So, hello, altogether. My name is Bernd Tomandl. I'm working as a neuroradiologist in University Hospital in Erlangen, Germany, and I'm gonna talk about my poster presentation here at the RSNA. The title is "The Three-Dimensional Imaging of Neurovascular Structures Around the Brain Stem for the Therapy Planning in Neurovascular Compression Syndromes." So first of all, I want to introduce to imaging of the cranial nerves. And the first to use the so-called CISS sequence for imaging of the cranial nerves was Jan Casselman. He is a radiologist in Belgium and he introduced this sequence, which is a high resolution T-2 weighted sequence, giving us the opportunity to see very, very small structures around the brain stem.

So if you look at the images, you can see, for example, the fifth nerve, which is the trigeminal nerve, and even its fibers within the gasserian ganglion. So what we wanted to do now is to use this data from high resolution T-2 weighted images and to create a 3-dimensional display out of these data.

So, the first thing we had to do is to put all this data within a computer. After that, of course, we have to do some kind of segmentation. That means we have to create volumes to tell the computers what we want to see. And so the first thing we did is to take a sub-volume of the brain stem, which is the big large black structure in the middle of the image, and then we created the second volume, which is ... the CSF space, containing the nerves and vessels. And so we have two sub-volumes. The brain stem, CSF volume, and we know that within the CSF volume, there have to be the nerves and vessels, and using an approach that's called "direct volume rendering", we can extract this information from our sub-volumes.

Now, as we have a 3-dimensional display, like it is shown here on the images, we can actually see mainly all of the cranial nerves, and their relationship to the vasculature around the brain stem ... in the 3-dimensional way, which is much more easy to understand than the 2-dimensional sliced images, of course.

And the next idea, when we show this to our neurosurgeons was ... we could use this method for imaging of patients with neurovascular compression syndromes. Well, what is this neurovascular compression syndromes? There are several symptoms may be related to neurovascular compression syndromes. For example, the most important is maybe trigeminal neuralgia where people have a lot of ache in their faces. And this can be so worse that they can't really live with that. And it was ... the approach of Professor Janetta some years ago in the 60s, when he said, Okay, we can maybe find a loop of vessel that is compressing the trigeminal nerve around the brain stem in the root-entry zone, and if we have such a loop, maybe we can do something between the nerve and the vessel, and help the patient with that.

And this is really working. And the surgery for that is called neurovascular decompression surgery. This is working pretty nice, meanwhile. And, of course, it's much more comfortable for the neurosurgeon when he has an idea of what he will find within surgery. And so we use this kind of imaging ... high-resolution imaging of the cranial nerve to, not only see the loops and the cranial nerves, but to provide the neurosurgeon with a 3-dimensional display, giving us ... giving him an idea what he will find in surgery.

And the results are shown on this poster. We have created several cases now. The first case is a 62-year-old male patient with a hemi-facial spasm, where we have only slice images here, but they nicely show how the vertebral artery has a very, very close relation to the seventh and eighth cranial nerves. And in the interoperative view, we see how the decompression works in this patient, and this patient became symptom-free after the decompression surgery.

The second case, where we have already made a 3-dimensional visualization, is a patient with a right-sided trigeminal neuralgia. And the interesting thing here is that we have two vessel loops on each side from the superior cerebellar artery and it's compressing the trigeminal nerve as well on the left, as on the right side. But on the left side it's somewhat peripheral of the trigeminal nerve. It's not in the root entry zone. So on this side, the patient was asymptomatic.

On the other side, it's more in the area of the root nerve entry zone and on this side the patient was symptomatic, so this side has been operated and, of course, here are the symptoms. And the symptoms relieve completely after surgery in this case. And the third case, we have here on the poster, is a patient with malignant hypertony ... malignant hypertonus, which is also believed to be caused by some kind of neurovascular compression in the area of the root entry zone of the tenth cranial nerve.

And in this patient here, you can rightly see the correlation between the 3-dimensional image showing a PICA (Posterior Inferior Cerebellar Artery) loop compressing the tenth cranial nerve and its root entry zone, and the interoperative view, which shows completely the same image, when we see the PICA loop and the tenth and ninth cranial nerve.

And also, in this case, the neurovascular decompression led to a relief of symptoms; the hypertony was better after surgery. Not completely removed, but the patient can now be treated by medical means. So there's a lot of discussion about neurovascular compression symptoms, whether we can look at the images and get some kind of, uh ... (Laughs) that we can say, okay, this patient has a loop. He should have the symptoms. This is not possible. The other way around is better. You see your patient with symptoms, you look at those images, and when there is a loop, you know, okay, surgery may be useful in this patient. And neurosurgeons like to have such information and now, with the 3-dimensional display, for the first time, it's possible to give them ... the same information than they get within the neurosurgical operation room.

And I think this is a very promising approach. Thank you.

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