Vascular Studies

 

 

Thermographic Assessment of a Vascular Malformation of the Hand: A New Imaging Modality.

Hardwicke JT, Titley OG

ABSTRACT

Vascular malformations of the hand are rare. Angiography is the current Gold Standard imaging modality. Thermal imaging is an emerging noninvasive, non-contact technology that does not require intravenous contrast agents. We present the case of a patient with an arteriovenous malformation affecting the hand in which thermal imaging has been used as an adjunct to capture baseline images to allow monitoring of progression. We suggest that thermal imaging provides an adjunct that can be used in addition to clinical examination and/or angiography for the diagnosis and routine follow-up of conservatively managed arteriovenous malformations, to monitor progression or vascular steal, and also for recording recurrence after surgical excision for which there is known to be a significant incidence. With the benefit of being a noninvasive imaging modality that does not require intravenous contrast, or ionizing radiation exposure, office-based thermal imaging may become commonplace.

www.ncbi.nlm.nih.gov/pubmed/27195175
 
 
 

Infrared thermal imaging as a novel evaluation method for deep vein thrombosis in lower limbs.

Deng F, TangQ, Zheng Y. Zeng G. Zhong N , State Key Laboratory of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical College, Guangzhou 510120, China.

Purpose

Early detection of deep vein thrombosis (DVT) is critical to prevent clinical pulmonary thromboembolism. However, most conventional methods for diagnosing DVT are functionally limited and complicated. The aim of this study was to evaluate the value of infrared-thermal-imaging (IRTI), a novel imaging detection or screening technique, in diagnosis of DVT in animal models.

 

Methods

DVT model of femoral veins was established in nine New Zealand rabbits. The right hind femoral vein was embolized and the contralateral one served as a nonembolized control. Measurements of IRTI, compression ultrasonography (CPUS), and angiography under ultrasonic observation (AGUO) were performed at three time points: T1 (baseline, 10 min prior to surgery), T2 (2 h after thrombin injection), and T3 (48 h postoperatively). Qualitative pseudo color analysis and quantitative temperature analysis were performed based on mean area temperature (Tav) and mean curvilinear temperature (Tca) of the region of interest as shown in IRTI. Temperature differences (TD) in Tav (TD(Tav)) and Tca (TD(Tca)) between the DVT and control sides were computed. Comparative statistical analysis was carried out by paired t-test and repeated measure, while multiple comparisons were performed by using Greenhouse-Geisser and Bonferroni approach. Values of P < 0.05 and P < 0.01 were considered statistically significant and highly significant.

 

Results

Modeling of DVT was successful in all rabbits, as confirmed by CPUS and AGUO and immediately detected by IRTI. IRTI qualitative analysis of pseudo color revealed that the bilateral temperatures were apparently asymmetrical and that there were abnormally high temperature zones on the DVT side where thrombosis formed. The results of paired t-test of Tav and Tca between DVT side and control sides did not reveal statistical difference at T1 (Tav: P = 0.817; Tca: P = 0.983) yet showed statistical differences at both T2 (Tav: P = 0.023; Tca: P = 0.021) and T3 (Tav: P = 0.016; Tca: P = 0.028). Results of repeated measure and multiple comparisons of TD(Tav) and TD(Tca) were highly different and significant differences across the T2 (TD(Tav): P = 0.009; TD(Tav): P = 0.03) and T3 (TD(Tav): P = 0.015; TD(Tav): P = 0.021).

 

Conclusions

IRTI temperature quantitative analysis may help further detection of DVT. Additionally, IRTI could serve as a novel detection and screening tool for DVT due to its convenience, rapid response, and high sensitivity.

www.ncbi.nlm.nih.gov/pubmed/23231273
 
 
 
 

Digital thermography of the fingers and toes in Raynaud’s phenomenon.

Lim MJ, Kwon SR, Jung KH, Joo K, Park SG, Park W.

