A survey of thyroid gland scintigraphy

The Society of Nuclear Medicine (SNM) published procedure guidelines for thyroid imaging in 1999. We wished to determine how many clinics performing thyroid imaging follow the guidelines and to what extent. Of particular interest to us was the choice of collimator.

We developed a 10-question survey to obtain information on how hospitals perform thyroid imaging. The questions were designed to cover the procedure recommendations of the SNM guidelines. The survey was sent to 350 hospitals randomly selected from 11 states in the northeastern United States.

One hundred sixty-five surveys (47%) were returned. Most of the clinics that responded obtain a history, hyperextend the neck, and obtain anterior and anterior oblique views. Twenty-five percent of the respondents obtain all their images with a parallel-hole collimator. Seventy-five percent use a pinhole collimator or a combination of parallel-hole and pinhole collimators. The number of counts and time used for acquiring the images vary greatly. Less than half the respondents palpate the neck for correlation with the scan.

The survey results indicated that many clinics do not follow the recommendations of the SNM guidelines. The major deviations from the guidelines were in the choice of collimator, the number of counts or amount of time used to acquire images, and the lack of neck palpation for correlation with the scan.