This expert system is designed to support diagnostics of thyroid gland diseases for all non-thyroid gland experts. This program is used at the beginning of the diagnostic and therapeutic process, which is usually done by a general practitioner and only rarely needs further clarification in thyroid gland ambulances or clinics. The majority of the (putative) thyroid gland derangements could be clarified quickly and cost-effectively at the general practitioner with the aid of this system. The program starts with information about possible symptoms of hypo- and hyperfunction of thyroid gland hormone production. The next step is the physical examination with documentation of blood pressure, pulse frequency, weight, orbithopathy and palpation of the thyroid gland; the physician is guided by the system through this step and supports him with the documentation. If possible, a sonography of the thyroid gland will be requested and documented.

Subsequently the physician will be asked to collect all applied medicines and diseases of the patient that influence the thyroid gland function and labororatory parameters. Regularly, we begin with the determination of basale TSH level, which solely can exclude nearly all functional derangements, if it is within normal range. If it is not, other tests and endocrine parameters will be asked, like TRH test, and tT4/tT3 (fT4/fT3). The analysis of the blood test results is the main part of the expert system; it yields information about the correct function of the thyroid gland, but not a clinical diagnose. For this purpose, we need further blood tests with the determination of antibodies (TR Ab, TPO Ab, Tg Ab) and of thyroid gland binding globulin (TBG). Taking these results into account together with the findings of the sonography and palpation, a suggestion of a diagnoses can be done, or further examination in a special ambulance will be recommended.

A foreseeable documentation of the symptoms should ease the observation of the state of the disease. The user should be informed about all steps of the medical examination and about all possible other (scarce) diagnoses, although usually they can be decided only by specialists. Usually, general practitioners cannot carry out scintigraphy, although they could process explanation to the patient, preparations for further treatment, like changing medication, test for gravidity, etc.

At present the prototypes are being further developed and reimplemented for routine clinical use.

THYRexpert I has been developed by the Department of Medical Computer Sciences, University of Vienna Medical School, Austria and the Department of Endocrinology and Metabolism, University of Vienna Medical School, Austria.

Core Unit for Medical Statistics and Informatics (MSI), Medical University of Vienna, Medical School, Spitalg. 23, A-1090 Vienna, Phone: +431 40400 6668, Internet: http://www.akh-wien.ac.at/mes.