What does Doppler mode add?
A routine thyroid examination measures the volume of the lobes, describes the structure of the parenchyma, and characterizes the nodules using the TI-RADS system. The Doppler mode adds information about the blood supply, which is often decisive.
The most striking example is the differential diagnosis of thyrotoxicosis. In Graves' disease, the gland is diffusely enlarged and the blood flow in it is sharply increased, up to a picture called “thyroid hell”: the color map is almost completely filled with vessels, the velocities in the lower thyroid arteries are greatly increased. In subacute de Quervain's thyroiditis and in thyrotoxicosis due to destruction of follicles, blood flow, on the contrary, is normal or reduced. Hormonal indicators in both cases are similar, but the treatment is fundamentally different - thyreostatics or anti-inflammatory therapy.
When assessing nodes, the nature of vascularization is one of the signs taken into account when deciding on puncture: the predominantly central, chaotic blood flow inside the node is more alarming than the rim of vessels along the periphery, typical of benign formations. In autoimmune thyroiditis, Doppler helps to assess the activity of the process and track its dynamics.
Ultrasound capabilities
Ultrasound remains the first choice for imaging in almost every situation: it is accessible, safe, does not require radiation, and provides images in real time. It perfectly shows parenchymal organs, fluid formations, walls of hollow organs and soft tissues, and in Doppler mode, blood flow in the vessels.
A separate advantage is the possibility of dynamic tests: the doctor can ask you to strain, change your body position, fill or empty an organ and see how the picture changes. Neither computed tomography nor magnetic resonance imaging provide such an opportunity.
What influences the quality of research
The main enemy of ultrasound is gas: it completely reflects the wave. Therefore, distended intestines can make the pancreas, aorta, and retroperitoneal structures invisible. For the same reason, preparation for examining the abdominal cavity is not a formality, but a condition for a reliable result.
Severe obesity, postoperative scars, bandages and open wounds in the area of interest also have an effect. If the picture turns out to be uninformative, the doctor indicates this in the protocol and recommends an alternative method - computed tomography or magnetic resonance imaging.
Doppler mode
Dopplerography shows the movement of blood: color mapping reflects the direction of flow, spectral analysis measures velocities and resistance indices. This allows you to assess the patency of the vessel, identify stenosis, thrombus, aneurysm, pathological reflux and the nature of the blood supply to the formation.
Increased blood flow in Doppler mode is an important sign of active inflammation or tumor growth, which is why many organ studies are supplemented with Doppler as a mandatory part of the protocol.