Hege Skogmo - Academia.edu (original) (raw)
Papers by Hege Skogmo
Norsk Veterinærtidsskrift, 2010
The clinical utility of boron neutron capture (BNC) with thermal/epithermal neutron beams has bee... more The clinical utility of boron neutron capture (BNC) with thermal/epithermal neutron beams has been limited to tumors located at shallow depths, such as in the brain and skin. Capture of the thermal neutron component within a predominantly fast neutron (FN) beam could selectively enhance cytotoxicity in deeply located tumors, such as lung cancer, thereby increasing the availability of this treatment to far greater numbers of cancer patients.1, 2, 3, 4 Even combining concurrent chemotherapy and photon radiation followed by surgery for treatment of locally advanced non-small cell lung cancer (NSCLC), local recurrence was detected in 40% of treatment failures.5 With improved effectiveness of systemic therapies, local control of bulky disease at the primary site becomes increasingly important for improving median survival and increasing probability of cure. The purpose of this ongoing study was to determine the feasibility and toxicity of BNC/FNT in a trial for dogs with spontaneous NSCLC.
Norsk Veterinærtidsskrift, 2010
Electron microscopy was used to diagnose primary ciliary dyskinesia in a litter of English pointe... more Electron microscopy was used to diagnose primary ciliary dyskinesia in a litter of English pointer dogs and in a golden retriever dog. A technique of membrane solubilization, fixation, and negative staining with glutaraldehyde tannic acid identified abnormally constructed central and B microtubules in respiratory cilia from dogs with primary ciliary dyskinesia. Shortened outer dynein arms commonly associated with primary ciliary dyskinesia actually represents the absence of a specific subset of the three most peripheral components of the whole outer dynein arm structure.
Frontiers in Veterinary Science
BackgroundRadiotherapy (RT) is increasingly being used on dogs with spontaneous head and neck can... more BackgroundRadiotherapy (RT) is increasingly being used on dogs with spontaneous head and neck cancer (HNC), which account for a large percentage of veterinary patients treated with RT. Accurate definition of the gross tumor volume (GTV) is a vital part of RT planning, ensuring adequate dose coverage of the tumor while limiting the radiation dose to surrounding tissues. Currently the GTV is contoured manually in medical images, which is a time-consuming and challenging task.PurposeThe purpose of this study was to evaluate the applicability of deep learning-based automatic segmentation of the GTV in canine patients with HNC.Materials and methodsContrast-enhanced computed tomography (CT) images and corresponding manual GTV contours of 36 canine HNC patients and 197 human HNC patients were included. A 3D U-Net convolutional neural network (CNN) was trained to automatically segment the GTV in canine patients using two main approaches: (i) training models from scratch based solely on cani...
Medical Physics, 2001
Our objective in this work was to assess the precision and degree of accuracy with which intensit... more Our objective in this work was to assess the precision and degree of accuracy with which intensity modulated radiation therapy ͑IMRT͒ can deliver highly localized dose distributions to tumors near critical structures using the dynamic sliding window technique. Measurements of dose distribution were performed both in vivo and in vitro using a combination of dosimeters ͓thermoluminescent dosimeters ͑TLD's͒, films, and diodes͔. In vivo measurements were performed in two groups of purpose-bred dogs: one receiving four-field three-dimensional ͑3D͒ conformal treatment and the other receiving IMRT. The algorithms used in the inverse planning process included the Macro Pencil Beam ͑MPB͒ model and Projections onto Convex Sets ͑POCS͒. Single beam measurements were performed in phantoms to verify the accuracy of monitor unit settings required for delivering the desired doses. The composite doses from the delivery of the seven beam intensity modulated plans were measured in phantoms and cadavers. Biological end points ͑spinal cord toxicity and neurolgic deficits due to irradiation͒ were evaluated at the end of one year to determine the spatial accuracy of the IMRT treatments over a fractionated course in live subjects. Results in single beam measurements were used at first to improve the dose calculation and translation algorithms. Results of the measurements for the delivery of all seven beams in phantoms confirmed that the system was capable of accurate spatial and dosimetric IMRT delivery. The in vivo results showed dramatic differences between control and IMRT-treated dogs, with the IMRT group showing no adverse effects and the control animals showing severe spinal cord injuries due to irradiation. The measurements presented in this paper have helped to verify the successful and accurate delivery of IMRT in a clinically related model using the University of Washington Medical Center ͑UWMC͒ system.
Journal of the American Veterinary Medical Association, 2001
A 9-year-old cat with hyperthyroidism was referred for radioactive iodine treatment. The cat also... more A 9-year-old cat with hyperthyroidism was referred for radioactive iodine treatment. The cat also had a ventral cervical mass that the owners reported had been present for several years and had increased in size during the past few weeks. On physical examination, the mass was found to have caused lateral displacement of the trachea, esophagus, jugular vein, and common carotid artery. The mass was aspirated and was determined to be cystic in nature. Concentrations of thyroid hormones in the cystic fluid were similar to serum concentrations, and nuclear scintigraphy revealed thyroactive tissue lining the cyst wall. Magnetic resonance imaging suggested that the cyst originated from the right lobe of the thyroid gland. The cat was treated with sodium iodide I 131 but died 4 days later, presumably as a result of aspiration of gastric or esophageal contents. A necropsy was not performed, but histologic examination of a biopsy specimen of the mass indicated that it was a cystic thyroid adenoma.
