Comparative US-MRI evaluation of the Insall-Salvati index.

PURPOSE: To investigate whether the universally accepted range of normal patellar height ratio derived from MRI for the Insall-Salvati (IS) method could be similarly applied to ultrasound (US). MATERIALS AND METHODS: This study included 52 patients (age range 11-75 years) who underwent a bi-modality (US and MRI) examination, with a total of 60 knees evaluated. IS index (ratio of the patella tendon length to length of the patella) was acquired with both methods. Two operators, with different experiences of musculoskeletal imaging and blinded to the results of other investigators, separately performed the MRI and US measurements. RESULTS: For the two operators, MRI reported a mean value of patellar height ratio of 1.10 ± 0.16 (mean ± standard deviation SD), while US a mean value of 1.17 ± 0.16 (mean ± SD). For comparable results, the small addition of 0.16 is needed for the measurements on US compared with MRI. Inter-observer agreements using intra-class correlation coefficient (ICC) was, respectively, 0.97 for MRI and 0.98 for US. The difference of mean values in patellar height ratios between MRI and US was not statistically significant (p = 0.15). The ICC between the two modalities was 0.94. CONCLUSION: According to our experience, IS index can be appropriately evaluated on US images, reducing the need of other imaging techniques.

Elastography in the diagnosis of breast lesions: comparison of different elastographic features.

Background Breast elastography is a non-invasive and widely accessible method used in the differential diagnostic procedure in addition to B-mode imaging. Purpose To assess the role of elastographic features in the differentiation of breast lesions and to evaluate the importance of depth in the choice of reference fat tissue for the calculation of strain ratio. Material and Methods From January to August 2015, 242 breast lesions were evaluated using elastographic assessment based on qualitative and semi-quantitative parameters (color map, strain ratio, length ratio) as well as elastographic analysis. Histological findings were considered as gold-standard. Results Sensitivity and specificity of B-mode ultrasound imaging were 90% and 60%, respectively. Color map sensitivity was 98% and specificity 46%; strain ratio sensitivity 81% and specificity 70%; length ratio sensitivity 64% and specificity 76%. Combined analysis of these three elastographic features improved the overall diagnostic performance of any of the three parameters alone, yielded sensitivity similar to that of color map (95%) and specificity comparable to strain ratio and length ratio (70%). There was no significant difference in strain ratio obtained from the reference fat tissue at the same depth as the lesion and at a different depth (sensitivity 77% versus 84%; specificity 70% versus 68%; P < 0.001). Conclusion In our experience, elastography can improve ultrasound characterization of the lesion, particularly if elastographic analysis is performed.

Ultrasound elastography in the evaluation of thyroid pathology. Current status.

Thyroid pathology including thyroid nodules and diffuse thyroid diseases represents often a diagnosing challenge for clinicians. US, although highly accurate in identifying thyroid nodules and diffuse thyroid diseases, is still not sufficiently accurate to evaluate them. US-elastography has been introduced in order to further increase US accuracy in many fields and eventually for thyroid disease. The aim of the present paper it to provide an update of the literature on different available techniques and the results reported both for thyroid nodules differentiation and for diffuse thyroid disease evaluation. Advantages and limitations of elastography are also discussed.

Q-elastosonography of solid thyroid nodules: assessment of diagnostic efficacy and interobserver variability in a large patient cohort.

OBJECTIVE: Evaluation of the diagnostic efficacy and interobserver agreement of Q-elastography in the differentiation of benign from malignant thyroid nodules. METHODS: A total of 344 thyroid nodules in 288 patients were examined with grey-scale and colour Doppler ultrasound (CDUS) and Q-elastography by two independent operators. Nodules with hypoechogenicity, poorly defined margins, microcalcifications, and intralesional vascularity were classified as suspicious. Diagnostic performances of CDUS features and Q-elastography for predicting thyroid malignancy were estimated using ROC analysis. Cytology or histopathology was the reference standard. Interobserver agreement in the evaluation of CDUS and Q-elastography was assessed using Cohen's k-statistic. RESULTS: Q-elastography showed excellent diagnostic performance for the prediction of thyroid malignancy, with sensitivity of 93 % and specificity of 92 % for operator 1 (best cutoff at 2.02), and sensitivity of 84 % and specificity of 79 % for operator 2 (best cutoff at 1.86). Performance of Q-elastography was superior to that of CDUS. Reproducibility of the findings was excellent for both Q-elastography and CDUS features as assessed with Cohen's k, which was highest for strain ratio measurements (0.95) and lowest for the echogenicity score (0.83). CONCLUSIONS: Q-elastography showed excellent performance. It is a valid and reproducible diagnostic method as well as a promising tool for identifying suspicious solid thyroid nodules needing cytological assessment and surgery. KEY POINTS: • Elastography is an additional tool for optimal characterisation of malignant thyroid nodules. • The use of semiquantitative elastographic evaluation increases the diagnostic performance, • The interobserver agreement of quantitative elastography can be considered to be good.

