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At least 469 records · Page 26Linked to original sources

PubMed1997

Dose-volume complication analysis for visual pathway structures of patients with advanced paranasal sinus tumors.

PURPOSE: The purpose of the present work was to relate dose and volume information to complication data for visual pathway structures in patients with advanced paranasal sinus tumors. METHODS AND MATERIALS: Three-dimensional (3D) dose distributions for chiasm, optic nerve, and retina were calculated and analyzed for 20 patients with advanced paranasal sinus malignant tumors. 3D treatment planning with beam's eye view capability was used to design beam and block arrangements, striving to spare the contralateral orbit (to lessen the chance of unilateral blindness) and frequently the ipsilateral orbit (to help prevent bilateral blindness). Point doses, dose-volume histogram analysis, and normal tissue complication probability (NTCP) calculations were performed. Published tolerance doses that indicate significant risk of complications were used as guidelines for analysis of the 3D dose distributions. RESULTS: Point doses, percent volume exceeding a specified published tolerance dose, and NTCP calculations are given in detail for patients with complications versus patients without complications. Two optic nerves receiving maximum doses below the published tolerance dose sustained damage (mild vision loss). Three patients (of 13) without optic nerve sparing and/or chiasm sparing had moderate or severe vision loss. Complication data, including individual patient analysis to estimate overall risk for loss of vision, are given. CONCLUSION: 3D treatment planning techniques were used successfully to provide bilateral sparing of the globe for most patients. It was more difficult to spare the optic nerves, especially on the ipsilateral side, when prescription dose exceeded the normal tissue tolerance doses. NTCP calculations may be useful in assessing complication risk better than point dose tolerance criteria for the chiasm, optic nerve, and retina. It is important to assess the overall risk of blindness for the patient in addition to the risk for individual visual pathway structures.

Blindness↗

PubMed2000

Trans-urethral ultrasound (TUUS) imaging for visualization and analysis of the prostate and associated tissues.

The incidence of prostate disease is high. However, accurate assessment of pathological conditions is still difficult. Although CT, MRI, and TRUS imaging methods provide useful information, each has specific drawbacks. Our work examines the potential and utility of 3D trans-urethral ultrasound (TUUS) for improved imaging of the prostate. Four normal canines were examined with TUUS. The catheter was placed in the urethra and used to image the prostate, rectum, bladder, ureter, neuro-vascular bundles, arteries, and surrounding tissue. 2D and 3D datasets were acquired and digitized. The 2D data provides useful visualization of the tissue. The clinician was also able to watch urine enter the bladder and perform a digital rectal exam in real-time. 3D data visualization required torodial reconstruction. The algorithm was optimized to provide very fast 3D reconstructions of the prostate. Segmentation of the data proved challenging, but 3D visualization, including volume rendered data and surface rendered data, were well accepted by clinicians. Clinicians and researchers determined a number of potential applications of these new techniques, including: prostate cancer diagnosis and staging, assessment of Benign Nodular Enlargement, assessment of physiologic function of the bladder, evaluation of morphologic properties of the prostate, and image guided biopsy and therapy.

Animals↗

PubMed2001

The Arabidopsis Information Resource (TAIR): a comprehensive database and web-based information retrieval, analysis, and visualization system for a model plant.

Arabidopsis thaliana, a small annual plant belonging to the mustard family, is the subject of study by an estimated 7000 researchers around the world. In addition to the large body of genetic, physiological and biochemical data gathered for this plant, it will be the first higher plant genome to be completely sequenced, with completion expected at the end of the year 2000. The sequencing effort has been coordinated by an international collaboration, the Arabidopsis Genome Initiative (AGI). The rationale for intensive investigation of Arabidopsis is that it is an excellent model for higher plants. In order to maximize use of the knowledge gained about this plant, there is a need for a comprehensive database and information retrieval and analysis system that will provide user-friendly access to Arabidopsis information. This paper describes the initial steps we have taken toward realizing these goals in a project called The Arabidopsis Information Resource (TAIR) (www.arabidopsis.org).

