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PubMedDate not supplied

[Role of high resolution color-Doppler US of the sentinel node in patients with stage I melanoma].

PURPOSE: The aims of the present work are to assess the diagnostic accuracy of high resolution color Doppler ultrasound (US) of the sentinel node (SN) in patients with cutaneous melanoma skin at stage I. The US findings of nodal involvement could spare the patient a surgical step (selective lymphaderectomy) allowing them to undergo radical lymphadenectomy directly. MATERIAL AND METHODS: From November 1998 to November 2000 94 patients (mean age 52.7 years) underwent lymphoscintigraphy in order to mark the SN site on their skin. An US scan (112 lymphatic basins) was performed within 24 hours with a 10-13 MHz electronic linear probe with color-power-Doppler (Esaote AU5 Idea Scanner, Genoa, Italy). The sonographic features we analysed were: shape (roundness index), hilum displacement, intranodal heterogenicity, eccentric cortical thickness, extranodal invasion, vessel irregularity. RESULTS: 26 nodes showed US findings consistent with malignant involvement, 86 were negative. All the nodes were surgically removed and controlled by histology. Sensitivity and specificity of US scanning were 89.4% and 90.3%, the positive and negative predictive values 65.3% and 97.6%, respectively. US correctly identified the involved SN in 15,1% cases, so that 17 patients could have avoided the selective lymphadenectomy CONCLUSION: Preoperative lymphoscintigraphy and high-resolution color-Doppler US scanning constitute a useful diagnostic tool in identifying the metastatic SN, with a low margin of error. False negatives were technically induced, even using the more recent scanners, by the low US probe resolution, unable to recognise metastatic microdeposits. The two most reliable parameters in identifying involved lymphnodes were the roundness index and the absence of hilar echo. The advent of technologically more advanced probes should allow better spatial resolution and assessment of lymph node vascularization, enabling diagnosis of metastasis measuring less than 2 mm in diameter.

Adolescent↗

PubMed1975

Spatial resolution of thermographic cameras.

To obtain an impression of the spatial resolution of a number of thermographic cameras, a method similar to that of DODD et al. [1969] was followed: a test pattern with a series of line groups was scanned and the relative amplitude of the videosignal was plotted as a function of the spatial frequency (MTF). To make it possible to compare the various cameras directly, the spatial frequency was expressed in radians-1 and not in lines per millimeter, which makes the result less dependent on the distance. For one of the cameras, the MTF was also measured densitometrically, which yielded a lower value of spatial resolution. In practice this is of minor importance, because temperature differences are measured directly with the videosignal (isotherm mode) and not by density measurements. In contrast to Macey and Oliver [1972] who assumed that the resolution is determined by the time constant of the detector only, the resolution of the cameras investigated in our laboratory depended only on the dimensions of the detector.

Electronics↗

PubMed2002

[Indigo carmine contrast staining in combination with high resolution electronic endoscopy].

INTRODUCTION: Chromoendoscopy is an old endoscopic technique which has a renascence in the era of high resolution electronic endoscopy. Indigo carmine, this deep blue stain is not absorbed by gastrointestinal epithelium. It pools in crevices and valleys and highlights small lesions and defines irregularities in mucosal architecture. METHOD: The indigo carmine dye contrast method was introduced in author's endoscopic laboratory in 1994 and high resolution (400 k.pixels) endoscopy in 1997. 0.1-0.5% indigo carmine solution was administered to the gastric, duodenal or colonic mucosa through the biopsy channel of the endoscope. The author found the dye method gave dramatic accentuation of abnormalities of mucosal architecture (i.e. small irregularities, ulcer scars, extent of small tumours, polyps) and was suitable to evaluate villous atrophy in the duodenum. RESULTS: Using indigo carmine and high resolution electronic endoscopy it was possible to diagnose 3 times more gastric adenomas than was in the past. In the colon it was studied the surface appearance of colonic crypts and was able to discriminate between hyperplastic polyps which had a tipical "pit" pattern ("dots") and adenomatous polyps, which had a "groove" or "sulci" pattern. After histological examination the diagnostic accuracy was proved 59/64 in adenomatous and 18/23 in hyperplastic polyps. CONCLUSION: One should improve minute endoscopical observation and it is believed the administration of indigo carmine dye and high resolution endoscopy are suitable method for that.

