Search

Purpose: To optimize the technique for radiographic studies of bone and joint damage in renal osteodystrophy., Material and Methods: Sixty-four patients with chronic renal failure on dialysis for 0-10 years, were divided into two homogeneous groups and submitted to two different radiographic examinations of the nondominant hand. Group A patients were examined with a conventional radiological unit and an industrial film and a conventional radiological unit with a mammographic film with a dedicated screen, while group B patients with a mammographic with an industrial film and a conventional radiologic unit with a mammographic film with a dedicated screen. The examinations were evaluated by three radiologists in a double-blind fashion., Results: Bone conditions such as osteoporomalacia, trabecular rarefaction, channel enlargement and intracortical absorption were equally demonstrated by mammographic films and the mammograph with industrial films. The mammographic film was superior to the mammograph with an industrial film in 8 cases, comparable in 25 and inferior in 6, but when compared with the conventional radiological unit with an industrial film it was superior in 19 cases, comparable in 2 and never inferior., Conclusions: The industrial film without a screen combined with a mammograph is considered the gold standard to study fine bone alterations in renal osteodystrophy. However the conventional radiological unit with a mammographic film with a dedicated screen provides the same results with lower irradiation doses and can therefore be considered a good alternative.

The clinical value of two digital fluoroscopy systems not connected to a PACS was investigated and compared with that of conventional radiology. Some critical variables were considered: image intensifier diameter, image definition, examination time, acquisition speed, patient exposure and finally film consumption. The main problems in the use of the digital techniques consisted in the limited size of the examination fields, which was not big enough to demonstrate the whole colon during double contrast enema, and in the difficult representation of the actual size on the image printed on the laser films. Definition was considered as sufficient for GI examinations. The main advantages consisted in acquisition speed, allowing detailed examinations of cervical esophagus, cardias and fistulous tracts, reduced patient dose and finally the real time visualization of the acquired image on the TV monitor.

The homogenization of conventional chest radiographs is obtained with mechanical filtration of the X-ray beam and it allows opacity compensation of the different anatomical structures under examination; consequently, more pieces of diagnostic information on the mediastinum can be obtained. The authors used a mechanical device for equalization (Tau-Gil, Gilardoni SpA) with five different X-ray film/rare-earth screen combinations (3M Trimax) to investigate the following problems: a) choice of the best film-screen combination; b) results of the dosimetric comparison of filtered and non-filtered examinations; c) qualitative evaluation of equalization in terms of diagnostic information. One thousand analogic chest studies, 500 with and 500 without hard-filtering equalization, were performed with high-tension technique and statistically evaluated with a dedicated program. The authors concluded that: 1) the best qualitative results are obtained with GTU film/T6 screen combination, which seems to make the most satisfying compromise between sensitivity and spatial resolution and allows low X-ray exposure to be combined with good diagnostic results; 2) dosimetric tests clearly show that in hard-filtered studies the average incident dose to the patient is 12% lower than that given with no filter. Particularly, skin and lung doses decrease, while mediastinum dose doubles to allow the simultaneous visualization of mediastinum and parenchyma; 3) a substantial difference exists between the frequencies of excellent, good and bad results in the comparative series (with and without equalization) for the evaluation of central chest areas, especially for mediastinum, retrocardiac region and carena. The overall rate of poor results was reduced by equalization, ranging 11.6% to 2.8% (mean: 6.3%) in equalized studies, and topping 64.2% (average: 35.5%) in non-equalized studies. Therefore, in the authors' experience, equalization with this type of mechanical device improves the depiction of the mediastinal region, with no significant imaging loss in lung parenchyma demonstration. Moreover, hard-filtering decreases average incident dose to the chest and skin-lung dose, increasing mediastinum dose to allow its correct demonstration.

Radiological units present different exposure values, (even by a factor 100), for the same radiological examination unless special programs are performed in order to optimize the examinations and to reduce variations. The program named DQM, mentioned in the Circular n. 62 of the Ministry of Health, is planned for mammographic optimization. The steps of the programme are: a) collection of the working parameters in each unit, b) dose and image quality evaluation, c) communication of the results and suggestion for corrective actions. The practical aspects of the program and the results of measurements in 65 mammographic units are presented and discussed. The importance of the Quality Assurance, performed by radiologists and physicists is underlined.

The clinical utility was evaluated of a computed radiographic system in urography. The system (FCR 101, Philips Medical Systems, Inc., Shelton, CT) is based on a photo-stimulatable phosphor screen (imaging plate) for X-ray image detection and storage. The X-ray information recorded on the imaging plate is converted into digital from and processed by means of a computer. After processing is completed, the digitized image is reversed back to analogic signals, which modulate the intensity of a laser beam scanning the image on a single-emulsion film (Fuji CR 633). Two hundred IVP's were obtained in four groups, of 50 patients each, with normal azotemic values by rapid infusion of a low osmolality contrast medium (iopamidol 150 mgI/ml). While conventional radiographs were performed on the first group of patients with the injection of 0.6 gI/kg body weight of contrast medium, digital examinations were carried out, in the remaining three groups, with the injection of 0.6, 0.3 and 0.12 gI/kg, respectively. The digital images were processed with the "Abdomen-routine" program. A specific algorithm was implemented in order to reduce the excessive contrast resolution of the bladder, which is due to the characteristics of the nonionic contrast medium and enhanced by the reading program. The image details were evaluated by two observers and then statistically analyzed with nonparametric tests. Statistical analysis did not show any difference in the quality of digital and screen-film images. Image processing improved some inadequate images, by reducing the contrast resolution of the bladder, and allowed a better detection of some details. Low doses (0.3 gI/kg) of a low osmolality (150 mgI/kg) contrast medium were enough to obtain good images. Another biological advantage was obtained by a consistent radiation dose reduction (about 40%).

Bedside chest radiography plays a considerable role in the whole of the exams carried out in hospitals, especially in intensive care units. Many clinical problems (pulmonary, cardiac, and mediastinal) are related to this examination and can be dealt with only when the radiologist is provided with high-quality radiographs. Therefore, it is extremely important for the radiologist himself to be aware of the various factors implied in the making and reproducing of bedside chest radiographs, which is a fundamental step in the monitoring of the patients undergoing intensive care. These factors can be divided into methodological factors (patient positioning, focus-film distance, and exposure) and technical factors (portable units, survey system). In this paper, a special emphasis is put on a survey system consisting in double differentiated screens and double film, which allows the acquisition of a normo-exposed radiograph of the parenchyma and of one of the mediastinum with a single exposure. Besides these technical and methodological elements, the radiologist must pay attention to the diagnostic-therapeutical means (such as tubes, small probes, and catheters) used on most patients in intensive care units. Their exact positioning must always be checked, and possible incorrect positioning and complications must be detected promptly. All these factors, as well as their scrupulous and constant application, contribute to markedly improve the dialogue between clinician and radiologist, by allowing a rapid evaluation of the cause of the clinical case under examination and its adequate treatment.

The authors report the results of a five-layer simultaneous multisection tomographic technique to be used in pediatric radiology, based on an appropriately selected series of Trimax rare-earth intensifying screens arranged in progressive speed order. The technique has been so far employed with excellent results in 100 children, especially during IVP, when X-ray examination is very frequently disturbed by ileocolic gas. The many advantages of the technique are emphasized: a) all sections are perfectly parallel and simultaneous, in the same respiratory phase and body position; b) film density is practically identical in all sections; c) there is considerable saving in time, machine consumption, and radiation dose.