Three-dimensional digital imaging is as accurate and reliable to measure leg ulcer area as transparent tracing with digital planimetry.

OBJECTIVE: An accurate and reliable method for measuring venous leg ulcer (VLU) area is important in assessing treatment effects. The new three-dimensional (3D) LifeViz digital imaging system (QuantifiCare S.A., Valbonne, France) combines a compact, easy to use stereovision camera and image management software to provide 3D medical images. The aim of this prospective study was to investigate whether the 3D LifeViz digital imaging system could be considered a suitable alternative to manual transparent wound tracing for the measurement of VLU area and 4-week healing rates. METHODS: A prospective cohort study was conducted in two tertiary centers between November 2013 and January 2014. The intrarater variability of the digital imaging system was assessed by comparison of the target wound (TW) areas obtained at the inclusion visit (W0) and 2 days after W0 for each local rater. The inter-rater variability of the two methods at W0 and the study end visit was assessed using the TW area measurements obtained by local and central raters. RESULTS: A total of 36 consecutive outpatients, each presenting with at least one VLU and representing a total of 44 TWs, were recruited. At inclusion, comparable results were observed with both methods in terms of mean VLU area, showing a good correlation of the digital imaging method with the transparent tracing method (concordance correlation coefficient [CCC], 0.989; 95% confidence interval [C], 0.983-0.992). Furthermore, this system detected the same changes in the 4-week healing rate as the transparent tracing method, showing that both methods were equivalent in measuring changes in VLU areas over time (CCC, 0.996; 95% CI, 0.994-0.997). Strong intrarater and inter-rater concordances demonstrated good reproducibility of the digital imaging system for VLU area measurements (CCC, 0.994 [95% CI, 0.992-0.995] for intrarater variability; and CCC ≥0.99 for each center for inter-rater variability). Moreover, regardless of the operator measuring the VLUs, the reliability of image capture and image quality remained excellent. CONCLUSIONS: The 3D LifeViz digital imaging system is a noncontact stereophotographic method that provides measurements of VLU area or changes in VLU areas that are as accurate and reliable as those obtained using the planimetry method and in conditions as close as possible to those of a clinical trial.

Quantification of skin lesions with a 3D stereovision camera system: validation and clinical applications.

BACKGROUND/PURPOSE: Three-dimensional (3D) imaging of the skin is a challenging technique. A new 3D digital camera system has been developed that enables 3D reconstruction of the skin and subsequently allows volumetric quantification. Herein we present validation data on calibrated phantoms and the clinical application of this technology. METHODS: Absolute and relative geometric 3D measurements were validated with a static imaging phantom manufactured by a metrology institution and a dynamic imaging phantom adjustable for different volume quantities, respectively. Consecutively, in a clinical study, 3D baseline and follow up images from 27 basal cell carcinomas under topical therapy were captured for volumetric analysis. RESULTS: Validation experiments have demonstrated an average accuracy for surface position of 55 µm and a precision of 8 µm, as well as excellent correlation (0.999) between injected and measured volumes. The geometric baseline analysis of 27 basal cell carcinomas exhibited a high correlation and agreement between 2D and 3D surface measurements. Under topical therapy, it was possible to gain statistically significant differences between verum- and vehicle-treated basal cell carcinomas when analyzing geometric measurements of 3D volume (P = 0.01) and 3D surface (P = 0.001). CONCLUSION: In our study we were able to demonstrate that this newly developed 3D camera system offers a precise objective dimensional representation of the skin. This technique is easily applicable and sensitive enough to measure small differences in area and volume before and after intervention.

Cardiovascular imaging to quantify the evolution of cardiac diseases in clinical development.

Cardiovascular diseases are the leading causes of mortality in western countries, leading to the development of a large set of preventive and curative treatments. Medical imaging is the gold standard to evaluate both cardiac perfusion and cardiac function and can be used even before the advent of hard events to accurately assess treatment effects. This study reviews the different image modalities that can be used to evaluate the evolution of cardiac diseases, especially coronary artery diseases. It also reviews different techniques heavily relying upon image co-registration techniques and population model designs that enable accurate quantitative evaluation of cardiac perfusion and cardiac function through time. It will draw the pros and cons of the different imaging modalities in actual clinical trials: Gated or tagged MRI, MRI for perfusion, PET, SPECT, Gated SPECT, MUGA, Ultrasound. This study also details the latest advances in quantification of cardiac SPECT, which has wide use in clinical trials today.

Assessment of myocardial reperfusion after myocardial infarction using automatic 3-dimensional quantification and template matching.

UNLABELLED: Assessment of perfusion defect extent is essential for determining prognosis after a myocardial infarction (MI), but quantification methods usually rely on segmental analysis, which may lack accuracy. We present an automated voxel-based and template-based approach for precise quantification of perfusion defect extent and reperfusion evolution. METHODS: Coronary angiography and stress/reinjection (201)Tl tomography were performed prospectively on 49 patients with recent MI (45 men; mean age +/- SD, 54 +/- 10 y), before and 3 mo after revascularization (40 angioplasties and 9 bypasses). Perfusion defect extent was quantified using expert 16-segment visual scoring of the slices and a 3-dimensional (3D) method with spatial normalization between times 1 and 2. Briefly, the latter automatically extracted myocardial edges, matched them to a reference template, and compared the perfusion intensity in each voxel with the intensity of the corresponding voxel in a control population of 100 healthy subjects. RESULTS: Reocclusion occurred in 12 patients within 3 mo of surgery (all had undergone angioplasty). The perfusion gain between times 1 and 2, assessed by visual analysis, was significantly higher in permeable patients than in reoccluded patients: 12.4% +/- 13.3% and 2.3% +/- 8.2% of the initial stress defect, respectively (P = 0.02). Proportional gains, measured with the quantitative 3D method, were 4.5% +/- 3.6% and 1.9% +/- 2.7%, respectively (P = 0.02). Furthermore, the 3D method allowed measurement within the initial ischemic defect (reversible part of the stress defect at time 1), the extent of myocardium whose perfusion improved at time 2 (reperfusion), and the extent of myocardium whose perfusion remained unchanged (residual ischemia). A voxel-by-voxel analysis of these regions revealed that the proportion of reperfusion was significantly higher in permeable patients than in reoccluded patients: 60.0% +/- 21.3% versus 40.0% +/- 22.5%, respectively (P = 0.008). This was cumbersome to quantify using visual analysis and did not reach statistical significance, likely because of segmental division (partial-volume effect) and absence of spatial normalization. CONCLUSION: The 3D voxel-based quantification allows satisfying assessment of reperfusion 3 mo after MI. Moreover, the automated analysis using spatial normalization should facilitate a reproducible assessment of large populations over time.