*Article* **Thermal, Hyperspectral, and Laser Doppler Imaging: Non-Invasive Tools for Detection of the Deep Inferior Epigastric Artery Perforators—A Prospective Comparison Study**

**Sebastian P. Nischwitz 1,2,\* , Hanna Luze 1,2, Marlies Schellnegger 2,3, Simon J. Gatterer <sup>4</sup> , Alexandru-Cristian Tuca <sup>1</sup> , Raimund Winter <sup>1</sup> and Lars-Peter Kamolz 1,2**


**Citation:** Nischwitz, S.P.; Luze, H.; Schellnegger, M.; Gatterer, S.J.; Tuca, A.-C.; Winter, R.; Kamolz, L.-P. Thermal, Hyperspectral, and Laser Doppler Imaging: Non-Invasive Tools for Detection of the Deep Inferior Epigastric Artery Perforators—A Prospective Comparison Study. *J. Pers. Med.* **2021**, *11*, 1005. https:// doi.org/10.3390/jpm11101005

Academic Editors: Andreas Arkudas and Raymund E. Horch

Received: 6 September 2021 Accepted: 4 October 2021 Published: 5 October 2021

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**Abstract:** Perforator flaps have become one of the leading procedures in microsurgical tissue transfer. Individual defects require a tailored approach to guarantee the most effective treatment. A thorough understanding of the individual vascular anatomy and the location of prominent perforators is of utmost importance and usually requires invasive angiography or at least acoustic Doppler exploration. In this study, we aimed at evaluating different non-invasive imaging modalities as possible alternatives for perforator location detection. After a cooling phase, we performed thermal, hyperspectral and Laser Doppler imaging and visually evaluated a possible detection of the perforator for a period of five minutes with an image taken every minute. We identified the most prominent perforator of the deep inferior epigastric artery by handheld acoustic Doppler in 18 patients. The detected perforator locations were then correlated. Eighteen participants were assessed with six images each per imaging method. We could show a positive match for 94.44%, 38.89%, and 0% of patients and 92.59%, 25.93%, and 0% of images for the methods respectively compared to the handheld acoustic Doppler. Sex, age, abdominal girth, and BMI showed no correlation with a possible visual detection of the perforator in the images. Therefore, thermal imaging can yield valuable supporting data in the individualized procedure planning. Future larger cohort studies are required to better assess the full potential of modern handheld thermal imaging devices.

**Keywords:** perforator flaps; flap imaging; microsurgery; DIEP; thermal imaging; hyperspectral imaging; laser Doppler
