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Biomedical subjects

N Hylton

Publications and source records attributed to N Hylton.

8 recordsLinked to original sources
PubMed2002

Magnetic resonance imaging for primary breast cancer management: current role and new applications.

Techniques for magnetic resonance (MR) imaging of the breast have been evolving over the past decade. The opportunities for integration of MR imaging into clinical breast cancer management and clinical research are increasing. In this paper, we will review the principles behind the creation of standard and MR images and use this as a platform to evaluate clinical studies and indications for the use and study of MR. In particular, we will focus on those areas where MR has the capability of changing care and/or improving our understanding of the biology of breast cancer. In addition, we will address areas where MR is not yet capable of adding value or where MR may lead to unnecessary procedures.

Breast Neoplasms↗
PubMed2001

MRI phenotype is associated with response to doxorubicin and cyclophosphamide neoadjuvant chemotherapy in stage III breast cancer.

BACKGROUND: The preferred management for women with stage II or locally advanced breast cancer (LABC) is neoadjuvant chemotherapy. Pathologic response to chemotherapy has been shown to be an excellent predictor of outcome. Surrogates that can predict pathologic response and outcome will fuel future changes in management. Magnetic resonance imaging (MRI) demonstrates that patients with LABC have distinct tumor patterns. We investigated whether or not these patterns predict response to therapy. METHODS: Thirty-three women who received neoadjuvant doxorubicin and cyclophosphamide chemotherapy for 4 cycles and serial breast MRI scans before and after therapy were evaluated for this study. Response to therapy was measured by change in the longest diameter on the MRI. RESULTS: Five distinct imaging patterns were identified: circumscribed mass, nodular tissue infiltration diffuse tissue infiltration, patchy enhancement, and septal spread. The likelihood of a partial or complete response as measured by change in longest diameter was 77%, 37.5%, 20%, and 25%, respectively. CONCLUSIONS: MRI affords three-dimensional characterization of tumors and has revealed distinct patterns of tumor presentation that predict response. A multisite trial is being planned to combine imaging and genetic information in an effort to better understand and predict response and, ultimately, to tailor therapy and direct the use of novel agents.

Adult↗
PubMed1999

Utility of magnetic resonance imaging in the management of breast cancer: evidence for improved preoperative staging.

PURPOSE: The staging and treatment for breast cancer are changing; there is an increase in the incidence of ductal carcinoma-in-situ, the use of fine-needle aspiration and stereotactic biopsy for diagnosis, and the use of neoadjuvant chemotherapy. Thus, there is a need for a tool to assess more precisely the extent of cancer in the breast before surgery. To better plan surgical and chemotherapeutic interventions, we evaluated high-resolution magnetic resonance imaging (MRI) as such a tool. PATIENTS AND METHODS: Fifty-seven patients with 58 cases of breast cancer were evaluated preoperatively with MRI using a technique called the triple-acquisition rapid gradient echo technique to maximize anatomic detail. Imaging results were compared with mammography and subsequent pathology results. RESULTS: Magnetic resonance imaging correctly identified residual or primary cancer in 55 of 58 cases and accurately predicted the extent of the cancer in 54 of 58 cases. The anatomic extent was more accurately defined with MRI compared with mammography (98% v 55%). Magnetic resonance imaging added the greatest value in cases of multifocal disease. CONCLUSION: By applying MRI selectively to patients with a known diagnosis of cancer and focusing on defining the extent of malignant lesions, we were able to obtain clear and accurate anatomic information. Our results suggest that MRI could provide very valuable information for preoperative planning and single-stage resection in breast cancer. Based on preliminary data from our series, MRI would be valuable as a staging tool in the preoperative setting even if the cost is in the range of $1,300 to $2,000. It is already significantly less than the target cost, so it is reasonable to refine this technique for clinical use to help plan the most appropriate surgical intervention and possibly reduce costs as well. A careful prospective study is warranted to validate our findings.

Adult↗
PubMed1984

Analytical tools for magnetic resonance imaging.

The response of different magnetic resonance (MR) techniques to tissue parameters - T1, T2, and N(H) - is a determinant of clinical efficacy. The large possible number of imaging techniques and range of variable parameters for each make it difficult to perform exhaustive evaluations in a single patient or even in animal models. In addition, changes in operating magnetic field strength change the relaxation times sufficiently so that the efficacy of a technique at a given field does not imply similar results at another field value. Tools are demonstrated that permit the evaluation of the efficacy of any model of response to tissue parameters, and also allow the investigation of the effects of changing magnetic field. Global maps of signal difference between tissues as well as calculated images are obtainable from a minimally sufficient data set. These tools serve as an important adjunct to experimental work.

Electron Spin Resonance Spectroscopy↗
PubMedDate not supplied

Evaluation of the effects of intravascular MR contrast media (gadolinium dendrimer) on 3D time of flight magnetic resonance angiography of the body.

The aims of this preliminary study were to establish the efficacy and minimum effective dose of TG(5)(FdDO3A)(52) gadolinium dendrimer for contrast-enhanced, three-dimensional (3D) time of flight (TOF) magnetic resonance angiography (MRA) of the body. In a dose ranging study in eight rabbits (Group A), each of two animals received 0.03; 0.02; 0.01; or 0.005 mmol/kg of the agent for 3D-TOF MRA of the pelvic circulation in the axial and coronal planes. An additional nine animals (Group B) received a dose of 0.02 mmol/kg for 3D-TOF MRA of the mediastinum, abdomen or of the lower limbs. Quantitative and qualitative analyses of the images from Group A demonstrated a dose-related reduction in saturation effects and improved visualization of vascular structures, with maximal augmentation of the contrast-to-noise ratio (CNR) at 0.03 mmol/kg. The dose of 0.02 mmol/kg was found to be the minimal effective dose at the three vascular regions.

Animals↗
PubMedDate not supplied

The development and use of SPIO Lycra compression bracing in children with neuromotor deficits.

The use of flexible compression bracing in persons with neuromotor deficits offers improved possibilities for stability and movement control without severely limiting joint movement options. At the Children's Therapy Center in Kent, Washington, this treatment modality has been explored with increasing application in children with moderate to severe cerebral palsy and other neuromotor deficits over the past 6 years, with good success. Significant functional improvements using Neoprene shoulder/trunk/hip Bracing led us to experiment with much lighter compression materials. The stabilizing pressure input orthosis or SPIO bracing system (developed by Cheryl Allen, parent and Chief Designer, and Nancy Hylton, PT) is custom-fitted to the stability, movement control and sensory deficit needs of a specific individual. SPIO bracing developed for a specific child has often become part of a rapidly increasing group of flexible bracing options which appear to provide an improved base of support for functional gains in balance, dynamic stability, general and specific movement control with improved postural and muscle readiness. Both deep sensory and subtle biomechanical factors may account for the functional changes observed. This article discusses the development and current use of flexible compression SPIO bracing in this area.

Bandages↗