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To retrospectively compare the diagnostic accuracy of attenuation imaging (ATI) to detect and grade hepatic steatosis as determined by liver biopsy in a cohort of adult patients with a variety of suspected liver pathologies referred for liver sonography and biopsy. 76 patients met the criteria of having a liver biopsy performed within 4 weeks of an ATI assessment with exclusion of malignancy and prior liver resection. Patients had a median age of 50.5 (range 18-83) years (51 women, 25 men) with median BMI of 28.9 kg/m2 (range 19.2-57.2, IQR 24-33.3). ATI, shear wave elastography (SWE), shear wave dispersion (SWD) and skin to liver capsule distance (SCD) measurements were obtained. Metavir fibrosis and Brunt steatosis grading as well as the presence/absence of inflammation were noted. Controlled attenuation parameter (CAP) values were also recorded, where available. The results were analysed using Spearman correlation coefficient, receiver operator characteristic and multiple logistic model performances to assess correlations, diagnostic performance and discriminate between steatosis grades according to ATI measurement. The distribution of steatosis according to histology was 33/13/23/7 for S0 (<5%), S1(5-33%), S2(33-66%) and S3(>66%). The median ATI value for each biopsy steatosis grade was 0.60 (IQR 0.52-0.65), 0.65 (IQR 0.6-0.71), 0.83 (IQR 0.74-0.90) and 0.90 (IQR 0.82-1.01) dB/cm/MHz for S0, S1, S2 and S3. The AUC of ATI for detection of any steatosis grade (S1-S3) and moderate to severe steatosis (S2-S3) was 0.85 (95% CI, 0.748-0.908) and 0.91 (95% CI, 0.830-0.986) with cutoffs of 0.55 and 0.62 dB/cm/MHz. Logistic regression boundary value of 0.74dB/cm/MHz was able to discriminate between S0-S1 and S2-3 with accuracy, CI and kappa statistic of 0.8889, 0.6529-0.0862 and 0.7534. ATI correlations were SCD (ρ=0.40), BMI (ρ=0.39), CAP (ρ=0.49), SWD (ρ=-0.21) and SWE (ρ=-0.04). There was good correlation between ATI and histological steatosis grade, which was the only significant factor affecting the ATI measurement. The most accurate discrimination was between none to mild (S0-1) and moderate to severe (S2-3) steatosis. [ABSTRACT FROM AUTHOR]

Globally, there is an increasing incidence of non-alcoholic fatty liver disease (NAFLD), a potential cause of chronic liver disease. NAFLD may result in non-alcoholic steatohepatitis (NASH) which can develop into end stage liver disease. Because of the increasing incidence of fatty liver disease it is critically important to improve our ability to diagnose the spectrum of NAFLD/NASH and its clinical pathways. The gold standard for assessing the degree of hepatic steatosis is biopsy, however the cost, patient intolerance, risk factors, processing artefacts and the small amount of tissue procured during biopsy may not reflect the global degree of fatty infiltration. Magnetic Resonance imaging (MRI) techniques show promise for assessment of steatosis but are more expensive and resource intensive than ultrasound techniques. Many novel on cart ultrasound tools are being made available for the assessment of hepatic parenchyma during an ultrasound examination – these include Attenuation Index (ATI), Liver-Kidney Ratio and Shear Wave dispersion (SWD). The echosens Fibroscan® unit utilises a tool "Controlled Attenuation Parameter (CAP)". CAP estimates the degree of fatty infiltration of the liver by producing a resultant dB/cm/Hz attenuation coefficient. This talk looks at the preliminary evaluation of some of these tools and their potential role. [ABSTRACT FROM AUTHOR]

Ultrasound shear wave elastography has the potential to assess the strength of the maternal cervix for signs of insufficiency.1, 2 The reliability of shear wave elastography in biological tissues can be affected by numerous ultrasound artifacts and prestress of tissues in the region of interest can also affect the shear wave speed. This study investigates the use of the transvaginal ultrasound approach to obtain shear wave speeds in the uterine cervix with the aim of identifying factors that affect shear wave speed and transmission. The primary aim of this study is to identify biological and technical confounders for the use of two dimensional shear wave elasography applied to the uterine cervix. The goal was to identify confounders, and develop shear wave technique in the low risk non-gravid population. Sixty nine non-gravid participants with varying medical history and ethnicity consented to be part of this research. Inter-operator testing was performed on fifteen participants.Imaging methodology As an adjunct to the normal imaging examination extra imaging of cervical speed measurements using two dimensional shear wave elastography was performed.The transvaginal approach utilises an endocavity transducer with an empty maternal bladder. Shear wave elastography speed measurements are acquired at the external and internal os anterior and posterior portions. Reliable measurements were obtained at the external os and internal os, anteriorly and posteriorly, in 63, 55, 55 and 26 patients respectively. The mean speed obtained at the external os, anteriorly and posteriorly, was 2.52 ± 0.49 m/s and 2.87 ± 0.63 m/s respectively, and at the internal os anteriorly and posteriorly, 3.29 ± 0.79 m/s and 4.10 ± 1.11 m/s respectively. The difference in speed between all regions was statistically significant] (p<0.05). The intraclass correlation coefficient obtained at the regions of the cervix was as follows - external os anterior 0.83 (CI 0.45 – 0.95), external os posterior 0.69 (CI 0.07-0.90), internal os anterior 0.92 (CI 0.76 – 0.97), internal os posterior 0.90 (CI 0.37-0.98) Biological factors and ultrasound induced artifacts appear to affect the transmission of the elastographic main pulse, with cervical position appearing to affect shear wave production. Reliable shear wave propagation can be achieved in the anterior cervix in most patients. [ABSTRACT FROM AUTHOR]

