[Design principles, structure, and specific features of kardiovid computer diagnostic system].

The design principles and hardware implementation of Kardiovid computer diagnostic system are considered. The system is intended for diagnosis of the state of cardiovascular system on the basis of the results of electrocardiographic and fluorographic examinations. It provides simulation and visualization of the state of cardiovascular system.

Comparison of a digital flat-panel versus screen-film, photofluorography and storage-phosphor systems by detection of simulated lung adenocarcinoma lesions using hard copy images.

The purpose of this study was to compare hard copy images from a flat-panel detector digital radiography system with conventional radiography, photofluorographic radiography and storage phosphor radiography for the detection of simulated lung adenocarcinoma lesions and also for radiation dose. To test the diagnostic performance of these four systems, the authors used 15 types of lung adenocarcinoma phantom according to Noguchi's classification and an anthropomorphic chest phantom. The visual evaluation of tumour detectability by four radiologists and two general thoracic surgeons was examined with a five-level confidence scale. Lung doses were measured with glass dosemeters for the chest radiology systems under the conditions used by each hospital and centre. Our results indicated that flat-panel detector digital radiography and storage phosphor radiography are not necessarily superior to conventional radiography and photofluorographic radiography for detecting lung adenocarcinomas when only hard copy images are used, and this suggests a need to carefully optimize chest radiography.

[Digital videofluorography and esophageal achalasia: from diagnosis to follow-up]. / Videofluorografia digitale e acalasia esofagea: dalla diagnosi al follow-up postoperatorio.

The aim of this retrospective study was to evaluate the use of digital videofluorography in the preoperative and postoperative management of esophageal achalasia surgical treatment. From 1990 to 2004, 25 patients with achalasia, diagnosed by digital videofluorography and confirmed by motility studies and endoscopy, underwent surgery. All patients underwent digital videofluorography at 1, 6 and 12 months in order to evaluate the completeness of the myotomy and the efficacy of the antireflux procedures. At postoperative videofluorography esophageal transit time was decreased in all patients (100%); esophageal motor activity was unchanged in 23 (92%), and modified in two patients (8%) with onset of peristaltic-like motor activity; 8 patients (35%) presented decreased preoperative dilatation; all patients had a WST negative for post-myotomy reflux. On the basis of our experience and the advantages of the procedure we suggest videofluorography as a first-approach diagnostic examination useful for surgical indications and postoperative follow-up in achalasic patients.

[On the X-ray acquisition parameters in AXIOM artis].

This article analyzes mainly the X-ray imaging acquisition parameters in AXIOM Artis X-ray equipment, the relationship between the parameters, and how to select acquisition parameters in cardioangiography. We have sought a set of X-ray imaging acquisition parameters for producing optimal image in cardioangiography.

[Information technologies for scanning X-ray radiography].

Digital technologies have been widely used in X-rays diagnostics, including computer tomography, magnetic-resonance tomography, digital radiography etc. Digital technologies for image analysis essentially change all arrangements and procedures of preventive examinations made at patient-care facilities. As for digital fluorography, the basic principles of fluorography diagnostic room are standard but for one arrangement-the unit is controlled via a computer-assisted working place (CAWP) by the radiologist assistant; the room of radiologist is also equipped with CAWP. Admittedly, a key issue in general fluorographic examinations is registration of patients and preparation of them for the procedure. Contemplated in the paper are new potentialities of digital fluorography of big number of patients by low-dose fluorography (LDF, equipment manufacturer/Orel, Russia) which enhance the rate and quality of diagnostics.

[Experience in using a mobile digital fluorograph-equipped laboratory].

The authors share their experience in using a KFP-FC-RP digital fluorograph for mass fluorographic studies in a mobile fluorographic laboratory (on the basis of a ZIL-5301 EO automobile with a module body and an APCF-01 (ProScan-2000) fluograph made by ZAO "RENTGENPROM"). Studies were performed at the enterprises of Moscow and the Moscow Region. How the work of the mobile laboratory is organized is described. Since the able-bodied population was chiefly surveyed, the efficiency of the work can be considered rather high. The experience has shown that the use of a mobile fluorographic laboratory for mass examinations at the enterprises by a health care facility is much more effective and profitable than that of a permanent laboratory.

