Christopher Uff

A novel technique of detecting MRI-negative lesion in focal symptomatic epilepsy: Intraoperative ShearWave Elastography

Focal symptomatic epilepsy is the most common form of epilepsy that can often be cured with surgery. A small proportion of patients with focal symptomatic epilepsy do not have identifiable lesions on magnetic resonance imaging (MRI). The most common pathology in this group is type II focal cortical dysplasia (FCD), which is a subtype of malformative brain lesion associated with medication‐resistant epilepsy. We present a patient with MRI‐negative focal symptomatic epilepsy who underwent invasive electrode recordings. At the time of surgery, a novel ultrasound‐based technique called ShearWave Elastography (SWE) was performed. A 0.5 cc lesion was demonstrated on SWE but was absent on B‐mode ultrasound and 3‐T MRI. Electroencephalography (EEG), positron emission tomography (PET), and magnetoencephalography (MEG) scans demonstrated an abnormality in the right frontal region. On the basis of this finding, a depth electrode was implanted into the lesion. Surgical resection and histology confirmed the lesion to be type IIb FCD.

Real-time ultrasound elastography in neurosurgery

This study furthers previous work by this group [1] on the use of ultrasound elastography intra-operatively in the brain. Real-time 2-dimensional (2D) ultrasound elastograms were acquired during neurosurgical operations for brain and spinal cord tumors, and, in select cases, approximately real-time 3-dimensional (3D) elastograms (volumes of axial strain data) were acquired in the brain. For the first time, elastograms were successfully generated in the spinal cord using vascular pulsations to generate internal strains. The results revealed strain data that correlated well with the surgeons assessment of the stiffness of the tissues, and areas of reduction in cross-correlation coefficient and very high axial strain at tumor boundaries were found to correspond to cleavage planes. Off-line axial normal strain and axial shear strain calculation assisted in image interpretation. Benefits of this method in neurosurgery include pre-informing the surgeon as to the stiffness of the lesion and identification of dissection planes, both of which can lead to safer surgery.

A new method for the acquisition of ultrasonic strain image volumes.

This article presents a new method for acquiring three-dimensional (3-D) volumes of ultrasonic axial strain data. The method uses a mechanically-swept probe to sweep out a single volume while applying a continuously varying axial compression. Acquisition of a volume takes 15-20 s. A strain volume is then calculated by comparing frame pairs throughout the sequence. The method uses strain quality estimates to automatically pick out high quality frame pairs, and so does not require careful control of the axial compression. In a series of in vitro and in vivo experiments, we quantify the image quality of the new method and also assess its ease of use. Results are compared with those for the current best alternative, which calculates strain between two complete volumes. The volume pair approach can produce high quality data, but skillful scanning is required to acquire two volumes with appropriate relative strain. In the new method, the automatic quality-weighted selection of image pairs overcomes this difficulty and the method produces superior quality images with a relatively relaxed scanning technique.

Sir Victor Horsley's 19th century operations at the National Hospital for Neurology and Neurosurgery, Queen Square.

Although he was not the first man to operate on the brain, Sir Victor Horsley was the worlds first surgeon appointed to a hospital post to perform brain surgery, which happened in 1886 at the National Hospital for Neurology and Neurosurgery, Queen Square, London. The authors examined the patient records between 1886 and 1899 and found 151 operations performed by Sir Victor Horsley at the National Hospital, including craniotomies, laminectomies, and nerve divisions. The authors present the outcome data and case illustrations of cerebral tumor resections and laminectomies from the nineteenth century. Outcomes and notable pioneering achievements are highlighted.

Spinal Epidural Hematoma Caused by Pseudogout: A Case Report and Literature Review

Study Design Case report. Objective We present the first reported case of spontaneous spinal epidural hematoma secondary to calcium pyrophosphate crystal deposition disease (pseudogout) in a 75-year-old woman. Methods A retrospective review of the patients case notes was undertaken and the limited literature on this subject reviewed. Results This patient presented with sudden-onset lower limb paresis, sensory loss, urinary retention, and back pain. Magnetic resonance imaging showed an epidural hematoma, which was evacuated. Histologic specimens of the clot showed calcium pyrophosphate dihydrate crystal deposits (pseudogout). Conclusion The importance of histopathologic review of surgical specimens is highlighted when considering the differential diagnosis of apparently spontaneous spinal epidural hematoma.

On the imaging of slip boundaries using 3D elastography

Slip elastography is a new branch of elastography which incorporates shear strain imaging and force estimation, with a view to detecting and characterizing slip boundaries between tumors and their surroundings. This paper introduces the principles of slip elastography. It is hypothesized that apparent shear strains may arise due to shear motion across a slip boundary. This is investigated through FEM simulation and phantom experiments. It was found that axial shear strain across a tumor boundary is greater when it may slip freely against the surrounding material compared to when it is adhered. Additional indicators of slip motion were found: discontinuous gradients in displacement data at the tumor boundary; high axial strain surrounding the tumor, as a result of high local spatial gradients in displacement at the tumor boundary; inhomogeneous distribution axial strain within the tumor; axial shear strain contrast inside the tumor. In the future, these indicators will be used to help locate slip boundaries in the scan plane.