HUNG THIEN NGUYEN, CUONG TUAN NGUYEN, XUAN THANH THI PHAM, HAI THANH PHAN MEDIC MEDICAL CENTER, HCMC, VIETNAM
Acoustic radiation force impulse (ARFI)-imaging is a new technology of elastography of ultrasound enabling quantitative measurement of tissue stiffness. Theaim of the present study was to evaluate the feasibility of ARFI-measurements in the thyroid nodule.
All patients underwent conventional ultrasound, ARFI-imaging and cytological assessment. ARFI-imaging (VTI and VTQ technologies) and eSie Touch technology were performed with 9L4 probe, using Siemens (ACUSON S2000) B- mode-ARFI combination transducer.
85 nodules were available for analysis. 67 nodules were benign on cytology, 13nodules were malignant (papillary carcinoma), and 5 follicular lesions.
Themedian velocity of ARFI-imaging in benign was of 2.06 m/s, andmalignant thyroid nodules, of 3.00 m/s, respectively.
Plot of 177 ARFI velocity measurements of 85 thyroid nodules
eSieTouch= malignant: red code (hard) homogenous or not VTI= malignant: dark color (hard) and bigger size than B-mode image VTI with dark color helps characterizing malignant nodule, from follicular lesions and dense colloidal cysts which have bright color on VTI.
eSie Touch of a papillary carcinoma, black (hard)
VTI of a papillary carcinoma, black (hard) and bigger size (R. panel) than B-mode image (L. panel)
eSie Touch of papillary carcinoma, inhomogenous black
VTQ of a papilary carcinoma with ARFI velocity in out of range
eSie Touch of a papillary carcinoma, color code (red= hard, purple= soft, yellow= between hard and soft). FNAC should perform at red region.
A specificity of ARFI-imaging of 95% could be achieved using a cut-off of 3.1 m/s (area under ROC curve is 0.778). A sensibility of ARFI-imaging of 86.49% and specificity of 59.29% could be achieved using a cut-off of 2.3 m/s (area under ROC curve is 0.778).
DISCUSSIONS1/ Specificity important than sensibility2/ The higher of ARFI velocity the harder ofthyroid nodule3/ Overlapping the ARFI velocities of benign andmalignant nodules: combining with VTI, eSieTouch to charaterize lesion4/ Inhomogenous structure of malignant thyroidnodules: more site measurements of VTQ basedon VTI and eSie Touch and biopsy
ARFI can be performed in thyroid nodule with reliable results. Notonly base on VTQ but should refer VTI and eSie Touch technologies. ARFI might be the reference criteria for differentiation of benign and malignant thyroid nodules.