Measurement Of Dermal Thickness Research Articles

Efficacy and Safety of Ablative Fractional Laser-Assisted Delivery of Methotrexate in Adults with Localized Scleroderma: A Randomized and Controlled Clinical Trial.

Localized scleroderma (LS) is an autoimmune disease with sclerosis of the skin as the main manifestation. Currently, there is no specific treatment for LS. The effectiveness of ablative fractional laser (AFL) therapy for LS has been demonstrated in several studies. Combining ablative fractional Er:YAG laser therapy with topical methotrexate may yield therapeutic benefits for patients with LS. To compare the efficacy and safety of AFL-assisted delivery of methotrexate in adults with LS, we randomly divided patients into an AFL therapy group and an ablative fractional laser-assisted delivery of methotrexate (AFL+MTX) therapy group. Laser and assisted drug delivery treatment were given every four weeks for four months, and 22 patients completed the trial. Ultrasound measurements of dermal thickness and histological fibrosis degree and the Localized Scleroderma Cutaneous Assessment Tool (LoSCAT) score were used to assess therapeutic effects. Treatment results showed that both AFL and AFL-assisted methotrexate delivery were effective in treating LS, and the laser combined with methotrexate therapy was more effective in improving clinical appearance (p value = 0.042) and dermal thickness (p value = 0.016). No serious adverse reaction occurred in either group. In conclusion, AFL and assisted delivery of methotrexate are effective and safe treatments for LS.

A Pilot Study to Quantify Breast Lymphedema for Patients Undergoing Breast Conserving Therapy (BCT) for Breast Cancer

<h3>Purpose/Objective(s)</h3> Upper extremity lymphedema after axillary lymph node dissection and radiation for breast cancer has been well described and studied. As modern treatment techniques have reduced the incidence of arm lymphedema, breast lymphedema has emerged as a common result of BCT and is associated with poor wound healing, infection and impact on quality of life. Because there is no established tool for its evaluation and quantification, we explored the feasibility of using ultrasound to measure breast lymphedema objectively. We evaluated whether this measure correlated with clinical assessment, treatment factors, and patient-reported outcomes. <h3>Materials/Methods</h3> We enrolled 30 women with malignant breast cancer treated with breast conserving surgery, sentinel lymph node biopsy, and breast radiation. Another 10 women with benign disease who had not undergone BCT were sampled as controls. Ultrasound measurements of dermal thickness were performed on the treated breast and untreated breast at the 6:00 position. Post-treatment assessments included physical exam and quality of life DASH questionnaire. We quantified breast lymphedema as the dermal thickness of the affected breast minus the dermal thickness of the unaffected breast. Breast lymphedema was considered present if dermal thickness difference was above the highest-observed value in the benign patients. <h3>Results</h3> Mean age (± SD) was SD 59 ± 13 in the malignant group and 46.4 ± 17 in the benign group and groups were similar with regard to body mass index. Mean dermal thickness difference was higher in the malignant group compared with the benign group (1.03 mm and 0 mm, respectively). Seventy percent of patients in the malignant group met our definition of breast lymphedema (n = 21) and were more likely to report impact on quality of life pertaining to sexual activity (24% vs 11%), breast sensation (52% vs 16%), sleep quality (33% vs 21%) and confidence (24% vs 5%) than patients without breast lymphedema. Extent of axillary surgery was associated with a 1.29 mm increase in difference in dermal thickness for patients with > = 4 nodes removed (95% CI: -0.22, 2.80). The volume of breast tissue radiated was also positively associated, with every 100cc increase in breast volume radiated associated with a 0.17mm greater dermal thickness difference (95% CI: 0.04, 0.30mm). However, there was no association with percent of breast tissue receiving > 105% of prescribed dose (95% CI: -0.07, 0.01), hypofractionation vs. standard fractionation (95% CI: -1.2, 0.68) or total radiation dose (95% CI: -0.5, 1.2). <h3>Conclusion</h3> Breast lymphedema is an impactful sequela of breast cancer treatment but remains understudied with no standard measurement tools. Our pilot study demonstrates that ultrasound is a promising tool for the characterization of breast lymphedema and may improve our understanding of patient and modifiable treatment risk factors.

