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Results for “pathological imaging data”

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At least 523 records · Page 29Linked to original sources

PubMed2005

Whole-body MR angiography using a novel 32-receiving-channel MR system with surface coil technology: first clinical experience.

PURPOSE: To demonstrate the feasibility of detecting atherosclerotic vascular disease using an innovative magnetic resonance angiography (MRA) protocol in combination with a dedicated whole-body MR scanner with new surface coil technology. MATERIALS AND METHODS: A total of 10 volunteers and eight patients with peripheral arterial occlusive disease (PAOD) were examined at 1.5 T. Conventional digital subtraction angiography (DSA) of the symptomatic region was available as a reference standard in all eight patients. Depending on subjects' size, four to five three-dimensional data sets were acquired using an adapted injection protocol. Images were assessed independently by two readers for vascular pathology. Additionally, signal-to-noise ratios (SNRs) and contrast-to-noise ratios (CNRs) were measured. RESULTS: Whole-body MRA yielded excellent sensitivity and specificity of more than 95% for both readers with high interobserver agreement (k = 0.93). Surface coil signal reception rendered a high SNR (mean 151.28 +/- 54.04) and CNR (mean 120.75 +/- 46.47). Despite lower SNR and CNR of the cranial and cervical vessels, a two-step injection protocol exhibited less venous superposition and therefore proved to be superior compared to single-bolus injection. CONCLUSION: Our approach provides accurate noninvasive high-resolution imaging of systemic atherosclerotic disease, covering the arterial vasculature from intracranial arteries to distal runoff vessels. The recently introduced MR scanner and coil technology is feasible to significantly increase the performance of whole-body MRA.

Adult↗

PubMed1994

Comparison between metacarpal bone measurements by computarized radiogrammetry and total body DEXA in normal and osteoporotic women.

We evaluated the precision of metacarpal radiogrammetry by computed radiography as a technique for bone mass measurement. Measurements obtained using this method were compared with densitometric measurements of total body bone mass using dual-energy X-ray absorptiometry. Our results showed that the coefficients of variation for radiogrammetric measurements were similar in 60 women with osteoporosis and in 100 normal women: 0.7% in both groups for external diameter of the second metacarpal, 2.41% in the normal women and 2.03% in the women with osteoporosis for internal diameter, and 2.3% and 2.4%, respectively, for cortical thickness. Except for external metacarpal diameter, which did not differ between normal and osteoporotic women, all the measurements were smaller in the women with osteoporosis (p < 0.001). The correlation between metacarpal cortical thickness and total body bone mineral content was r2 = 0.462 in the women with osteoporosis, r2 = 0.476 in the controls, and r2 = 0.522 in the two groups combined (all p < 0.001). There was a significant correlation (p < 0.001) between cortical thickness and densitometric metacarpal measurements of both the diaphysis and epiphysis. These results confirm the value of radiogrammetry as a technique for quantitating bone mass under normal and pathological conditions. Additional advantages of the method are minimal radiation dose delivered, possibility for storing the image and data, and technical facility.

Absorptiometry, Photon↗

PubMed2002

Disorders of cortical formation: radiologic-pathologic correlation.

The advent of newer imaging techniques, such as high-resolution MR imaging and surface reconstructions of three-dimensional data sets, has led to a greater in vivo understanding of cortical malformations of the brain. Disorders of cortical formation are illustrated with routine imaging, surface reconstruction, and pathogenic specimens.

Brain Neoplasms↗

PubMed2005

Imaging angiogenesis: applications and potential for drug development.

