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[Conventional roentgen functional diagnosis--videodensitometry. 1. Densitometric and topometric measurements of roentgen video images: technique and method of measuring].

It is possible to measure movements in the human body with the help of X-ray television systems. A great number of different techniques has been published in the scientific literature. They all based on only two principles with qualitative differences in signal acquisition. The densitometric and topometric measurements are assessed and compared. Neither the densitometric nor the topometric principle seems to be superior. To support the experimental work the videoanalyser VIANA MP was developed on the Ilmenau Institute of Technology.

Computer Systems↗

[Conventional roentgen functional diagnosis--videodensitometry. 2. Clinical imaging site for noninvasive diagnosis of organ motion].

By means of the described system it is possible to measure and as well analog as digital process the organ movement, needing a X-ray television system for flouroscopy and a videotape for continuously recording. Using the densitometric principle measurements of time and a quantitative form analysis of the curves are performed. After border recognition and using the topometric principle, the local organ motion can be evaluated. The levels of signal and noise in the measured curves are computed by a fourier transformation. In the field of functional cardiology the video signal is recorded and processed synchronously with the electrocardiogram.

Computer Systems↗

[Quantitative analysis of pneumoconiosis in standard chest radiographs].

A computerized method to quantify and characterize interstitial diseases by using physical texture measures obtained from an analysis of the power spectrum of lung textures in digital chest radiographs was applied to Japanese standard radiographs of pneumoconiosis. Texture measures were determined from standard radiographs of silicosis, asbestosis, and other types of pneumoconiosis as well as chest radiographs of normal lungs. Our preliminary results indicated that the texture measures obtained from computer analysis corresponded closely with the standard categories of silicosis. However, there was no significant correlation between texture measures and the categories for asbestosis and other types of pneumoconiosis in terms of texture pattern. Japanese standard radiographs of pneumoconiosis are categorized according to the profusion of opacities, without reference to the size and shape of the opacities. Furthermore, in some films the size and shape of the opacities vary considerably within the same category. Therefore, it is considered that these characteristics of the standard films affected the results of our texture measures. It also considered that a large ROI and other texture measures are needed to characterize large opacities and mixed-shaped opacities of pneumoconiosis.

Humans↗

[The use of digital techniques with storage phosphors for orthopantomography. Preliminary note].

Digital panoramic tomographies with light-emitting phosphors were obtained in 39 patients, during a study on the clinical applications of digital imaging. Performing digital panoramic radiographies required the preliminary adaptation of the imaging plates to the cassette holder of the radiographic equipment. The digital images were post-processed according to two different protocols, both of which were recorded for each patient. The former image was quite similar to standard X-ray films and was called "analogic-like". The latter, called "xeroradiographic-like", featured a flattening of the overall contrast together with detail contrast enhancement due to the presence of an edge effect, as it occurs in xeroradiography. Digital panoramic tomography allows a marked reduction in patient's exposure to X-rays. In addition, this technique offers constant high-quality results, due to the possibility of recovering over- or under-exposed images during post-processing. Xeroradiographic-like digital films may reduce the sharp contrast that is often present between the anterior and the lateral portions of the maxillary and mandibular arches, thus improving the diagnostic reliability of the examination. Other modalities of digital post-processing may be helpful to depict gingival soft tissues, with obvious advantages for the study of periodontal diseases.

Adolescent↗

Visualization of multimodal image information in medicine.

Radiological and clinical practice can be enhanced by improved access to multimodal image informations. Analysis, visualization, method characteristic image processing and image synthesis is needed not only for the interpretation of the images but also for performing effective consultations with clinical colleagues and computer supported therapy planning and control strategies. The distributed system RADVIS (radiological visualization) is presented which enables the fast display, three dimensional visualization and the modality oriented analysis of multimodal image informations. Based on a unique image format, modality specific evaluation procedures and two- or three dimensional processing tools of image analysis produce the input data for therapy planning programs. The easy use of this multimedia visualisation tool enables radiologists and clinicians to deal with their image data. The description of methods and procedures of the prototype, as well as typical examples of radiologic practice will demonstrate the efficiency of the presented system.

Humans↗

[Surgery of scoliosis. Decision aid by three-dimensional imaging (3D)].

Scoliosis is a spatial deformations of the spine not reducible to a plan. Usually perception of this phenomena is made from frontal and lateral radiographies and needs a mental process to construct a 3D form. The proposed aid-system consists, firstly, to construct a 3D model from digitalised characteristic points on radiographies, and to visualize this model from any point of view, even the above view. Secondly, corrective bending posture radiographies are used to estimate kinematic spine variables and then to simulate optimal orthopedic correction. Methods and materials are adaptable for other osteo-articular systems.