Abstract 41: Reactions of Fibrotic Skin To Fat Grafting In A Rodent Model

Purpose: The chronic cutaneous fibrosis associated with scleroderma is a significant source of morbidity for patients and impairs activities of daily living. This study evaluates the hypothesis that fat grafting or injection of isolated adipose-derived stem cells (ADSC) will induce regenerative skin changes and ameliorate fibrosis in a murine model of cutaneous fibrosis. Methods: Cutaneous scleroderma-like fibrosis was induced via subcutaneous bleomycin injections into 66 adult nu/nu mice. These were divided into 4 groups and treated via subcutaneous injection of murine whole fat, ADSCs suspended in matrigel, matrigel alone (control for ADSC group), or saline (sham graft, control for whole fat group). Five mice from each group (and 7 mice from sham graft group) were selected at 14, 28, and 35 day time points, and underwent laser Doppler analysis of tissue perfusion prior to euthanization. Harvested skin was subjected to dermal thickness measurement and Trichrome staining for quantification of Type I collagen content. Gene expression analysis targeting pro-sclerotic cytokines TGFβ and endothelin-I (ET-I) was performed using quantitative polymerase chain reaction (qPCR). Results: Groups treated with ADSCs showed significantly more Type I collagen and greater tissue perfusion than control at 2 weeks, but these differences progressively decreased over time and were absent at 5 weeks. Additionally ADSC-treated tissue was thicker than control at all time points and continued to thicken over time, where control skin thickness remained stable.Whole fat-treated skin showed a decrease in type I collagen as compared to control, and an increased dermal thickness. There was no difference between whole fat and control dermal thickness at any time. Gene expression analysis revealed higher endothelin expression in ADSC group over control at week 5, and no difference in TGFβ expression at any time point. Whole fat treated groups had no significant difference from control in either gene, though did trend toward an initial spike in both Endothelin and TGFβ at 2 weeks followed by a progressive decline to at or below control levels at weeks 4 and 5, while control levels remained stable. Conclusion: Despite a significant body of evidence extolling benefits of fat grafting in skin rejuvenation, improvement of scarring, and inhibition of the pro-sclerotic pathways in a typical patient, the murine model suggests that this may not translate to amelioration of scleroderma symptoms. In this model injection of whole fat or its constitutive parts was detrimental and caused increased fibrosis and dermal thickness over time.

Performance of ultra-high-frequency ultrasound in the evaluation of skin involvement in systemic sclerosis: a preliminary report.

High frequency ultrasound allows visualization of epidermis, dermis and hypodermis, precise measurement of skin thickness, as well as assessment of skin oedema, fibrosis and atrophy. The aim of this pilot cross-sectional observational study was to assess the performance and multiobserver variability of ultra-high-frequency (UHF) (50 MHz) ultrasound (US) in measuring skin thickness as well as the capacity of UHF-derived skin features to differentiate SSc patients from healthy controls. Twenty-one SSc patients (16 limited and five diffuse SSc) and six healthy controls were enrolled. All subjects underwent US evaluation by three experts at three anatomical sites (forearm, hand and finger). Dermal thickness was measured and two rectangular regions of interest, one in dermis and one in hypodermis, were established for texture feature analysis. UHF-US allowed a precise identification and measurement of the thickness of the dermis. The dermal thickness in the finger was significantly higher in patients than in controls (P < 0.05), while in the forearm it was significantly lower in patients than in controls (P < 0.001). Interobserver variability for dermal thickness was good to excellent [forearm intraclass correlation coefficient (ICC) = 0.754; finger ICC = 0.699; hand ICC = 0.602]. Texture computed analysis of dermis and hypodermis was able to discriminate between SSc and healthy subjects (area under the curve >0.7). These preliminary data show that skin UHF-US allows a very detailed imaging of skin layers, a reliable measurement of dermal thickness, and a discriminative capacity between dermis and hypodermis texture features in SSc and healthy subjects.

Reliability and Diagnostic Thresholds for Ultrasound Measurements of Dermal Thickness in Breast Lymphedema.

