摘要:

Like all other important advances, the addition of megavoltage radiations to the armamentarium of the radiologist has brought its own problems. Whether these rays are produced by direct physical methods or are derived from radioactive isotopes, we are faced with the questions how to measure them and how to protect ourselves from them. First steps to answer these questions are contained in the reports of the International Commissions on Units and on Radiological Protection which are published in full in this issue of the Journal.

DOI:10.1259/0007-1285-24-277-1

出版商:The British Institute of Radiology    

年代:1951

数据来源: WILEY

摘要:

The history of the development of radiation dosimetry is closely associated with the history of International Congresses of Radiology. At each one, units and measuring methods have been discussed, clarified and standardised by International committees. At the Fifth Congress it was suggested that the formulation of the definition of the röntgen then adopted be regarded as provisional and that a more exact definition, to include all classes of radiation, should be prepared for the next Congress. Of course, neither the lapse of 13 years before another international gathering, nor the tremendous development of new radiation sources was anticipated.At that time the practical limit for X rays was about one million volts, and the γ rays of naturally radioactive substances represented an electromagnetic radiation not much more penetrating. Artificially radioactive isotopes of a few substances had been produced in minute quantities, but the importance of their use in medicine was not foreseen. A few small neutron generators had been built, and a small amount of biological work done with these rays, but again the progress due to the development of efficient sources was not envisaged. During the ensuing dozen years tremendous technical advances have made available multi-million volt X rays, isotopes in very large quantities, and powerful beams of charged and uncharged particles.For scientific development of radiobiology, for intelligent progress in radiotherapy, and for adequate protection of workers in these fields and all others involving use of ionizing radiations, it is essential to develop an adequate and comprehensive system of dosimetry.

DOI:10.1259/0007-1285-24-277-2

出版商:The British Institute of Radiology    

年代:1951

数据来源: WILEY

摘要:

The use of the new radioactive isotopes in clinical medicine has introduced some new hazards and intensified some old ones. Many hospital organisations used to handling large quantities of radium and X rays are familiar with the risks of external irradiation, but are not familiar with those arising from the use of watery solutions or solids not enclosed in sealed containers. It is necessary therefore to extend organisation, to introduce new precautions, and to educate staff in the new outlook. The clinical problems may be thought to be simpler than those arising in Atomic Energy Projects inasmuch as the very difficult questions of α-ray emitters and particularly α-ray dusts do not arise, but on the other hand the quantities of β- and γ-ray emitters now used clinically are frequently involve hundreds of millicuries of high energy γ-ray emitters and the new telecurie sources may well reach thousands of curies.It is wrong, therefore, for those who are embarking on therapeutic investigations to assume that the elaborate precautions known to be taken in Atomic Energy Projects are not necessary in clinical practice.

DOI:10.1259/0007-1285-24-277-6

出版商:The British Institute of Radiology    

年代:1951

数据来源: WILEY

摘要:

A neon lamp radium detector for use on radium wards is described which will detect ½ mg. of radium at distances in excess of 8 in. The correct functioning of the detector is checked by illuminating the detector lamp with the light from a second neon lamp in order to produce the same degree of ionization in the gas of the detector as is obtained when the radium is in the detecting position. The cost of the instrument is approximately 50s.

DOI:10.1259/0007-1285-24-277-12

出版商:The British Institute of Radiology    

年代:1951

数据来源: WILEY

摘要:

Cardiac enlargement has always been considered to be an important indication of heart disease, and recent advances in pædiatric cardiology and in the field of cardiac surgery have shown the limitations of existing radiological methods of assessing cardiac size.

DOI:10.1259/0007-1285-24-277-13

出版商:The British Institute of Radiology    

年代:1951

数据来源: WILEY

摘要:

It is stressed that in routine clinical diagnosis using I131the drink should not be greater than 10 μc and that rapidity in carrying out measurements is important. Physical methods are described for meeting these more stringent requirements. Backscatter measurements are described which show that the backscatter factor in measuring thyroid uptake increases for Geiger counter cathodes of higher atomic number. A double counter arrangement is described for reducing geometrical variations of thyroid position with only a single measurement. A more sensitive γ ray counting method for urine samples has been devised.

DOI:10.1259/0007-1285-24-277-14

出版商:The British Institute of Radiology    

年代:1951

数据来源: WILEY

摘要:

It was a great loss to radiology when Professor Forssell died on November 13, 1950, at the age of 74. With his death comes to an end that epoch in which medical radiology was developed to the science it now is, of which he was one of the acknowledged leaders, and with which his name will be always associated.When, at the opening of the century as a young student, Forssell decided to devote himself entirely to radiology, many of his teachers and colleagues thought it a pity that such a brilliant man should put science aside in order to give his time to “photography”.

DOI:10.1259/0007-1285-24-277-17

出版商:The British Institute of Radiology    

年代:1951

数据来源: WILEY

摘要:

In procuring radiographs of the human foot for comparative purposes it was found that, by using the methods described, measurements of a chosen dimension (arch-height) on 36 films showed a standard deviation of ± 1·17 mm. In 10 contactcopies of a given radiograph the standard deviation of the measurements taken by two observers of this same dimension was ± 0·212 mm. It was not possible definitely to allocate the difference between these deviations to any particular source of variation.In the plantar view, measurements of angle between the axes of the first two metatarsals showed a standard deviation of ± 0·436 deg. (16 observations on contact-copies).In a series of 10 subjects each subjected to 10 different sets of circumstances under otherwise standard conditions, certain large alterations in the arch-height dimension were observed. Thus, flexing the weight-bearing knee in an otherwise standard position leads to a mean depression of the archheight of 3·9 mm. ± 0·933 mm. If in this position the trunk and leg are rotated internally (amounting to a forced, passive eversion of the foot in a weightbearing position) a mean diminution of 7·55 mm. ± 0·837 mm. is observed (approximately 14·5 per cent. of the total). Both these diminutions are very highly significant (probably<·001). Active contraction of tibialis posterior with knee extended in a weightbearing position (standard stance) raises the “archheight” by a mean distance of 2·475 mm. ± 0·386 mm. This is also very highly significant (probably<·001). A half-inch wedge under the medial border of the heel produces no significant raising of the arch.These results confirm the necessity for strict observation of the standard conditions laid down and themselves serves as a test of the validity of the method in a behavioural study.In the dimension used as an illustration the standard deviation of observations made under the conditions laid down may be expected not to exceed ± 1·5 mm.

DOI:10.1259/0007-1285-24-277-18

出版商:The British Institute of Radiology    

年代:1951

数据来源: WILEY

摘要:

Mr. Sims has verified, as did I, that Professor Röntgen referred to a Ruhmkorff coil in his original paper. Mr. Sims, however, states in addition that from the same source one can learn that there were electric current and electric lamps in Röntgen's laboratory.

DOI:10.1259/0007-1285-24-277-26

出版商:The British Institute of Radiology    

年代:1951

数据来源: WILEY

摘要:

1. Two cases in one family of Kartagener's syndrome are described, and the radiological findings are illustrated.2. One case presented with an anomalous left subclavian artery passing behind the œsophagus. This diagnosis is based on radiographic and fluoroscopic findings.3. As far as can be ascertained an anomalous left subclavian artery in a case of dextrocardia has not been recorded previously.4. No symptoms accompanied this anomalous great vessel development.5. The two cases described appear to support the theory that the syndrome described by Kartagener is a triad of congenital origin.

DOI:10.1259/0007-1285-24-277-27

出版商:The British Institute of Radiology    

年代:1951

数据来源: WILEY