Arabidopsis↗

PubMed1994

A system for the on-line acquisition, visualization, and analysis of pressure-area loops.

Transesophageal echocardiography is a widely accepted technique for the assessment of left ventricular (LV) function in the operating room, intensive care unit, and cardiac catheterization suite. Not only do the images generated by these systems provide the observer with dynamic views of currently ongoing cardiac mechanics, but the computed LV area values obtained by the automated border detection system can be converted to an analog signal and then used to generate pressure-area loops if LV pressure is measured simultaneously. The intraventricular area has been shown to correlate closely with intraventricular volume and to vary proportionately. Therefore, it can be substituted for volume to generate pressure-area loops that display equivalent behavior to external perturbations as pressure-volume loops. Visualization of these waveforms and the values extracted from them, along with the associated hemodynamic values, provide valuable insight into ventricular function and heart-lung interactions. This paper describes a system that was designed and developed to acquire, display, store, and analyze pressure-area loops in addition to other associated hemodynamic signals of interest.

Computer Systems↗

PubMed2005

Computational tools for the analysis and visualization of multiple protein-ligand complexes.

Modern methods in genomics and high-throughput crystallography have ensured that we have access to a large and rapidly increasing, number of X-ray structures of protein-ligand complexes. A structure-based approach to drug design aims to exploit this information, but current methods are not suited to the examination of the large numbers of complexes available. We present computational tools that analyse and display multiple protein-ligand interactions and their properties in a simplified way. We illustrate how a novel binding-mode similarity metric is able to cluster 20 ligands complexed to HIV-1 reverse transcriptase into distinct groups. The properties of each cluster are then projected onto a group surface as a series of color gradients. Analysis of these surfaces reveals fundamental similarities and differences in the binding modes of these diverse compounds. In addition, the simplicity of the surface representations facilitates the transfer of information between the crystallographer, computational chemist and the chemist. We also show how two- and three-dimensional (2- and 3-D) similarities can be combined to provide enhanced understanding of 33 factor Xa inhibitor complexes. This methodology has enabled us to identify pharmaceutically relevant relationships between ligands and their binding modes that had previously been hidden in a wealth of data.

Cluster Analysis↗

PubMed1999

Feasibility of fluorodeoxyglucose dual-head gamma camera coincidence imaging in the evaluation of lung cancer: comparison with FDG PET.

UNLABELLED: The purpose of this study was to elucidate the feasibility of fluorodeoxyglucose gamma camera coincidence imaging (FDG GCI) in the evaluation of lung cancer in comparison with FDG PET. METHODS: Twenty-three patients with recently diagnosed lung cancer were examined with both FDG PET and FDG GCI on the same day. Pulmonary lesions were analyzed visually and semiquantitatively using the ratio of lesion-to-background counts (L/B ratio). The L/B ratio of FDG PET without attenuation correction (AC) was also calculated and compared. Nodal stations were only visually analyzed. RESULTS: FDG GCI and FDG PET could detect 22 and 23, respectively, of 23 pulmonary lesions by visual analysis (95.7% versus 100%). The L/B ratio of FDG GCI was 4.26 +/- 2.55, and significantly lower than that of FDG PET (9.29 +/- 4.95; P < 0.01). The L/B ratio of FDG PET was significantly higher with AC than that without AC (9.29 +/- 4.95 vs. 6.66 +/- 4.65; P < 0.01). When the L/B ratio threshold was set at 5.0 for FDG PET and 2.7 for FDG GCI, their sensitivity was 87.0% and 73.9%, respectively. Of the 3 and 6 patients with false-negative results on semiquantitative analysis, the lesions in 3 patients on FDG PET and 4 patients on FDG GCI were less than or equal to 2.0 cm in greatest diameter, respectively. In the assessment of mediastinal involvement, FDG PET was 77.8% sensitive, 78.6% specific and 78.3% accurate, whereas FDG GCI was 77.8% sensitive, 92.9% specific and 87.0% accurate. In the hilar regions, FDG PET was 100% sensitive, 84.2% specific and 87.0% accurate, whereas FDG GCI was 75.0% sensitive, 89.5% specific and 87.0% accurate. CONCLUSION: In this study, FDG GCI yielded results comparable to FDG PET on visual analysis to detect pulmonary lesions and lymph node metastases. However, the lesion-to-background contrasts of pulmonary lesions and nodal involvement were lower in FDG GCI than in FDG PET. Comparison between the L/B ratio of FDG PET with and without AC indicated that, with AC, FDG GCI would be closer to FDG PET in the evaluation of lung cancer.