Decision Support Techniques↗

[Three-dimensional evaluation of computerized tomography images of pediatric fractures].

Three-dimensional reconstruction from CT was performed in pediatric patients after joint, facial, or spinal injury. Three-dimensional reconstruction proved particularly helpful in children with reduced post-trauma joint mobility. Free fragments, joint dislocations, and articulate surface defects were demonstrated. Here, as well as in facial and spinal injury, three-dimensional CT may facilitate and augment the understanding of two-dimensional displays.

Adolescent↗

[Densitometry determination of coronary flow rates using digital subtraction angiography (DSA). Methods, multiple examinations and interobserver comparison].

In invasive diagnostics of coronary heart disease (CHD), three each DSA examinations of the left coronary artery were performed at 2-minute intervals in ten patients subsequent to conventional examination by means of a left-side cardiac catheter and coronary angiography. While placing the patient in left anterior oblique (60 degrees) position, 6 ml each of ionic contrast medium were injected mechanically with a flow of 4 ml/sec at a pacemaker-induced heart rate of 100/min. Examinations were performed according to a standard mode and were evaluated via the image analysing computer APU of the Philips DVI-DSA system. The purpose of this approach was to analyse the examination conditions and a new improved evaluation algorithm in respect of stability, feasibility and sensitivity. 17 series were evaluated by two examiners who were independent of each other. The interobserver differences obtained were between 5% at the time of maximum density (Tmax) and 25% with exponential downward slope of the curve (lambda), with reference to the median value in each case. Scatter of the individual examinations around the median value of all the three DSA runs is 11 to 17% with the exception of lambda. A significant rise can be proven in the RCX region for the curve slope rise parameters "slope" and "RFL2". We interpret this as a genuine 1.2 to 1.3 fold regional flow increase due to the residual effect of the contrast medium. At the same time, this can be interpreted as an indicator for the good sensitivity of the method.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Percutaneous transhepatic dissolution of gallbladder stones.

The method of percutaneous transhepatic dissolution with methyl tert-butyl ether (MTBE) has been used at the Zagreb Clinical Hospital Department of Medicine since 1989. From December 1989 until December 1991, 69 patients, 51 (74%) females and 18 (26%) males, with symptomatic and cholesterol gallbladder stones were hospitalised at the Department. All patients preferred percutaneous transhepatic dissolution to surgical treatment of gallbladder stones. The gallbladder was successfully punctured and the catheter placed into the gallbladder lumen in 63 (91%) patients, whereas complete dissolution was achieved in 59 (85.5%) patients. In 21 (33.9%) of these 59 patients, after completed dissolution computer-processed roentgenograms and ultrasonic scan of the gallbladder revealed residual particles of debris sized up to 2 mm. Six patients in whom puncture, i.e. the placement of the catheter into the lumen was unsuccessful, were electively operated on the following day without any complications. The mean duration of hospitalisation for 63 patients was 4.5 days.

Adult↗

Three-dimensional computed tomography image of small pulmonary lesions.

To evaluate diagnostic imaging of small lesions in the peripheral lung, three-dimensional (3D) reconstruction CT images were used to study 36 cases (including which had been 19 resected) of pulmonary nodules less than 3 cm in diameter. Rapid scanning was employed in 17 cases and helical scanning (in which the X-ray tube rotates continuously with simultaneous table sliding) in 19 cases. The rapid scanning could not be evaluated in two cases because respiratory motion resulted in discontinuous image data. We were able to evaluate 34 cases. The addition of 3D images to the conventional images made it possible for us to obtain useful information on visualizing relations between nodules and vascular structures in 32% (11/34) of the cases. The 3D images enabled us to visualize the lesions and pulmonary vessels three-dimensionally. It was, however, difficult to evaluate lesion shape since we were able to obtain useful information in only 3% (1/34) of the cases. In helical scanning, data are acquired from an extensive area within a short time, providing consecutive axial-slice images remain free of any respiratory artifacts. In this regard, helical scanning is suitable for generating 3D images. A diagnostic procedure based on 3D lesion analysis should be developed and standardized.

Aged↗

Anatomical macroelements in the study of craniofacial rat growth.