Lymphedema of the breast, secondary to treatment for breast cancer, is difficult to assess due to the shape of the breast and the nature of the tissue. Ultrasound measurement of dermal thickness has been previously used to assess breast swelling; however, the reliability of the measurements, or what should be considered an abnormal thickness, is currently known. Thirty-eight women with breast edema were recruited and underwent assessment using ultrasound. During the assessment, the four quadrants (superior, inferior, medial, and lateral) of the affected and unaffected breasts were imaged three times each. Dermal thickness was then measured by two assessors, on two occasions for each captured image. The interimage, intrarater, and inter-rater reliability was all found to be excellent (Cronbach's alpha = 0.995; ICC(3,1) = 0.962 and 0.851; and ICC(2,1) = 0.977, respectively). A dermal thickness of >1.6 mm in the superior and lateral quadrants and 2.0 mm in the medial and inferior quadrants was determined, by receiver-operating characteristics curve analysis, as the optimal diagnostic threshold to detect breast edema. Dermal thickness measurements can be reliably completed on breasts with edema secondary to breast cancer. Future study is needed to determine the utility of the dermal thickness thresholds established as well as to investigate changes in dermal thickness as a response to treatment of breast edema.

A comparison of 20-MHz and 50-MHz ultrasonography in imaging and measuring the skin

Objective To investigate imaging characteristics of human skin in different sites by using 20-MHz and 50-MHz high-frequency ultrasonography, and to compare the reliability of skin thickness measurement by the above two approaches of ultrasonography. Methods A total of 39 healthy volunteers aged 18-39 years were enrolled into this study. Then, 20-MHz and 50-MHz ultrasonography were separately performed to image 20 different sites on the body, and the thickness of the epidermis and dermis were measured and evaluated by 3 dermatologists independently. The ultrasonic images were analyzed, and the intraclass correlation coefficient (ICC) was used to assess and compare the reliability of skin thickness measurement by 20-MHz and 50-MHz ultrasound. Results The ICC values were less than or close to 0.7 in epidermal thickness measurement at almost all the tested sites between 20-MHz and 50-MHz ultrasono-graphy, suggesting poor reliability. However, 20-MHz and 50-MHz ultrasonography showed excellent reliability in dermal thickness measurement with the ICC greater than 0.75 at almost all the tested smooth and flat body sites. The 20-MHz ultrasound could provide clear images of the dermis and subcutaneous tissue, while 50-MHz ultrasound could only provide clearer images of the dermis in details. In some uneven sites with complex anatomical structures, 20-MHz and 50-MHz ultrasound probes had their own advantages and disadvantages in imaging depth and detail resolution. Conclusions The 20-MHz and 50-MHz ultrasono-graphy both can serve as non-invasive imaging techniques to show structures of the epidermis and dermis better. In different parts of human body, ultrasound frequencies should be selected according to their imaging characteristics. Key words: Ultrasonography; Skin structure; Skin thickness; Interclass correlation coefficient

Strengthening the Skin with Topical Delivery of Keratinocyte Growth Factor-1 Using a Novel DNA Plasmid

Fragile skin, susceptible to decubitus ulcers and incidental trauma, is a problem particularly for the elderly and for those with spinal cord injury. Here, we present a simple approach to strengthen the skin by the topical delivery of keratinocyte growth factor-1 (KGF-1) DNA. In initial feasibility studies with the novel minimalized, antibiotic-free DNA expression vector, NTC8385-VA1, the reporter genes luciferase and enhanced green fluorescent protein were delivered. Transfection was documented when luciferase expression significantly increased after transfection. Microscopic imaging of enhanced green fluorescent protein–transfected skin showed green fluorescence in hair follicles, hair shafts, and dermal and superficial epithelial cells. With KGF-1 transfection, KGF-1 mRNA level and protein production were documented with quantitative reverse transcriptase–polymerase chain reaction and immunohistochemistry, respectively. Epithelial thickness of the transfected skin in the KGF group was significantly increased compared with the control vector group (26 ± 2 versus 16 ± 4 µm) at 48 hours (P = 0.045). Dermal thickness tended to be increased in the KGF group (255 ± 36 versus 162 ± 16 µm) at 120 hours (P = 0.057). Biomechanical assessment showed that the KGF-1–treated skin was significantly stronger than control vector–transfected skin. These findings indicate that topically delivered KGF-1 DNA plasmid can increase epithelial thickness and strength, demonstrating the potential of this approach to restore compromised skin.

SP0149 How to implement technical improvements in existing imaging modalities in clinical practice: Ultrasonography

The value of ultrasound in rheumatology is supported by a consistent body of evidence. The number of studies has progressively increased documenting the interest for this imaging tool especially in...

