Diagnostic Rooms Research Articles

A filter bank system for scattered spectrum analysis in collective Thomson scattering diagnostic on JT-60

In JT-60, a collective Thomson scattering (CTS) diagnostic system based on a pulsed CO2 laser (wavelength 10.6 μm, beam energy 15 J, pulse width 1 μs) has been developed to measure ion temperature and velocity distribution of fast ions to demonstrate the feasibility of measurements of confined alpha particles. A high power pulsed CO2 laser and heterodyne receiver system using a quantum-well infrared photodetector (QWIP) has been developed and installed in the diagnostic room. In order to resolve frequency distribution of pulsed scattered light (1 μs), we developed a wideband filter bank system (0.4–4.5 GHz) for scattered spectrum analysis in JT-60 CTS diagnostic. The detector bandwidth and frequency resolution are both determined by the calculation results of expected scattered spectrum. In order to realize wideband multichannel detection, cascade connected seventh order simultaneous-Chebyshev (elliptic) bandpass filters were adopted. Signal to noise ratio based on the noise equivalent power of the QWIP receiver and laser pulse length are also evaluated.

Computer-aided design and modeling of workstations and radiology reading rooms for the new millennium.

Three-dimensional (3D) computer modeling, simulation, and rendering techniques were used to redesign the diagnostic workstations and radiology reading rooms for a proposed hospital with particular attention given to lighting conditions, noise reduction, and optimal use of limited workspace. The results were presented to a panel of multidisciplinary experts and iteratively improved and redesigned with the development or addition of new design criteria or requirements. These 3D techniques allowed faster, more efficient design and presentation of multiple options than is possible with traditional two-dimensional drawings, thereby expediting decision making and resulting in significant savings. The current workstation designs can easily be developed and implemented with available technology at a reasonable cost. They can also accommodate anticipated advances in computer and display technology as well as new imaging paradigms (eg, changes in keyboard and control ergonomics such as adjustable virtual keys on touch-sensitive screens, digital drawing tablets for annotations and controls, direct film digitizing, personal identification devices, offline media readers such as compact disks and digital videodisks, and speech recognition and voice activation). Use of 3D techniques in designing other parts of the radiology department (eg, examination rooms, technologists' areas, physicians' offices) could greatly improve and facilitate the design and implementation of complex settings in these work areas.

ECONOMIC CHALLENGES IN BREAST IMAGING: A Survivor's Guide to Success

Most breast imaging centers today operate under financial strain. Among strategies designed to improve their bottom line, more efficient use of the radiologist's time is the most fundamental strategy and the one most likely to succeed in all breast imaging centers. Tasks performed by the radiologist that are not directly related to interpretation and consultation should be shifted to other personnel. Other strategies that may help some breast imaging centers include accepting only self-paying patients, renegotiating the hospital contract, performing more interventional procedures, and extending the hours of operation. Measures that can improve the economic efficiency of screening mammography include batch interpretation of mammograms; paperwork reduction; brief automated reports; limiting requests for previous films from other facilities to only potentially necessary cases; dedicated screening mammography examination rooms; reduction in recall rates; and, in certain circumstances, extension of breast center hours. Measures that can improve the economic efficiency of diagnostic mammography performance and interpretation include dedicated diagnostic mammography examination rooms, automated film rotators, improved scheduling, and efficient work-flow patterns for examination performance. Measures that can improve the economic efficiency of both screening and diagnostic mammography include improved triage of screening and diagnostic patients, reminder telephone calls to confirm mammography appointments, greater use of medical assistants to help the radiologists and technologists, and streamlined film library procedures and operations. Measures that can improve the economic efficiency of breast interventional procedures include preprocedure work-up, establishment of scheduling protocols, and greater involvement of technologists and medical assistants in assisting the radiologist who performs the interventional procedures. All of these methods are intended to create a breast imaging center that is cost efficient while maintaining a patient-friendly atmosphere and diagnostic accuracy.

Model for determination of protective shielding needed for diagnostic radiology rooms (in Portuguese)

The objective of the research was the development and evaluation using modern techniques to calculate radiation protection barriers in clinical radiographic facilities. Our methodology uses realistic primary and scattered spectra. The primary spectra were computer simulated using a wave form generalization and a semiempirical model (the TBC model). The scattered spectra were obtained from published data. An analytical function was used to produce attenuation curves from polychromatic radiation for specified wave form, and filtration. The results of this analytical function are given in ambient dose equivalent units. The attenuation curves were obtained by application of Archer's model to the computer simulation data. We determined the parameters that gave the best fit to our model using primary and secondary radiation data from different radiographic procedures. These resulted in an optimized model for the shielding calculation for any radiographic room. The method was used to determine the shielding needed for two different radiographic room designs using typical workloads and spectra. The shielding costs were about 50% lower than those calculated using the traditional calculation based on NCRP Report No. 49.