Recognition of the importance of angiogenesis to tumor growth and metastasis has led to efforts to develop new drugs that are targeted to angiogenic vasculature. Clinical trials of these agents are challenging, both because there is no agreed upon method of establishing the correct dosage for drugs whose mechanism of action is not primarily cytotoxic and because of the long time it takes to determine whether such drugs have a clinical effect. Therefore, there is a need for rapid and effective biomarkers to establish drug dosage and monitor clinical response. This review addresses the potential of imaging as a way to accurately and reliably assess changes in angiogenic vasculature in response to therapy. We describe the advantages and disadvantages of several imaging modalities, including positron emission tomography, x-ray computed tomography, magnetic resonance imaging, ultrasound, and optical imaging, for imaging angiogenic vasculature. We also discuss the analytic methods used to derive blood flow, blood volume, empirical semiquantitative hemodynamic parameters, and quantitative hemodynamic parameters from pharmacokinetic modeling. We examine the validity of these methods, citing studies that test correlations between data derived from imaging and data derived from other established methods, their reproducibility, and correlations between imaging-derived hemodynamic parameters and other pathologic indicators, such as microvessel density, pathology score, and disease outcome. Finally, we discuss which imaging methods are most likely to have the sensitivity and reliability required for monitoring responses to cancer therapy and describe ways in which imaging has been used in clinical trials to date.

Angiogenesis Inhibitors↗

PubMed1997

The present and future role of intraoperative MRI in neurosurgical procedures.

OBJECTIVE: We have worked in conjunction with scientists from the General Electric Corporation over 6 years to develop an open-bore MR imaging system (0.5 T) enabling optimal vertical access of surgeon and assistant to the patient, and real-time imaging during major neurosurgical procedures. METHODS: The intraoperative MR system (MRT) is located in a specially modified operative suite that combines the features of an MR-imaging suite with a fully functional operating room. An MR-compatible anesthesia machine and patient-monitoring device are located next to the magnet. The position of instruments, platforms and supports may be mapped in the operative field using 3 charge-coupled device video cameras mounted in the overhead support truncheon that follow various light-emitting diodes on the devices (Pixsys). The MR image plane can be defined as the axial, coronal or sagittal views through a point along the vector beneath the Pixsys tripod. A variety of surface coils were designed to take full advantage of full open patient access. The software, implemented by a technologist located outside the MR room, is now equivalent to that available on the commercial 0.5-tesla Signa Advantage system. Development of very robust 3-dimensional software in conjunction with the Surgical Planning Laboratory (SPL) at the Brigham & Women's Hospital is the subject of significant effort. The MRT system has been shown to possess imaging capabilities comparable, or even slightly superior (by 10%), to a conventional 0.5-tesla MR scanner. Two modified liquid-crystal display screens are mounted on the magnet housing for the surgeon to monitor the images during the procedures. Projection into larger screens or the operating microscope is under development. RESULTS: We have performed 110 neurosurgical cases in MRT as of January 29, 1997, including 47 biopsies, 6 catheter placements, 4 cyst drainages, 47 craniotomies for resection, 3 spinal cases (1 syrinx drainage), and 3 laser tumor ablations. CONCLUSIONS: MRT is especially useful in guiding biopsies and resections near cysts, ventricles and critical vascular structures where preoperative images with framed/frameless techniques would be inadequate to show anatomic changes during the procedure. Real-time images of a biopsy needle within the abnormal area are very useful in cases of subtle pathologic change. More complete resection of infiltrative tumor is readily accomplished. SPL image fusion of SPECT and neurofunctional data (e.g. from magnetic stimulation preoperatively) into the imaging space enables the surgeon to better visualize tumor invasion or neural function in real-time imaging during resection. Imaging of thermal gradients for cryoprobe or laser ablation, and combination with endoscopy and robotics will offer additional benefit in the performance of difficult neurosurgical procedures.

Biopsy↗

PubMed1997

[Binswanger's disease: clinicopathological study of a case].

The authors describe a case of Binswanger's disease in a female patient with arterial hypertension followed during 10 years, before and after the demential syndrome. The clinical diagnosis was established through history, clinical and neurological examination, and neuropsychologic evaluation. Computed tomography and particularly magnetic resonance imaging suggested the diagnosis, that was confirmed by the anatomo-pathological study. They discuss behavioral and clinical data, and radiological and histopathologic aspects, comparing them with data found in the literature.