In order to avoid the arbitrary division of biological structures, rational polynomial interpolants are utilized to study growth. The major advantage of this method is the elimination of artificial internal element boundaries through anatomical structures. Since the boundary element methodology is employed in the finite element setting, other benefits, without additional computer coding, include the ability to use elements with any number of sides and reference frame invariance. Longitudinal landmark coordinates from midsagittal X-ray tracings of 22 albino female rat skulls of various ages were averaged. The skull was partitioned into three macroelements: a neural skull and two functionally distinct portions of the facial skull--olfactory and respiratory. The digital computer programming was carried out in the computer mathematics environment of Mathematica. Maximum elongation ratios were calculated for approximately 400 interior points. The elongation ratios in the neural skull compared well with previously documented growth behavior of internal brain structures. The calculated ratios from the facial skull were used to analyze the behavior of macroelement interpolation close to common anatomical boundaries.

Animals↗

[Three dimensional display of cerebral vessels using a personal computer].

A new method for a 3-D reconstruction of angiographic cerebral vessels was developed. This system was constructed from inexpensive equipment such as a personal computer, a video camera, a video display, and a digitizer. The input of the vessel images on anteroposterior and lateral angiograms was performed using a video camera with a personal computer and an image processing program (FDM 98-4; Fotoron Co.). These processed images were modified with our original editorial method. This can contribute a lot to the erasing of "non-vessel" images such as skull bone and other noise. It also adds concerning vessels which cannot be clearly taken from angiograms with the video camera. The most beneficial point of the editorial method was to reduce the time consumed in the reconstruction. The spatial points of X-ray discharging boxes against the AP and lateral films were calculated from the length and width of the radiated images of metal bars. These bars were attached to the 3 planes of the lucent box in which the patient's head was inserted to take the angiograms. The 3-D points of the vessels were calculated as follows; one point of a vessel on the lateral image and the spatial point of the X-ray discharging box against the image were linked by a line on which a point moved within a Z range. When the extended line which linked the point and the position of the X-ray discharging box against the AP view crossed the AP image, the Z value of the point was adopted and X and Y values were gained.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebral Angiography↗

Clinical evaluation of assistant diagnostic system for mammograms using the auto-analyzing method.

Clinical usefulness of a newly developed auto-analyzing system of mammograms to search the abnormal dense areas such as cancer lesions was studied. 345 breasts including 86 cancers, 52 mastopathies, 18 fibroadenomas, 13 cysts, 4 lipomas and 172 normals were analyzed and compared with final diagnosis. 84 of 86 cancer lesions were correctly pointed out (sensitivity: 97.9%). Based on the gradient of the density, the ranking of the cancer or calcified lesions among suspected regions in a mammogram was decided. 55 lesions of them (64.0%) were ordered at the first rank and 83 (96.5%) were in the upper three ranks. 68 of 74 breasts with calcifications were correctly diagnosed and 48 of them were ranked in the upper three ranks. Although further improvement of the system is needed, this system will be a useful assistance for screening the breast cancer in the analyses of mammograms.

Breast Neoplasms↗

Computable radiology.

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Radiographic Image Interpretation, Computer-Assist↗

Three-dimensional imaging of the musculoskeletal system: an overview.

The clinical applications of three-dimensional computed tomography (3-D CT) reconstruction continue to expand rapidly. Recently, the field of three-dimensional magnetic resonance (3-D MR) reconstruction has also been developing. Three dimensional imaging offers a new approach to the analysis of complex anatomic relationships. The spatial configuration of an object can be directly displayed without observers requiring mental integration of a series of two-dimensional images. The easily interpretable images of 3-D CT have proven to be useful for surgical planning. Three-dimensional CT displays have used widely in the preoperative planning of craniofacial surgery, dysplastic hips in children, and complex fractures of skeletal systems. However, 3-D MR displays are technically more difficult than those of CT scans, and 3-D MR displays of the musculaskeletal system are still in a developing stage. Recently, we explored the feasibility of 3-D MR displays. This article provides an overview of those areas of the musculoskeletal system where the use of 3-D MR has proven valuable. The current techniques and ongoing applications are also presented. We believe that this exciting development will expand our ability to visualize pathologic anatomy in the near future.

Algorithms↗

Computerized angiographic study of the vascular supply of the pectoralis major muscle.

The pectoralis major muscle or musculocutaneous flap is well suited to repair immediately wide defects following surgical removal of carcinomas or traumas of the cervicofacial and thoracic regions. Microsurgery has recently suggested exciting and successful solutions for the same purposes, but we think it is still important to reassess and perfect the flaps already known in order to achieve a better cost-benefit ratio. We examined the intramuscular vascular anatomy of 22 pectoralis major muscles using an image analyzer and a computerized measuring system to quantify the essential features objectively. The data show the segmentation of the pectoralis major muscle into two subunits, each provided with its own vascular supply. Slight anatomical differences and the presence of a well-developed intramuscular vascular supply makes the pectoralis major muscular and musculocutaneous flap a useful and safe procedure.

Aged↗