1992, The British Journal of Radiology, 65, 1055-1057
Correspondence (The Editors do not hold themselves responsible for opinions expressed by correspondents) The role of "Tcm-HMPAO white cell imaging in suspected orthopaedic infection The Editor—Sir, I wonder why we need a new nuclear medicine technique for the clinical problem of suspected infection of total joint prosthesis. It seems to me that if this diagnosis is strongly suspected the appropriate investigation is aspiration of the joint. If the tap is dry, contrast should be injected to confirm that the nededle was correctly placed. This will exclude infection that warrants early treatment, avoid the unneccessary contamination of operating theatres used for aseptic orthopaedic surgery and provide the organism in infected cases. A nuclear medicine study is appropriate in borderline cases when the risk of infecting a normal joint outweighs the suspicion of sepsis. Here nuclear medicine has a place as a screening tool. The investigation should be designed to suffer the minimum of false negative results. In this role the new and more complex technique that the authors describe, appears less effective than routine "Tcm-MDP scintigraphy. Positive cases should all undergo aspiration of the joint. To confound my quandary regarding the author's recommendations for clinical practice, I see problems in method that may throw further doubt on their conclusions. They assume that a patient who responds to antibiotics must have been infected. Would not an uninfected prosthesis do as well on antibiotics? Equally, how can they be sure that low grade infection did not resolve or at least improve on conservative treatment. Yours etc., D. WILSON
Nuffield Orthopaedic Centre, Windmill Road, Headington, Oxford 0X3 7LD (Received 16 April 1992 and accepted 18 June 1992)
C. COPPING S. M. DALGLIESH N. J. DUDLEY P. A. GRIFFITHS M. HARRINGTON R. POTTER B. D. SMITH
Departments of Medical Physics and Computing and Orthopaedic Surgery, County Hospital, Lincoln L12 5QY (Received 18 May and accepted 18 June 1992) Reference COPPING, C , DALGLIESH, S. M., DUDLEY, N. J., GRIFFITHS, P. A., HARRINGTON, M., POTTER, R. & SMITH, B. D., 1992. The role of
"Tcm-HMPAO white cell imaging in suspected orthopaedic infection. British Journal of Radiology, 65, 309-312.
Coil embolization using a saline flush technique
Reference COPPING, C , DALGLIESH, S. M., DUDLEY, N. J., GRIFFITHS, P. A., HARRINGTON, M., POTTER, R. & SMITH, B. D., 1992. The role of
"Tcm-HMPA0 white cell imaging in suspected orthopaedic infection. British Journal of Radiology, 65, 309-312.
Authors'
contrast is used in conjunction with an image intensifier. Such patients are not referred for nuclear medicine tests and were, therefore, not included in the study. However, following scanning, aspiration was conducted in our study when it was considered appropriate. With regard to using the response of patients to antibiotics following positive scans as confirmation of the presence of infection, we found that long term follow-up revealed no recurrence of their initial symptoms. Similarly, those patients having negative scans who were conservatively managed have remained symptom free since discharge. We therefore feel that our assumptions are justified. Yours etc.,
reply
The Editor—Sir, We thank you for the opportunity to respond to the interesting letter from Dr Wilson concerning our recent article (Copping et al, 1992). The group of patients included in the study were those with suspected latent infection. They presented with pain, no elevation of temperature and subsequent negative blood tests. In our opinion, aspiration is not the primary investigation of choice for such patients. Only when florid infection is strongly suspected do patients undergo routine aspiration prior to surgery. If the tap is dry, Vol. 65, No. 779
