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High resolution MR of the inner ear with 3-D visualization in cochlear implant candidates
Clinical Radiology (1997) 52, 872-873
Royal College of Radiologists Annual Undergraduate Prize The following papers won prizes in the 1997 Royal College o f Radiologists Annual Undergraduate Prize Competition. Our congratulations go to Srilakshmi Sharma, Paul Hans and Gideon Paul. EQUAL PRIZE WINNER
- CATEGORY
1
Bone Mineral Density and Fractal Signature Analysis in Hip Osteoarthritis - a Study of a Post-mortem and a Postoperative Population* SRILAKSHMI M. SHARMA, J. ROGERS, I. WATT and C. BUCKLAND-WRIGHT
Rheumatology Unit, Bristol University Department of Medicine, Bristol Royal Infirmary, Bristol, UK Subchondral bone mineral density measurement (BMD) and fractal signature analysis (FSA) may be used to quantify certain features of osteoarthritis (OA). Subchondral sclerosis and osteophytosis are recognized as hypertrophic responses in a single osteoarthritic process. Objective: To test the hypothesis that increasing subchondral sclerosis (cortical bone mineral density) and increasing changes in fractal signature accompany advancing OA in the hip using post-mortem and postoperative specimens. Materials and Methods: (1) Archaeological population: 58 skeletal femoral heads were classified as normal, osteophytic or eburnated; the later being a visual marker for advanced OA. (2) Modern population: nine normal postmortem and 32 postoperative femoral heads were macerated and classified as normal or eburnated. Bone mineral density (BMD) was assessed at the circumference of the femoral heads by DEXA. Fractal signature analysis (FSA) was
performed in 31 hips for compressive and tensile trabeculae at the primary loading site. Areas occupied by osteophyte were measured. Results: FSAs were significantly differen( in the compressive trabeculae of the osteophytic group compared with normal and eburnated (P < 0.001). No changes on FSA were seen for eburnated specimens from either population. BMD was significantly elevated in both eburnated groups (P = 0.002) for archaeological, P < 0.01 for modern populations) confirming subchondral sclerosis in this group. Conclusion: Eburnation and osteophytosis are independent responses to disease rather a progression in parallel. An inverse relationship between them is shown. Eburnated hips from both populations had increased bone density and normal FSA whereas the osteophytic hips had altered compressive trabecular FSA and normal density. These findings suggest two independent responses to disease within a single anatomical site.
* The following describes the investigation of the above in two parts using an archaeological and a modem population executed as part BSc Project and part independent research.
EQUAL PRIZE WINNER
- CATEGORY
1
High Resolution MR of the Inner Ear with 3-D Visualization in Cochlear Implant Candidates PAUL HANS (supervised by Professor A. Jackson, Professor Ramsden, Mr C. Ivers and Mr A. Grant)
University of Manchester, Manchester, UK The development of implantable cochlear electrodes for the treatment of sensorineural hearing loss (SNHL) has increased the importance of accurate diagnostic imaging of cochlear abnormalities. Insertion of an electrode array into the cochlea requires a patent fluid channel - either the scala tympani or scala vestibuli. Unfortunately, many of the pathologies leading to SNHL can cause obliteration of these channels. Magnetic resonance imaging (MRI) has become the imaging modality of choice for the pre-operative assessment of cochlear implant candidates in order to detect any obstruction to the passage of an electrode array. However, © 1997 The Royal College of Radiologists.