Adenocarcinoma↗

PubMed1999

Effects of genotype x sex interaction on linkage analysis of visual event-related evoked potentials.

Autosomal genes contributing to variation in many complex traits are influenced by male or female physiological "environments." Accounting for such genotype-by-sex (G x S) interactions has been shown to be important in quantitative genetic, segregation, and linkage analyses of a number of sexually dimorphic traits. In analyses of data simulated for GAW10, we showed that incorporating sex-specific variance components into a variance components-based linkage method increased the power to detect linkage in a trait that exhibited G x S interaction. The goals of this study of data from the Collaborative Study on the Genetics of Alcoholism (COGA) were to screen the event-related brain potential (ERP) data from COGA participants for G x S interaction, and then to conduct variance components linkage analysis of ERP phenotypes showing evidence of G x S interaction using models incorporating sex-specific variance components. Significant G x S interaction was found in four ERP phenotypes: N100 measured at occipital leads 1 and 2, and P300 measured at occipital leads 1 and 2. In linkage analyses of these traits, the most significant lod score found was that between N100 occipital lead 1 amplitude and marker D7S490. The peak lod score at the D7S490 locus was 2.45 without sex-specific variance components, and 3.25 with sex-specific marker and residual polygenic components.

Alcoholism↗

PubMed2006

Analysis and visualization of chromosomal abnormalities in SNP data with SNPscan.

BACKGROUND: A variety of diseases are caused by chromosomal abnormalities such as aneuploidies (having an abnormal number of chromosomes), microdeletions, microduplications, and uniparental disomy. High density single nucleotide polymorphism (SNP) microarrays provide information on chromosomal copy number changes, as well as genotype (heterozygosity and homozygosity). SNP array studies generate multiple types of data for each SNP site, some with more than 100,000 SNPs represented on each array. The identification of different classes of anomalies within SNP data has been challenging. RESULTS: We have developed SNPscan, a web-accessible tool to analyze and visualize high density SNP data. It enables researchers (1) to visually and quantitatively assess the quality of user-generated SNP data relative to a benchmark data set derived from a control population, (2) to display SNP intensity and allelic call data in order to detect chromosomal copy number anomalies (duplications and deletions), (3) to display uniparental isodisomy based on loss of heterozygosity (LOH) across genomic regions, (4) to compare paired samples (e.g. tumor and normal), and (5) to generate a file type for viewing SNP data in the University of California, Santa Cruz (UCSC) Human Genome Browser. SNPscan accepts data exported from Affymetrix Copy Number Analysis Tool as its input. We validated SNPscan using data generated from patients with known deletions, duplications, and uniparental disomy. We also inspected previously generated SNP data from 90 apparently normal individuals from the Centre d'Etude du Polymorphisme Humain (CEPH) collection, and identified three cases of uniparental isodisomy, four females having an apparently mosaic X chromosome, two mislabelled SNP data sets, and one microdeletion on chromosome 2 with mosaicism from an apparently normal female. These previously unrecognized abnormalities were all detected using SNPscan. The microdeletion was independently confirmed by fluorescence in situ hybridization, and a region of homozygosity in a UPD case was confirmed by sequencing of genomic DNA. CONCLUSION: SNPscan is useful to identify chromosomal abnormalities based on SNP intensity (such as chromosomal copy number changes) and heterozygosity data (including regions of LOH and some cases of UPD). The program and source code are available at the SNPscan website http://pevsnerlab.kennedykrieger.org/snpscan.htm.