The 800-nm diode laser irradiation induces skin collagen synthesis by stimulating TGF-β/Smad signaling pathway

The 800-nm diode laser is used clinically for hair removal and leg vein clearance. However, the effects of the laser on skin collagen synthesis have not been established. This study aims to research whether the 800-nm laser can be used for non-ablative rejuvenation and its possible mechanism by using an animal model. Eight 2-month-old rats were irradiated with the 800-nm diode laser at 20, 40, and 60J/cm(2), respectively. Skin samples were taken for histological study and dermal thickness measurement at day 30 after laser irradiation. The expression of procollagen type I, III, IV, transforming growth factor-β (TGF-β), Smad2, 3, 4, and phosphorylated-Smad2, 3 in the rat skin was analyzed 24 h after completing all laser treatments by using RT-PCR and Western blot. Immunohistochemistry was performed to evaluate the content of type I collagen in the skin at day 30 after laser irradiation. The 800-nm diode laser treatments markedly improved the histological structure and increased dermal thickness compared to the non-irradiated controls. Laser irradiation at 40J/cm(2) significantly up-regulated the expression of procollagen type I and IV, TGF-β and Smad2, 3, 4. The p-Smad2 and p-Smad3 levels were also enhanced in the laser-irradiated skin. The 800-nm laser is effective in improving skin structure and inducing skin new collagen expression. New collagen synthesis induced by the 800-nm laser was mediated by TGF-β/Smad signaling pathway. Thus, it seemed that the 800-nm laser could be used for non-ablative rejuvenation in the future.

Transplantation of acellular dermis and keratinocytes cultured on porous biodegradable microcarriers into full-thickness skin injuries on athymic rats

In search of an optimal transplantation regime for sufficient dermal and epidermal regeneration after a full-thickness skin injury, wounds on athymic rats were grafted with split-thickness skin grafts or acellular human dermis followed by transplantation with human keratinocytes either in single-cell suspension or cultured on porous biodegradable microcarriers. After 2 weeks, all wounds grafted with acellular human dermis showed a well organised and vascularised dermal component and reepithelialisation on the grafted dermal matrix was complete 21 days after transplantation with human keratinocytes. Wounds grafted with human keratinocytes seeded on biodegradable microcarriers or split-thickness skin grafts displayed over time (i.e. 16–21 days post-transplantation) a significantly thicker epithelial cell layer in comparison to wounds grafted with keratinocytes in single-cell suspensions or microcarriers not seeded with cells. Furthermore, measurements of dermal thickness in the closed wounds 21 days after grafting showed a significantly thicker and well organised neodermal component in wounds transplanted with keratinocytes seeded on microcarriers or split-thickness skin grafts compared to all other wounds. Positive immunostaining towards von Willebrand factor revealed the plausible proangiogenic effects of transplantation with keratinocytes seeded on microcarriers. Analysis of representative tissue sections after fluorescence in situ hybridisation visualised that grafted human keratinocytes were present in the epidermal layers covering the wounds 16 and 21 days after transplantation, strongly indicating preservation of cell viability. These results shows that the use of biodegradable microcarriers in the culture of autologous keratinocytes for treatment of full-thickness wounds not only facilitate the cultivation, transportation and transplantation processes but also enhances the dermal regeneration induced by a dermal scaffold which results in a clinical result that is significantly superior to the one obtained when keratinocytes are transplanted in a single-cell suspension.

High-frequency ultrasound measurement for assessing post-thrombotic syndrome and monitoring compression therapy in chronic venous disease