Adult↗

PubMed2006

Diagnosis of respiratory bronchiolitis associated interstitial lung disease.

BACKGROUND: Respiratory Bronchiolitis (RB), described by Niewoehner et al in 1974, is a common finding in heavy smokers and is characterised by the presence of pigmented macrophages within respiratory bronchioles and adjacent alveoli. In the 1980s, Myers et al described RB associated with interstitial lung disease (RBILD), which is a rare entity expressed as an amplified respiratory bronchiolitis in response to cigarette smoke. METHODS: The authors studied a group of 8 patients with biopsy-proven RBILD diagnosed within the last five years, and assessed epidemiological data, clinical and imaging features, lung function tests, bronchoalveolar lavage findings, therapeutic approaches and clinical evolution. RESULTS AND CONCLUSIONS: The most difficult differential diagnosis is between RBILD and Desquamative Interstitial Pneumonia (DIP), which seems to suggest that these disorders are either end of the same spectrum, although the authors claim that there are some clinical, morphological and prognostic distinctions. The diagnosis of RBILD requires an appropriate clinical setting (including smoking habits), characteristic image findings (like ground glass shadowing and centrilobular nodules), and Bronchoalveolar Lavage (BAL) data to exclude other diagnosis. Pathological confirmation may also be important, not only to exclude more adverse interstitial lung disease, such as idiopathic pulmonary fibrosis, but also, as in the eight cases presented, to illustrate some specific features such as the prevalence of lymphocytosis in BAL.

Adult↗

PubMed1992

[Herpetic encephalitis with biphasic course. A case report and review of the literature].

Encephalitis represents an important event in pediatric practice. Between the different causes Herpes Simplex Virus (HSV) seems to be the most significant etiological agent, not only for its frequency but chiefly for conditioning prognosis. The Authors report a new case of HSV encephalitis with biphasic course illustrating the most recent pathologic, diagnostic and therapeutic features in the attempt to individualize those factors, between clinical data, laboratory findings and imaging that allow early diagnosis and consequently precocious specific antiviral therapy.

Child↗

PubMed2004

Evaluation of enhancement patterns of focal nodular hyperplasia in contrast-enhanced, wide-band phase-inversion harmonic power Doppler imaging of the liver.

BACKGROUND: The purpose of the study was to assess the quality of performance of wideband, phase inversion harmonic power Doppler sonography in the diagnosis of focal nodular. MATERIAL/METHODS: During a period of one year, thirty-one patients with FNH previously confirmed by ultrasound-guided biopsy, surgical resection, dynamic helical computed tomography or magnetic resonance imaging were examined. The study protocol consisted of B-mode gray scale sonography, color Doppler, power Doppler examinations, and helical CT scans. Then PI scans were performed after the injection of 2.5 g of Levovist intravenously. RESULTS: The images obtained by the B-mode gray scale were typical for focal nodular hyperplasia in 13 lesions only (32.5%), and obtained by color, power Doppler sonography in 25 lesions (62%). On the contrary all patients with focal nodular hyperplasia were diagnosed based on the wide-band, phase inversion power Doppler sonography findings. The common enhancement pattern at pulseinversion harmonic US was filling in a central tumor artery with further centrifugal development of contrast. Then during early arterial phase, all typical anatomical features of FNH as 'star sign 'or 'spoke-wheel 'pattern were clearly visible .In 3 cases ,computed tomography and magnetic resonance imaging have failed to disclose pathology while phase inversion sonographic images were completely suggestive which was later confirmed by histologic examination. CONCLUSIONS: Our data demonstrates the usefulness of wide-band, phase inversion harmonic power Doppler sonography in the differential diagnosis of hepatic focal nodular hyperplasia by visualizing all characteristic anatomical details.

Adult↗

PubMedDate not supplied

Multiplanar imaging of the hip: a systematic approach.