Base Sequence↗

PubMed1997

Grasping an illusion.

In the present study we attempted to determine the nature of the visual analysis that is performed on an object in order to grasp it. We required eight healthy subjects to reach and grasp a wooden bar which was superimposed over the shaft of the Müller-Lyer illusion. Vision of both the hand and the bar was allowed. Three different bar lengths were used. Two additional control tasks in which the subjects were required to reproduce the length of the shafts were carried out. The results showed that hand shaping while grasping the bar was influenced by the illusion configurations on which it was superimposed. However, this effect was smaller than that observed in the two tasks of length reproduction. These results support the notion that visual analysis performed on the object of a grasp movement is global and takes into account the object itself, as well as its relationships with surrounding cues. We propose, as suggested previously for reaching movements (Gentilucci, M. et al., Neuropsychologia, 1996, 34, 369-376), two partially independent stages during visuo-motor integration for grasping an object. In the first stage, the object is coded inside an object-centred frame of reference. In the second stage it is transposed in an egocentric frame of reference, in which the spatial relations between object and agent are computed. In this second stage the influence of cues surrounding the target is minimized.

Adult↗

PubMed1995

Computer simulation of nerve growth cone filopodial dynamics for visualization and analysis.

The neuronal growth cone plays a fundamental role in nerve development and regeneration. A sensory-motile structure, it determines the path of axonal extension through its interactions with the extracellular environment, ultimately directing the formation of functional connections in the nervous system. Though several mechanisms of interaction have been proposed, these have been difficult to describe quantitatively due to the complexity of growth cone behavior, as manifested in the randomly and rapidly changing shape of the growth cone. The application of mathematical techniques to model growth cone shape and motility in terms of underlying processes represents a promising approach with untapped potential for helping to unravel this complexity while revealing new insights into axonal pathfinding events. This paper presents a simulation model for filopodial dynamics, a primary feature of the motile growth cone. The model produces realizations of dynamic filopodial structure on representative growth cones for a given set of model parameters, which include the rates of filopodial initiation, extension, and retraction, filopodial length at maximum extension, and angular orientation. These parameters are based on recent experimental characterization of filopodial dynamics [Buettner et al., 1994: Dev. Biol. 163:407-422]. The mathematical relationship between the model parameters and average filopodial number and length per growth cone is described, and the contribution of individual parameters to overall filopodial morphology is illustrated both visually and numerically. In addition, the model is used to simulate filopodial encounter with a target for various conditions of filopodial dynamics. The result is characterized in terms of a mean encounter time for a population of growth cones and provides an indication of the effect of individual parameters of filopodial dynamics on the encounter process. Future experimental testing will be required to develop the model further. However, in its current form, the model enables a first approximation analysis of many hypothesis of growth cone migration and pathfinding and offers insight into the the underlying mechanisms of nerve growth and regeneration.

Cell Size↗

PubMed2002

Genome-wide pathway analysis and visualization using gene expression data.

Visualization of results for high performance computing pose special problems due to the complexity and the volume of data these systems manipulate. We present an approach for visualization of c-DNA microarray gene expression data in metabolic and regulatory pathways using multi-resolution animation at different levels of detail. We describe three scoring functions to characterize pathways at the transcriptional level based on gene expression, coregulation and cascade effect. We also assess the significance of each pathway score on the basis of their biological connotation.

Animals↗

PubMed2002

Three-dimensional visualization and analysis in prostate cancer.