Adult↗

PubMed2002

High-resolution line scan diffusion tensor MR imaging of white matter fiber tract anatomy.

BACKGROUND AND PURPOSE: MR diffusion tensor imaging permits detailed visualization of white matter fiber tracts. This technique, unlike T2-weighted imaging, also provides information about fiber direction. We present findings of normal white matter fiber tract anatomy at high resolution obtained by using line scan diffusion tensor imaging. METHODS: Diffusion tensor images in axial, coronal, and sagittal sections covering the entire brain volume were obtained with line scan diffusion imaging in six healthy volunteers. Images were acquired for b factors 5 and 1000 s/mm(2) at an imaging resolution of 1.7 x 1.7 x 4 mm. For selected regions, images were obtained at a reduced field of view with a spatial resolution of 0.9 x 0.9 x 3 mm. For each pixel, the direction of maximum diffusivity was computed and used to display the course of white matter fibers. RESULTS: Fiber directions derived from diffusion tensor imaging were consistent with known white matter fiber anatomy. The principal fiber tracts were well observed in all cases. The tracts that were visualized included the following: the arcuate fasciculus; superior and inferior longitudinal fasciculus; uncinate fasciculus; cingulum; external and extreme capsule; internal capsule; corona radiata; auditory and optic radiation; anterior commissure; corpus callosum; pyramidal tract; gracile and cuneatus fasciculus; medial longitudinal fasciculus; rubrospinal, tectospinal, central tegmental, and dorsal trigeminothalamic tract; superior, inferior, and middle cerebellar peduncle; pallidonigral and strionigral fibers; and root fibers of the oculomotor and trigeminal nerve. CONCLUSION: We obtained a complete set of detailed white matter fiber anatomy maps of the normal brain by means of line scan diffusion tensor imaging at high resolution. Near large bone structures, line scan produces images with minimal susceptibility artifacts.

Adult↗

PubMed1975

Analytical study of a high-resolution positron ring detector system for transaxial reconstruction tomography.

This paper presents an analytical study of a high-resolution positron ring detector system for transaxial reconstruction tomography. Our goal is a combination of good spatial resolution, high sensitivity, rejection of scattered photons, variable section thickness, and the minimization of the number of photomultipliers and coincidence circuits. A circular ring of 288 NaI(Tl) crystals 0.8 cm wide should provide a resolution of 4--7 mm FWHM over a circular region 30 cm in diameter. Coded light pipes permit readout using only 72 photomultipliers and 12 coincidence circuits. With properly designed shielding and an energy resolution of 30% FWHM, a positron activity of 200 muCi per axial centimeter in a 20-cm-diam cylinder of tissue should provide approximately 7,000 events/sex from a 2-cm-thick transaxial section (including a 5% accidental coincident background and a 26% scattered coincident background). This rate is adequate for both static and dynamic imaging. The device can operate at two to three times higher event rates with increased backgrounds.

Elementary Particles↗

PubMed2002

Magnetic Resonance Imaging of the anal canal using high resolution sequences and phased array coil: visualization of anal sphincter complex.

PURPOSE: To assess the normal anatomy of the anal sphincter complex using high-resolution MR imaging with phased -array coil. MATERIAL AND METHODS: Twenty patients, 13 males and 7 females, ranging in age between 27 and 56 years underwent MRI evaluation of the pelvic region, using a superconductive 1.5 T magnet (maximum gradient strength, 25 mT/m; minimum rise time 600 microseconds, equipped with phased-array coil. High-resolution T2-weighted Turbo Spin Echo sequences (TR, 4055 ms; TE, 132 ms; matrix 390x512; in-plane resolution, 0.67x0.57 mm) were acquired on multiple axial, sagittal and coronal planes. Images were reviewed by two experienced gastrointestinal radiologists in order to evaluate the normal anal sphincter complex. RESULTS: Optimal image quality of the anal sphincter complex was obtained in all cases. Different muscular layers were observed between the upper and lower aspects of the anal canal. In the lower part of the anal canal, internal and external sphincter muscles could be observed; in the upper part, puborectal and internal sphincter muscles were depicted. Good visualization of intersphincteric space, levator ani muscle and ischioanal space was also obtained in all cases. CONCLUSIONS: High-resolution MR images with phased-array coil provide optimal depiction of the anal canal and the anal sphincter complex.

