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Olbert balloons
Clinical Radiology (1990) 42, 142 144
Correspondence Letters are published at the discretion o f the Editor. Opinions expressed by correspondents are not necessarily those of the Editor. Unduly long letters may be returned to the authorsfor shortening. Letters in response to a paper may be sent to the author of the paper so that the reply can be published in the same issue. Letters should be typed double spaced and should be signed by all authors personally. References should be given in the style specified in the Instruction to Authors at the front of the Journal.
OLBERT BALLOONS
References
SIR With reference to recent letters (Dacie/Hartnell/Sampson) involving the Olbert catheter, we write to express our concern about the problems experienced by the correspondents. Although the Olbert catheter was introduced in 1982 and many thousands have been used successfully in the UK, the level of reported instances of this nature has been very small indeed. The Company takes its obligation to evaluate fully any returned catheter most seriously and a review of product records of the appropriate batches did not point to any manufacturing difficulties. Of those returned, analysis showed they were manufactured several years ago since when continuous product development has resulted in a number of design improvements to meet the exacting conditions involved in interventional procedures today. Although the Olbert catheter is featured in this correspondence, most clinicians will be aware that angioplasty balloon catheter problems are not restricted to this design alone, so we look forward to the imminent publication of the relevant British Standard for balloon dilatation catheters. - -
P. R. D R A Y C O N
General Manager Meadox (UK) Ltd
References
Hartnell, G G (1990). Correspondence. Clinical Radiology, 41, 292. Law, P & Dacie, JE (1989). Correspondence. ClinicalRadiology, 40, 543. Sampson, M A & Wilkins, RA (1990). Correspondence. Clinical Radiology, 41, 292.
EXTREMITY DOSES DURING INTERVENTIONAL RADIOLOGY SIR I read with interest the paper by Ramsdale et al. (1990) regarding extremity doses during interventional radiological procedures. The implication in the paper that doses can be kept to 'acceptable levels' assumes that the 3/10 limit specified by the National Radiation Protection Board is a level up to which it is reasonable to work, rather than the maximum level allowed before classification is required. In line with the A L A R P principle recommended by the International Commission on Radiological Protection (ICRP), it seems untenable that, when under-couch screening equipment dramatically reduces extremity doses, many interventional procedures in the U K still have to be performed on obsolete, over-couch equipment. Whatever the experience of the radiologist performing interventional procedures, there will be some cases where exposure of the hands to the direct beam may not be preventable. As the authors have shown, this is even more likely to occur with inexperienced operators. This emphasizes the need to provide safe equipment for radiologists in training. The ICRP have expressed concern about the use of over-couch screening. The recent devolution of equipment budgets from Regional to District Health Authority level will only increase the difficulty of replacing out-of-date equipment. Ramsdale et al. imply that, even using a careful technique, designation of interventional radiologists as classified personnel would be necessary with only an average workload. Rather than suggesting that this is an acceptable situation, I feel that the information obtained by the authors should be used to put pressure on the appropriate authorities to replace obsolete and dangerous installations with modern equipment.
gamsdale, ML, Walker, WJ & Horton, PW (1990). Extremity doses during interventional radiology. Clinical Radiology, 41, 34-36. ICRP (1985). Statement from the 1985 Paris meeting of the International Commission on Radiological Protection. British Journal of Radiology, 58, 910. SIR We are pleased to agree with the general tenor of Dr Odurny's letter in that under-couch screening is much preferable to the use of over-couch tubes as a means of reducing the dose received by the fingers or eyes of a radiologist or surgeon during interventional procedures. His expression 'obsolete and dangerous' is however rather an overstatement in that the over-couch tube is not intrinsically hazardous but is a disadvantage only when staff are required to remain close to the X-ray table during fluoroscopy. We are also happy to endorse the concept of A L A R P although we should point out that this implies a balance as to what is 'reasonably practicable'. One should always attempt to reduce doses but the cost, including that of replacement equipment or reduced room utilization, must be considered. We have not assumed that 3/10 of the dose limit is a level to which itis reasonable to work. Doctor A's doses were considered reasonable in view of the doses recorded elsewhere and despite carrying out many interventionat procedures in which a high level of exposure to his hands could easily have occurred. This is ascribed to meticulous technique and the fact that the light beam was used at critical points in the procedure to indicate the irradiated area. The use of the light beam for this purpose is not possible of course when an under-couch X-ray tube is used. Taking into account the workload Radiologist A's annual doses were acceptable and well below the 3/10 level. Our article does not purport to pass an opinion about the advisability of over or under-couch tubes, but simply to report on the doses received during this study on an over-couch unit which is in the process of being replaced by a new under-couch angiographic facility.
