Skin and subcutaneous tissue strain in legs with lymphedema and lipodermatosclerosis

The Intra-rater reliability and validity of ultrasonography in the evaluation of hypertrophic scars caused by burns

PURPOSE

Hypertrophic scars that occur after burns are less flexible and less elastic than normal skin. Objective measurement tools are required to assess hypertrophic scars after thermal injury. Cutometer® MPA 580 has been widely used for evaluating the properties of hypertrophic scars. Ultrasonography can evaluate elasticity, stiffness, and structure of tissues simultaneously using elastography and B-mode. This study aimed to investigate the intra-rater reliability and validity of elastography to visualize hypertrophic scars.

METHODS

Sixteen participants with a total of 96 scars were evaluated. The measurement sequence was elastography, Cutometer®, and elastography every 10 min. We then analyzed the intra-rater reliability using intraclass correlation coefficients (ICC). The results measured using elastography on the hypertrophic scars and surrounding normal skin were compared. The relationships between the elastographic and Cutometer® measurements using the 2-and 8-mm probes were compared.

RESULTS

The intra-rater reliability of elastographic measurements was acceptable for clinical use in terms of strain ratio (SR), shear-wave elastography (SWE), shear-wave speed (SWS), and SWE ratio ( ICC = 0.913, ICC=0.933, ICC = 0.842, and ICC = 0.921). The average SWS and SWE in hypertrophic scars were significantly greater than that for normal skin ( p < 0.001 and p < 0.001). SWE showed correlations with the R0 (r = -0.32, p = 0.002) and R8 (r = -0.30, p = 0.003) measured with the 8-mm probe. The SWE ratio was correlated with the R7 (r = -0.34, p = 0.001) measured with the 2-mm probe. The thickness of hypertrophic scars showed correlations with the R5 (r = 0.33, p < 0.001), R6 (r = 0.44, p < 0.001) and R8 (r = -0.35, p < 0.001) measured with the 8-mm probe. R0-R9 measured with 2-mm Cutometer® probes were not correlated with scar thickness ( r < 0.30, P > 0.05). The total scores of mVSS showed correlations with the R0 (r = 0.35, p < 0.001), R1(r = 0.32., p = 0.001), R3 (r = 0.38, p < 0.001), R4 (r = 0.38, p < 0.001), R8 (r = 0.34, p = 0.001), and R9 (r = 0.34, p = 0.001) measured with the 2-mm probe. R0-R9 measured with 8-mm Cutometer® probes were not correlated with mVSS ( r < 0.30, P > 0.05). The thickness of hypertrophic scars showed correlations with the SWE (r = 0.38, p < 0.001) and SWE ratio (r = 0.35, p < 0.001). Elastographic findings were not correlated with mVSS ( r < 0.30, P > 0.05).

CONCLUSION

In this study, together with the Cutometer®, ultrasound was confirmed as an evaluation tool that can objectively compare and analyze the difference between normal skin and hypertrophic scars.

Acoustic Radiation Force Impulse Elastography Assessment of Lymphoedema Tissue: An Insight into Tissue Stiffness

Palpation remains essential for evaluating lymphoedema to detect subtle changes that may indicate progression. As palpation sense is not quantifiable, this study investigates the utility of ultrasound elastography to quantify stiffness of lymphoedema tissue and explore the influence of the pitting test on tissue stiffness. Fifteen women with unilateral arm lymphoedema were scanned using a Siemens S3000 Acuson ultrasound (Siemens, Germany) with 18 MHz and 9 MHz linear transducers to assess tissue structure and tissue stiffness with Acoustic Radiation Force Impulse elastography. Ninety sites were assessed, three on each of the lymphoedema-affected and contralateral unaffected arms. A subgroup of seven lymphoedema-affected sites included additional elastography imaging after a 60-s pitting test. Dermal tissue stiffness was greater than subcutaneous tissue stiffness regardless of the presence of pathology (p < 0.001). Lymphoedematous tissue exhibited a higher dermal to subcutaneous tissue stiffness ratio than contralateral sites (p = 0.005). Subgroup analysis indicated that the pitting test reduces dermal tissue stiffness (p = 0.018) and may alter the stiffness of the subcutaneous tissue layer. Elastography demonstrates potential as a complement to lymphoedema palpation assessment. The novel pre-test and post-pitting elastography imaging protocol yielded information representative of lymphoedema tissue characteristics that could not be ascertained from pre-test elastography images alone.