Display of epicardial ischemia by reduced nicotamide adenine dinucleotide fluorescence photography, electron microscopy, and ST segment mapping.

Reduced nicotinamide adenine dinucleotide (NADH) fluorescence photography, a technique of assessing myocardial ischemia, was correlated with ischemia as identified by ST segment mapping and electron microscopy (EM) in 25 Langdneorff perfused rabbit hearts following coronary occlusion. Nicotinamide adenine dinucleotide (NAD), a component of the intramitochondrial electron transport chain, becomes reduced during periods of ischemia (NADH). NADH fluoresces when excited by ultraviolet light. NAD does not. All three techniques were compared to assess their resolution of the "border zone" between ischemia and nonischemic myocardium. The border zone defined by NADH fluorescence is 0.1 mm or less. Areas of high NADH fluorescence invariably revealed ST segment elevation, whereas minimally fluorescent areas did not. St segment mapping yields a border zone of approximately 7 mm. Areas of high NADH fluorescence following 1 hour of ischemia displayed severe damage on EM as compared to matched controls. A zone of intermediate ultrastructural damage is identified in a 1 mm biopsy taken between fluorescent and nonfluorescent myocardium. This evidence confirms epicardial NADH fluorescence photography as an assay of myocardial ischemia. This high resolution technique delineates a border zone of narrow dimensions as compared with ST segment mapping.

Performance characteristics of a real-time digital x-ray fluoroscopic system using an intensified charge injection device camera and CsI:Na crystal.

A digital x-ray photoelectronic imaging system has been constructed using an optically flat 152-mm-diam, 2.5-mm-thick CsI:Na scintillating crystal. X-ray images formed by the scintillator are viewed by a single microchannel plate intensified charge injection device (ICID) camera and digitized at a real-time rate by a computerized frame-grabbing system. Video images are recorded and selected image frames are subjected to image processing and analysis schemes. Parameters governing the performance characteristics of the system are determined accordingly. For a 152-mm field size at the crystal plane, a spatial resolution limit of 1.50 +/- 0.10 1p/mm (1 sigma) measured at the 4% level of the modulation transfer function of the system has been obtained. This result is consistent with the measurements of the full width at half-maximum of the line spread function which is found to be 645 +/- 35 microns (1 sigma). Similarly, the intrinsic resolution of the CsI:Na scintillator only was found to be 6.5 +/- 0.5 1p/mm (1 sigma). Contrast ratio measurements, which are mainly determined by the quality of phosphor, have indicated a value of 12.1 +/- 0.6, whereas minimum visible details are observed at radiation exposure rates of 100 microR/s. This limit has been reduced to 10 microR/s using the single-scan integrating option provided by the ICID camera. A maximum contrast resolution of 1% corresponding to 100 statistically significant meaningful gray levels is achieved at a maximum exposure rate of 1000 microR/s. Consequently, although the imaging capability of the present system compares favorably with that of conventional x-ray video-fluoroscopic systems, a better performance may be achieved by using a higher resolution cooled dual-microchannel intensified CID camera in conjunction with a thinner CsI:Na crystal and a real-time digital image processing subsystem.

Videofluorography: the role of temporal averaging.

Videofluorography is the technique of obtaining radiographic images by photographing with a multiformat camera the television images produced during x-ray image intensified fluoroscopy. This technique of producing images has received considerable clinical use, but the radiation exposure used has been in doubt. Experiments were performed to evaluate this radiation exposure. It was found that the imaging chain was reducing mottle by temporal integration. These results were tested by comparing the image quality of videofluorographs with that of photofluorographs . The blurring effect of motion on images was also evaluated as this is a factor which must be balanced against the improvement of mottle due to temporal integration. It was found that exposures used for videofluorography were of the order of 10 microR (2.58 X 10(-9) C kg-1) to the input of the x-ray image intensifier.