Adult↗

PubMed2002

[High-resolution computer tomography in cystic fibrosis].

BACKGROUND: Worsening lung disease is the most important factor concerning quality of life and survival rate in the approximately 250 patients with cystic fibrosis in Norway. Pulmonary high-resolution CT has been advocated as a precise diagnostic method, that offers the opportunity to detect slight disease progression. MATERIAL AND METHODS: We examined 21 patients (age 6-34) with high-resolution CT. The findings were scored using a modified Bhalla method, where score 0 is normal and score 27 reflects a maximal degree of e.g. bronchiectasis and mucous plugging. RESULTS: Mean high-resolution CT score was 8.0 (range 0-22). Bronchiectasis was found in 17 out of 21 patients, peribronchial wall thickening in 15 patients and mucous plugging in 14 patients. The Bhalla score showed a close correlation with forced expiratory volume in one second (r = -0.844, p < 0.01). INTERPRETATION: High-resolution CT characterises very well the lung pathology in patients with cystic fibrosis. The degree of pathology assessed with a modified Bhalla score correlates well with forced expiratory volume in one second.

Adult↗

PubMed1988

Resolution No. 863, 1 December 1988.

This Resolution stipulates that the marriage advance provided for in Iraq Resolution Number 1517 of 12 November 1979 will be granted to persons who remarry a widow, as of the date this Resolution comes into force (not fixed in the Resolution).

Asia↗

PubMed2002

[Rapid spontaneous resolution of acute subdural hematoma].

Acute subdural hematomas are usually neurosurgical emergencies, although a conservative therapy is indicated in selected cases. In some of these patients a progressive resolution is appreciated. However, rapid spontaneous resolution of an acute suddural hematoma is seldom reported. A patient with antecedent of chronic alcoholism and spontaneous resolution of acute subdural hematoma in less than 18 hours after the head injury is described. The possible mechanisms of this rapid resolution are discussed. A tear in the arachnoid with spilling of CSF into the subdural space and the effect of intracranial antihypertensive measures together with cerebral atrophy, are factors that possibly contribute to dilution and redistribution of blood with hematoma disappearing in CT scan.

Atrophy↗

PubMed2001

[Resolution of overlapping chromatographic peaks by radial basis function neural network].

A new algorithm-resolution of overlapping chromatographic peaks by radial basis function neural network(RBFNN) is presented. A two-phase genetic algorithm(GA) which has robustness and random globe optimization is used to train RBFNN so that it has the ability on the resolution of overlapping chromatographic peaks. The two-phase genetic algorithm involves two procedures: training structure and optimizing parameter. The first procedure uses GA to train the architectures of RBFNN, the second procedure uses gradient descent to train the center(tR) and the width(sigma) of RBFNN. The alternate use of these two procedures makes the network having the ability to learn structure, therefore makes itself adaptable to resolution of the chromatographic peaks with unknown number of components. The method proposed here needs no artificial interference, not only has it robustness and globalism, but also the ability of accurate resolution to completely overlapped chromatographic peaks. The simulation experiments show that this method is more accurate than other methods.

Algorithms↗

PubMed2001

[The effect of temperature on the enantiomeric resolutions on albumin and beta-cyclodextrin chiral stationary phases].

The effect of column temperature on enantiomeric resolutions of tryptophan, warfarin and ketoprofen was investigated on bovine and human serum albumin (BSA and HSA) stationary phases, which were synthesized with s-triazine as the activator. It was observed that the entropy change made a great contribution to the separation of those enantiomers on albumin chiral stationary phases. The column temperature for the maximal resolution of tryptophan on the BSA stationary phase prepared by this method was about 35 degrees C, which was not 24 degrees C as reported for the BSA stationary phase synthesized with glutaric dialdehyde as the activator. This results may come from the different conformation of the immobilized BSA and HSA due to the different coupling methods used. On the other hand, it was indicated that the resolution of enantiomers on beta-CD chiral stationary phase was mainly contributed from the change of enthalpy, which means the resolution of chiral solutes on albumin and beta-CD stationary phases has different thermodynamic behaviors.

Chromatography↗

PubMed2002

Ex vivo high-resolution magnetic resonance imaging of the brain in Joubert's syndrome.

