Strain ratio ultrasound elastography increases the accuracy of colour-Doppler ultrasound in the evaluation of Thy-3 nodules. A bi-centre university experience.
OBJECTIVE
To assess whether ultrasound elastography (USE) with strain ratio increases diagnostic accuracy of Doppler ultrasound in further characterisation of cytologically Thy3 thyroid nodules.


METHODS
In two different university diagnostic centres, 315 patients with indeterminate cytology (Thy3) in thyroid nodules aspirates were prospectively evaluated with Doppler ultrasound and strain ratio USE before surgery. Ultrasonographic features were analysed separately and together as ultrasound score, to assess sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). Receiver operating characteristic (ROC) curves to identify optimal cut-off value of the strain ratio were also provided. Diagnosis on a surgical specimen was considered the standard of reference.


RESULTS
Higher strain ratio values were found in malignant nodules, with an optimum strain ratio cut-off of 2.09 at ROC analysis. USE with strain ratio showed 90.6% sensitivity, 93% specificity, 82.8% PPV, 96.4% NPV, while US score yielded a sensitivity of 52.9%, specificity of 84.3%, PPV 55.6% and NPV 82.9%. The diagnostic gain with strain ratio was statistically significant as proved by ROC areas, which was 0.9182 for strain ratio and 0.6864 for US score.


CONCLUSIONS
USE with strain ratio should be considered a useful additional tool to colour-Doppler US, since it improves characterisation of thyroid nodules with indeterminate cytology.


CONCLUSIONS
• Strain ratio measurements improve differentiation of thyroid nodules with indeterminate cytology • Elastography with strain ratio is more reliable than ultrasound features and ultrasound score • Strain ratio may help to better select patients with Thy 3 nodules candidate for surgery.
Department of Radiology, Anatomical Pathology and Oncology, "Sapienza" University of Rome, Policlinico Umberto I, Viale del Policlinico 155, 00161, Rome, Italy. vito.cantisani@uniroma1.it.
Vito
V
Cantisani
Department of Diagnostic Imaging for Surgery, Orthopaedics and Traumatology, "Sapienza" University of Rome, Rome, Italy.
Piero
P
Maceroni
Department of Surgical Sciences, "Sapienza" University of Rome, Rome, Italy.
Vito
V
D'Andrea
Department of Surgical Sciences, "Sapienza" University of Rome, Rome, Italy.
Gregorio
G
Patrizi
Department of Radiology, Anatomical Pathology and Oncology, "Sapienza" University of Rome, Policlinico Umberto I, Viale del Policlinico 155, 00161, Rome, Italy.
Mattia
M
Di Segni
Department of Public Health and Infectious Diseases, "Sapienza" University of Rome, Rome, Italy.
Corrado
C
De Vito
Department of Radiology, Anatomical Pathology and Oncology, "Sapienza" University of Rome, Policlinico Umberto I, Viale del Policlinico 155, 00161, Rome, Italy.
Hektor
H
Grazhdani
Department of Experimental Medicine, "Sapienza" University of Rome, Rome, Italy.
Andrea M
AM
Isidori
Department of Experimental Medicine, "Sapienza" University of Rome, Rome, Italy.
Elisa
E
Giannetta
Department of Surgical Sciences, "Sapienza" University of Rome, Rome, Italy.
Adriano
A
Redler
Department of Surgical Sciences, "Sapienza" University of Rome, Rome, Italy.
Fabrizio
F
Frattaroli
Department of Surgical Sciences, "Sapienza" University of Rome, Rome, Italy.
Laura
L
Giacomelli
Department of Surgical Sciences, "Sapienza" University of Rome, Rome, Italy.
Giorgio
G
Di Rocco
Department of Radiology, Anatomical Pathology and Oncology, "Sapienza" University of Rome, Policlinico Umberto I, Viale del Policlinico 155, 00161, Rome, Italy.
Carlo
C
Catalano
Department of Radiology, Anatomical Pathology and Oncology, "Sapienza" University of Rome, Policlinico Umberto I, Viale del Policlinico 155, 00161, Rome, Italy.
Ferdinando
F
D'Ambrosio
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity; D016606:Thyroid Nodule / Q000000981:diagnostic imaging*; D018615:Ultrasonography, Doppler, Color / Q000379:methods*; D055815:Young Adult
Indeterminate cytology; Strain ratio; Thy3 thyroid nodules; Ultrasound; Ultrasound strain elastography