the series of 2-D slices through the inner ear produced by MRI can be difficult to interpret due to the complex anatomy of the inner ear. Because of this, computerized 3-D reconstruction of MRI data may improve diagnostic capabilities. Objective: The clinical efficacy of 3-D visualization of T2-weighted MRI of the inner ear using a surface extraction algorithm within a visualization program from Advanced Visualization Systems (AVS) - AVS5 was evaluated. Patients and Methods: Twenty patients attending Manchester Royal Infirmary's ENT department underwent MRI investigation on a Philips ACS NT 1.5 Tesla Scanner, with
tmozr~artAi~UATE~'R~ZE 3-D visualization in AVS5. Imaging results were compared with surgical findings in patients undergoing implantation. Results: 3-D visualization in combination with review of primary images allowed diagnosis of scala tympani occlusion (two cases), occlusion of the basal turn of the cochlea (one case), semicircular canal occlusion (four cases) and
PRIZE
WINNER
-
CATEGORY
873
congenital inner ear deformities (five cases). One patient predicted to have occlusion of the scala tympani was found not to upon implantation. All patients with normal imaging studies had this confirmed upon surgery. Conclusion: 3-D visualization improves comprehension of abnormalities.
2
Prostate Cancer GIDEON A. PAUL
University College of London Medical School, London, UK Prostate cancer is the second leading cause of death from all malignancies. Owing to its rise in prevalence there has been a major focus on screening for this neoplasm to aid early detection and treatment. Objective: To review the arguments for and against screening. In particular to examine whether five screening requirements are fulfilled; (a) Does the prevalence justify the costs? (2) Does early diagnosis and treatment improve survival? (3) Is screening accurate? (4) Is it harmful? (5) Is it available at a reasonable cost? Method: Through research, through Medline, of literature published in the UK and USA. Results: (1) Prostate cancer has a varied and unpredictable course: research has shown that many men die with
© 1997 The Royal College of Radiologists, Clinical Radiology, 52, 872-873.
rather than from the disease. (2) Despite several studies there is no clear consensus on how best to treat clinically localized prostate cancer. (3) Prostate specific antigen (PSA) is, by itself, not accurate enough in the detection of early prostate cancer. (4) The test itself has low morbidity but the incidence of false positives remains a significant issue. (5) The high cost must be balanced against the effectiveness of the programme. Conclusion: There is no doubt as to the increase in histologically diagnosed prostate cancer but it is still unclear if this will be reflected in a similar increase in biologically significant disease. A long-term, randomized controlled trial is necessary to show if screening can reduce the diseasespecific mortality of prostate cancer.
Royal College of Radiologists Annual Undergraduate Prize The following papers won prizes in the 1997 Royal College o f Radiologists Annual Undergraduate Prize Competition. Our congratulations go to Srilakshmi Sharma, Paul Hans and Gideon Paul. EQUAL PRIZE WINNER
- CATEGORY
1
Bone Mineral Density and Fractal Signature Analysis in Hip Osteoarthritis - a Study of a Post-mortem and a Postoperative Population* SRILAKSHMI M. SHARMA, J. ROGERS, I. WATT and C. BUCKLAND-WRIGHT
Rheumatology Unit, Bristol University Department of Medicine, Bristol Royal Infirmary, Bristol, UK Subchondral bone mineral density measurement (BMD) and fractal signature analysis (FSA) may be used to quantify certain features of osteoarthritis (OA). Subchondral sclerosis and osteophytosis are recognized as hypertrophic responses in a single osteoarthritic process. Objective: To test the hypothesis that increasing subchondral sclerosis (cortical bone mineral density) and increasing changes in fractal signature accompany advancing OA in the hip using post-mortem and postoperative specimens. Materials and Methods: (1) Archaeological population: 58 skeletal femoral heads were classified as normal, osteophytic or eburnated; the later being a visual marker for advanced OA. (2) Modern population: nine normal postmortem and 32 postoperative femoral heads were macerated and classified as normal or eburnated. Bone mineral density (BMD) was assessed at the circumference of the femoral heads by DEXA. Fractal signature analysis (FSA) was
performed in 31 hips for compressive and tensile trabeculae at the primary loading site. Areas occupied by osteophyte were measured. Results: FSAs were significantly differen( in the compressive trabeculae of the osteophytic group compared with normal and eburnated (P < 0.001). No changes on FSA were seen for eburnated specimens from either population. BMD was significantly elevated in both eburnated groups (P = 0.002) for archaeological, P < 0.01 for modern populations) confirming subchondral sclerosis in this group. Conclusion: Eburnation and osteophytosis are independent responses to disease rather a progression in parallel. An inverse relationship between them is shown. Eburnated hips from both populations had increased bone density and normal FSA whereas the osteophytic hips had altered compressive trabecular FSA and normal density. These findings suggest two independent responses to disease within a single anatomical site.