ABSTRACT

The aim of this study was to determine whether skin temperature measurement by digital thermography on hands and feet is useful for diagnosis of Raynaud‘s phenomenon (RP). Fifty-seven patients with RP (primary RP, n = 33; secondary RP, n = 24) and 146 healthy volunteers were recruited. After acclimation to room temperature for 30 min, thermal imaging of palmar aspect of hands and dorsal aspect of feet were taken. Temperature differences between palm (center) and the coolest finger and temperature differences between foot dorsum (center) and first toe significantly differed between patients and controls. The area under curve analysis showed that temperature difference of the coolest finger (cutoff value: 2.2℃) differentiated RP patients from controls (sensitivity/specificity: 67/60%, respectively). Temperature differences of first toe (cutoff value: 3.11℃) also discriminated RP patients (sensitivity/specificity: about 73/66%, respectively). A combination of thermographic assessment of the coolest finger and first toe was highly effective in men (sensitivity/specificity : about 88/60%, respectively) while thermographic assessment of first toe was solely sufficient for women (sensitivity/specificity: about 74/68%, respectively). Thermographic assessment of the coolest finger and first toe is useful for diagnosing RP. In women, thermography of first toe is highly recommended.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3991792/
 
 
 

Vascular surgical society of great Britain and Ireland: analysis of cold provocation thermography in the objective diagnosis of the hand-arm vibration syndrome.

Coughlin P, Chetter IC, Kent PJ, Kester RC; St James’s University Hospital, Leeds, UK.

BACKGROUND

The hand-arm vibration syndrome (HAVS) is the commonest prescribed disease in the UK. Presently the diagnosis is subjective and the need for an objective investigation to support the diagnosis has been highlighted. This study analyses the potential of cold provocation thermography (CPT) to fulfill this role.

 

METHODS

CPT was performed in ten controls (five men, five women; median age 35 (range 24-78) years) and 21 patients with HAVS (20 men, one woman; median age 45 (range 29-81) years). With an infrared camera, a pre-cooling (PC) image was taken and then, following hand cooling in water at a temperature of 5 degrees C for 1 min, further rewarming images were taken every minute for 10 min.

 

RESULTS

Patient finger tip temperatures were significantly cooler than control temperatures at all time points (P < 0.01, Student’s t test). The following Table shows the sensitivity, specificity and PPV of CPT.

 

CONCLUSION
CPT provides strong objective evidence to support the clinical diagnosis of HAVS.

http://www.ncbi.nlm.nih.gov/pubmed/10361321
 
 
 

Detection of dialysis access induced limb ischemia by infrared thermography in children.

Novljan G, Rus RR, Koren-Jeverica A, Avčin T, Ponikvar R, Buturović-Ponikvar J.
Departments of Pediatric Nephrology, University Medical Centre Ljubljana, Ljubljana, Slovenia. gregor.novljan@mf.uni-lj.si

 

Abstract

High arteriovenous fistula (AV fistula) blood flow may impair distal limb perfusion and cause irreversible ischemic damage. Since tissue temperature reflects blood perfusion, we tried to assess distal blood flow using an infrared camera. We examined all 12 patients with an AV fistula in our dialysis unit. Seven were pediatric patients aged 11.0-18.9 years (mean 14.9 years) and five were adults aged 26.9-62.1 years (mean 38.6 years). Infrared thermal imaging (thermography) of their hands was performed after the completion of their regular dialysis sessions. In each patient, the spot temperature of each fingertip on both hands was assessed separately, with three measurements being performed for each measuring point. The mean spot temperature of all fingertips was calculated for each hand and the results compared. A statistically significant difference (P < 0.05) indicated distal perfusion insufficiency. Perfusion of the hands was also assessed by inspecting the visualized temperature distribution on the thermal image. Finally, we compared the results to the clinical findings in relevant patients. In 8/12 patients (66.7%), the mean spot temperature of the fingertips was statistically significantly lower on the fistula side (P < 0.05). Only 4/12 patients (33.3%) had clinical symptoms, and all were detected by thermography. Abnormal findings were more frequent in elderly patients. Although we realize that the diagnosis of steal syndrome is primarily clinical, thermography might be a safe, noninvasive, cheap tool for the timely detection of children at risk of developing symptoms of hand ischemia.

© 2011 The Authors. Therapeutic Apheresis and Dialysis © 2011 International Society for Apheresis.

http://www.ncbi.nlm.nih.gov/pubmed/21624080