Hardness Sensed by Skin Palpation in Legs with Lymphedema Is Predominantly Correlated with Dermal Thickening

Background: We aimed to clarify whether pathological changes in skin and subcutaneous tissue with lymphedema affected the skin hardness sensed by palpation. Methods and Results: In 50 patients with unilateral legs with lymphedema (LE), the skin hardness of the lower inner thigh and lower inner calf was determined using a scale ranging from 1 (softest) to 7 (hardest) based on palpation. Then, the skin hardness was correlated with the measurements of skin/subcutaneous tissue ultrasonography images obtained from the palpated parts. Multivariate logistic regression analysis demonstrated that dermal thickness was a significant factor that affected the difference in skin hardness between the LE and the contralateral asymptomatic leg for both thigh (p < 0.05) and calf (p < 0.01). When the thigh and calf in the LE were individually studied, subcutaneous echogenicity (p < 0.05), indicating subcutaneous inflammation/fibrosis, and subcutaneous thickness (p < 0.01) also seemed to affect skin hardness, respectively. Conclusions: The skin hardness sensed in the LE seemed to be affected predominantly by dermal thickening. In addition, the pathological changes in the subcutaneous tissue caused by LE seemed to have an impact on skin hardness. Clinical Trial Registration number 2020-150.

Skin biomechanical properties and leg volume in aging healthy adults

BACKGROUND

In adults ageing is accompanied by changes in limb volume and skin biomechanical properties.

OBJECTIVES

To explore the relationship between body size, aging, skin biomechanics, and leg volume, V_Leg and to define predictive equations linking leg volume with these properties.

METHODS

Sixty-two healthy adults (Age 18-80 years, M:F 45:55) were recruited. Anthropomorphic measures were recorded along with V_Leg (via circumferential method) and skin tone, stiffness, and elastance (via tonometry). Regression analysis was performed to define relationship between the measured parameters.

RESULTS

In healthy adults bilateral V_Leg were the same regardless of leg or sex, 5791 ± 1363 for females and 6151 ± 1203 mls for males. V_Leg was positively correlated to body weight, where V_Leg (mls) = 1058 + 69 × Wt (kg) for females and V_Leg (mls) = 539 + 65 × Wt (Kg) of body weight for males. Skin surface biomechanical properties varied with sex, leg volume, and location on the leg with the malleolus exhibiting the stiffest surface.

CONCLUSION

The study shows that anthropometric measures change with sex and leg size are multifactorial and body weight, sex, and skin condition as important determinant factors of leg volume.

Noninvasive, objective evaluation of lower extremity lymphedema severity using shear wave elastography: A preliminary study

BACKGROUND

Increased skin and subcutaneous tissue stiffness in patients with early-stage lymphedema has been reported. The purpose of this study was to examine the use of shear wave elastography (SWE) for evaluating lower extremity lymphedema (LEL).

METHODS

For 10 lower extremities of normal controls and 72 limbs of patients with gynecological cancer whose lymphatic function was categorized into six stages based on the range of dermal backflow (DBF) observed in indocyanine green (ICG) lymphography, SWE was performed and shear wave velocity (SWV) of the dermis and three layers of subcutaneous tissue at the thigh and calf were recorded. Twenty-five patients underwent thigh tissue histological and dermal thickness examinations.

RESULTS

The strongest correlation between the ICG DBF stage and SWV during SWE was observed on the dermal layer of the thigh (p < 0.01, R = 0.67). There was a significant correlation between the dermal thickness of the thigh and the ICG DBF stage (p < 0.01, R = 0.87) and also between the dermal thickness of the thigh and SWV (p < 0.01, R = 0.73).

CONCLUSION

Noninvasive, objective evaluation of LEL severity using SWE was well correlated with lymphatic function as determined by ICG lymphography. The DBF changes in the dermis of the thigh best reflected the changes in lymphatic function. Dermal thickness variations may partially account for differences in SWV.

Ultrasound Vibroelastography for Evaluation of Secondary Extremity Lymphedema: A Clinical Pilot Study

BACKGROUND

Lymphedema treatment is an ongoing challenge. It impacts quality of life due to pain, loss of range of motion of the extremity, and repeated episodes of cellulitis. Different modalities have been used to evaluate lymphedema; some are more error-prone and some are more invasive. However, these measurements are poorly standardized, and intrarater and interrater reliabilities are difficult to achieve. This pilot study aims to assess the feasibility of ultrasound vibroelastography for assessing patients with extremity lymphedema via measuring shear wave speeds of subcutaneous tissues.

METHODS

Patients with clinical and lymphoscintigraphic diagnosis of secondary lymphedema in the extremities without prior surgical treatment were included. A 0.1-s harmonic vibration was generated at three frequencies (100, 150, and 200 Hz) by the indenter of a handheld shaker on the skin. An ultrasound probe was used for noninvasively capturing of wave propagation in the subcutaneous tissue. Wave speeds were measured in the subcutaneous tissues of both the control and affected extremities.

