Table 2.
Summary of Findings
| Diagnostic Group | Main Objective | UE type | Sample size | Elastogram Analysis | Results | Reference |
|---|---|---|---|---|---|---|
| Cutaneous Melanoma | 1. Criterion validity, Convergent validity | SI | N=39 patients (42 lesions) Total lesions included =37 | 1. Intra dermal descriptive analysis: (low = red, medium = green or high = blue) | 1. Histology: Diagnosis confirmed: 45% tumors were stiff (blue) and 43% moderate (green). | Assessment of Cutaneous Melanoma by Use of Very-High-Frequency Ultrasound and Real-Time Elastography. Botar-Jid et al. 2016 [33] |
| 2. Sensitivity/specificity | 2. Strain ratio (tumor/dermis & tumor/hypodermis. | 2. UE appearance and US thickness: rs=-0.305, p=0.049. Thicker tumors were stiffer. | ||||
| 3. Strain ratio average tumor/dermis =1.02 tumor/hypodermis =2.16 | ||||||
| Malignant and benign skin tumors | 1. Criterion validity | SI | N=55 patients, (69 lesions) Total lesions included =67 | 1. Intradermal descriptive analysis: Blue =less elastic; red more elastic. | 1. Histology: diagnosis confirmed 43% malignant, 57% benign. | Quantified ultrasound elastography in the assessment of cutaneous carcinoma Dasgeb et al. 2015 [17] |
| 2. Sensitivity/specificity | 2. Strain ratio (tumor/adjacent ‘green’ tissue | 2. Strain ratio of malignant lesions =3.9-32.2; & Benign lesions =0.01-3.0. | ||||
| Mixed tumor of scalp | Describe unique finding. | SI | N=1 | Descriptive analysis of color (red = soft, blue = hard) | Histology confirmed diagnosis. Tumor interior was island shaped with a red (soft) cord-like portion, with a green (medium elasticity) background. Green portion correlated with closely aggregated myoepithelial cells around the sweat gland. The yellow area corresponded to a broad mucinous region, empty space and the chondroid portion. | Ultrasound B-mode and Elastographic Findings of Mixed Tumour of the Skin on the Scalp. Imafuku et al. 2016 [18] |
| Angiomatoid fibrous histiocytoma | Describe unique finding | SI | N=1 | Descriptive analysis of color. Blue = stiff, red = soft. | Histology confirmed diagnosis. An area of increased elasticity (soft) within the tumor corresponded to a pseudovascular structure. | Ultrasound B-mode and elastographic findings of angiomatoid fibrous histiocytoma. Hata et al. 2014 [52] |
| Melanoma | Describe a unique finding. | SI | N=2 | Descriptive analysis of color. Blue = stiff, red = soft | Histology confirmed diagnosis, Breslow thickness was 1.5 mm and 0.95 mm. The tumor had dark blue areas within lesion, whereas a benign nevus had a green pattern on UE. | Real-time tissue elastography: a helpful tool in the diagnosis of cutaneous melanoma? Hinz et al. 2011 [53] |
| Cutaneous T-cell Lymphoma | Describe a unique finding. | SI | N=1 | Descriptive analysis of color. Blue = stiff, red= soft. | Histology confirmed diagnosis, tumor had dark blue appearance, whereas epidermal cyst had a green appearance | Real time tissue elastography for diagnosis of cutaneous T-cell lymphoma. Schmid-Wendher et al. 2011 [54] |
| Systemic Sclerosis and diffuse cutaneous systemic sclerosis | 1 Discriminant validity, Convergent validity, Interrater reliablity | SWEI | N=15 patients N=15 matched healthy controls 17 body sites on each participant Total sample: 510 skin sites. | SWV | 1. Patients had increase SWV at 6/17 body sites. mRSS 0, 1 & 2 were significantly higher than healthy controls (p<0.001). | A preliminary study of acoustic radiation force impulse quantification for the assessment of skin in diffuse cutaneous systemic sclerosis. Hou et al. 2015 [38] |
| 2. Significant differences in SWV between mRSS levels 0 and 1; and between 0 and 2 (both p<0.001). However, level 3 was not significantly different to the other levels. Sum of SWV values from17 sites correlated with total mRSS (r=0.841, p<0.001) | ||||||
| 3. ICC good for 15/17 body sites (ICC=0.613-0.916), moderate for left middle finger (ICC=0.535) and poor for right middle finger (ICC=0.247). | ||||||
| Systemic Sclerosis, Morphea and GVHD | 1. Convergent validity, Discriminant validity, Test retest reliability | ARFI-D and SWEI | N=4 healthy N=12 morphes N=1 SSc N=5 GVHD with contralateral site matched controls Total sample: 22 participants | 1. ARFI-D | Descriptive analysis of selected case examples demonstrating: | Preliminary Results on the Feasibility of Using ARFI/SWEI To assess Cutaneous Sclerotic Diseases. Yun Lee et al. 2015 [35] |
| 2. SWV | 1. Both SWV and ARFI-D can detect differences between SSc and healthy controls. | |||||
| 2. SWV more sensitive than ARFI-D for detecting severity. | ||||||
| 3. SWV showed less errors than ARFI-D | ||||||
| 4. SWV were more consistent than ARFI-D over time. | ||||||
| 5. Had inconsistent results over fingers. | ||||||
