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Anatomic Imaging (anatomic + imaging)
Selected AbstractsEvolution of Mapping and Anatomic Imaging of Cardiac ArrhythmiasJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 7 2004DOUGLAS L. PACKER M.D. First page of article [source] Pharmacokinetic mapping for lesion classification in dynamic breast MRIJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 6 2010Matthias C. Schabel PhD Abstract Purpose: To prospectively investigate whether a rapid dynamic MRI protocol, in conjunction with pharmacokinetic modeling, could provide diagnostically useful information for discriminating biopsy-proven benign lesions from malignancies. Materials and Methods: Patients referred to breast biopsy based on suspicious screening findings were eligible. After anatomic imaging, patients were scanned using a dynamic protocol with complete bilateral breast coverage. Maps of pharmacokinetic parameters representing transfer constant (Ktrans), efflux rate constant (kep), blood plasma volume fraction (vp), and extracellular extravascular volume fraction (ve) were averaged over lesions and used, with biopsy results, to generate receiver operating characteristic curves for linear classifiers using one, two, or three parameters. Results: Biopsy and imaging results were obtained from 93 lesions in 74 of 78 study patients. Classification based on Ktrans and kep gave the greatest accuracy, with an area under the receiver operating characteristic curve of 0.915, sensitivity of 91%, and specificity of 85%, compared with values of 88% and 68%, respectively, obtained in a recent study of clinical breast MRI in a similar patient population. Conclusion: Pharmacokinetic classification of breast lesions is practical on modern MRI hardware and provides significant accuracy for identification of malignancies. Sensitivity of a two-parameter linear classifier is comparable to that reported in a recent multicenter study of clinical breast MRI, while specificity is significantly higher. J. Magn. Reson. Imaging 2010;31:1371,1378. © 2010 Wiley-Liss, Inc. [source] Continuous arterial spin labeling using a train of adiabatic inversion pulses,JOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 3 2005Bradford A. Moffat PhD Abstract Purpose To develop a simple and robust magnetic resonance imaging (MRI) pulse sequence for the quantitative measurement of blood flow in the brain and cerebral tumors that has practical implementation advantages over currently used continuous arterial spin labeling (CASL) schemes. Materials and Methods Presented here is a single-coil protocol that uses a train of hyperbolic secant inversion pulses to produce continuous arterial spin inversion for perfusion weighting of fast spin echo images. Flow maps of normal rat brains and those containing a 9L gliosarcoma orthotopic tumor model conditions were acquired with and without carbogen. Results The perfusion-weighted images have reduced magnetization transfer signal degradation as compared to the traditional single-coil CASL while avoiding the use of a more complex two-coil CASL technique. Blood flow measurements in tumor and normal brain tissue were consistent with those previously reported by other CASL techniques. Contralateral and normal brain showed increased blood flow with carbogen breathing, while tumor tissue lacked the same CO2 reactivity. Conclusion This variation of the CASL technique is a quantitative, robust, and practical single-coil method for measuring blood flow. This CASL method does not require specialized radiofrequency coils or amplifiers that are not routinely used for anatomic imaging of the brain, therefore allowing these flow measurements to be easily incorporated into traditional rodent neuroimaging protocols. J. Magn. Reson. Imaging 2005;21:290,296. © 2005 Wiley-Liss, Inc. [source] Basal ganglia physiology and deep brain stimulation,MOVEMENT DISORDERS, Issue S1 2010Andres M. Lozano FRCSC Abstract Despite improvements in anatomic imaging of the basal ganglia, microelectrode recording is still an invaluable tool in locating appropriate targets for neurosurgical intervention. These recording also provide an unparalleled opportunity to study the pathophysiological aspects of diseases. This article reviews the principles of microelectrode recording in functional neurosurgery and discusses the pathologic neurophysiologic findings commonly encountered. It also highlights some of the potential mechanisms of action of both dopaminergic drugs and deep brain stimulation. In addition we review the recent work on pedunculopontine nucleus neurophysiology and trials of deep brain stimulation in that region for gait disturbances in Parkinson's disease. © 2010 Movement Disorder Society [source] Radioembolization of colorectal hepatic metastases using yttrium-90 microspheresCANCER, Issue 9 2009Mary F. Mulcahy MD Abstract BACKGROUND: The objective of the current study was to determine the safety and efficacy of Yttrium-90 (Y90) microsphere treatment in patients with liver-dominant colorectal metastases. METHODS: Seventy-two patients with unresectable hepatic colorectal metastases were treated at a targeted absorbed dose of 120 Gray (Gy). Safety and toxicity were assessed using version 3 of the National Cancer Institute Common Terminology Criteria. Response was assessed by anatomic imaging and positron emission tomography (PET). Survival from the diagnosis of hepatic metastases and first treatment were estimated using the Kaplan-Meier method. Substratification analyses were performed. RESULTS: The median dose delivered was 118 Gy. Treatment-related toxicities included fatigue (61%), nausea (21%), and abdominal pain (25%). Grade 3 and 4 bilirubin toxicities were observed in 9 of 72 patients (12.6%). The tumor response rate was 40.3%. The median time to hepatic progression was 15.4 months, and the median response duration was 15 months. The PET response rate was 77%. Overall survival from the first Y90 treatment was 14.5 months. Tumor replacement (,25% vs >25%) was associated with significantly greater median survival (18.7 months vs 5.2 months). The presence of extrahepatic disease was associated negatively with overall survival (7.9 months vs 21 months). Overall survival from the date of initial hepatic metastases was 34.6 months. A subset analysis of patients who had an Eastern Cooperative Oncology Group performance status of 0 demonstrated a median survival of 42.8 months and 23.5 months from the time of hepatic metastases and Y90 treatment, respectively. CONCLUSIONS: Y90 liver therapy appears to provide sustained disease stabilization with acceptable toxicity. Asymptomatic patients with preserved liver function at the time of Y90 appeared to benefit most from treatment. Cancer 2009. © 2009 American Cancer Society. [source] Electron beam angiography for the evaluation of percutaneous atrial septal defect closureCATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 4 2005Jamil AboulHosn MD Abstract Electron beam angiography (EBA) provides excellent anatomic imaging in patients with congenital heart disease and may be useful in the assessment of atrial septal defects (ASDs). We present four patients with an ASD who were considered for percutaneous closure and underwent EBA for measurement of defect size and assessment of rim adequacy, adjacent cardiac structures, and associated congenital anomalies. © 2005 Wiley-Liss, Inc. [source] | ||||||||||