摘要:

Calculations suggest that the flux of fast neutrons corresponding in biological effects to a dose of 0·1 r of the usual filtered γ radiation from radium of approximate mean energy 0·8 Mev. delivered in 8 hours has the approximate constant value of 85 neutrons per cm.2per sec. for neutrons of energy 2–20 Mev.On account of the uncertainties involved, it is recommended that the provisional tolerance flux of fast neutrons of energy 2–20 Mev. should not exceed 20 neutrons per cm.2per sec. during a period of 8 hours in any one day. This value of the tolerance flux can be doubled for neutrons of energy 0·5 Mev.

DOI:10.1259/0007-1285-20-233-177

出版商:The British Institute of Radiology    

年代:1947

数据来源: WILEY

摘要:

The technique of randon is an elaborate one and demands a high degree of skill from those engaged in it. The volume of radon in equilibrium with one gram of radium element (1 curie) is almost exactly 0·6 c.mm. and as many of the needs of the radiotherapist are in terms of millicuries it is obvious that we are dealing with much smaller volumes than are met with in most gaseous processes.Under ordinary working conditions if a particular requirement of X millicuries is in question, then it can be said that X millicuries is in question, then it can be said that X millicuries within a very few per cent. will be supplied. If, however, this quantity X has to be divided among N items, the question arises as to how the accuracy suffers in the subdivision, as it undoubtedly does.The small quantities mostly involved are called “seeds” their dimensions vary in length from 5–17 mm., the average bore of the glass capillaries is 0·45 mm. diameter external and 0·2 mm. internal. The method of making the seeds is first to draw out a length of capillary tubing from 20–40 cm. long; purified radon under less than atmospheric pressure is then passed into the capillary tube which has previously been exhausted to a pressure of about ·001mm. Hg as measured on a Pirani gauge.

DOI:10.1259/0007-1285-20-233-181

出版商:The British Institute of Radiology    

年代:1947

数据来源: WILEY

摘要:

In Dr. J. F. Brailsford's acknowledgment at the end of his article on “Roentgen's Discovery of X rays”, Vol. XIX, No. 227, p. 461, the word “translation” should be in the plural and read “translations”.

DOI:10.1259/0007-1285-20-233-189

出版商:The British Institute of Radiology    

年代:1947

数据来源: WILEY

摘要:

Relative sensitivity curves are given for an end window type β- particle counter. The curves are contours of equal sensitivity, to a radio phosphorus point source placed in front of the window, in a plane through the axis of the counter. Surfaces of equal sensitivity may be generated by rotating the curves about the axis of the counter. These surfaces approximate to spherical surfaces near the counter axis. The sensitivity curves were obtained with a counter of average sensitivity. They were checked against two other counters representative of the least and most sensitive counters of this type, and the divergence from equal sensitivity along the curves was less than 2 per cent.

DOI:10.1259/0007-1285-20-233-190

出版商:The British Institute of Radiology    

年代:1947

数据来源: WILEY

摘要:

The Holt Radium Institute has produced in this report a model of clear factual statement which should act as a stimulus to radiotherapists to do the same. The high standard both of conception and execution of the report is what we have learned to expect from Manchester, and Dr. Paterson and his collaborators are to be congratulated on the report as it stands, as well as on the results of treatment, and the skill, intelligence, and organisation which lie behind them.

DOI:10.1259/0007-1285-20-233-191-a

出版商:The British Institute of Radiology    

年代:1947

数据来源: WILEY

摘要:

