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Improving the image of the dense breast
58
ABSTRACTS
vaccination. Over half of those not vaccinated had simply not got around to it, whereas 13% felt the vaccine was of unproven efficacy and 13% were concerned about side effects. Further education about, and encouragement to accept, vaccination is required.
I M P R O V I N G T H E I M A G E O F T H E DENSE BREAST J. LAW, A. E. K I R K P A T R I C K and G, N E E D H A M
Western General Hospital, Edinburgh Approximately 15 % of all breast films reveal dense structures. These do not generally lie directly over the automatic exposure control detector, and are consequently underexposed (i.e. their exposure corresponds to the curved portion below the linear part of the characteristic curve) and hence show correspondingly reduced contrast. This reduction in contrast can be avoided if the kV is increased at constant mAs, or if the m A s is increased at constant kV. This paper discusses the magnitude required for each of these increases. Films of a realistically simulated dense structure in a p h a n t o m were taken at various kV and m A s settings. These films were scored by 15 consultant radiologists and ranked in order of preference. The preferences showed a high degree of consistency, independent of the radiologist's length of experience. It is not normally possible to tell in advance ifa dense breast structure is present. Practical problems of using a modified technique are discussed, as are the dose implications. Its applications are thought to be at assessment, repeat screening, and in symptomatic patients. Edinburgh experience in applying the modified technique will be reported.
P R I M A R Y I N T R A T H O R A C I C R H A B D O M Y O S A R C O M A IN CHILDREN V. G. M. M C D E R M O T T , B. L A N G D A L E - B R O W N , S. M A C K E N Z I E and G. M. A. H E N D R Y
Royal Hospital for Sick Children, Edinburgh
graphy was performed in LC cases; four (8.3%) underwent preoperative ERCP, demonstrating choledocholithiasis in only one (2.1%) case. Post-operative T-tube cholangiography was performed in five CC cases, but in no case after LC. Ultrasound demonstrated a postoperative intraperitoneal collection in one CC and four LC cases, enabling percutaneous drainage in three cases. Although institutional policy will vary, we conclude that LC will probably result in less per-operative and T-tube cholangiography, while increasing the frequency of intravenous cholangiography and ERCP. Ultrasonography provides important pre-operative information and assists with the diagnosis and management of post-operative complications.
T E L E R A D I O L O G Y IN DISTRICT GENERAL H O S P I T A L S T. M E A G H E R and A . T A S K E R
John Radcliffe Hospital, Oxford As computed tomography has become available in District General Hospitals, m a n y departments have also become equipped with teleradiology links allowing transmission of images by telephone. We prospectively examined all cases whose images were transmitted over a 6 m o n t h period from six District General Hospitals to determine indications for referral, the effect on patient management, and whether the original diagnosis was altered following referral of the CT images. Results to date (over 3 months) show that of a total o f 98 referrals, 93 were to the Regional Neurosurgical Unit, concerning assessment for patient referral. Use of the system outside neurosurgical referrals was limited, with five referred to the Regional CT Unit for opinions on body and musculoskeletal CT.
GATED C A R D I A C R A D I O N U C L I D E S C A N N I N G IN CANDIDATES FOR MAJOR ARTERIAL SURGERY S. J. A R M S T R O N G , U. B H O N S L E and J. B. W I T C O M B E
Gloucestershire Royal Hospital, Gloucester The thorax is a rare primary site for rhabdomyosarcoma in children. We studied four children, aged 2 11 years who were diagnosed and treated over the past l 1 years. All cases have histological correlation and two have undergone extensive surgery. All four cases presented were investigated with radiographs, three with CT, two with thoracic ultrasound and one with angiography. One case presented on chest radiograph as a mediastinal mass radiologically indistinguishable from lymphoma. One case presented with bilateral chylothoraces due to pleural rhabdomyosarcoma. CT initially did not show any pleural disease and diagnosis was difficult. The two other cases presented with large masses occupying a hemithorax with mediastinal shift. Ultrasound and C T confirmed the presence of soft tissue density masses with associated pleural effusions. The diagnosis in one case was complicated by the presence of an underlying congenital cyst, an association described only once before. Angiography was performed in the latter case and showed extensive vascular supply from the aorta with venous drainge above and below the diaphragm. Despite aggressive therapy two cases have died and one has cerebral metastases. Primary intrathoracic rhabdomyosarcoma is a rare t u m o u r with a prognosis worse than for rhabdomyosarcoma arising at other sites. The zadiological manifestations are varied but a large soft tissue mass with compression of adjacent structures is commonest. The radiologist should be aware of the rare associations with chylothorax and congenital pulmonary cysts.