The Editor—Sir, We read with great interest the article by Makita et al (1991). We would like to report our experience with the saline flush technique for coil embolization. We have been using a similar technique since 1982. The saline flush manoeuvre was carried out in about 200 patients (approximately 400 coils). The splenic, hepatic, renal and hypogastric arteries were successfully embolized. We used 5 F, 7 F or (in early years) 9 F sized catheters and home-made coils (Ryzhkov et al, 1988) prepared from suitable guidewires (0.95 mm or 1.38 mm in diameter, respectively). The coils had 3-10 rings and were 4-15 cm long when stretched. In most cases coils could be accurately placed using the flush technique. A few serious complications occurred, however. In spite of a carefully checked catheter position by making a strong hand injection of saline under fluoroscopic control, there were four cases of unwanted movement of the catheter tip. Inadvertent embolization of the left common femoral artery by a coil occurred in one patient with gynaecological cancer during therapeutic occlusion of
1055
Correspondence the left hypogastric artery; emergency surgical removal of the coil was needed. In two other patients (both with renal carcinoma), the proximal coil was partially situated in the abdominal aorta postembolization. Fortunately both devices were gently removed during subsequent elective nephrectomy 1 week later. Inadvertent embolization of the coeliac trunk caused no sequelae in the remaining patient with liver cancer. Following this, we now use the saline flush technique with particular caution. We usually perform this manoeuvre for passing the coil to the catheter tip or for positioning the coil partially extruded from the catheter. The final extrusion is made with a guidewire. Coiling inside the catheter occurred in three of six cases, when relatively large (9 F) catheters and smaller coils (made from 7 F corresponded guidewire) were used. Removal of the catheter together with the impacted coil and repeat catheterization were needed in all three patients. We would like to congratulate Dr Makita and colleagues on their excellent results. We feel that our complications with flush technique are related to the use of our home-made coils which are longer and had more rings than the standard ones. It should be considered, however, that extensive experience in embolization procedures and undoubted caution are essential prerequisites for the clinical use of saline flush technique. Yours etc., P. G. TARAZOV E. M. GAPCHENKO I. A. DMITRIEVA V. K. RYZHKOV
Department of Diagnostic Radiology, Central Research Institute of Roentgenology and Radiology, Pesochny-2, St Petersburg 189646, Russia (Received 21 May 1992 and accepted 18 June 1992) References MAKITA, K., FURUI, S., IRIE, T., HIRATA, J., YAMAUCHI, T., TSUCHIQA, K., TAKENAKA, E., OHTOMO, K. & IBUKURO, K., 1991. Emboliza-
tion with steel coils using a saline flush technique. British Journal of Radiology, 64, 708-710. RYZHKOV, V. K., BORISOVA, N. A., GAPCHENKO, E. M. & DMITRI-
IEVA, I. A., 1988. Verschluss von Arterien durch vergrossert Spiralembolisate. Radiologia Diagnostica (Berlin), 29, 713-717.
Imaging of organ function The Editor—Sir, Although the main emphasis of radiology has been the demonstration of disease through observation of changes in structure, imaging of organ function is becoming an increasingly important part of diagnostic radiology. A brief review of papers published in the British Journal of Radiology over a 1 year period (May 1991April 1992) revealed 23 articles concerned with functional aspects of imaging, comprising 24% of the non-therapy papers in this period. 11 of these papers involved Doppler ultrasound, 8 nuclear medicine, 2 computed tomography and 2 magnetic resonance imaging. (There were no papers involving digital subtraction angiography which can be used to estimate blood flow.)