Before I begin to read my paper, I wish to present very hearty compliments to the English Radiologists from your Swedish colleagues, especially from Professor Gösta Forssell, our grand old man, and from my chief, Professor Ake Akerlund, generally considered by us to be the leading Swedish radiologist of to-day. Next, I warmly thank the chairman for his most kind reception.Personally I feel very honoured indeed to read a paper for this faculty, and I am glad to have met so many excellent English colleagues during my stay here in your hospitable country. I only hope that what I have to say about the X-ray diagnosis of cholesteatoma in the temporal bone may be of some interest to you.At the Caroline Hospital—one of the two University Hospitals in Stockholm—there is, among other departments, one for ear, nose, and throat diseases, with eighty-nine beds. Here they do about 4000 operations a year on the in-patients and have 35,000 out-patients.Our X-ray department deals with about 50,000 examinations a year. We are ten radiologists, with Professor Akerlund as chief. As one of the three assistant chiefs there I am responsible for the X-ray examinations of the patients from the Ear clinic.My lecture is based on the experience I have gained from the large material which has been at my disposal. I may tell you that so far I have examined well over 4000 mastoids.

DOI:10.1259/0007-1285-20-233-192

出版商:The British Institute of Radiology    

年代:1947

数据来源: WILEY

摘要:

A Cholesteatoma of the mastoid requires two conditions for its formation: firstly, a lowgrade, chronic infection and, secondly, a diplœtic or poorly pneumatised mastoid.The condition is associated with a long-standing history of a copious and foul aural discharge.Almost all middle-ear infections commence in the naso-pharynx and spread up the Eustachian tube into the middle ear. The accompanying diagram, though not intended to be anatomically correct, shows the path which these infections take (Fig. 1).In a cellular mastoid, the infection spreads from the middle ear, through the aditus ad antrum into the mastoid antrum and, thence, into the mastoid cells. In an acellular mastoid, if the infection is of some virulence, the diplœtic bone is infiltrated by the organisms and diffuse bone infection takes place; but if the invasion of the acellular mastoid is by an organism of low virulence, then a much slower process takes place. The normal mucosa of the middle ear is destroyed and gradually replaced by epidermal cells, either by extension of the epidermis from the external auditory canal through the ruptured drum, or by cellular metaplasia. These epidermal cells are continually being desquamated by the infection and replaced, and they collect in a slow, but constantly enlarging mass in the epitympanic recess, the aditus as antrum or the mastoid antrum. The organism is not sufficiently virulent to infiltrate to any extent the surrounding acellular bone, but it gradually softens it by infection and erodes it by the pressure of the constantly enlarging mass of dead cells.

DOI:10.1259/0007-1285-20-233-202

出版商:The British Institute of Radiology    

年代:1947

数据来源: WILEY

摘要:

Examination of the course of labour in relation to variations in selected pelvic characteristics suggests that on the basis of pelvic mensuration alone a reasonably accurate prognosis of the probable mechanical course of labour can be offered in the majority of cases. From my own experience and from a limited review of the pertinent literature, the following table (Table VIII) is offered as a tentative guide to prognosis. The table is based on the assumption that the fœtal head is of fixed standard size, 100 mm. in diameter: if there is evidence that the head is smaller or larger than this assumed normal, the interpretation will require modification accordingly.

DOI:10.1259/0007-1285-20-233-205

出版商:The British Institute of Radiology    

年代:1947

数据来源: WILEY

摘要:

Four hundred cases were seen in fourteen years in the Cleveland Clinic:—Acute myeloid 16·5 per cent.Chronic myeloid 24·7 per cent.Acute lymphoid 15·3 per cent.Chronic lymphoid 29·5 per cent.Acute and chronic monocytic 14 per cent.Sixty-one per cent. were men. All ages were affected. Many of the characteristic signs, specially in acute leukæmia, are due to toxæmia.

DOI:10.1259/0007-1285-20-233-218-b

出版商:The British Institute of Radiology    

年代:1947

数据来源: WILEY

摘要:

The treatment of the primary carcinoma of the bladder has always been one of the most ungrateful and difficult problems of urology. Up to the present time the opinions as to the best therapeutic procedure differ considerably.1. E.C. has been found of value by the majority of urologists in the treatment of benign papilloma of the bladder.2. Transurethral E.C. has been found of certain value in cases of pedunculated papillomatous carcinoma.

DOI:10.1259/0007-1285-20-233-219

出版商:The British Institute of Radiology    

年代:1947

数据来源: WILEY