R A D I O L O G I C A L I N V E S T I G A T I O N IN L A P A R O S C O P I C CHOLECYSTECTOMY COMPARED TO CONVENTIONAL C H O L E C Y S T E C T O M Y - AN EARLY A S S E S S M E N T R. F. M C L O U G H L I N , R. G. GIBNEY, K. M E A L Y and J. H Y L A N D
St Vincent's Hospital, Dublin The implications of laparoscopic cholecystectomy (LC) for radiology were assessed by the retrospective comparison of imaging investigations in 96 consecutive cholecystectomy patients (48 LC and 48 conventional cholecystectomy (CC)). Pre-operatively, ultrasound and oral cholecystography were used equally in both groups. Ultrasound indicated a very contracted gallbladder in three of five failed LC cases. Other parameters (gall-bladder wall thickness, calculus size) did not predict per-operative difficulties. Cholangiography was performed either per-operatively or by perioperative E R C P in 40 (83.3%) CC cases demonstrating choledocholithiasis in eight (16.7%) cases. Neither intravenous nor per-operative cholangio-
A gated cardiac radionuclide scan was used to assess left ventricular function in 95 candidates for major arterial surgery over a 3 year period. The patients had either peripheral vascular disease or an aortic aneurysm and were studied retrospectively to determine if and how the result of the scan influenced management, and to assess the cost benefit of the investigation. Eleven patients had left ventricular ejection fractions less than 40%. In three patients with peripheral vascular disease, surgery was modified as a result of the low ejection fraction, and six patients were advised against surgery. The financial savings as a result of not performing elective aortic aneurysm repair in this group of patients offset the total cost of the radionuclide studies. We conclude that a radionuclide scan provides useful and cost-effective information when deciding whether the benefits of surgery outweigh the potential risks.
THE ROLE OF INDIUM-Ill LABELLED WHITE CELL S C A N N I N G IN T H E DIAGNOSIS OF V E R T E B R A L OSTEOMYEL1TIS C. J. B A R B E R and D. A. C U N N I N G H A M
St Mary's Hospital, London Early and accurate diagnosis of vertebral osteomyelitis remains difficult. Plain films are generally held to be unhelpful, certainly in the early stages. 99rnTcM D P bone scanning has a proven high sensitivity but lacks specificity. In-III white cell scanning has both high specificity and sensitivity in the diagnosis of soft tissue sepsis but anecdotal cases suggest that these results m a y not be true of infection in the axial skeleton. We present the data of 20 patients with back pain all of w h o m were suspected of having spinal sepsis on the basis of clinical features, plain radiographs and 99mTc M D P scanning. All underwent In-III white cell scanning. Infection was confirmed or refuted on the basis of biopsy and blood culture. The results show that i f a n indium white cell scan positive for infection is defined as one showing a 'hot spot', then the sensitivity is indeed poorer than that expected from the data relating to soft tissue infections. Both unequivocally normal scans and scans with focal cold areas were seen in proven sepsis. Focal cold areas were also seen in severe degenerative change. If scans showing focal cold areas are also interpreted as positive for infection, sensitivity is increased but of course only at the expense of specificity.
