title: Effectiveness of digital infrared thermal imaging in detecting lower extremity deep venous thrombosis.
abstract: OBJECTIVE
  The authors aimed to determine the effectiveness of infrared thermal imaging (IRTI) as a novel, noninvasive technique in adjunctive diagnostic screening for lower limb deep venous thrombosis (DVT).
  
  
  METHODS
  The authors used an infrared thermal imaging sensor to examine the lower limbs of 64 DVT patients and 64 healthy volunteers. The DVT patients had been definitively diagnosed with either Doppler vascular compression ultrasonography or angiography. The mean area temperature (T_area) and mean linear temperature (T_line) in the region of interest were determined with infrared thermal imaging. Images were evaluated with qualitative pseudocolor analysis to verify specific color-temperature responses and with quantitative temperature analysis. Differences in T_area and T_line between the DVT limb and the nonaffected limb in each DVT patient and temperature differences (TDs) in T_area (TDarea) and T_line (TDline) between DVT patients and non-DVT volunteers were compared.
  
  
  RESULTS
  Qualitative pseudocolor analysis revealed visible asymmetry between the DVT side and non-DVT side in the presentation and distribution characteristics (PDCs) of infrared thermal images. The DVT limbs had areas of abnormally high temperature, indicating the presence of DVT. Of the 64 confirmed DVT patients, 62 (96.88%) were positive by IRTI detection. Among these 62 IRTI-positive cases, 53 (82.81%) showed PDCs that agreed with the DVT regions detected by Doppler vascular compression ultrasonography or angiography. In nine patients (14.06%), IRTI PDCs did not definitively agree with the DVT regions established with other testing methods, but still correctly indicated the DVT-affected limb. There was a highly significant difference between DVT and non-DVT sides in DVT patients (P < 0.01). The TDarea and TDline in non-DVT volunteers ranged from 0.19 ± 0.15 °C to 0.21 °C ± 0.17 °C; those in DVT patients ranged from 0.86 °C ± 0.71 °C to 1.03 °C ± 0.79 °C (P < 0.01).
  
  
  CONCLUSIONS
  Infrared thermal imaging can be effectively used in DVT detection and adjunctive diagnostic screening because of its specific infrared PDCs and TDs values.
authors.affiliation: State Key Laboratory of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510120, China.
authors.forename: Fangge
authors.initials: F
authors.lastname: Deng
authors.affiliation: Department of Ultrasound, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510120, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Tang
authors.affiliation: State Key Laboratory of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510120, China.
authors.forename: Guangqiao
authors.initials: G
authors.lastname: Zeng
authors.affiliation: State Key Laboratory of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510120, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Wu
authors.affiliation: State Key Laboratory of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510120, China.
authors.forename: Nuofu
authors.initials: N
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510120, China.
authors.forename: Nanshan
authors.initials: N
authors.lastname: Zhong
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography; D005260:Female; D006801:Humans; D007259:Infrared Rays; D008140:Lorazepam; D035002:Lower Extremity / Q000098:blood supply / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D013817:Thermography / Q000295:instrumentation / Q000379:methods*; D018608:Ultrasonography, Doppler; D020246:Venous Thrombosis / Q000175:diagnosis* / Q000503:physiopathology*; D055815:Young Adult
chemical_list: D008140:Lorazepam