This study employs ex vivo high-resolution magnetic resonance imaging (MRI) to examine anatomic structures in an intact brain of a child with Joubert's syndrome. Several of the specific hindbrain malformations associated with Joubert's syndrome are well resolved with ex vivo MRI, including the "molar tooth sign," which arises from enlarged and maloriented superior cerebellar peduncles, hypoplastic vermis, and deepening of the interpeduncular fossa. Superior resolution was achieved compared with that of in vivo MRI and included visualization of the inferior olives. One high-resolution study also showed that the decreased width of the brainstem isthmus is probably caused by failure of superior cerebellar peduncles to cross the midline at that level. The results of this study suggest that high-resolution MRI may be useful in screening the brainstem for malformations that can be studied histologically in a much more targeted fashion.

Child, Preschool↗

PubMed2001

Factors associated with the resolution of postoperative ileus in newborn infants.

Reliable indicators of ileus resolution following laparotomy have not been identified in newborn infants. The purpose of this study was to correlate commonly available clinical parameters with the resolution of postoperative ileus in newborn infants after abdominal procedures. The presentation, treatment, and postoperative abdominal examination of 60 consecutive newborn infants who underwent a heterogeneous group of primary abdominal operations were evaluated. No significant association was observed between the time to first bowel movement (resolution of ileus) and age, postconceptual age, weight, degree of intraabdominal contamination, duration of surgery, type of operative procedure, presence or absence of abdominal distension, and time to first bowel sounds. Opioid use was associated with a delay in the time to first bowel movement that was not accounted for by the effects of any other variable. Easily obtainable clinical parameters are not universally useful for predicting the duration of ileus in newborn infants after abdominal surgery. The use of opioids is associated with delayed resolution of ileus. Measures to limit the use of opioids may be effective in shortening the duration of postoperative ileus in newborn infants.

Abdomen↗

PubMed2003

Cervical dentin hypersensitivity. Part III: resolution following occlusal equilibration.

OBJECTIVE: This retrospective study was designed to investigate changes of cervical dentin hypersensitivity (CDH) in response to occlusal equilibration. METHOD AND MATERIALS: Written records for 250 active-care patients were randomly selected and analyzed for associations between CDH, and its resolution following occlusal equilibration. Patients in group A (treatment) and B (delayed treatment) received occlusal equilibration following the detection of verified CDH using the air indexing method. Group C patients were not detected with verified CDH during the study period of 17 years. The resolution of CDH was measured by the loss of a positive patient threshold response to air stimulation. RESULTS: Significant associations existed between CDH, hyperfunction, parafunction, and abfractive lesions. Furthermore, it was found that occlusal equilibration resulted in the long-term resolution of CDH. CONCLUSIONS: The resolution of CDH by occlusal equilibration, thus negating the null hypothesis, suggests that further studies are indicated to evaluate the impact of these findings upon restoring and maintaining health of the masticatory system.

Adult↗

PubMed2001

Monitoring Resolution of Postconcussion Symptoms in Athletes: Preliminary Results of a Web-Based Neuropsychological Test Protocol.

OBJECTIVE: A new Web-based neuropsychological test was field tested to determine usefulness in detecting and monitoring resolution of symptoms after sport-related concussions and in providing objective information for return-to-play decisions. DESIGN AND SETTING: We obtained neuropsychological baseline data on all subjects. After concussion, subjects were administered alternate, equivalent follow-up tests until symptoms resolved. Follow-up testing typically occurred at 1- to 2-day intervals after the concussion. SUBJECTS: Baseline testing was obtained for 834 athletes as part of ongoing field trials. Subsequently, 26 athletes sustained concussions and were studied. MEASUREMENTS: We administered The Concussion Resolution Index (CRI) at baseline and alternate forms posttrauma. Follow-up tests included a self-report inventory of neurophysiologic symptoms. RESULTS: A total of 88% of patients were identified as symptomatic on initial postconcussion testing. The CRI appeared relatively resistant to retest effects, and multiple administrations tracked resolution of symptoms over short and extended time periods. CONCLUSIONS: Although the CRI is still in field trials, preliminary data indicate that the CRI may be a useful method for athletic trainers and other professionals to expeditiously track resolution of symptoms after sport-related concussion.