Computed tomography has become an invaluable adjunct for the evaluation of musculoskeletal pathology. Although the transaxial image presentation has distinct advantages over conventional radiography, the ability to reformat the acquired data into coronal, sagittal, or oblique planes contributes to a more thorough understanding of complex anatomy such as that of the hip joint. This article reviews our experience with a series of over 500 hip cases using the multiplanar reformatting and display [MPR/D] package developed for use on the Siemens Somatom DR-3 scanner.

Acetabulum↗

PubMed1987

Rapid cytophotometry and its application to diagnostic pathology.

Computer processing of microscopic imagery of cervical lesions can provide novel quantitative diagnostic information. Interpretation of this information, from the level of the image itself to that of diagnostic truth, calls for the use of appropriate data structures. The resolution of the problems of diagnostic consensus and truth may be furthered by the use of these techniques in conjunction with diagnostic expert systems. The impact of our expanded ability to differentiate and to extract diagnostic and prognostic information will lead to changes in the way we practice clinical pathology. Technologic advances have now made it possible to perform quantitative measurements in a very rapid fashion as a practical part of routine clinical pathology activity.

Carcinoma↗

PubMed1989

Information characteristic of morphology of the adaptational norm, disadaptation, and pathology under the aspect of diagnostic microscopy.

The information theory is introduced for the morphological description of adaptation and disadaptation processes. The introduction of an information characteristic set into the system of identification of microscopic images allows to standardize the approaches to the generalization of a morphometric data complex as well as to the evaluation of the irregularity degree of morphological systems with the adaptational norm, disadaptation, and pathology.

Adaptation, Biological↗

PubMed2004

TOSCA-Imaging--developing Internet based image processing software for screening and diagnosis of diabetic retinopathy.

The primary aim of TOSCA-Imaging, which was a part of the TOSCA Project financed by EU's Fifth Framework IST Programme, was to develop Internet based software and image data bases for screening and diagnosis of diabetic retinopathy and implementing it into a real life situation. The work consisted of: 1) Construction of an Internet based communication platform for transmitting and analyzing retinal images. 2) Implementation of routines for detecting the first microaneurysm (transition from normal to pathologic), detecting patients needing referral for treatment (presence of venous beading or hard exudates near the fovea), and for serial analysis (image alignment). 3) Construction of a reference image data base. A preliminary validation showed that decisions that depended on a precise detection of individual lesions, e.g. the detection of normality, had a sensitivity and specificity of around 80%, whereas decisions that depended on the detection of lesion patterns, e.g. clinically significant macular oedema, had a sensitivity and specificity of more than 95%. Validation of the reference image data base by double grading by two expert graders suggested a sensitivity and a specificity of just below 90% for any lesion and of more than 95% for predicting the overall retinopathy grade. TOSCA-Imaging has succeeded in its primary aim of developing Internet based software and implementing it into a real life situation, integrating work within image processing done in four different European countries (England, Germany, Ireland, and Denmark) to be accessed from one Internet web site.

Algorithms↗

PubMed1995

Quantitative analysis of retroillumination images.

We have developed a semi-automated image processing system for analysis and evaluation of retroillumination images. This paper describes methods used to compensate for illumination variations in the images, separation of data into cataractous and non-cataractous portions, how quantitative measurements are made and how they assess the pathological condition. In addition to the traditional area measurement, this system computes the net integral of density and several measurements involving the location of the opacity in relation to the pupillary margin. The computer measures of area, integral of density, area centrality, weighted area, density centrality and weighted density provide more data than previously described systems. Data produced by this interactive and automated system can be used in studies of posterior subcapsular and cortical cataracts, and to study the effect of these opacities on vision.

Cataract↗

PubMed1992

Detection of significant features and statistical analysis of 2D and 3D images of 31P metabolites.