RESULTS

A total of 11 female patients with secondary lymphedema in the extremities were enrolled in this study. The magnitudes of the wave speeds of the region of interest in the subcutaneous tissue at lymphedema sites in the upper extremity (3.9 ± 0.17 m/s, 5.96 ± 0.67 m/s, and 7.41 ± 1.09 m/s) were statistically higher than those of the control sites (2.1 ± 0.27 m/s, 2.93 ± 0.57 m/s, and 3.56 ± 0.76 m/s) at 100, 150, and 200 Hz (P < 0.05), and at 100 and 200 Hz (P < 0.05) between lymphedema (4.33 ± 0.35 m/s, 4.17 ± 1.00 m/s, and 4.56 ± 0.37 m/s) and controls sites (2.48 ± 0.43 m/s, 2.77 ± 0.55 m/s, and 3.06 ± 0.29 m/s) in the lower extremity.

CONCLUSIONS

These preliminary data suggest that ultrasound vibroelastography may be useful in the evaluation of secondary lymphedema and can be a valuable tool to noninvasively track treatment progress.

The basics of ultrasound elastography for diagnosis, assessment, and staging breast cancer-related lymphedema: a systematic review of the literature

Breast cancer-related lymphedema (BCRL) incidence has been increasing overtime. Currently, there is not a preferred imaging tool for diagnosis, staging, and assessment of the disease. We aim to review the use of ultrasound elastography (UE) in BCRL patients. A systematic review was performed by querying PubMed, EMBASE, Ovid Healthstar, and Ovid Medline databases for studies that evaluated the use of UE in BCRL. The keywords "elastography" AND "lymphedema" in titles and abstracts were used for the search. The search retrieved 12, 12, 5 and 6 articles in each database, respectively. From these, only 4 met the inclusion criteria. UE methods included two-dimensional strain imaging, shear wave elastography (SWE), and global UE. Two of the studies evaluated the use of UE in the assessment of BCRL, while only 1 considered its use for diagnosis and staging. Based on our systematic review, UE appears to be a great tool in the assessment of BCRL to differentiate affected from non-affected arms.

Ultrasound Elastography Use in Lower Extremity Lymphedema: A Systematic Review of the Literature

Lower extremity lymphedema (LEL) is mainly assessed clinically. Ultrasound elastography (UE) is a promising imaging tool to assess this disorder. We conducted a systematic literature review to describe the studies evaluating the use of UE in LEL. The PubMed database was queried for studies that evaluated the use of UE in LEL. The keywords "elastography" AND "lymphedema" were used for the search. Original articles in English were included in our study, whereas reviews were excluded. Our search resulted in 12 articles, 4 of which met the inclusion criteria. UE methods included free-hand real-time tissue elastography and UE with transducer in B mode. The imaging parameters applied were the tissue strains and the area of red region, respectively. All studies tested UE use in the assessment of LEL, and only one considered its use for staging. All studies but one found a difference in strain parameters for assessment of patients with LEL. Our systematic review has shown that UE appears to be a great tool in the assessment of LEL in moderate-to-advanced stages of disease. However, further studies using new effective methods are needed to evaluate patients with early lymphedema.

A preliminary study on ultrasound techniques applied to cicatricial alopecia

BACKGROUND

Cicatricial alopecia (CA) is a group of disorder characterized by permanent destruction of the hair follicle. Shear wave elastography (SWE) and superb microvascular imaging (SMI) are noninvasive ultrasonic techniques which evaluate thickness, stiffness, and vascular index of tissues.

OBJECTIVES

This study explored the ranges of cicatricial alopecia area and normal scalp with a combined modality of SMI and SWE and investigated the feasibility of their use in assessing these diseases.

METHODS

Seventeen patients diagnosed with CA and twenty healthy controls were included in the study. SWE and SMI were performed with an Aplio 500 ultrasound system.

RESULTS

The mean age of patient group was 37.00 ± 13.16, and the mean age of the healthy controls were 36.00 ± 11.79. SWE results as m/s in cicatricial plaques ( x ¯  = 5191) were higher than non-alopecic scalp areas ( x ¯  = 4460) in patient group (t (16) = 2260; P = 0.038 < 0.05). SMI values in patient group (cicatricial plaques) ( x ¯  = 1200) were significantly higher than control group SMI values ( x ¯  = 0.005) (t (35) = 3.075; P = 0.012 < 0.05).

CONCLUSIONS

To the best of our knowledge, this is the first study to evaluate SWE and SMI scores in cicatricial alopecia. We found higher stiffness and vascularity in patient group. We conclude that SWE and SMI can show fibrosis and inflammation like previous studies. Especially, SWE as m/s is more sensitive than as kPa for cicatricial alopecia.

