modality that requires intravenous contrast injection and exposes patients to ionizing radiation. More recently, dynamic infrared thermography (DIRT) has been proposed as an alternative imaging modality for perforator identification. DIRT appears to be an ideal alternative technique not only for the identification of the dominant perforators, but also for the mapping of the individual influence of each perforator on the flap perfusion. Multiple studies have been performed with the use of DIRT, unfortunately without standardisation of the measurement set-up. In this technical note we propose a standardised and reproducible measurement set-up for the use of DIRT during breast reconstructions with a free DIEP flap. This set-up can be used pre-, intra- and postoperatively. A standardised measurement set-up will improve the quality of measured data and ensure reproducibility.