Current and emerging three- and four-dimensional medical imaging modalities, along with development of efficient 3-D computer rendering and modeling of multidimensional volume image data and image-guided navigation, are significantly advancing our capabilities for improved and minimally invasive diagnosis and treatment of prostate cancer, obviating the need for exploratory surgery, physical dissection, blind biopsies and mental reconstruction of anatomy and pathology. Currently, both diagnostic and therapeutic procedures require x-ray fluoroscopy, transrectal ultrasound, CT and/or MRI for assessing the condition of the prostate and/or the outcome of any therapeutic procedure. New imaging approaches based on three-dimensional ultrasound transducers placed on catheters for easy insertion into the urethra are demonstrating significant promise for improved diagnosis and treatment of prostate disease. Microwave thermal ablation shows promise for reduction of prostate size and tumor volume, and preliminary data from cryosurgery suggests improvements in tumor reduction and/or management while minimizing the risk of serious complications. Prostate brachytherapy is becoming a more popular and effective alternative to surgery. All of these methods, either independently or combined through image fusion, are providing an exciting and rapid evolution in capabilities for visualizing the prostate and its anatomic environment, extending from physical to functional forms and from macro to micro orders of scale. Traversing the scale distances between these imaged objects within the prostate and its environs will be made automatic and instantaneous in the near future with the expected advances in miniaturization of powerful computing and electronic sensing elements. Imaging devices will continue to improve in resolution, speed and affordability and will be deployed harmlessly within the body, as well as outside of it. Diagnosis and therapy of prostate disease will become fully noninvasive and synchronous.

Adult↗

PubMed2004

MotifViz: an analysis and visualization tool for motif discovery.

Detecting overrepresented known transcription factor binding motifs in a set of promoter sequences of co-regulated genes has become an important approach to deciphering transcriptional regulatory mechanisms. In this paper, we present an interactive web server, MotifViz, for three motif discovery programs, Clover, Rover and Motifish, covering most available flavors of algorithms for achieving this goal. For comparison, we have also implemented the simple motif-matching program Possum. MotifViz provides uniform and intuitive input and output formats for all four programs. It can be accessed at http://biowulf.bu.edu/MotifViz.

Algorithms↗

PubMed2005

Menstrual cycle-dependent changes in white-on-white visual field analysis of diabetic women.

AIM: To determine the effect of the menstrual cycle on white-on-white perimetry (WWP) tests of diabetic women. SUBJECTS AND METHODS: Left eyes of 129 normally menstruating women (81 type 1 diabetes mellitus (DM) with mild (n = 43) and severe (n = 38) non-proliferative diabetic retinopathy (NPDR), and 48 healthy control females) were included in the study. All subjects underwent complete ocular examination and WWP tests both in the follicular (7-10th day of the cycle) and luteal phases (days 3-7 before the bleeding) of two consecutive menstrual cycles. WWP was performed using Humphrey Field Analyzer II with SITA Standard, central 30-2 program. Mean sensitivity (MS) of points located at central 3, 9, 15, 21 and 27 degrees retinal locations (4, 12, 18, 24 and 16 points, respectively) were calculated in all menstrual phases. RESULTS: The mean age of diabetic patients with mild and severe NPDR and control subjects were 28.8 +/- 4.7, 30.1 +/- 5.9 and 29.4 +/- 5.1 years, respectively (p > 0.05). Their mean MS values were 30.7 +/- 1.0, 30.4 +/- 1.0 and 30.8 +/- 0.8 dB, respectively (p > 0.05). Diabetic patients with severe NPDR demonstrated significant decreases in mean MS values of peripheral 21 and 27 degrees visual field locations in the luteal phase (p < 0.05). However, changes in that of the locations within central 15 degrees visual field were non-significant (p > 0.05). Diabetic patients with mild NPDR and control subjects demonstrated no significant changes in mean MS values of any of the visual field locations (p > 0.05). CONCLUSION: Peripheral, rather than central, locations of central visual field of diabetic women with severe NPDR demonstrated a significant retinal sensitivity loss in the luteal phase. These findings should be taken into consideration during the clinical follow-up of diabetic women at risk of glaucoma and ocular hypertension.