ABSTRACTS
vaccination. Over half of those not vaccinated had simply not got around to it, whereas 13% felt the vaccine was of unproven efficacy and 13% were concerned about side effects. Further education about, and encouragement to accept, vaccination is required.
I M P R O V I N G T H E I M A G E O F T H E DENSE BREAST J. LAW, A. E. K I R K P A T R I C K and G, N E E D H A M
Western General Hospital, Edinburgh Approximately 15 % of all breast films reveal dense structures. These do not generally lie directly over the automatic exposure control detector, and are consequently underexposed (i.e. their exposure corresponds to the curved portion below the linear part of the characteristic curve) and hence show correspondingly reduced contrast. This reduction in contrast can be avoided if the kV is increased at constant mAs, or if the m A s is increased at constant kV. This paper discusses the magnitude required for each of these increases. Films of a realistically simulated dense structure in a p h a n t o m were taken at various kV and m A s settings. These films were scored by 15 consultant radiologists and ranked in order of preference. The preferences showed a high degree of consistency, independent of the radiologist's length of experience. It is not normally possible to tell in advance ifa dense breast structure is present. Practical problems of using a modified technique are discussed, as are the dose implications. Its applications are thought to be at assessment, repeat screening, and in symptomatic patients. Edinburgh experience in applying the modified technique will be reported.
P R I M A R Y I N T R A T H O R A C I C R H A B D O M Y O S A R C O M A IN CHILDREN V. G. M. M C D E R M O T T , B. L A N G D A L E - B R O W N , S. M A C K E N Z I E and G. M. A. H E N D R Y
Royal Hospital for Sick Children, Edinburgh
graphy was performed in LC cases; four (8.3%) underwent preoperative ERCP, demonstrating choledocholithiasis in only one (2.1%) case. Post-operative T-tube cholangiography was performed in five CC cases, but in no case after LC. Ultrasound demonstrated a postoperative intraperitoneal collection in one CC and four LC cases, enabling percutaneous drainage in three cases. Although institutional policy will vary, we conclude that LC will probably result in less per-operative and T-tube cholangiography, while increasing the frequency of intravenous cholangiography and ERCP. Ultrasonography provides important pre-operative information and assists with the diagnosis and management of post-operative complications.
T E L E R A D I O L O G Y IN DISTRICT GENERAL H O S P I T A L S T. M E A G H E R and A . T A S K E R
John Radcliffe Hospital, Oxford As computed tomography has become available in District General Hospitals, m a n y departments have also become equipped with teleradiology links allowing transmission of images by telephone. We prospectively examined all cases whose images were transmitted over a 6 m o n t h period from six District General Hospitals to determine indications for referral, the effect on patient management, and whether the original diagnosis was altered following referral of the CT images. Results to date (over 3 months) show that of a total o f 98 referrals, 93 were to the Regional Neurosurgical Unit, concerning assessment for patient referral. Use of the system outside neurosurgical referrals was limited, with five referred to the Regional CT Unit for opinions on body and musculoskeletal CT.
GATED C A R D I A C R A D I O N U C L I D E S C A N N I N G IN CANDIDATES FOR MAJOR ARTERIAL SURGERY S. J. A R M S T R O N G , U. B H O N S L E and J. B. W I T C O M B E
Gloucestershire Royal Hospital, Gloucester The thorax is a rare primary site for rhabdomyosarcoma in children. We studied four children, aged 2 11 years who were diagnosed and treated over the past l 1 years. All cases have histological correlation and two have undergone extensive surgery. All four cases presented were investigated with radiographs, three with CT, two with thoracic ultrasound and one with angiography. One case presented on chest radiograph as a mediastinal mass radiologically indistinguishable from lymphoma. One case presented with bilateral chylothoraces due to pleural rhabdomyosarcoma. CT initially did not show any pleural disease and diagnosis was difficult. The two other cases presented with large masses occupying a hemithorax with mediastinal shift. Ultrasound and C T confirmed the presence of soft tissue density masses with associated pleural effusions. The diagnosis in one case was complicated by the presence of an underlying congenital cyst, an association described only once before. Angiography was performed in the latter case and showed extensive vascular supply from the aorta with venous drainge above and below the diaphragm. Despite aggressive therapy two cases have died and one has cerebral metastases. Primary intrathoracic rhabdomyosarcoma is a rare t u m o u r with a prognosis worse than for rhabdomyosarcoma arising at other sites. The zadiological manifestations are varied but a large soft tissue mass with compression of adjacent structures is commonest. The radiologist should be aware of the rare associations with chylothorax and congenital pulmonary cysts.
