Intraoperative US in interactive image-guided neurosurgery.
Explore the source record for details and available documents.
Artifacts↗
Biomedical subjects
T M Peters
Publications and source records attributed to T M Peters.
Bilateral thalamic glioma: review of eight cases with personality change and mental deterioration.
PURPOSE: To describe the clinical, radiographic, and neuropathologic features of bilateral thalamic glioma. METHODS: We searched our hospital records (1963 to present) to identify patients diagnosed as having the disease. RESULTS: Our search revealed eight patients, ranging in age from 8-63 years, with bithalamic tumor diagnosed by angiography, CT, and/or MR. All patients displayed personality changes and/or mental deterioration, including memory loss, inattention, confusion, hallucination, hyperphagia, or slow mentation. Unilateral motor weakness was also noted in six cases. The tumor always involved the medial aspect of the left and right thalami, but was often more extensive. The pathology was determined to be grades I-IV astrocytoma, confirmed by stereotactic biopsy or autopsy in six. Mild to moderate hydrocephaly occurred in some cases and was considered to be a contributing factor to mental deterioration. No correlation was found between age and type of tumor. CONCLUSIONS: Bilateral glioma of the dorsomedial and intralaminar nuclei of the thalamus can be a primary cause of dementia that has not been well-recognized in the past. CT and particularly MR should be considered for patients presenting with personality change or dementia, because of the possible presence of this unusual but devastating disease.
Adolescent↗
A low resolution CT scanner in radiotherapy planning.
Explore the source record for details and available documents.
Humans↗
Stereoscopic digital subtraction angiography in neuroradiologic assessment.
Digital subtraction angiography (DSA) with stereoscopic imaging was performed in 40 patients for evaluation of a variety of cerebrospinal disorders. It was facilitated by a C-arm mounted x-ray tube and imaging chain with 7 degrees angulation between image pairs. Stereoscopic digital imaging proved particularly useful in the preoperative assessment of aneurysms, arteriovenous malformations, and primary and metastatic tumors. The technique was also found to be useful as a real-time adjunct to therapeutic radiographic procedures, as an aid in stereotaxic procedures, and in follow-up of postsurgical patients. Although the intravenous route was occasionally used, especially in postoperative follow-up of aneurysms, the procedure was most often carried out via an intraarterial approach. Stereoscopy was useful in supplying depth information regarding the relations between lesions and surrounding normal and abnormal vasculature. This technique combines the demonstrated advantages of intraarterial DSA with the unique advantage of stereoscopic imaging to demonstrate three-dimensional detail, thus contributing significantly to diagnostic confidence. Disadvantages are discussed. Further refinements in the equipment are expected: generation of stereo images with one injection, thus increasing procedure efficiency and patient safety; a video stereoscopic viewing unit; and the ability to obtain precise measurements via computer of depth, position, distance between, and true size of objects.
Adolescent↗
Automatic 3D intersubject registration of MR volumetric data in standardized Talairach space.
OBJECTIVE: In both diagnostic and research applications, the interpretation of MR images of the human brain is facilitated when different data sets can be compared by visual inspection of equivalent anatomical planes. Quantitative analysis with predefined atlas templates often requires the initial alignment of atlas and image planes. Unfortunately, the axial planes acquired during separate scanning sessions are often different in their relative position and orientation, and these slices are not coplanar with those in the atlas. We have developed a completely automatic method to register a given volumetric data set with Talairach stereotaxic coordinate system. MATERIALS AND METHODS: The registration method is based on multi-scale, three-dimensional (3D) cross-correlation with an average (n > 300) MR brain image volume aligned with the Talariach stereotaxic space. Once the data set is re-sampled by the transformation recovered by the algorithm, atlas slices can be directly superimposed on the corresponding slices of the re-sampled volume. the use of such a standardized space also allows the direct comparison, voxel to voxel, of two or more data sets brought into stereotaxic space. RESULTS: With use of a two-tailed Student t test for paired samples, there was no significant difference in the transformation parameters recovered by the automatic algorithm when compared with two manual landmark-based methods (p > 0.1 for all parameters except y-scale, where p > 0.05). Using root-mean-square difference between normalized voxel intensities as an unbiased measure of registration, we show that when estimated and averaged over 60 volumetric MR images in standard space, this measure was 30% lower for the automatic technique than the manual method, indicating better registrations. Likewise, the automatic method showed a 57% reduction in standard deviation, implying a more stable technique. The algorithm is able to recover the transformation even when data are missing from the top or bottom of the volume. CONCLUSION: We present a fully automatic registration method to map volumetric data into stereotaxic space that yields results comparable with those of manually based techniques. The method requires no manual identification of points or contours and therefore does not suffer the drawbacks involved in user intervention such as reproducibility and interobserver variability.
Algorithms↗
Peripheral nerve catheterization in the management of terminal cancer pain.
BACKGROUND AND OBJECTIVES: Peripheral nerve catheterization techniques were used in two patients with severe pain associated with the terminal stages of metastatic cancer. The first patient had severe upper limb pain and lymphedema secondary to breast carcinoma, and the second patient had an acutely ischemic leg secondary to pelvic obstruction from an ovarian tumor. The goal of treatment was to relieve the pain, which was resistant to opioid drugs, and to optimize the quality of life that remained, estimated to be only a few weeks. METHODS: The first patient received a continuous brachial plexus block via an epidural catheter, introduced by means of a Tuohy needle and a peripheral nerve stimulator to locate the plexus accurately. The second patient required catheterization of both the sciatic and femoral nerves, again with a peripheral nerve stimulator used to locate the nerves prior to inserting the catheters. RESULTS: Analgesia was established with a bolus of local anesthetic and maintained with a continuous infusion of local anesthetic in the first patient. For the second patient, fentanyl was added to the local anesthetic, as it had been shown to improve analgesia in the lower limb in previous work. In the first patient, the analgesia allowed active treatment of the lymphedema and mobilization of the limb, and she remained pain free until her death 2 weeks later. In the second patient, the infusions controlled the pain both before and after surgical amputation of the limb, until the stump was well healed. CONCLUSIONS: Peripheral nerve catheterization proved beneficial in two patients who presented with difficult pain management problems and should be more widely considered for the relief of severe cancer-related pain in both the upper and lower limbs.
Aged↗