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Title:	A study on the diagnostic criteria for optimal application of quantitative shear wave elastography in pre-operative risk stratification for thyroid malignancy in UKM Hospital
Authors:	Nattabi Haliimah (P86155)
Supervisor:	Ahmad Nazlim Yusoff, Assoc. Prof. Dr.
Keywords:	Thyroid Ultrasound Dissertations, Academic -- Malaysia
Issue Date:	23-Sep-2018
Description:	Preliminary studies found 2D-shear wave elastography [2D-SWE] to be valuable in preoperative differential diagnosis of thyroid nodules, justifying the increasing body of evidence to this effect. However, there is marked disparity in the acquisition protocols used, because the diagnostic criteria for optimal application of this quantitative technique alone or in combination with conventional ultrasound have not been stipulated. We aimed to assess the impact of methodological factors, grey scale ultrasound features of thyroid nodules, TIRADS score and TIRADS class on nodule elasticity. Methodological factors were evaluated and the optimal 2D-SWE protocol as applied herein determined through meta-analysis of 14 studies that assessed the diagnostic value of 2D-SWE for detection of thyroid malignancy in 2851 thyroid nodules (1092 malignant, 1759 benign from 2139 patients. In our experimental study, 149 thyroid nodules from 73 patients were assessed with conventional ultrasound and 2D-SWE using the Toshiba Aplio 500 US system. Nodule size, composition, margins, shape, presence of calcifications, and Doppler vascular flow pattern were noted, scored and then classified from TIRADS 2-5 using a weighted TIRADS tool. Average 2DSWE stiffness values from the mean elasticity index (E-mean) and standard deviation (ESD) parameters were obtained in the stiffest areas of the nodule, using 5 or more 2mm/less regions of interest (ROIs) at minimal and high levels of pre-compression [LoP]. 111 healthy volunteers were also recruited and independently examined by 2 raters to constitute TIRADS 1. Absolute agreement in acquisition of 2D-SWE elasticity indices (EIs) of the thyroid gland was determined. A 2-tailed p-value <0.05 was considered statistically significant. We found that E-mean and E-SD of thyroid nodules were significantly different from those of the normal thyroid gland at both LoPs (p<0.01). E-mean and E-SD were higher at high LoP compared to minimal LoP (p<0.001). Microcalcifications, macrocalcifications and hypoechogenicity significantly increased E-mean at minimal (p=0.012, 0.004, 0.045 and high (p=0.016, 0.002, 0.019) LoPs. Interestingly, isthmal nodule-localization affected E-mean at minimal (p=0.024) but not at high LoP (p=0.638) while solid composition showed significance at high LoP (p=0.021). A significant positive correlation between TIRADS score and E-mean was registered at both minimal (r=0.24, p=0.005) and high (r=0.23, p=0.006) LoPs. E-mean was significantly different between TIRADS classes at minimal (p=0.021) and high LoP (p=0.032). Presence of incidentalomas (33.3%) significantly increased E-mean (p=0.035; CI: 0.10-2.79) at minimal but not at high LoP (p=0.360; CI: -3.38-10.36). Intrarater agreement was moderate to good (Intraclass correlation coefficient [ICC] range=0.53-0.926) while interrater agreement was only poor to moderate (ICC range=0.25-0.68) at both LoPs. In conclusion, E-mean of the smallest ROI in the stiffest region can be reliably utilized during 2D-SWE acquisition to increase interrater reliability, while excluding microcalcifications. The TIRADS score and subsequently, the TIRADS class can be raised for stiffer thyroid nodules. Further research is required to determine the score for high elasticity. Our findings present a preview of potential preliminary protocols of reference that can be adopted to facilitate more objectively apt thyroid 2D-SWE criteria.,Sarjana Sains Kesihatan
Pages:	120
Call Number:	WN180.N281s 2018 9
Publisher:	UKM, Kuala Lumpur
Appears in Collections:	Faculty of Health Sciences / Fakulti Sains Kesihatan

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