* The following describes the investigation of the above in two parts using an archaeological and a modem population executed as part BSc Project and part independent research.
EQUAL PRIZE WINNER
- CATEGORY
1
High Resolution MR of the Inner Ear with 3-D Visualization in Cochlear Implant Candidates PAUL HANS (supervised by Professor A. Jackson, Professor Ramsden, Mr C. Ivers and Mr A. Grant)
University of Manchester, Manchester, UK The development of implantable cochlear electrodes for the treatment of sensorineural hearing loss (SNHL) has increased the importance of accurate diagnostic imaging of cochlear abnormalities. Insertion of an electrode array into the cochlea requires a patent fluid channel - either the scala tympani or scala vestibuli. Unfortunately, many of the pathologies leading to SNHL can cause obliteration of these channels. Magnetic resonance imaging (MRI) has become the imaging modality of choice for the pre-operative assessment of cochlear implant candidates in order to detect any obstruction to the passage of an electrode array. However, © 1997 The Royal College of Radiologists.
the series of 2-D slices through the inner ear produced by MRI can be difficult to interpret due to the complex anatomy of the inner ear. Because of this, computerized 3-D reconstruction of MRI data may improve diagnostic capabilities. Objective: The clinical efficacy of 3-D visualization of T2-weighted MRI of the inner ear using a surface extraction algorithm within a visualization program from Advanced Visualization Systems (AVS) - AVS5 was evaluated. Patients and Methods: Twenty patients attending Manchester Royal Infirmary's ENT department underwent MRI investigation on a Philips ACS NT 1.5 Tesla Scanner, with
tmozr~artAi~UATE~'R~ZE 3-D visualization in AVS5. Imaging results were compared with surgical findings in patients undergoing implantation. Results: 3-D visualization in combination with review of primary images allowed diagnosis of scala tympani occlusion (two cases), occlusion of the basal turn of the cochlea (one case), semicircular canal occlusion (four cases) and
PRIZE
WINNER
-
CATEGORY
873
congenital inner ear deformities (five cases). One patient predicted to have occlusion of the scala tympani was found not to upon implantation. All patients with normal imaging studies had this confirmed upon surgery. Conclusion: 3-D visualization improves comprehension of abnormalities.
2
Prostate Cancer GIDEON A. PAUL
University College of London Medical School, London, UK Prostate cancer is the second leading cause of death from all malignancies. Owing to its rise in prevalence there has been a major focus on screening for this neoplasm to aid early detection and treatment. Objective: To review the arguments for and against screening. In particular to examine whether five screening requirements are fulfilled; (a) Does the prevalence justify the costs? (2) Does early diagnosis and treatment improve survival? (3) Is screening accurate? (4) Is it harmful? (5) Is it available at a reasonable cost? Method: Through research, through Medline, of literature published in the UK and USA. Results: (1) Prostate cancer has a varied and unpredictable course: research has shown that many men die with
© 1997 The Royal College of Radiologists, Clinical Radiology, 52, 872-873.
rather than from the disease. (2) Despite several studies there is no clear consensus on how best to treat clinically localized prostate cancer. (3) Prostate specific antigen (PSA) is, by itself, not accurate enough in the detection of early prostate cancer. (4) The test itself has low morbidity but the incidence of false positives remains a significant issue. (5) The high cost must be balanced against the effectiveness of the programme. Conclusion: There is no doubt as to the increase in histologically diagnosed prostate cancer but it is still unclear if this will be reflected in a similar increase in biologically significant disease. A long-term, randomized controlled trial is necessary to show if screening can reduce the diseasespecific mortality of prostate cancer.