Ultrasonographic elastography in the evaluation of normal and pathological skin - a review

The aim of this review article is to discuss the role of ultrasonographic elastography, a technique used to quantify tissue stiffness, in the evaluation of normal and pathological skin. A growing body of evidence suggests that elastography may be used for the diagnosis and monitoring of skin pathologies, in particular tumors, and fibrotic and sclerotic processes. Our knowledge about the elastographic parameters of normal skin is sparse, which together with the lack of reference values for cutaneous stiffness constitutes a serious limitation to the use of elastography in some medical disciplines, including aesthetic medicine.

Correlation Between the Severity of Subcutaneous Echo-Free Space and the Amount of Extracellular Fluid Determined by Bioelectrical Impedance Analysis of Leg Edema

BACKGROUND

Both subcutaneous echo-free space (SEFS) observed by ultrasonography and the ratio of intracellular fluid resistance to extracellular fluid resistance (R_i/R_e) calculated from bioelectrical impedance analysis (BIA) represent extracellular edema status in the extremities. We tried to correlate these parameters.

METHODS AND RESULTS

In 70 legs with venous edema (VE) and 68 legs with lymphedema (LE), subcutaneous tissue ultrasonography to determine SEFS severity (range, 0-2) and BIA to calculate R_i/R_e were performed. In the calf, SEFS severity showed good linear correlation with R_i/R_e, particularly in the lower lateral calf where the mean R_i/R_e for LE (SEFS grade 0: 3.2 ± 0.8; SEFS grade 1: 4.0 ± 0.9; SEFS grade 2: 6.3 ± 3.6) and VE (SEFS grade 0: 3.6 ± 0.6; SEFS grade 1: 4.4 ± 1.6; SEFS grade 2: 5.3 ± 2.0) was similar. In the thigh, a mild correlation was confirmed only in LE.

CONCLUSIONS

It may be concluded that SEFS in the lower calf area well represents the local fluid status regardless of the type of edema, but not so in the thigh.

Skin and Subcutaneous Tissue Ultrasonography Features in Breast Cancer-Related Lymphedema

Objective: To investigate skin, subepidermal low echogenic band (SELEB), and subcutaneous tissue (SCT) thickness as well as the degree of increase in subcutaneous echogenicity (SEG) and subcutaneous echo-free space (SEFS) in arms with lymphedema (LE). Materials and Methods: The skin and SCT of both arms of 30 patients with unilateral stage II breast cancer-related LE were scanned at five points (medial/lateral upper arm/forearm and dorsum of the hand). SEG and SEFS grades were determined according to severity (range: 0-2). Results: All measured parameters, except the SEFS in the medial upper arm, were significantly higher on the LE side than on the normal (N) side. The parameters differed most remarkably in the medial forearm (MFA; skin: LE 1.7 ± 0.8 mm vs. N 0.8 ± 0.2 mm; SELEB: LE 1.0 ± 0.6 mm vs. N 0.3 ± 0.1 mm; SCT: LE 8.7 ± 3.4 mm vs. N 3.8 ± 2.0 mm; SEG: LE 0.9 ± 0.5 vs. N 0.1 ± 0.3; and SEFS: LE 0.5 ± 0.7 vs. N 0). Conclusion: The differences in the thickness of the skin, SELEB, and SCT and the SEG and SEFS grades between the LE and N arms seemed most evident in the MFA.

Immediate Changes to Skin and Subcutaneous Tissue Strains Following Manual Lymph Drainage in Legs with Lymphedema

OBJECTIVES

To study the immediate impact of manual lymph drainage (MLD) on skin and subcutaneous tissue strains in legs with lymphedema using free-hand real-time tissue elastography (RTE).

METHODS

Skin and subcutaneous tissue strain measurements were taken at the middle of the inner thigh and calf by RTE in 20 legs with lymphedema of 18 patients (stage II: 11, late stage II: 7, stage III: 2) and in 70 legs of 35 normal subjects. In patients with lymphedema, the same measurements were repeated immediately following MLD.

RESULTS

Significant negative correlations were found between pre-MLD strains and the MLD-induced changes in thigh and calf skin strains (thigh skin: p <0.01, calf skin: p = 0.05), but not in subcutaneous tissue strains. Pre-MLD intercepts of these regression lines were closer to normal values as compared to mean pre-MLD values (normal thigh skin: 0.54% ± 0.30%, calf skin: 0.25% ± 0.18%, Pre-MLD thigh skin: 0.39% ± 0.20%, calf skin: 0.17% ± 0.12%, Pre-MLD intercept of thigh skin: 0.48%, Pre-MLD intercept of calf skin: 0.31%).

CONCLUSIONS

It appears that MLD did not simply soften the skin, but rather normalized it in terms of strain. However, this was not confirmed in the subcutaneous tissue.