Optical beam transport system at FEL-SUT

Kawasaki Heavy Industries Ltd. has installed an FEL beam transport system at the IR FEL Research Center of the Science University of Tokyo (FEL-SUT). This system transports the FEL output beam from the FEL machine room to the optical diagnostic room through a vacuum tube. The in-vacuum multi-mirror synchronized system operated from the FEL control room enables the operator to control the multiple mirrors simultaneously on or off axis of the FEL beam and to distribute the FEL output to one of the laboratories. The essential component of the transport system is the passive control optics that is composed of an elliptical and parabolic mirror couple. Once the control optics is aligned, a parallel FEL beam with a good pointing stability is obtained without any active operation to tune the optical system for different wavelengths.

CTA and DSA Evaluation of Patients with Subarachnoid Haemorrhage

We correlate digital subtraction angiography (DSA) and computed tomography with angiographic 3D reconstruction (CTA) in patients with subarachnoid haemorrhage. 45 patients were evaluated with both techniques (CTA and DSA) within 3–4 days after acute haemorrhage: source CT images, MIP and 4D-angio reconstruction and standard DSA were performed and correlated. The MIP tecnique is very easy and quick to perform and operator independent, while 4D-angio reconstruction requires at least 30 minutes to obtain good quality images. CTA and DSA were equivalent in demonstrating the presence of all 57 aneurysms in the 45 patients. Most aneurysms were located at the level of the circle of Willis; CTA was not adequate to demonstrate the neck of aneurysms in 7 cases located in of the syphon, vertebral artery and posterior communicating artery; CTA gave a good display of the thrombus within the aneurysm. Patients could go directly from the CT diagnostic room to the operating room in certain types of aneurysm such as those in the anterior communicating artery or middle cerebral artery in which there is a correlation between site of the haemorrhage and the aneurysm. In the future, improvements in MR technology will also exclude aneurysms in sites difficult to evaluate by CTA such as the syphon, so that DSA will be performed only in selected doubtful cases.

Determination of Conversion Coefficients Between Air Kerma or Photon Fluence and Ambient Dose Equivalent for Diagnostic X Ray Beams

Conversion coefficients between air kerma or photon fluence and ambient dose equivalent were experimentally determined for diagnostic X ray qualities at depths of 10 mm, 50 mm and 60 mm in a PMMA sphere phantom, which was used as a substitute for the ICRU sphere. For this purpose, the air kerma in free air was measured by an ionisation chamber and the ambient dose equivalent was determined by LiF thermoluminescence dosemeters. The X ray qualities used were those recommended by the IEC for primary diagnostic X rays and for X ray beams attenuated by aluminium foils. The values obtained are compared with data derived from the literature. In addition, conversion coefficients for X ray qualities after penetration of lead layers were studied to get data which might be of interest concerning the shielding of diagnostic rooms.

Divertor impurity monitor for the International Thermonuclear Experimental Reactor

The divertor impurity monitoring system of the International Thermonuclear Experimental Reactor has been designed. The main functions of this system are to identify impurity species and to measure the two-dimensional distributions of the particle influxes in the divertor plasmas. The wavelength range is 200–1000 nm. The viewing fans are realized by molybdenum mirrors located in the divertor cassette. With additional viewing fans seeing through the gap between the divertor cassettes, the region approximately from the divertor leg to the x point will be observed. The light from the divertor region passes through the quartz windows on the divertor port plug and the cryostat, and goes through the dog-leg optics in the biological shield. Three different type of spectrometers: (i) survey spectrometers for impurity species monitoring, (ii) filter spectrometers for the particle influx measurement with the spatial resolution of 10 mm and the time resolution of 1 ms, and (iii) high dispersion spectrometers for high resolution wavelength measurements are designed. These spectrometers are installed just behind the biological shield (for λ<450 nm) to prevent the transmission loss in fiber and in the diagnostic room (for λ⩾450 nm) from the point of view of accessibility and flexibility. The optics have been optimized by a ray trace analysis. As a result, 10–15 mm spatial resolution will be achieved in all regions of the divertor.