-
A. O D U R N Y
Departmen t of Radiology East Birmingham Hospital Bordesley Green East Birmingham B9 5ST
M. L. R A M S D A L E W. F. W A L K E R * P. W. H O R T O N
Department of Medical Physics St Lukes Hospital Guildford, Surrey GU1 3NT and *Royal Surrey County Hospital Guildford, Surrey GU2 5XX
C O M P U T E D T O M O G R A P H Y IN ADULT OBLITERATIVE BRONCHIOLITIS S m - I would like to make the following comments on the,article by Dr Sweatman et al. (1990) which reported the observation of widespread areas of increased attenuation in computed tomography (CT) of the lungs in 15 patients with obliterative bronchiolitis (OB): 1 The authors surprisingly omitted to include lung transplantation amongst the several causes of OB which they mentioned. OB is the most common cause of late morbidity and mortality after lung transplan" tation (Dark and Corris, 1989). 2 The statement in the abstract that .CT revealed more extensive changes than the bronchogram is rather misleading and was not justified in the discussion. I presume the authors were referring to the three patients who had only a limited bronchographic examination and could not tolerate the full procedure. The limitation of the bronchogram was caused by poor patient tolerance and was not due to lack of sensitivity 10 demonstrating the extent of the disease. The characteristic changes of OB were demonstrated in all five patients who had bronchography. The sensitivity of bronchography in detecting OB was therefore 100%, similar to that reported by Breatnach and Kerr (1982), whereas the sensitivity of CT was 87%.
Correspondence Letters are published at the discretion o f the Editor. Opinions expressed by correspondents are not necessarily those of the Editor. Unduly long letters may be returned to the authorsfor shortening. Letters in response to a paper may be sent to the author of the paper so that the reply can be published in the same issue. Letters should be typed double spaced and should be signed by all authors personally. References should be given in the style specified in the Instruction to Authors at the front of the Journal.
OLBERT BALLOONS
References
SIR With reference to recent letters (Dacie/Hartnell/Sampson) involving the Olbert catheter, we write to express our concern about the problems experienced by the correspondents. Although the Olbert catheter was introduced in 1982 and many thousands have been used successfully in the UK, the level of reported instances of this nature has been very small indeed. The Company takes its obligation to evaluate fully any returned catheter most seriously and a review of product records of the appropriate batches did not point to any manufacturing difficulties. Of those returned, analysis showed they were manufactured several years ago since when continuous product development has resulted in a number of design improvements to meet the exacting conditions involved in interventional procedures today. Although the Olbert catheter is featured in this correspondence, most clinicians will be aware that angioplasty balloon catheter problems are not restricted to this design alone, so we look forward to the imminent publication of the relevant British Standard for balloon dilatation catheters. - -
P. R. D R A Y C O N
General Manager Meadox (UK) Ltd
References
Hartnell, G G (1990). Correspondence. Clinical Radiology, 41, 292. Law, P & Dacie, JE (1989). Correspondence. ClinicalRadiology, 40, 543. Sampson, M A & Wilkins, RA (1990). Correspondence. Clinical Radiology, 41, 292.
