What is Focused Ultrasound?

Focused ultrasound is a technology which can be used in noninvasive medical treatment of several conditions, including uterine fibroids, some cancers, and atrial fibrillation. It is more properly known as high intensity focused ultrasound (HIFU), reflecting the fact that the technology includes a very high intensity beam, in addition to a tight focus which targets a specific area of the body. This treatment is an option for some patients which can be considered as an alternative to more invasive medical procedures.

In a focused ultrasound procedure, the doctor uses either a magnetic resonance imaging (MRI) machine or an ultrasound machine as a guide. These medical imaging machines are used to pinpoint the precise spot where the focused ultrasound needs to be directed. In the case of MRI-guided focused ultrasound, the patient lies on a specially-prepared table inside the ultrasound machine, and the doctor controls the ultrasound remotely. In ultrasound-guided focused ultrasound, the doctor uses an ultrasound machine to image the area, and then directs the HIFU as needed.

The focused ultrasound procedure works to break up masses such as tumors or fibroids. The sound waves generate a great deal of heat which breaks up the unwanted tissue in a process known as thermal ablation. In addition to being used to break up or destroy masses like fibroids and tumors, HIFU can also be used to temporarily breach the blood-brain barrier to deliver medications to the brain in the treatment of conditions such as stroke.

To prepare for focused ultrasound, a patient will usually be asked to wear a hospital gown, and in the case of MRI-guided procedures, all metal will need to be removed from the patient's body. He or she will be supported in a cradle which also holds the body still so that the ultrasound ends up in the right location. During the activation of the high intensity focused ultrasound, the patient may feel some heat or warmth, but the procedure should not be painful. If pain does develop, the patient should request an immediate stop to the procedure.

The noninvasive nature of these procedure makes it much less risky than surgeries, but there are some potential complications. The ultrasound waves can create small bubbles in the body which may burst, releasing heat which could damage the internal organs. While the equipment is carefully calibrated to avoid this, every body is slightly different, and this is a definite risk. The procedure may also be ineffective, which means that it may be necessary to receive surgery or an invasive procedure after focused ultrasound fails.