Ultrasound strain elastography may be able to identify women presenting with a normal cervical length, who are at an increased risk of preterm birth due to softening of the cervix.1,2 Shear wave elastography (SWE) uses acoustic radiation force impluse to produce shear waves.3 It is expected that SWE will produce a more objective and reproducible mechanical evaluation of the cervix than strain elastography.4,5 There is promise for the use of SWE on the maternal cervix to assess cervical strength.6,7 The primary aim of this study is to assess if reduced cervical strength and imminent cervical insufficiency can be identified by shear wave elastography. This is a cross-sectional study of patients presenting for their mid-trimester ultrasound examination. Ethics approval was from the Curtin University Human Research Ethics Committee and SKG Radiology Clinical Standards Committee. All data has been collected at sites of SKG Radiology in Perth, Western Australia. Informed consent was required to participate. The transabdominal approach utilizes a 6C1 curvilinear transducer and a partially full maternal bladder.8 The transvaginal approach utilises an endocavity transducer with an empty maternal bladder. Shear wave elastography speed measurements are acquired at the external and internal os anterior and posterior portions.8,9 Data assessment currently includes 156 of the 473 participants enrolled to date. Participants were from varying ethnicity with a mean age of 29 years (18-33 years), mean gestation of 2(0-5), mean number of births 1(0-5), 102 cases of spontaneous labour, 38 of induced labour and 16 planned c-section. Mean shear wave speeds and number of cases at varying gestation for patients going into spontaneous labour are as follows: Early results indicate the shear wave speeds may be reduced in patients with a subsequent preterm birth. Larger numbers will need to be assessed to substantiate these findings. [ABSTRACT FROM AUTHOR]

Quantifying the extent of liver fibrosis is important in the management of patients with chronic liver disease. Liver biopsy is the gold standard for diagnosis and grading of liver fibrosis. However, liver biopsy is costly, invasive and may have associated complications. Liver biopsy may also be limited by sampling variability due to the heterogeneous nature of liver fibrosis. Liver biopsy limitations have led to the development of non-invasive techniques for the evaluation of and monitoring of liver fibrosis. These include transient elastography (TE) (Fibroscan©), shear wave elastography (SWE) and magnetic resonance elastography (MRE). These technologies use algorithms for quantifying liver elasticity and have all shown promising results for non-invasive fibrosis staging. However, both TE and SWE have limitations including in patients with inflammation (hepatitis) and/or steatosis. Liver diseases such as non-alcoholic steatohepatitis (NASH), non-alcoholic fatty liver disease (NAFLD) and acute hepatitis have been reported to increase liver viscosity. It is proposed that these alterations in liver viscosity alter the propagation of shear waves, and that a more accurate assessment would be obtained by assessing both the elasticity and viscosity i.e. viscoelastic properties in the liver. Shear wave dispersion (SWD) is a new imaging technology software that has been developed on the Canon Aplio i-series for assessing the dispersion of the shear wave. In viscoelastic tissue, shear wave speed undergoes frequency dispersion i.e. change in the shear wave speed dependent on the shear wave frequency. The units of measurement are m/s/kHz. In perfectly elastic tissue, shear wave speed is constant regardless of the shear wave frequency. However, in viscoelastic tissue, shear wave speed varies depending on the shear wave frequency i.e. shear wave dispersion. We present the initial findings of using this new liver imaging tool in a sequential group of patients referred for liver biopsy in a tertiary level hospital. The indications were for the assessment of chronic liver disease, with exclusion of patients with suspected or confirmed malignancy. In this group, the manufacturer recommended SWD reference value was compared to liver biopsy findings to identify whether it could discriminate between patients with, and without inflammation (hepatitis). [ABSTRACT FROM AUTHOR]