The purpose of this study was to validate high-frequency ultrasound (HFU) measurement of dermal thickness for quantification of edema in patients with different severities of chronic venous disease. HFU measurements of dermal thickness were made with a 17-MHz probe (Philips iU22 Ultrasound scanner, Bothell, Wash) or a 20-MHz medium-focus probe (DermaScan-C, Cortex Technology, Denmark), 7.5 cm above the medial malleolus. For validation, 20 patients with venous leg ulcers who were not receiving compression therapy, 20 patients with previous deep vein thrombosis (DVT) and symptoms of post-thrombotic syndrome (PTS) without ulceration, and 31 age-matched healthy controls were measured on a single occasion. To investigate the effect of compression on dermal thickness, the leg ulcer patients from the validation study were treated with compression therapy for 7 weeks and measured after 1, 3, 5, and 7 weeks. The association between dermal thickness and the clinical (C) component of the CEAP classification was examined in a cross-sectional analysis of 157 patients with a confirmed history of DVT >or=3 years ago. Dermal thickness in patients with venous leg ulcers before compression therapy (median, 2.56 mm; interquartile range [IQR], 2.31-2.82 mm) was significantly greater (P = .002) than that in patients with symptoms of PTS without ulceration (median, 2.16 mm; IQR, 1.90-2.36 mm). Dermal thickness in both groups was significantly greater (P < .0001) than the control group (median, 1.34 mm; IQR, 1.29-1.44 mm). Compression therapy caused a steady and significant decrease in dermal thickness during the first 5 weeks until normal control levels were achieved. Dermal thickness increased with increasing CEAP category. In 121 patients with a positive diagnosis of DVT >or=3 years ago from Radiology Department records, a hypothetical test cutoff of 1.985 mm for the prediction of severe PTS noted as C(4b), C(5), and C(6) (lipodermatosclerosis or leg ulceration) had a positive predictive value of 46.9% and a negative predictive value of 90.3%. HFU measurement of dermal thickness enables the monitoring of edema reduction by compression therapy. A prospective study is required to determine the temporal dynamics of dermal thickness changes after DVT and the relationship to the development of PTS. This test has the potential to be beneficial in the follow-up of patients after a DVT and provide clinical evidence for using graduated elastic compression stockings to control edema and prevent the development of more advanced skin changes.

Automatic measurement of dermal thickness from B‐scan ultrasound images using active contours

Measurement of dermal thickness is useful in the evaluation of dermo-cosmetics for assessing not only morphological changes but also mechanical properties of this layer. Our aim was first to standardise the manual dermal thickness measurement procedure on B-scan ultrasound images, then to develop an automatic operator independent method to detect the boundaries of the dermis. The Dermcup 20 MHz B-scan ultrasound system was used. The method used for detecting the boundaries was adapted from active contour algorithms. The innovative aspect of the method consists in an automatic initialization of the first step of the algorithm. To validate the method, we correlated measurements obtained by the manual and automatic approaches from a set of images from different anatomical sites. The results showed for the two measurement methods, 72% of the images were perfectly correlated. The remaining images required manual initialization of the boundaries by a non-expert operator before the active contour process could be used. Subsequent to this semi-automatic procedure, the correlation was very high.

Effects of a 1 per cent hydrocortisone conditioner on the prevention of immediate and late‐phase reactions in canine skin

Ten laboratory beagles were used to determine whether a 1 per cent hydrocortisone conditioner applied topically for three consecutive days would inhibit IgE-mediated immediate and late-phase reactions induced in their skin. The trial was blinded, controlled with the product's vehicle and designed with a crossover. It consisted of three phases: one period without treatment (control phase) and two periods of treatment with either the active ingredient or the vehicle. Immediate and late-phase reactions were induced by the intradermal injection of rabbit anti-canine IgE polyclonal antibodies. Twenty minutes after the intradermal challenge, the diameter of the wheal, but not the erythematous flares, were significantly reduced after the application of the active product. In contrast, IgE-mediated cutaneous late-phase reactions, evaluated by measurements of dermal thickness and eosinophil counts six hours after challenge and the numbers of dermal CD3-positive T lymphocytes after 24 hours, were not reduced by its application.

Dose- and Source-Size-Related Changes in the Late Response of Pig Skin to Irradiation with Single Doses of β Radiation from Sources of Differing Energy