Adult↗

PubMedDate not supplied

Prognostic validation of a 17-segment score derived from a 20-segment score for myocardial perfusion SPECT interpretation.

BACKGROUND: Recently, a 17-segment model of the left ventricle has been recommended as an optimally weighted approach for interpreting myocardial perfusion single photon emission computed tomography (SPECT). Methods to convert databases from previous 20- to new 17-segment data and criteria for abnormality for the 17-segment scores are needed. METHODS AND RESULTS: Initially, for derivation of the conversion algorithm, 65 patients were studied (algorithm population) (pilot group, n = 28; validation group, n = 37). Three conversion algorithms were derived: algorithm 1, which used mid, distal, and apical scores; algorithm 2, which used distal and apical scores alone; and algorithm 3, which used maximal scores of the distal septal, lateral, and apical segments in the 20-segment model for 3 corresponding segments of the 17-segment model. The prognosis population comprised 16,020 consecutive patients (mean age, 65 +/- 12 years; 41% women) who had exercise or vasodilator stress technetium 99m sestamibi myocardial perfusion SPECT and were followed up for 2.1 +/- 0.8 years. In this population, 17-segment scores were derived from 20-segment scores by use of algorithm 2, which demonstrated the best agreement with expert 17-segment reading in the algorithm population. The prognostic value of the 20- and 17-segment scores was compared by converting the respective summed scores into percent myocardium abnormal. Conversion algorithm 2 was found to be highly concordant with expert visual analysis by the 17-segment model (r = 0.982; kappa = 0.866) in the algorithm population. In the prognosis population, 456 cardiac deaths occurred during follow-up. When the conversion algorithm was applied, extent and severity of perfusion defects were nearly identical by 20- and derived 17-segment scores. The receiver operating characteristic curve areas by 20- and 17-segment perfusion scores were identical for predicting cardiac death (both 0.77 +/- 0.02, P = not significant). The optimal prognostic cutoff value for either 20- or derived 17-segment models was confirmed to be 5% myocardium abnormal, corresponding to a summed stress score greater than 3. Of note, the 17-segment model demonstrated a trend toward fewer mildly abnormal scans and more normal and severely abnormal scans. CONCLUSION: An algorithm for conversion of 20-segment perfusion scores to 17-segment scores has been developed that is highly concordant with expert visual analysis by the 17-segment model and provides nearly identical prognostic information. This conversion model may provide a mechanism for comparison of studies analyzed by the 17-segment system with previous studies analyzed by the 20-segment approach.

Aged↗

PubMed2001

Parametric oesophageal multiple swallow scintigraphy for validation of dysphageal symptoms during external beam irradiation of mediastinal tumours.

The aim of the study was to evaluate dysphageal symptoms and to measure the effect of local analgesic treatment using parametric oesophageal multiple swallow scintigraphy (PES) during external beam irradiation of the mediastinal region. Fifteen patients (most with lung cancer) with dysphagia grade II underwent PES during external beam radiotherapy of the mediastinum before and after application of local analgesics. Dynamic parametric condensed images were recorded. The intensity of clinical symptoms was correlated with the emptying rate at 10 s (ER-10 s) and the mean transit time (MTT). Visual analysis of the images was performed and the results were correlated with the fields of irradiation portals. Of the 15 patients, 12 showed a correlation between irradiation portals and the region of oesophageal motility disorder. Concordant results of clinical symptoms and PES data were found. In nine patients with a decrease in dysphagia following local analgesia, an increase in mean ER-10 s and a decrease in MTT were observed. In three patients with deterioration in clinical symptoms after analgesic treatment, a similar decrease in mean ER-10 s was found, though MTT remained constant. In three patients with normal values, motility disorders were detected in the dynamic study. In conclusion, PES was found to be a sensitive tool for the validation of dysphageal symptoms in patients during external beam irradiation of mediastinal tumours and for the evaluation and quantification of the efficacy of local analgesic treatment. Additional visual analysis of the dynamic study is helpful in diagnosing minimal disorders.