| Systemic Sclerosis (perioral region) | 1. Discriminant validity, Interrater reliability | SI | N=6 female patients N=6 female age-matched controls 4 body sites on each participant | 1. Descriptive analysis and score: Blue score=1 Green score=2 Red score=3. 4 locations measured on each patient and summated for a total score ranging from 4-12 | 1. American College of Rheumatology criteria: Found SSC was predominantly blue with green spots stiffer than controls (p=0.01) | Technical feasibility of real-time elastography to assess the peri-oral region in patients affected by systemic sclerosis Cannao et al. 2014 [30] |
| 2.Two raters. Cohen’s K=1 (p<0.0-05) for both the summated score and individual measurements. | ||||||
| Systemic Sclerosis | 1. Test-retest reliability | SWEI | 1. N=4 patients N=2 controls | SWV | 1. Very good test-retest reliability ICC>0.08, tested 1 week apart. | A preliminary study using virtual touch imaging and quantification for the assessment of skin stiffness in systemic sclerosis Santiago et al. 2016 [19] |
| 2. Discriminate validity and Convergent validity | 2. N=26 patients N=17 age and gender matched controls. | 2. Patients with SSc showed increased stiffness compared to controls (p<0.01) | ||||
| 3. Stiffness correlated with mRSS | ||||||
| 4. Increased stiffness recorded in clinically ‘unaffected’ skin, mRSS*=0. | ||||||
| Systemic sclerosis | 1. Discriminant validity, Interrater reliability, Intra rater reliability, Test-retest reliability | SI | N=18 patients N=15 age matched control | 1. Descriptive color scale: red = soft green/pale blue = soft blue = hard | 1. mRSS*: Sclerotic dermis was blue, healthy control dermis was green with pale blue spots. Dorsal fingers obtained inconsistent results. | Ultrasound elastography assessment of skin involvement in systemic sclerosis: lights and shadows. Iagnocco et al. 2010 [55] |
| 2. two raters: No data presented, stated that both assessors had 100% agreement. | ||||||
| 3. No data only statement of 100% agreement. | ||||||
| 4. No data: Images stored and re-evaluated 4 weeks post initial assessment. | ||||||
| Lymphedema and LDS. | 1. Convergent validity | SI | N=62 Lymphedema legs N=15 LDS legs | Strain ratio: skin/phantom & scAT/phantom | 1. No difference between ISL stages O, I, II, III of skin or scAT in thigh. | Skin and subcutaneous tissue strain in legs with lymphedema and lipodermatosclerosis. Suehiro et al. 2015 [34] |
| 2. No difference between ISL stages 0, I, II, III of scAT of calf. | ||||||
| 3. LDS was stiffer than ISL stages 0, I, II (p<0.05). | ||||||
| 4. Calf skin was stiffer in ISL stage III compared to stage I and II, but no difference between stage I or O (p<0.05) | ||||||
| 5. LDS calf was stiffer than ISL 0, I, II (p<0.05). | ||||||
| Lymphedema | 1. Protocol validity | SI | 1. 7mm gel standoff | 1. Peak force strain | 1. Optimal manual compression force on 7mm gel standoff =50<F<200gf | Real-time tissue elastography assessment of skin and subcutaneous tissue strains in legs with lymphedema. Suehiro et al. 2014 [56] |
| 2. Sensitivity in normal controls | 2. N=35 healthy controls | 2. Strain ratio: skin/phantom & scAT/phantom | 2. Normal control demonstrated greatest strain in the ScAT thigh, followed by ScAT calf, skin thigh then skin calf. | |||
| 3. Discriminate validity | 3. N=15 patients each with affected leg and non-affected control leg. | 3. linear regression | 3. No difference detected between ISL stage II unilateral lymphedema leg and non-affected leg. | |||
| Skin and subcutaneous abscess | Discriminate validity. | SI | N=50 patients | Descriptive analysis: red = softest, yellow = soft, green = medium. blue = firm confluent bands large spot small speckles | B-mode ultrasound and drainage of purulent material confirmed diagnosis: UE: abscesses were mixed red and yellow to mixed yellow and green. Tissue Induration: blue with sharp delineation. | Use of ultrasound elastography for skin and subcutaneous abscesses Gaspari et al. 2009 [21] |
| Post Irradiation neck fibrosis. | 1. Interrater, Intrarater reliability | SWEI | 1. N=30, 14 patients and 16 controls | The system software calculated a mean stiffness value for the ROI. | 1. Interrater: ICC=0.77-0.94 Intrarater: ICC=0.90-0.99 | Shear Wave Elastography-A New Quantitative Assessment of Post-Irradiation Neck Fibrosis. Liu et al. 2015 [57] |
| 2. Discriminate validity, convergent validity | 2. N=50, 25 patients and 25 controls. | 2. Irradiated neck tissue stiffer than normal control: 63.9±53.1 vs 15.3±8.37 kPa, p<0.001. | ||||
| 3. Stiffness progressively became stiffer with time post irradiation. | ||||||
| 4. US thickness negatively correlated with stiffness (p<0.001) |
ARFI: Acoustic Radiation Force Impulse; ARFI-D: Acoustic Radiation Force Impulse - Displacement; GVHD: Graft versus host disease; ICC: intraclass Correlation; ISL: International Society of Lympedema; LDS: Lipodermatosclerosis; mRSS: modified Rodnan Skin Score; ROI: Region of Interest ; SI: Strain Imaging; ScAT: Subcutaneous Adipose Tissue; SSc: Systemic sclerosis; SWEI: Shear wave elasticity imaging; SWV: Shear Wave Velocity; UE: Ultrasound Elastography.