Late radiation damage to pig skin has been assessed at 104 weeks after exposure to sources of 90Sr/90Y (Emax 2.2 MeV) and 170Tm (Emax 0.9 MeV). Damage was assessed from measurements of dermal thickness in histological sections of irradiated skin and was compared with that of unirradiated skin to establish the relative reduction in dermal thickness. The size of the source varied from 0.1 to 40.0 mm in diameter; this covered the range of source sizes designed to simulate exposure to radioactive "hot" particles (< or = 1.0 mm diameter) up to the lower range of field size that patients may be exposed to in radiotherapy treatments. Radiation doses were measured using an extrapolation chamber with a collecting electrode of 1.1 mm2, and thus the quoted doses represent an average dose over this area. For the larger 90Sr/90Y sources of > or = 5 mm diameter and the larger 170Tm sources of > or = 2 mm diameter there was no evidence, based on levels of damage consistent with a > or = 10, > or = 20, > or = 30, and > or = 40% reduction in relative dermal thickness, for any effect of source size on the ED50 value for each of these specified levels of effect. However, there was a marked effect of beta-particle energy; the skin surface doses associated with the ED50 values (+/- SE) for a > or = 20% reduction in relative dermal thickness were approximately 12 and approximately 40 Gy for 90Sr/90Y and 170Tm, respectively. This difference in skin surface dose for an equivalent level of dermal injury reflects the variation in the depth dose from these two beta-particle emitters. These skin surface doses, for what was considered to be a clinically detectable dermal effect, were below the ED10 for the early skin response of moist desquamation. This supports the selection of late dermal thinning as the effect on which to base dose limits in radiation protection for more generalized larger area skin exposures. In comparison, single exposures to a small area, from sources designed to simulate those from hot particles, reinforced the view that acute ulceration should be the effect on which dose limitation is based. Either the isoeffect doses for a clinically detectable reduction in relative dermal thickness of > or = 20%, following a single exposure to a small area, were higher than the ED10 for acute ulceration or the area of skin showing dermal thinning was so small that it was not considered to be detrimental.

The influence of histamine and PGE2-induced hyperaemia and oedema on respiratory metabolism in normal human forearm skin

Transcutaneous measurements of pO2 and pCO2 were made on the forearm skin after intradermal injection of histamine, PGE2, and saline. The mediators, used at concentrations which induce intense hyperaemia, did not modify the steady state tcpO2/pCO2 levels measured with a sensor head temperature of 44 degrees C when breathing air or hyperbaric (2ATA) oxygen. It was deduced that gas transport is unaffected by mediator-induced conditions in the skin. The rates of fall of tcpO2 and of rise of tcpCO2 after arresting the forearm circulation by cuff occlusion of the arm were significantly less at the histamine site than at the PGE2 and saline sites. The values over the PGE2 and saline injection sites were less than those over undisturbed skin. The dynamic tests of respiratory gas exchange indicate that the skin metabolic rate is reduced at all injection sites and the greatest effect was seen with histamine. Measurement of dermal thickness after saline injection has shown that the excess interstitial fluid persists at the time of maximal hyperaemia: this is further accentuated at the histamine site through active oedema formation. Accumulation of excess interstitial fluid (persistence of aqueous injection or oedema generated by the action of mediator) separates the tissue cells. The reduction in the number of cells per unit volume is sufficient to explain the observed reduction in oxygen consumption per unit volume of skin. It is concluded that the increased diffusional distances in mediator-induced oedema are unimportant for the respiration of otherwise normal tissues, but that oedema by reducing oxygen flux may contribute appreciably to the hypoxia of inflamed tissue infiltrated with metabolically active cells.

Late Nonstochastic Changes in Pig Skin after β Irradiation

Late radiation-induced changes in pig skin have been assessed following irradiation with beta-rays from a 22.5- or 15-mm-diameter 90Sr/90Y source and a 19- or 9-mm-diameter 170Tm source. Late damage, in terms of dermal atrophy, was assessed 2 years after irradiation from measurements of dermal thickness in irradiated and normal skin. After 90Sr irradiation maximum atrophy, a dermal thickness of 40-50% of the control value, occurred at a dose of approximately 40 Gy from the 22.5-mm source and approximately 75 Gy from the 15-mm source. In the case of 170Tm the 19- and 9-mm sources produced similar degrees of atrophy at equal doses. Maximum atrophy occurred at approximately 70 Gy, when the dermis was approximately 70% of the thickness of normal skin. Significant late tissue atrophy was seen at doses, from both types of radiation, which only produced minimal erythema in the early reaction. Such late reactions need to be taken into account when revised radiological protection criteria are proposed for skin.

Measurement of dermal thickness with the Harpenden skinfold caliper.

A simple method of determining skin thickness using the Harpenden Skinfold Caliper is described. Using this technique the atrophy caused by the topical application of Fluocinolone acetonide in normal volunteers has been detected. As a comparison the skin thickness was also measured in the same individuals by an established x-ray technique. Not only was a similar degree of atrophy observed but also a high degree of correlation (r=0.82, n=32, P less than 0.001) was found between the values obtained with both techniques.