R A D I O L O G I C A L I N V E S T I G A T I O N IN L A P A R O S C O P I C CHOLECYSTECTOMY COMPARED TO CONVENTIONAL C H O L E C Y S T E C T O M Y - AN EARLY A S S E S S M E N T R. F. M C L O U G H L I N , R. G. GIBNEY, K. M E A L Y and J. H Y L A N D
St Vincent's Hospital, Dublin The implications of laparoscopic cholecystectomy (LC) for radiology were assessed by the retrospective comparison of imaging investigations in 96 consecutive cholecystectomy patients (48 LC and 48 conventional cholecystectomy (CC)). Pre-operatively, ultrasound and oral cholecystography were used equally in both groups. Ultrasound indicated a very contracted gallbladder in three of five failed LC cases. Other parameters (gall-bladder wall thickness, calculus size) did not predict per-operative difficulties. Cholangiography was performed either per-operatively or by perioperative E R C P in 40 (83.3%) CC cases demonstrating choledocholithiasis in eight (16.7%) cases. Neither intravenous nor per-operative cholangio-
A gated cardiac radionuclide scan was used to assess left ventricular function in 95 candidates for major arterial surgery over a 3 year period. The patients had either peripheral vascular disease or an aortic aneurysm and were studied retrospectively to determine if and how the result of the scan influenced management, and to assess the cost benefit of the investigation. Eleven patients had left ventricular ejection fractions less than 40%. In three patients with peripheral vascular disease, surgery was modified as a result of the low ejection fraction, and six patients were advised against surgery. The financial savings as a result of not performing elective aortic aneurysm repair in this group of patients offset the total cost of the radionuclide studies. We conclude that a radionuclide scan provides useful and cost-effective information when deciding whether the benefits of surgery outweigh the potential risks.
THE ROLE OF INDIUM-Ill LABELLED WHITE CELL S C A N N I N G IN T H E DIAGNOSIS OF V E R T E B R A L OSTEOMYEL1TIS C. J. B A R B E R and D. A. C U N N I N G H A M
St Mary's Hospital, London Early and accurate diagnosis of vertebral osteomyelitis remains difficult. Plain films are generally held to be unhelpful, certainly in the early stages. 99rnTcM D P bone scanning has a proven high sensitivity but lacks specificity. In-III white cell scanning has both high specificity and sensitivity in the diagnosis of soft tissue sepsis but anecdotal cases suggest that these results m a y not be true of infection in the axial skeleton. We present the data of 20 patients with back pain all of w h o m were suspected of having spinal sepsis on the basis of clinical features, plain radiographs and 99mTc M D P scanning. All underwent In-III white cell scanning. Infection was confirmed or refuted on the basis of biopsy and blood culture. The results show that i f a n indium white cell scan positive for infection is defined as one showing a 'hot spot', then the sensitivity is indeed poorer than that expected from the data relating to soft tissue infections. Both unequivocally normal scans and scans with focal cold areas were seen in proven sepsis. Focal cold areas were also seen in severe degenerative change. If scans showing focal cold areas are also interpreted as positive for infection, sensitivity is increased but of course only at the expense of specificity.