Tongue-jaw linkages in human feeding: a preliminary videofluorographic study.

Motions of the tongue and jaw are closely coupled during feeding in mammals, but this relation has not been studied in humans. A videofluorographic method for measuring tongue movement relative to jaw motion using small radiopaque markers affixed to the tongue with dental adhesive was developed and tested in five individuals. Sagittal movements of the anterior tongue marker (ATM) and the lower jaw were measured for complete feeding sequences with a computerized image-analysis system. The ATM and jaw moved in loosely linked, semirhythmic cycles. Vertical and horizontal maxima of ATM motion were determined for each motion cycle in relation to maximum and minimum gape (greatest jaw opening and closing, respectively). The amplitude of tongue movements and their timing differed between hard and soft foods (p < 0.001). For both food types, motions varied as the feeding sequence progressed from ingestion to terminal swallow (p < 0.001). A basic temporal sequence was found in 70% of the 224 cycles analysed. On average, the ATM reached its most inferior position just after maximum gape, its most posterior during jaw closing, its most superior just after minimum gape, and its most anterior during jaw opening (p < 0.001). This study confirms that tongue and jaw movements are linked during human feeding, as they are in other mammals.

[Reduction of the radiation exposure in photofluorography by using rare earth-based fluorescent screens]. / Verminderung der Strahlenexposition bei Schirmbildaufnahmen durch den Einsatz von Leuchtschirmen auf der Basis der Seltenen Erden.

The use of highly sensitive fluorescent screens based on gadolinium in photofluorography results in considerable reduction of radiation exposure compared with conventional screens. The exposure to radiation can be reduced to a value which is hardly higher than that of a large format image. The image quality is enhanced by the incorporation of new screens because of shorter exposure times. Gadolinium foils with high image amplification are already available on a commercial basis. Exchanging them in photofluorograph equipment presents no problem.

[Image quality in medium format film technique (fluorography) (author's transl)]. / Bildgüte bei der Mittelformat-Aufnahmetechnik (Fluorographie).

The paper deals with image quality of films using a medium format type film and fluorography. Contrast transmission function is achieved by special calcium tungstate screens. In practice, image quality equals that of full size films with universal screens. By increasing lens size it is possible to reduce the necessary x-ray dose without losing image quality.

Nasendoscopy: significant refinements of a direct-viewing technique of the velopharyngeal sphincter.

The need for a three-dimensional record of velopharyngeal sphincter function in patients with craniofacial anomalies and speech problems is discussed. A refined split-screen video technique using color nasendoscope image, lateral video-fluoroscopy, and synchronous speech recording with the patient awake and in supine position is described. A special signal processor is used to position the color nasendoscopy image. The examination is recorded on 1-in. videotape. The technique allows three-dimensional appraisal of sphincter function with direct viewing and enables assessment of a range of abnormalities, assessment of the effectiveness of pharyngoplasties, and prediction of speech deformities and their management following midface craniofacial surgery.

An analysis of studies comparing electrical impedance tomography with x-ray videofluoroscopy in the assessment of swallowing.

Electrical impedance tomography can be used to record the conductivity change occurring in the neck during a swallow. X-ray videofluoroscopy provides excellent anatomical detail of the structures involved in swallowing and of the position of the swallowed bolus. The two techniques have been performed simultaneously on seven patients with swallowing problems to establish what produces the peak change in conductivity when a solution of low conductivity is swallowed. The results suggest that the exclusion of air from the larynx and pharynx is the major factor influencing the change in conductivity when a solution of low conductivity is swallowed.

Double contrast cervical esophagography: use of a specially designed cup to aid double-contrast cervical esophagography.