Journal Article↗

PubMed1992

[Paroxysmal atrial fibrillation in patients with chronic ischemic cardiopathy: a study of high-resolution atrial activation].

BACKGROUND: Patients with ischemic heart disease and episodes of paroxysmal atrial fibrillation are at major risk of stroke. In order to prevent such episodes, through the identification of patients prone to atrial fibrillation, we investigated the high-resolution atriogram of 65 patients with chronic ischemic heart disease, 54 male and 11 female, mean age 60.22 +/- 9.04 years. Based on previous documented episodes of atrial fibrillation, the patients were divided into two groups: group A, 45 males and 3 females, mean age 58.92 +/- 7.68 years, without atrial fibrillation; group B, 9 males and 8 females, mean age 63.88 +/- 11.6 years, with atrial fibrillation. RESULTS: High resolution atrial duration (100-300 Hz) in group B (with atrial fibrillation) was higher than in group A (without atrial fibrillation) (140.59 +/- 16.85 ms vs 121.77 +/- 11.27 ms, p < 0.001); Non filtered atrial duration (0-300 Hz) was not different between the two groups, A and B (118.54 +/- 10.96 ms vs 123.53 +/- 18.77 ms, p = NS); The prevalence of late atrial potentials was higher in group B than in group A (60.8% vs 7.1%, p < 0.001); No relation was observed between high resolution atriogram data and echocardiographic measurements; Sensibility was 82%, specificity 81%, and predictivity 60%. CONCLUSIONS: Data from our study show that high resolution electrocardiography is a valid tool for identifying patients prone to atrial fibrillation. Such patients can be identified by the presence of "late atrial potentials" that, like late ventricular potentials for ventricular tachycardia, are correlated with atrial fibrillation. Nevertheless, a larger cohort of patients is necessary to confirm these results.

Aged↗

PubMed1992

High-resolution cardiac SPET study using fanbeam collimators in infants.

High-resolution three-headed single photon emission computed tomography (SPET) equipped with fan-beam collimators was applied to myocardial perfusion imaging in infants aged from 1 to 11 months (n = 5). A tabletop designed specifically for infants was fixed on the SPET couch to reduce the radius of camera rotation to 13.2 cm. Significant improvement in resolution was achieved with the fan-beam collimators compared to parallel-hole high-resolution collimators. With the administration of approximately 37 MBq (26-44 MBq) 201Tl, 5 min acquisition time was possible for SPET imaging, which provided good image quality in all patients. Thus, a smaller administration dose is possible within a practical short acquisition time. High-resolution fan-beam SPET imaging can be a routine diagnostic method for heart disease in newborn babies and infants.

Female↗

PubMed2004

Altitude decompression sickness symptom resolution during descent to ground level.

INTRODUCTION: Altitude decompression sickness (DCS) is a health risk associated with the conduct of high altitude airdrop operations, high altitude reconnaissance, future fighter operations, hypobaric chamber training, unpressurized flight, and extravehicular activity (EVA) in space. The treatment for DCS includes the provision of 100% oxygen (O2) at ground level (GLO) and/or hyperbaric oxygen therapy (HBO). In this paper we examine the effect of repressurization to ground level from hypobaric conditions on DCS symptoms. Timely recompression (descent at first recognition of any DCS symptom) may be a safe, effective treatment for the large majority of DCS symptoms. METHODS: Data from altitude chamber exposures recorded in the Air Force Research Laboratory (AFRL) Altitude DCS Database were reviewed to determine the level of recompression required for complete resolution of 1,699 observed symptoms. RESULTS: Of the 1,699 DCS symptoms reviewed, 66 (3.9%) resolved at altitude, 117 (6.9%) resolved at ground level, and 1,433 (84.3%) resolved during descent. Increasing the pressure by 138 mmHg from the altitude of exposure where symptoms occurred resolved roughly 50% of symptoms. Little resolution of symptoms was noted with recompressions of < 50 mmHg. The greatest rate of symptom resolution occurred with recompressions of 50-250 mmHg. CONCLUSION: These findings support the concept that descent and postflight, ground-level oxygen may be sufficient to relieve the majority of altitude DCS symptoms. HBO may be reserved for serious, recurring, delayed, or refractory symptoms. The findings also suggest a need for further study of DCS symptom resolution.

Aerospace Medicine↗