FEL facilities and application researches at the FELI

Four FEL facilities (FEL-1, FEL-2, FEL-3 and FEL-4) achieved lasing at FELI in October 1994, in February 1995, in December 1995 and in October 1996, respectively. They are open for users and can supply several MW-level FELs covering the wavelength range of 0.3–40 μm. Total operation time in 1996 was about 2400 h. The visible- and UV-facility FEL-3 has broken the world record for the shortest wavelength oscillation of linac-based FELs with a thermionic gun up to 0.278 μm. The FEL beams are delivered from the optical cavities to the diagnostic room and four users rooms (18 stations) through the pipe lines. The beam can be shared by using fan-shaped Au-coated mirrors to several stations including two manipulators simultaneously for isotope separation, bio-medical and semiconductor applications.

Esperienza di teleconsultazione radiologica a basso costo di gestione

The purpose of this paper is to show how to obtain a qualified system for teleradiology using with already available resources in the diagnostic room, such as a workstation used to post-process CT and MR images. Thank to a personal computer (PC), a software translating workstation CT and MR images compatible with PC standard, software working along with the File Transfer Protocol (FTP), and finally a connection with world wide web by modem and Internet provider, it was possible to send images from CT and MR devices to the workstation and from there to the PC. The images were formatted in JPG files and then compressed in ZIP files to reduce those files and to have a faster transmission. The files were sent by modem to the e-mail box of the doctor whose opinion was sought and he could return his diagnosis in the same way. Basically, the costs were represented by the PC, the modem, the yearly subscription to an internet provider and time/telephone charge.

The FELI FEL facilities — challenges at simultaneous FEL beam sharing systems and UV-range FELs

Two infrared free electron lasers (FELs) facilities are operational to cover the wavelength range of 1–20 μm. We are challenged to simultaneously deliver an FEL beam to the diagnostics room and eight user's stations. We also wish to produce 0.3 μm-FEL oscillations using a 2.68 m undulator (λu = 4 cm) installed at the 160-MeV beam line of the FELI linac with a thermionic gun. Two IR-FEL facilities and the simultaneous beam sharing systems will be opened for FEL users in this October.

FEL beam sharing systems for eight user's stations at the FELI

Abstract Au-coated mirrors with fan-shaped holes are used instead of a beam splitter such as a Ge plate, to share FEL beams to the diagnostics room and following eight user's stations, since the maximum diameter of FEL beams is 63.7 mm in the wavelength range of 1–20 μm and an opening angle, the number and position of the fan-shaped holes can change a sharing ratio of delivering FEL average power for user's stations.

Quality Control in Conventional Diagnostic Radiology in Greece

Four hundred tubes in 187 X ray diagnostic units were tested according to the protocol for the quality control of conventional X ray units issued by the Hellenic Association of Medical Physicists. The analysis of test results showed that 70% of diagnostic rooms were adequately shielded but only 30% had warning labels or signs. Of the generators assessed, 55% showed acceptable linearity, 65% had good kVp accuracy whereas 25% operated with single-phase waveform. Of the X ray tubes checked, 70% had adequate beam filtration, 40% had a focal spot size less than 1.3 mm and 75% had proper beam alignment. Eighty per cent of the standing buckies tested had FFD = 1 m. Of the fluoroscopic units assessed, 80% were equipped with image intensifier, 60% had a proper limit timer whereas in 25% beam limitation was performed automatically. Moreover, in 60% of the radiographs image quality could be improved by improving the working condition of film processors and intensifying screens. The results confirm the need for the propagation of Quality Assurance in Greece.

The Audio Visual Sexual Stimulation (AVSS) Test in the Clinical Approach to Erectile Disorders