1056
Despite this trend towards increasing involvement in functional aspects of disease, there remains very little formal training in physiology within the FRCR. Also workers in these areas frequently appear to be unaware of what functional information can be derived from the techniques other than their own. There seems to be a need for a forum to allow an exchange of ideas between the different groups with an interest in imaging organ function and I would be keen to hear from anybody interested in becoming involved in such a forum. This would inevitably involve input from multiple disciplines and thus perhaps would be most appropriately organized within the British Institute of Radiology. Yours etc., K. A. M I E S
Department of Nuclear Medicine, Addenbrooke's Hospital, Hills Road, Cambridge CB2 2QQ (Received 26 May 1992 and accepted 18 June 1992)
Fluid levels in a spinal aneurysmal bone cyst following biopsy The Editor—Sir, In their recent article on computed tomography (CT) of osseous lesions (Davies et al, 1992) the authors emphasize the high sensi* tivity and specificity of the presence of fluid-fluid levels within a lesion for the diagnosis of aneurysmal bone cyst (ABC). In their experience fluid-fluid levels were not seen on CT of ABC following disruption of the tumour by biopsy or previous surgery even when they had been present before the intervention. We have recently seen a spinal ABC with multiple fluid levels following open biopsy. A 14-year-old boy presented with a 2 week history of a painful lump in the mid lumbar spine and signs and symptoms of progressive cauda equina compression. Plain radiographs showed a lytic lesion involving L3 and L4. Surgical exploration revealed a blood filled cavity approximately 3 cm in diameter. Two biopsies of the lining were taken. Curettage was considered unwise in view of the proximity to the cauda equina. Histology of the specimens confirmed the diagnosis of ABC. He subsequently made rapid neurological improvement but, 3 weeks later, he was readmitted as an emergency unable to walk. A plain radiograph (Fig. 1) showed the lesion now had a calcified rim and extended into the paraverteWal soft tissues. Computed tomography of the spine (Fig. 2) showed an extensive mass with a partly calcified rim. Multiple fluid levels were present within the lesion. The mass encroached on the spinal canal and a subsequent myelogram showed a complete block at the level of the L2/3 disc space. The patient was treated with radiotherapy and has made an almost complete neurological recovery. This case illustrates that fluid-fluid levels may occur in ABC following surgical intervention although it would appear that they are uncommon. The cause for their disappearance is uncertain but presumably reflects healing of the lesion which commonly occurs' within 2 months of any form of treatment including biopsy alone (Hayetal, 1978;Ohryetal, 1988;DeRosaetal, 1990). It is possible that fluid-fluid levels would not have been seen lesion if it had not
The British Journal of Radiology, Novemberl992
Correspondence (The Editors do not hold themselves responsible for opinions expressed by correspondents) The role of "Tcm-HMPAO white cell imaging in suspected orthopaedic infection The Editor—Sir, I wonder why we need a new nuclear medicine technique for the clinical problem of suspected infection of total joint prosthesis. It seems to me that if this diagnosis is strongly suspected the appropriate investigation is aspiration of the joint. If the tap is dry, contrast should be injected to confirm that the nededle was correctly placed. This will exclude infection that warrants early treatment, avoid the unneccessary contamination of operating theatres used for aseptic orthopaedic surgery and provide the organism in infected cases. A nuclear medicine study is appropriate in borderline cases when the risk of infecting a normal joint outweighs the suspicion of sepsis. Here nuclear medicine has a place as a screening tool. The investigation should be designed to suffer the minimum of false negative results. In this role the new and more complex technique that the authors describe, appears less effective than routine "Tcm-MDP scintigraphy. Positive cases should all undergo aspiration of the joint. To confound my quandary regarding the author's recommendations for clinical practice, I see problems in method that may throw further doubt on their conclusions. They assume that a patient who responds to antibiotics must have been infected. Would not an uninfected prosthesis do as well on antibiotics? Equally, how can they be sure that low grade infection did not resolve or at least improve on conservative treatment. Yours etc., D. WILSON
Nuffield Orthopaedic Centre, Windmill Road, Headington, Oxford 0X3 7LD (Received 16 April 1992 and accepted 18 June 1992)
C. COPPING S. M. DALGLIESH N. J. DUDLEY P. A. GRIFFITHS M. HARRINGTON R. POTTER B. D. SMITH
Departments of Medical Physics and Computing and Orthopaedic Surgery, County Hospital, Lincoln L12 5QY (Received 18 May and accepted 18 June 1992) Reference COPPING, C , DALGLIESH, S. M., DUDLEY, N. J., GRIFFITHS, P. A., HARRINGTON, M., POTTER, R. & SMITH, B. D., 1992. The role of
"Tcm-HMPAO white cell imaging in suspected orthopaedic infection. British Journal of Radiology, 65, 309-312.
