TCD (Trans-Cranial Doppler study) and CDS (Carotid Duplex Scan) are medical diagnosis tests that concentrate on how the inter-cranial and carotid arteries are functioning. This is usually performed if there are abnormalities in the blood pressure of a person. It can also be done to find out if the reason for the stroke or ischemia (loss of oxygen due to blockage) is in those arteries. It can also be used on some other illnesses especially they are related to the circulatory system.
Now how are they actually performed? If you’ve had an ultrasound before, it’s basically the same thing. The difference is that in TCD, they perform it on your head. Well, on the sides of your head actually. And the CDS is done on your neck where you can find the carotid arteries. They use ultrasound to view the arteries inside our head and neck and it can be seen in real time. These are usually performed lying down. I’m not sure if it can be performed while sitting, well it could be but it’s better if you’re lying down and relaxed.
Anyway, a soft (and often cold) gel is applied to the scanner and then placed on your head and neck. It serves as a lubricant so that they can navigate the device on your skin if they’re looking for something. This procedure usually takes a while. In my case, it took around 45 minutes to an hour if I remember correctly.
The reason why it’s long is because they will be recording the entire or a part of the session. They will take snapshots of the arteries and how the blood flows. You can actually see it in real-time on the monitors. You’ll see the bursts of blood through the arteries.
I am not a doctor or a medical technologist so I do not understand most of the terminologies they are using but to put it simply, the machine checks how efficient the blood flow on the arteries or if there are any abnormalities on the arteries themselves. The machine can measure the size or width of the arteries. They can even spot blood clots that could possibly be the reason why the arteries are blocked.
It is quite uncommon to have this procedure though and my cardiologist at that time said that it is among the few tests that are performed when the other more common tests appear to be ok such as CT scans and ECG. But again, it’s better to be sure that there no problems in those very important arteries as they both carry blood to your brain.
As for preparation for the procedure, there isn’t any needed so don’t worry. You don’t have to fast or anything. It is not that expensive as CT scans and MRI but probably more expensive that your regular ultrasound because of the more special equipment used. In any case, it is recommended that you go and have routing medical tests to make sure everything is ok or if there’s something wrong, it could be cured early and lessen the risk of it getting worse. Remember, prevention is the best cure.
Wikipedia – Artery