Shear-wave elastography (SWE) is an ultrasound based technology that can provide reliable measurements (velocity) of scar stiffness. The aim of this research was to evaluate the concurrent validity of using both the measured velocity and the calculated difference in velocity between scars and matched controls, in addition to evaluating potential patient factors that may influence the interpretation of the measurements.Methods: A cross-sectional study of 32 participants, with 48 burn scars and 48 matched contralateral control sites were evaluated with SWE, the Vancouver Scar Scale (VSS) and the Patient and Observer Scar Assessment Scale (POSAS) tactile sub-scores.Results: Spearman's rho demonstrated high correlations (r > 0.7) between the measured scar velocity and both the POSAS and VSS pliability sub-scores, whereas moderate correlations (r > 0.6) were found with the calculated difference in velocity. Regression analysis indicated that the association of increased velocity in scars, varied by length of time after burn injury and gender. Body location and Fitzpatrick skin type also demonstrated significant associations with velocity, whereas age did not.Conclusion: SWE shows potential as a novel tool to quantify burn scar stiffness, however patient factors need to be considered when interpreting results. Further research is recommended on a larger variety of scars to support the findings. [ABSTRACT FROM AUTHOR]

The aim of this research was to investigate the use of shear wave elastography as a novel tool to quantify and visualize scar stiffness after a burn. Increased scar stiffness is indicative of pathologic scarring which is associated with persistent pain, chronic itch and restricted range of movement. Fifty-five participants with a total of 96 scars and 69 contralateral normal skin sites were evaluated. A unique protocol was developed to enable imaging of the raised and uneven burn scars. Intra-rater and inter-rater reliability was excellent (intra-class correlation coefficient >0.97), and test-retest reliability was good (intra-class correlation coefficient >0.85). Shear wave elastography was able to differentiate between normal skin, pathologic scars and non-pathologic scars, with preliminary cutoff values identified. Significant correlations were found between shear wave velocity and subjective clinical scar assessment (r = 0.66). Shear wave elastography was able to provide unique information associated with pathologic scarring and shows promise as a clinical assessment and research tool. [ABSTRACT FROM AUTHOR]

Shear wave elastography (SWE) is an emerging ultrasound-related technology for assessment of liver fibrosis. The usefulness and reliability of SWE is unclear relative to other markers of liver fibrosis. We compared the clinical usefulness of SWE relative to transient elastography (TE), liver ultrasound and other standard biochemical markers of chronic liver disease in patients with varied liver disorders. SWE assessment was performed using a Toshiba Aplio 500 or Canon Aplio i800 machine, concurrently with liver ultrasound on 421 adult patients. Amongst these patients 227 also had liver transient elastography (TE). Patient age, gender, body mass index (BMI), alcohol history, liver disease diagnosis, and laboratory results were recorded. Associations between SWE, TE and patient factors were sought. Suspected significant liver fibrosis was defined by liver stiffness measurement interpretation of ≥ F2 equivalent using Metavir staging. Patients were predominantly male (67.5%). Males and females were matched as regards age and BMI. The indications for SWE included nonalcoholic fatty liver disease (10%), chronic hepatitis B (22%), chronic hepatitis C (38%), alcohol-related liver disease (18%) and others (12%). 23%The mean (standard deviation) age was 53 (14) years, body mass index 27.7 (6.3) kg/m2, ultrasound-measured skin to liver capsule distance 20.0 (7.3)mm, serum ALT 39(27) U/L and AST 48(32) U/L. The median (IQR) liver stiffness was 9.9 (6.4-20.0) kPa with SWE and 9.2 (5.8-20.9) kPa with TE. Patients with suspected significant liver fibrosis determined by SWE, compared with patients not suspected of having significant fibrosis, were significantly older, had higher BMI, skin to liver capsule distance, TE liver stiffness measurement, alcohol consumption, and blood based assessments AST (but not ALT), AST/ALT ratio, AST to platelet ratio index (APRI), Fibrosis-4 index (FIB-4), Hepascore and NAFLD fibrosis score (NFS), but lower platelet count and serum albumin (p < 0.05 for all). There was a strong correlation between SWE and TE liver stiffness measurement (r = 0.77, p < 001). The strength of correlation between SWE and TE varied by aetiology of liver disease; alcohol (r = 0.6, p = 0.005), hepatitis B (r = 0.5, p < 0.001), hepatitis C (r = 0.73, p < 0.001), NAFLD (r = 0.87, p < 0.001). Using multiple logistic regression analysis, independent predictors of significant liver fibrosis using either SWE or TE were FIB-4, BMI and male sex (after adjusting for other covariates). SWE was found to be a useful test for suspected liver fibrosis in various liver disorders, and results were found to correlate with TE liver stiffness measurement plus clinically relevant anthropometric and laboratory parameters. [ABSTRACT FROM AUTHOR]