The application of spectroscopy techniques to the study of normal and pathological tissue is currently limited by the difficulties of acquiring precisely localized spectra and analyzing the resulting, relatively low signal-to-noise data. Interpretation of multivoxel spectroscopy data is greatly facilitated by estimating peak parameters and representing their spatial distribution as metabolite images. We present here the new algorithm MIMSTATS, which performs an analysis of these images and determines whether the variations in the images are statistically significant. The algorithm has been developed and tested by application to 31P CSI data from the human forearm and brain. Our results demonstrate that MIMSTATS can detect signal at a very low signal-to-noise ratio in a reliable and reproducible fashion and provides a sound basis for testing hypotheses concerning differences in distribution of metabolites.

Algorithms↗

PubMedDate not supplied

Digital image fusion of CT and PET data sets--clinical value in abdominal/pelvic malignancies.

PURPOSE: We investigated the clinical relevance of digital image fusion of CT and 2-[18F]fluoro-2-deoxy-D-glucose ([18F]FDG) positron emission tomography (PET) studies in patients with suspected abdominal and/or pelvic metastasis. METHOD: Nineteen patients with suspected residual/recurrent malignancies underwent CT and [18F]FDG PET studies of the abdomen and/or pelvis. The data sets of both modalities were fused on a digital workstation by automatic adaptation of the pixel size and the slice thickness. Different body positions were corrected by semiautomatic adaptation of the body axes. The fused images were reconstructed in sagittal, coronal, and axial planes. RESULTS: Good spatial correlation between both modalities was achieved in all patients. Image fusion improved the spatial allocation of pathologically increased [18F]FDG uptake in 7 of 35 lesions (20%). CONCLUSION: This work suggests that digital image fusion of CT and [18F]FDG PET data sets improves the anatomical localization of foci with increased [18F]FDG enhancement of the retroperitoneum and the abdominal/pelvic wall, respectively.

Abdominal Neoplasms↗

PubMed2001

[Modeling the eye based on simulated refractive surgery].

PURPOSE: To achieve three-dimensional modelizing of the eyeball (morphological and mechanical behavior) in order to simulate the impact of various refractive surgery techniques and to study the normal and pathological states of the eye. METHOD: Rebuilding the ocular shell is based on different kinds of imaging (MRI, ultrasound) including information provided by video topography. Image data are treated using suitable numerized filters that allow automatic segmentations of ocular globus edges. Reconstruction is based on specific mathematical functions (B-splines). The mechanical behavior of a reconstructed model is simulated by solving equations of linearized elasticity with the finitude elements method. RESULTS: Numerous simulations mimmed different refractive surgical techniques and, then validated the model. In addition, simulations of various pathologies allowed us to verify certain clinical hypotheses. CONCLUSION: This work, although still experimental, demonstrates the advantages of such simulations and will allow novice physicians an easier approach to different surgical techniques and will help them understand their effect. Furthermore, it might be useful for simulation of new surgical concepts even before their in vivo evaluation.

Computer Simulation↗

PubMed2006

[Rectal carcinoma: is too much neoadjuvant therapy performed? Proposals for a more selective MRI based indication].

The present-day optimised surgery (concept of total mesorectal excision) with quality assurance by standardized pathologic examination, advances in radiotherapy and the possibilities of high-spatial-resolution MR imaging require reconsideration of pros and contras of neoadjuvant therapy and respective data. According to the resulting new proposal neoadjuvant long-course radiochemotherapy is indicated for patients with 1) fixed questionably R0 resectable tumors, 2) mobile tumors with the MRT finding of tumor involving the mesorectal fascia or 1 mm or less from it, 3) low rectal tumors extending below the levator origin and invading beyond the muscularis propria. If a high risk of local recurrence becomes apparent during surgery (tumor perforation, incision into or through tumor) or after pathologic examination (incomplete mesorectal excision, tumor 1 mm or less from the circumferential resection margin) adjuvant radiochemotherapy is indicated. In case of lymph node metastasis postoperative chemotherapy is given.

Combined Modality Therapy↗