We designed a cup to aid double-contrast cervical esophagography using photo fluorography and an image intensifier. The cup allows an adequate amount of air to be delivered with the contrast media so that the cervical esophageal lumen expands to give an ideal double contrast image. The clear image is obtained, having to calculate exact timing. The timing sequence we used during the serial radiography was 4 seconds at 2 radiographs per second while the patient continually swallowed the contrast medium and air.

[Experience in the use of gastrofluorography in the Byelorussian SSR]. / Opyt primeneniia gastrofliuorografii v BSSR.

The paper discusses the major stages of long-term studies of the effectiveness of application of gastrofluorography for detection of cancer and precancerous lesions in the stomach conducted during mass screenings in the Byelorussian SSR. The test results for the first Soviet-made on-site gastrofluorographic installation are presented. Successful applications of the installation for both screening and primary detection of the lesions are discussed.

[Effect of x-ray hardness on the informativeness of fluorograms]. / O vliianii zhestkosti rentgenovskogo izlucheniia na informativnost' fliuorogramm.

The power unit model URP-phi built on a single-phase generator supplied by a full-wave rectification circuitry along with an X-ray image intensifier model URI-230/150 enable the fluorography under radioscopy control. During X-ray examinations it automatically selects anode voltage of the X-ray tube depending on both the density of the subject under study and the examining angle. Specified in the URP-phi the anode voltage-current relationship provides higher X-ray intensity attenuation through the subject for anode current 3 mA compared to the current 1 mA, the detection of low contrast abnormalities being virtually the same for the fluorograms of the stepped phantoms.

[Use of low-dose digital fluorography in patients with acute infiltrative pulmonary processes]. / Ispol'zovanie malodoznoi tsifrovoi fliuorografii v obsledovanii bol'nykh s ostrymi infil'trativnymi protsessami v legkikh.

Basic purpose of issue was the attempt of a rating of a role and place modern digital chest fluorography in complex diagnostics of lower respiratory diseases accompanied acute pulmonary infiltrates. We studied 232 adults who hospitalized with community-acquired pneumonia (CAP) to Saratov Military Medical School Hospital during 1999-2003. In integration of methods of research the role digital chest fluorography as way of primary diagnostics and conducting means of the analysis of technology of rendering of medical aid is emphasized. At the expense of use of the developed algorithm of methods of beam visualization at the control of a course of stationary treatment of the patients CAP it was possible to decrease length of stay for 2.5 day.

Accuracy of a 3D fluoroscopic navigation system using a flat-panel detector-equipped C-arm.

OBJECTIVE: The aim of this study was to evaluate the accuracy of a novel 3-dimensional (3D) fluoroscopic navigation system using a flat-panel detector-equipped C-arm, focusing on the influence of the distance from the center of fluoroscopic imaging on navigation accuracy. MATERIALS AND METHODS: A geometric phantom was made using a Styrofoam cube with 25 markers, each consisting of a metal ball 1.5 mm in diameter, fixed in a cross arrangement at 1-cm intervals. Hip joint surgery was simulated using a set of dry pelvic and femoral bones. A total of eight markers were fixed to the acetabulum and proximal femur. RESULTS: In the geometric phantom study, mean target registration error (TRE) was 0.7 mm (range: 0.1-1.5). The TRE of markers located at 5 cm from the imaging center was significantly higher than the TRE of markers located at 1 and 2 cm. However, the TRE was <1 mm in 90% of the overall trials and <1.5 mm in 100%. In the dry bone study, the mean TRE was 0.9 mm (range: 0.7-1.5) over the acetabulum and 1.0 mm (range: 0.5-1.4) over the femur. No significant difference in TRE was seen between the acetabulum and proximal femur. CONCLUSION: The accuracy of this novel 3D fluoroscopic navigation system was considered acceptable for clinical application. A 3D C-arm equipped with a flat-panel detector could increase the feasibility of 3D fluoroscopic navigation by reducing the effects of image distortion on navigation accuracy.