ABSTRACT
A study has been conducted to asses the impact of radiological practice in 1983 in Friuli-Venezia Giulia, a region of North-east Italy with 1,250,000 inhabitants. The design involved three phases: a region-wide frequency survey; dosimetric measurements on patients in all public X-ray facilities; derivation of organ doses from those measurements. Frequencies by type, age and sex and values of the main technical parameters of radiological examinations are presented. Organ doses, effective dose equivalents and risk estimates are given for 14 selected examinations. The annual per-capita effective dose equivalent and the genetically significant dose are estimated at 0.848 mSv and 0.253 mSv, respectively. From these values, collective risks have been predicted by using the risk factors given in the International Commission on Radiological Protection Publication 26. The results indicate that 14 persons risk induced malignancies and 2.5 persons risk genetic detriment.
Subject(s)
Radiation Dosage , Radiography/adverse effects , Female , Humans , Italy , Male , Neoplasms, Radiation-Induced/epidemiology , Pregnancy , Radiation Genetics , Radiation Protection , RiskABSTRACT
The linear model of the nerve compound action potential (CAP) depends on the assumed waveform for the single fibre action potential (SFAP). A general method has been developed to investigate the influence of the unknown features of the SFAP on the estimation of nerve fibre conduction velocity (CV) distribution. A SFAP waveform is considered consistent with the model and the experimental data if recorded and reconstructed CAPS fit and the distribution is physically meaningful. Experimental CAPS were monopolarly recorded using surface electrodes over the median nerve at the wrist. To fit the model, SFAP waveforms must satisfy some internal relationship. The most important feature is that the ratio between positive and negative areas of the SFAP is almost one and does not vary in different subjects and recording sites. Many SFAP waveforms fit the model, and the relative conduction velocity distributions may be very different. These must be regarded as conventional distributions. As for inter-subject comparison, the dependence of the method on the recording site has been reduced by choosing the place where stimulus intensity and relative motor response amplitude have given values. In this recording environment CV distributions of normal subjects can be properly compared using the same SFAP and deviations from normality evidenced.
Subject(s)
Action Potentials , Models, Neurological , Peripheral Nerves/physiology , Humans , Mathematics , Median Nerve/physiology , Neural ConductionABSTRACT
A method for evaluating the thyroid uptake function, based on the work of De Garreta, Williams, Glass, Atkins, Higgins et al., was developed using 99mTc-pertechnetate and a scintillation camera connected to a minicomputer system. The method has the advantages of a single visit, a low-dose examination, and the reliability of a full automated technique. The clinical results of the studies performed to date are in close correlation with those obtained from the radioactive iodine uptake test, and in good agreement with the findings of the above-mentioned authors.
Subject(s)
Radionuclide Imaging/methods , Technetium/metabolism , Thyroid Gland/metabolism , Computers , Humans , Scintillation Counting/methods , Thyroid Gland/diagnostic imagingABSTRACT
Normal and pathological anatomy of the brain can be studied in different cross-sectional planes. Of specific interest here are sagittal and coronal views obtained by computer reconstruction procedures. The three different planes for the reconstruction of the images are complementary, of real clinical interest, and are particularly useful for an accurate localization of lesions, either for surgical intervention or for radiotherapy planning purposes.
Subject(s)
Brain Diseases/diagnostic imaging , Brain Neoplasms/diagnostic imaging , Cysts/diagnostic imaging , Tomography, X-Ray Computed/methods , Cranial Nerve Neoplasms/diagnostic imaging , Humans , Neoplasm Metastasis , Neurilemmoma/diagnostic imaging , Vestibulocochlear NerveABSTRACT
We report on our preliminary experience with sagittal computed tomography of the orbit. We have found this technique to be useful in the evaluation of the orbit and orbital contents.
Subject(s)
Orbit/diagnostic imaging , Tomography, X-Ray/methods , HumansABSTRACT
The Authors analyse the results of cerebral angioscintigraphy, performed with gamma camera on-line with a MED II system, in 158 cases of ischemic stroke, 13 cases of hemorragic stroke and 29 cases of cerebral neoplasm. 84 cases of ischemic stroke and all the cases of hemorragic stroke and neoplasm had contrast angiography. The dynamic study has provided additional information in 51.3% of the cases of ischemic stroke (63.7% when the internal carotid artery involvement alone is considered), in 84.6% of the cases of hemorragic stroke and in 58.6% of the neoplasm cases. The same information moreover is almost always able to clarify the cause of the positive rectilinear brain scans, frequently uncertain in strokes. In cases of ischemic stroke correlations are considered between angiography and angioscintigraphy. In particular the value of the method is discussed as a screening procedure for the detection of extra-cranial vascular disorders, amenable of surgical therapy. The authors conclude that angioscintigraphy is the method that, separately considered, provides most of the useful information in the diagnosis of stroke.
Subject(s)
Cerebrovascular Disorders/diagnosis , Radionuclide Imaging , Brain/blood supply , Brain Neoplasms/diagnosis , Brain Neoplasms/diagnostic imaging , Carotid Artery Diseases/diagnosis , Carotid Artery Diseases/diagnostic imaging , Cerebral Angiography , Cerebral Hemorrhage/diagnosis , Cerebral Hemorrhage/diagnostic imaging , Cerebrovascular Disorders/diagnostic imaging , Diagnosis, Differential , HumansABSTRACT
A program is described, which performs automatic uptake, plotting and processing of radio-hippuran renograms obtained from a gamma camera, using an on-line minicomputer system. The program is written in machine language for a ND 50/50 system equipped with a PDP8-L processor, but translation for other nuclear medicine EDP system is easy. Minimum configuration requirements are: (i) 4K processor with TTY; (ii) external clock; (iii) magnetic tape transport; and (iv) 4K + 4K buffered camera interface or additional 8K of storage plus camera interface. Camera interface is computer-controlled and includes two AD-converters, a display unit for buffer storage and interest-areas selection facility. Operation starts recording 40 scintiphotographs of 30 sec each. Then, kidney uptake curves are obtained by subtraction of blood and tissue background, and diagnostic parameters, such as the initial slope, the maximum uptake point and 50% activity time, are computed. The only manual intervention required is the computer-assisted selection of interest-areas of kidneys, and blood and tissue background. Time required is 20 min for uptake of renograms and 5 min for processing and output, thus allowing routine execution of good quality renography, including hardcopy printout of both kidney uptake curves and diagnostic paramerers.