Coil embolization using a saline flush technique
Reference COPPING, C , DALGLIESH, S. M., DUDLEY, N. J., GRIFFITHS, P. A., HARRINGTON, M., POTTER, R. & SMITH, B. D., 1992. The role of
"Tcm-HMPA0 white cell imaging in suspected orthopaedic infection. British Journal of Radiology, 65, 309-312.
Authors'
contrast is used in conjunction with an image intensifier. Such patients are not referred for nuclear medicine tests and were, therefore, not included in the study. However, following scanning, aspiration was conducted in our study when it was considered appropriate. With regard to using the response of patients to antibiotics following positive scans as confirmation of the presence of infection, we found that long term follow-up revealed no recurrence of their initial symptoms. Similarly, those patients having negative scans who were conservatively managed have remained symptom free since discharge. We therefore feel that our assumptions are justified. Yours etc.,
reply
The Editor—Sir, We thank you for the opportunity to respond to the interesting letter from Dr Wilson concerning our recent article (Copping et al, 1992). The group of patients included in the study were those with suspected latent infection. They presented with pain, no elevation of temperature and subsequent negative blood tests. In our opinion, aspiration is not the primary investigation of choice for such patients. Only when florid infection is strongly suspected do patients undergo routine aspiration prior to surgery. If the tap is dry, Vol. 65, No. 779
The Editor—Sir, We read with great interest the article by Makita et al (1991). We would like to report our experience with the saline flush technique for coil embolization. We have been using a similar technique since 1982. The saline flush manoeuvre was carried out in about 200 patients (approximately 400 coils). The splenic, hepatic, renal and hypogastric arteries were successfully embolized. We used 5 F, 7 F or (in early years) 9 F sized catheters and home-made coils (Ryzhkov et al, 1988) prepared from suitable guidewires (0.95 mm or 1.38 mm in diameter, respectively). The coils had 3-10 rings and were 4-15 cm long when stretched. In most cases coils could be accurately placed using the flush technique. A few serious complications occurred, however. In spite of a carefully checked catheter position by making a strong hand injection of saline under fluoroscopic control, there were four cases of unwanted movement of the catheter tip. Inadvertent embolization of the left common femoral artery by a coil occurred in one patient with gynaecological cancer during therapeutic occlusion of
1055
Correspondence the left hypogastric artery; emergency surgical removal of the coil was needed. In two other patients (both with renal carcinoma), the proximal coil was partially situated in the abdominal aorta postembolization. Fortunately both devices were gently removed during subsequent elective nephrectomy 1 week later. Inadvertent embolization of the coeliac trunk caused no sequelae in the remaining patient with liver cancer. Following this, we now use the saline flush technique with particular caution. We usually perform this manoeuvre for passing the coil to the catheter tip or for positioning the coil partially extruded from the catheter. The final extrusion is made with a guidewire. Coiling inside the catheter occurred in three of six cases, when relatively large (9 F) catheters and smaller coils (made from 7 F corresponded guidewire) were used. Removal of the catheter together with the impacted coil and repeat catheterization were needed in all three patients. We would like to congratulate Dr Makita and colleagues on their excellent results. We feel that our complications with flush technique are related to the use of our home-made coils which are longer and had more rings than the standard ones. It should be considered, however, that extensive experience in embolization procedures and undoubted caution are essential prerequisites for the clinical use of saline flush technique. Yours etc., P. G. TARAZOV E. M. GAPCHENKO I. A. DMITRIEVA V. K. RYZHKOV
Department of Diagnostic Radiology, Central Research Institute of Roentgenology and Radiology, Pesochny-2, St Petersburg 189646, Russia (Received 21 May 1992 and accepted 18 June 1992) References MAKITA, K., FURUI, S., IRIE, T., HIRATA, J., YAMAUCHI, T., TSUCHIQA, K., TAKENAKA, E., OHTOMO, K. & IBUKURO, K., 1991. Emboliza-
tion with steel coils using a saline flush technique. British Journal of Radiology, 64, 708-710. RYZHKOV, V. K., BORISOVA, N. A., GAPCHENKO, E. M. & DMITRI-
IEVA, I. A., 1988. Verschluss von Arterien durch vergrossert Spiralembolisate. Radiologia Diagnostica (Berlin), 29, 713-717.
