De Quervain's subacute thyroiditis -- colour Doppler sonography findings

De Quervain's subacute nonsuppurative thyroiditis has been well characterised clinically: there usually is pain in the region of the thyroid due to local pressure. Typically, the patient feels generally ill with fever. Signs of inflammation (raised ESR and CRP) are measurable laboratory parameters. Occasionally, there is transient hyperthyroidism followed by hypothyroidism. Little data is available on the vascularisation of the thyroid in this clinical entity.

Twenty-one patients with confirmed De Quervain's subacute thyroiditis were investigated and the findings were analysed retrospectively (clinical features, sonography, cytology in some cases). Ultrasound devices (Siemens Elegra and Acuson Sequoia) with 7 and 12 MHz ultrasound transducers and modern technology (harmonic imaging, panorama imaging and sensitive colour Doppler units with standardised instrument settings) were used.

The structures of the thyroid was found to be inhomogeneous. The hypoechoic to nonechoic areas corresponded to the inflamed areas. An alteration in the morphology and topographic distribution was observed in the course of the illness. Normal or slightly increased vascularisation in the echogenically "healthy" regions of the thyroid were found in colour Doppler sonography. The peak systolic velocity (PSV) in the afferent arteries (superior and inferior thyroid arteries) was in the normal range (< 40 cm/s). The hypoechoic/nonechoic map-like areas showed a reduction or complete absence of blood flow.

De Quervain's subacute thyroiditis can be conclusively diagnosed by sonography in more than 90 % of cases based on the history, typical clinical features and clinical test parameters indicating signs of inflammation. Colour Doppler sonography can be useful in differential diagnosis of unclear cases.