Adult↗

PubMed1996

Clinical significance of increased uptake of HMPAO on brain SPECT scans in acute stroke.

Single-photon emission computed tomography (SPECT) with 99mtechnetium-hexamethylpropylamineoxime (HMPAO) noninvasively shows brain perfusion in patients after acute stroke. However, the clinical significance of the increased HMPAO uptake remains unclear. In this study, consecutive patients with hemispheric hemorrhagic and ischemic stroke admitted to the hospital were evaluated prospectively. The increased uptake of HMPAO was determined by visual analysis of SPECT images. The pathogenic mechanism of ischemic stroke was determined using the clinical and computed tomography (CT) criteria including the Toronto Embolic Scale. Of the 500 consecutive patients with acute hemispheric stroke, SPECT was performed in 458 at a mean time 5 +/- 7 days after the onset of symptoms. A strong association was found between SPECT perfusion patterns and pathogenic subtypes of stroke (p < 0.0001). Thus, in 95% of patients with intracerebral hemorrhage the focal absence of perfusion was found, and 26% of lacunar infarctions presented with a normal SPECT appearance. The mean volume of lacunar lesions that did not produce significant abnormalities on SPECT was 2.5 +/- 1.2 ml. Increased HMPAO uptake was associated with a cardioembolic mechanism of stroke: High and mixed perfusion patterns were present subacutely in 29% of patients with cardioembolic stroke, compared to 15% of patients with other types of ischemic stroke (p < or = 0.0006). The increased uptake of HMPAO on SPECT as determined by visual analysis is associated with a cardioembolic mechanism of cerebral ischemia, which could be explained by glutathione-mediated trapping of the tracer during reperfusion and later in newly developed granulation tissue. HMPAO-SPECT may help in early management decisions since it indicates stroke pathogenesis and evolution.

Acute Disease↗

PubMed1993

Evaluation of myocardial perfusion defects by means of "bull's eye" images.

The purpose of this study was to evaluate the usefulness of so-called "bull's eye" imaging as a simplified display of tomographic slices in the detection of coronary artery disease (CAD). A total of 64 patients were studied at stress and at rest, by single photon emission computed tomography (SPECT), either with thallium-201 (201Tl) or with technetium-99m methoxy-isobutyl-isonitril (Tc-MIBI). The myocardial perfusion defects detected by bull's eye image alone and in combination with visual analysis of tomographic images were evaluated in all cases, taking coronary arteriographic results as a gold standard. The overall sensitivity and specificity for detection of CAD were as follows: bull's eye imaging, 100% and 70.8%; tomographic imaging (SPECT), 90% and 91.6%. The results of bull's eye imaging and SPECT interpreted together were 96.6% and 83.3%. The regional sensitivity and specificity of bull's eye for individual coronary arteries were: right coronary artery (RCA), 100% and 73.7%; left anterior descending (LAD), 100% and 87.2%; left circumflex (LCx), 100% and 97.3%. For SPECT they were: RCA, 93.7% and 89.5%; LAD, 86.6% and 92.3%; LCx, 73.3% and 97.4%. For bull's eye with SPECT they were: RCA, 94.4% and 86.1%; LAD, 87.5% and 92.1%; LCx, 82.3% and 97.2%. We conclude that the bull's eye image display allows an easier and more objective assessment of myocardial perfusion defects and shows higher sensitivity. However, it has a relatively low specificity which can cause an overestimation of perfusion defects. Thus, visual analysis of bull's eye imaging is a useful diagnostic tool but must be evaluated in conjunction with tomographic imaging.

Adult↗