EXTREMITY DOSES DURING INTERVENTIONAL RADIOLOGY SIR I read with interest the paper by Ramsdale et al. (1990) regarding extremity doses during interventional radiological procedures. The implication in the paper that doses can be kept to 'acceptable levels' assumes that the 3/10 limit specified by the National Radiation Protection Board is a level up to which it is reasonable to work, rather than the maximum level allowed before classification is required. In line with the A L A R P principle recommended by the International Commission on Radiological Protection (ICRP), it seems untenable that, when under-couch screening equipment dramatically reduces extremity doses, many interventional procedures in the U K still have to be performed on obsolete, over-couch equipment. Whatever the experience of the radiologist performing interventional procedures, there will be some cases where exposure of the hands to the direct beam may not be preventable. As the authors have shown, this is even more likely to occur with inexperienced operators. This emphasizes the need to provide safe equipment for radiologists in training. The ICRP have expressed concern about the use of over-couch screening. The recent devolution of equipment budgets from Regional to District Health Authority level will only increase the difficulty of replacing out-of-date equipment. Ramsdale et al. imply that, even using a careful technique, designation of interventional radiologists as classified personnel would be necessary with only an average workload. Rather than suggesting that this is an acceptable situation, I feel that the information obtained by the authors should be used to put pressure on the appropriate authorities to replace obsolete and dangerous installations with modern equipment.
gamsdale, ML, Walker, WJ & Horton, PW (1990). Extremity doses during interventional radiology. Clinical Radiology, 41, 34-36. ICRP (1985). Statement from the 1985 Paris meeting of the International Commission on Radiological Protection. British Journal of Radiology, 58, 910. SIR We are pleased to agree with the general tenor of Dr Odurny's letter in that under-couch screening is much preferable to the use of over-couch tubes as a means of reducing the dose received by the fingers or eyes of a radiologist or surgeon during interventional procedures. His expression 'obsolete and dangerous' is however rather an overstatement in that the over-couch tube is not intrinsically hazardous but is a disadvantage only when staff are required to remain close to the X-ray table during fluoroscopy. We are also happy to endorse the concept of A L A R P although we should point out that this implies a balance as to what is 'reasonably practicable'. One should always attempt to reduce doses but the cost, including that of replacement equipment or reduced room utilization, must be considered. We have not assumed that 3/10 of the dose limit is a level to which itis reasonable to work. Doctor A's doses were considered reasonable in view of the doses recorded elsewhere and despite carrying out many interventionat procedures in which a high level of exposure to his hands could easily have occurred. This is ascribed to meticulous technique and the fact that the light beam was used at critical points in the procedure to indicate the irradiated area. The use of the light beam for this purpose is not possible of course when an under-couch X-ray tube is used. Taking into account the workload Radiologist A's annual doses were acceptable and well below the 3/10 level. Our article does not purport to pass an opinion about the advisability of over or under-couch tubes, but simply to report on the doses received during this study on an over-couch unit which is in the process of being replaced by a new under-couch angiographic facility.
-
A. O D U R N Y
Departmen t of Radiology East Birmingham Hospital Bordesley Green East Birmingham B9 5ST
M. L. R A M S D A L E W. F. W A L K E R * P. W. H O R T O N
Department of Medical Physics St Lukes Hospital Guildford, Surrey GU1 3NT and *Royal Surrey County Hospital Guildford, Surrey GU2 5XX
C O M P U T E D T O M O G R A P H Y IN ADULT OBLITERATIVE BRONCHIOLITIS S m - I would like to make the following comments on the,article by Dr Sweatman et al. (1990) which reported the observation of widespread areas of increased attenuation in computed tomography (CT) of the lungs in 15 patients with obliterative bronchiolitis (OB): 1 The authors surprisingly omitted to include lung transplantation amongst the several causes of OB which they mentioned. OB is the most common cause of late morbidity and mortality after lung transplan" tation (Dark and Corris, 1989). 2 The statement in the abstract that .CT revealed more extensive changes than the bronchogram is rather misleading and was not justified in the discussion. I presume the authors were referring to the three patients who had only a limited bronchographic examination and could not tolerate the full procedure. The limitation of the bronchogram was caused by poor patient tolerance and was not due to lack of sensitivity 10 demonstrating the extent of the disease. The characteristic changes of OB were demonstrated in all five patients who had bronchography. The sensitivity of bronchography in detecting OB was therefore 100%, similar to that reported by Breatnach and Kerr (1982), whereas the sensitivity of CT was 87%.