ABSTRACT: The Audio Visual Sexual Stimulation (AVSS) test represents a simple method to investigate impotence (Condra et al, 1991). It represents the most physiological and less invasive test that is able to induce an erectile response in the laboratory (Wagner et al, 1981). It does not require complicated tools and gives us much information concerning the nature of erectile disorders and also a first insight on the etiological causes (Virag, 1987). The patient is placed in a diagnostic room that should be sufficiently comfortable and watches an “erotic” videotape. The patient also uses earphones to stimulate the hearing and to be isolated from the ambient.A Rigiscan Is applied to obtain a real‐time recording of the erectile response elicited by the AVSS (Pozza et al, 1990). The same procedure is utilized performing the AVSS after intracavemous Injection (ICI) test if the induced erection is not completely rigid.We can have four different responses to AVSS: (1) completely negative or absent response with a fiat tracing on Rigiscan, (2) feeble erectile activity when the Rigiscan shows erectile activity with rigidity of less than 50%, (3) moderate or fair activity if the erection is between 50 and 70% in rigidity, (4) good response when the patient gets an erection with rigidity above 70%.We can also obtain an erectile response characterized by moderate to good but of very brief duration. That means that there is a loss of rigidity during the blank periods of the AVSS.A group of 250 patients complaining of erectile disorders was investigated. The relationships with intracavernous injection of vasoactive drugs and conclusive diagnosis were evaluated.Good responses exclude the presence of relevant organic disease. Negative responses to the AVSS test could be due to relevant organic disease but also to cultural, social, and angiogenic factors. Feeble or moderate responses are considered to be related to organic factors and require other investigations. The presence of alternating erections is independent from the degree of penile rigidity. This pattern is very frequent in patients affected by venogenic impotence. Only 10 psychogenic patients (14.2%) showed feeble response compared to 42 arteriogenic (46.1%) and 19 venogenic ones (40.4%). A good response was observed in 13 venogenic patients (27.6%) even if with alternating erections. It was also observed in seven arteriogenic (7.7%), whereas it was present in 22 psychogenic patients (31.4%). Actually, we found that a feeble erection was associated with organicity in 84.8% of cases (73 out of 86), and a good one was associated with psychogenic causes in 37.5% (15 out of 40).A particular group of patients is that affected by corporal venoocclusive dysfunction (CVOD). Many of these patients show a peculiar erectile response characterized by good, complete erections during the AVSS with sudden decrease of rigidity during the blank periods of the video. Many patients (41 out of 54 cases: 75.9%) with such erectile response showed CVOD, which was confirmed by dynamic cavernometry. The AVSS represents the ideal test in the diagnostic approach to erectile disorders also because it is simple, cheap, and not invasive. The test could represent an acceptable diagnostic tool for those patients who refuse the ICI test or who have diseases that make the ICI dangerous (coagulation problems, hemodialysis, etc.).

A Monte Carlo model for retrospective analysis of shield design in a diagnostic x-ray room.

Recent recommendations by the NCRP and the ICRP have lowered the nonoccupational dose limit from 5 mSv y-1 to 1 mSv y-1 [corrected]. This change has also been incorporated in the recently revised Title 10 Code of Federal Regulations, Part 20. Shielding installed in most current diagnostic x-ray rooms was based on the 5-mSv limit when rooms or corridors adjacent to the x-ray room were unrestricted areas. A computer model for evaluating shielding in a diagnostic x-ray room has been developed using the following: the Monte Carlo Code MCNP, all materials that would normally attenuate the beam in an x-ray room, realistic assumptions for work load, and a spectrum of tube potentials based on actual usage. Results indicate that most radiographic x-ray rooms with shielding designed using the conservative assumptions in NCRP 49 will meet the new standards.

Ambient noise levels in audiometric test rooms

Octave-band ambient noise levels measured in 136 diagnostic and 202 industrial audiometric test rooms were compared with the maximum permissible ambient noise levels (MPANLs) specified in ANSI S3.1-1991. The mean octave-band ambient noise levels for the diagnostic rooms were less than the ears covered but higher than the ears not covered MPANLs for each test frequency range specified in ANSI S3.1-1991. Specifically, 68 (50%), 69 (51%), and 112 (82%) of the diagnostic rooms met the ANSI ears covered MPANLs for the 125- to 8000-Hz, 500- to 8000-Hz test frequency ranges, respectively; however, only 14 (11%) for the 125- to 8000-Hz and 250- to 8000-Hz test frequency ranges and 39 (29%) for the 500- to 8000-Hz test range met the ANSI ears not covered MPANLs. The mean octave-band noise levels for industrial rooms were lower than the ANSI ears covered MPANLs for the 500- to 8000-Hz test frequency range except at 250 and 500 Hz where the levels exceeded the ANSI MPANLs by 2.4 and 6.4 dB, respectively. For the industrial rooms, 66 (33%) met the ANSI ears covered MPANLs for the 500- to 8000-Hz test range. Overall, both the diagnostic and industrial test rooms most often failed to meet the ANSI MPANLs at 250 and 500 Hz. Implications for diagnostic and industrial hearing testing will be discussed.

360. X 線撮影空間の散乱線の挙動(保健物理-5 施設装置管理)

360. X 線撮影空間の散乱線の挙動(保健物理-5 施設装置管理)

62. X 線診療室におけるしゃへい壁透過後の X 線スペクトル測定(被曝計測技術)

62. X 線診療室におけるしゃへい壁透過後の X 線スペクトル測定(被曝計測技術)

360. X 線撮影空間の散乱線の挙動(第 49 回総会学術大会一般研究発表予稿)

360. X 線撮影空間の散乱線の挙動(第 49 回総会学術大会一般研究発表予稿)

62. X 線診療室におけるしゃへい壁透過後の X 線スペクトル測定(第 20 回秋季学術大会一般研究発表予稿)

62. X 線診療室におけるしゃへい壁透過後の X 線スペクトル測定(第 20 回秋季学術大会一般研究発表予稿)