Clinical application of breast elastography: state of the art.

Breast elastography is a new sonographic imaging technique for the characterization of focal breast lesions in addition to conventional ultrasonography (US) and mammography. Elastography provides a non-invasive evaluation of the stiffness of a lesion. Two different technical approaches are available for clinical use: free-hand elastography (USE) and shear wave elastography (SWE). Initial results of these techniques in clinical trials suggest that elastography substantially improves the US capability in differentiating benign from malignant breast lesions, thus reducing the number of breast biopsies in benign nodules. This review paper, based on an extensive literature search, highlights the basics of breast elastography, including main technical features, how to do suggestions, limit and pitfalls, and presents the results of major clinical studies.

Ultrasound evaluation of liver fibrosis: preliminary experience with acoustic structure quantification (ASQ) software.

PURPOSE: The aim of our study was to assess the diagnostic accuracy of acoustic structure quantification (ASQ) ultrasound software in estimating the degree of hepatic fibrosis compared to Fibroscan and liver biopsy. MATERIALS AND METHODS: Seventy-seven patients with chronic viral hepatitis B and C underwent standard ultrasound examination, ASQ, Fibroscan and liver biopsy. ASQ analysis was conducted by placing a single region of interest (ROI) on each image captured, and calculating mode, average and standard deviation. The sonographic technique was developed through a preliminary evaluation of 20 healthy volunteers. RESULTS: The area under the receiver operating characteristic (AUROC) curve for the diagnosis of cirrhosis (F≥4) with ASQ was 0.77, whereas for the diagnosis of any degree of fibrosis (F≥1) it was 0.71. The AUROC for the diagnosis of cirrhosis (F≥4) with Fibroscan was 0.98, while for the diagnosis of any degree of fibrosis (F≥1) it was 0.94. The difference between the AUROC was statistically significant (p<0.05). CONCLUSIONS: ASQ is a promising new ultrasound software programme which offers encouraging results in the diagnosis of both liver cirrhosis (F=4) and fibrosis (F≥1). However, to date it has not attained the same level of diagnostic performance as Fibroscan.

Prospective evaluation in 123 patients of strain ratio as provided by quantitative elastosonography and multiparametric ultrasound evaluation (ultrasound score) for the characterisation of thyroid nodules.

PURPOSE: This study was done to compare quantitative elastosonography and ultrasound analysis in the characterisation of thyroid nodules. MATERIALS AND METHODS: From July 2009 to September 2011, 123 patients with 147 thyroid nodules were included in our study. All patients enrolled had to undergo thyroidectomy because of nodular thyroid disease (goitre or nodules). After preliminary examination with conventional ultrasound (US) and colour Doppler US, the patients were examined with elastosonography, using high-level equipment (Toshiba Aplio XG) and quantitative software (Elasto-Q). Each lesion was characterised using an US score (echogenicity, borders, microcalcifications and colour Doppler pattern), and then by elastosonographic strain ratio. Each patient subsequently underwent thyroidectomy. Histological results were used as the gold standard. RESULTS: Histological examination demonstrated 89 benign and 58 malignant lesions. On average, the strain ratio value was 2.84±2.69 (range, 0.05-14.5; p=0.001). Sensitivity and specificity of the US score were about 56% and 72%, respectively, whereas those of the strain ratio were 93% and 89%, using a cut-off of 2 obtained with receiver operating characteristic (ROC) curve analysis. Elastosonography was more accurate than US and colour Doppler US in characterising thyroid nodules (p=0.002). CONCLUSIONS: Quantitative elastosonography is a useful diagnostic tool in the evaluation of thyroid lesions, and can be used to limit fine-needle aspiration cytology and improve the selection of patients for thyroidectomy.