Imaging of organ function The Editor—Sir, Although the main emphasis of radiology has been the demonstration of disease through observation of changes in structure, imaging of organ function is becoming an increasingly important part of diagnostic radiology. A brief review of papers published in the British Journal of Radiology over a 1 year period (May 1991April 1992) revealed 23 articles concerned with functional aspects of imaging, comprising 24% of the non-therapy papers in this period. 11 of these papers involved Doppler ultrasound, 8 nuclear medicine, 2 computed tomography and 2 magnetic resonance imaging. (There were no papers involving digital subtraction angiography which can be used to estimate blood flow.)
1056
Despite this trend towards increasing involvement in functional aspects of disease, there remains very little formal training in physiology within the FRCR. Also workers in these areas frequently appear to be unaware of what functional information can be derived from the techniques other than their own. There seems to be a need for a forum to allow an exchange of ideas between the different groups with an interest in imaging organ function and I would be keen to hear from anybody interested in becoming involved in such a forum. This would inevitably involve input from multiple disciplines and thus perhaps would be most appropriately organized within the British Institute of Radiology. Yours etc., K. A. M I E S
Department of Nuclear Medicine, Addenbrooke's Hospital, Hills Road, Cambridge CB2 2QQ (Received 26 May 1992 and accepted 18 June 1992)
Fluid levels in a spinal aneurysmal bone cyst following biopsy The Editor—Sir, In their recent article on computed tomography (CT) of osseous lesions (Davies et al, 1992) the authors emphasize the high sensi* tivity and specificity of the presence of fluid-fluid levels within a lesion for the diagnosis of aneurysmal bone cyst (ABC). In their experience fluid-fluid levels were not seen on CT of ABC following disruption of the tumour by biopsy or previous surgery even when they had been present before the intervention. We have recently seen a spinal ABC with multiple fluid levels following open biopsy. A 14-year-old boy presented with a 2 week history of a painful lump in the mid lumbar spine and signs and symptoms of progressive cauda equina compression. Plain radiographs showed a lytic lesion involving L3 and L4. Surgical exploration revealed a blood filled cavity approximately 3 cm in diameter. Two biopsies of the lining were taken. Curettage was considered unwise in view of the proximity to the cauda equina. Histology of the specimens confirmed the diagnosis of ABC. He subsequently made rapid neurological improvement but, 3 weeks later, he was readmitted as an emergency unable to walk. A plain radiograph (Fig. 1) showed the lesion now had a calcified rim and extended into the paraverteWal soft tissues. Computed tomography of the spine (Fig. 2) showed an extensive mass with a partly calcified rim. Multiple fluid levels were present within the lesion. The mass encroached on the spinal canal and a subsequent myelogram showed a complete block at the level of the L2/3 disc space. The patient was treated with radiotherapy and has made an almost complete neurological recovery. This case illustrates that fluid-fluid levels may occur in ABC following surgical intervention although it would appear that they are uncommon. The cause for their disappearance is uncertain but presumably reflects healing of the lesion which commonly occurs' within 2 months of any form of treatment including biopsy alone (Hayetal, 1978;Ohryetal, 1988;DeRosaetal, 1990). It is possible that fluid-fluid levels would not have been seen lesion if it had not
The British Journal of Radiology, Novemberl992
