Patient population:
A prospective study included 184 nodules detected in 70 patients (M/F 18/52) with ages ranged from 25 to 73 years (mean,
45.3 years).
They were referred from the general surgery,
otolaryngeology,
oncology and pathology departments to our radiology department for thyroid ultrasound and ultrasound guided fine needle aspiration (FNA) biopsy
Data acquisition:
- All patients underwent ultrasound examination of the neck and thyroid gland using the linear transducer with frequencies of 8-10 MHz of a GE LOGIQ P3 (General Electric,
Milwaukee,
WI,
USA).
Patients were examined in the supine position with a pillow underneath the shoulders to extend the neck slightly,
allowing the head to rest on the examination table.
The thyroid gland was then imaged in both the axial and longitudinal planes with assessment of size,
echogenicity,
borders and vascularity of the gland.
Both thyroid lobes and isthmus were assessed for the presence of nodules.
- Each nodule was assessed for its size,
location in the gland,
morphology,
composition,
echogenicity,
margins,
extent,
halo,
presence of calcifications and its type.
- Color Doppler was then applied to assess color mapping of the nodule and the surrounding thyroid tissue
FNA technique:
- For US-guided FNA,
the patient was placed in supine position with the neck slightly extended.
- After the lesion was localized,
the overlying skin was cleansed with a 10% povidone-iodine solution.
A 25- to 27-gauge needle attached to 10–20-mL syringe was used.
The transducer was placed directly over the lesion.
Before aspiration,
scanning was performed in the transverse plane for lesion localization,
followed by color Doppler mapping to depict any large blood vessels in and around the nodule.
The patients were instructed not to swallow or speak during the insertion of the needle.
- The perpendicular approach for needle introduction was used in which the nodule is imaged and positioned in the mid portion of the screen.
The needle bevel was introduced with the bevel facing upward toward the transducer to reflect the ultrasound waves and detect its bright echoes as it crosses the azimuthal plane during needle penetrance of the nodule.
The needle tip was carefully monitored during the procedure.(figure1,
video) Fig. 1
- Aspiration technique was used in which the needle tip is advanced into various positions in the nodule and moved to and fro while suction was performed.
- During the procedure,
all needle movements were continuously visualized in real time.
- The collected material was placed on glass slides,
smeared,
and fixed in 95% ethyl alcohol.
The syringe was rinsed with normal saline solution to obtain any remaining material.
The specimen was then sent for cytological analysis
Data analysis:
- Each of the assessed ultrasonographic gray-scale and color Doppler features of the determined thyroid nodules were analyzed and compared with the final diagnoses obtained from postoperative histopathology results and the sensitivities of the different features were calculated
Statistical analysis
- All statistical calculations were done using computer program IBM SPSS (Statistical Package for the Social Science; IBM Corp,
Armonk,
NY,
USA) release 22 for Microsoft Windows.