Veterinary Parasitology, 1997
This is the first report describing the finding of the canine nasal mite, Pneumonyssoides caninum... more This is the first report describing the finding of the canine nasal mite, Pneumonyssoides caninum, in a silver fox (Vulpes vulpes). It is also the first time P. caninum has been found in a species other than the dog (Canis familiaris). A severely debilitated 10-month-old, male silver fox was euthanised due to suspected renal failure. During autopsy, a female mite matching the description of P. caninum was found in the nasal cavity of the fox. The finding of P. caninum in the fox suggests the existence of a new host, or at the very least a transient host. The fox's role in maintaining and/or propagating canine nasal mite infection needs to be explored.
Veterinary Clinics of North America: Small Animal Practice, 1998
This article includes imaging of the glenohumeral (shoulder), elbow, stifle, and tarsal joints. T... more This article includes imaging of the glenohumeral (shoulder), elbow, stifle, and tarsal joints. The imaging modalities discussed are survey radiography, contrast arthrography, linear tomography, ultrasound, computed tomography, scintigraphy and magnetic resonance. Survey radiography is the first choice imaging modality for diagnosing osteochondrosis dissecans in dogs. In cases where survey radiography fail to demonstrate a lesion other modalities such as scintigraphy, linear tomography, computed tomography, and magnetic resonance may be helpful. Survey radiography, contrast arthrography, computed tomography, and magnetic resonance may also provide additional information contributing to early diagnosis and treatment.
Frontiers in Neutron Capture Therapy, 2001
Dogs develop spontaneous brain tumors as in humans and serve as a large animal model for evaluati... more Dogs develop spontaneous brain tumors as in humans and serve as a large animal model for evaluation of BNCT for treatment of brain tumor. In this study, 13 dogs with spontaneous brain tumors were treated surgery (SX) followed by BNCT and the median survival of was determined. The median survival was also determined for a group of dogs with spontaneous brain tumors previously treated with BNCT alone (n = 20). All dogs had histologic confirmation of tumor type either at the time of surgery or at necropsy. Of the dogs treated surgically, BNCT followed 3 to 6 weeks after surgery. Dogs of each group had various tumor types, however, the majority were meningiomas (13/20 BNCT; 9/13 SX + BNCT). Of the dogs in the surgery group, all had incomplete resections of the tumor primarily due to tumor location or infiltration of surrounding brain. In both groups, BSH or p-BPA were used for the boron agent. Peak brain dose was 10 to 12.5 Gy- equivalent.
The Use of Computers in Radiation Therapy, 2000
Dose distribution delivered in multiple complex field irradiations can often be improved signific... more Dose distribution delivered in multiple complex field irradiations can often be improved significantly by modulation of the 2-D intensity profiles of each beam [?, ?]. Intensity modulated radiation therapy (IMRT) delivered with dynamic multileaf collimators (MLC) promises increased local control of certain tumors by providing improved dose localization within the target volume and minimal damage to surrounding tissues with low tolerance to ionizing radiation. With this irradiation technique, the tumor dose can be substantially escalated, thereby improving the probability of tumor control [?].
The Use of Computers in Radiation Therapy, 2000
Intensity modulated radiation therapy is pushing the frontiers of radiation therapy in several di... more Intensity modulated radiation therapy is pushing the frontiers of radiation therapy in several different areas simultaneously. Broadly speaking, these areas are (a) the dose calculation algorithms, (b) the use of inverse planning or plan optimization algorithms, (c) the complexity of the treatment plan in terms of the large increase in the number of variables that define the treatment, and (d) the enlarged scope of manufacturer-provided software needed to deliver the entire treatment. These advances are, of course, not independent. The optimization algorithms produce fluence distributions that result in a large number of time-dependent variables being required. In turn, this increase in the number of states of the delivery needing to be modelled (such as leaf edge penumbra at nearly every point within the field) has required a more sophisticated dose calculation algorithm, since relatively small errors per field become much more important with so many segments. And finally, the large number of variables results in the need for computer control of the treatment delivery since no person could manage the complexity.
Frontiers in Neutron Capture Therapy, 2001
Boron neutron capture therapy (BNCT) treatments utilizing epithermal neutron beams and available ... more Boron neutron capture therapy (BNCT) treatments utilizing epithermal neutron beams and available boron compounds result in a mixed irradiation field of low and high linear energy components (LET). Previous studies attempting to measure the repair of the low LET component, comparing a multifraction study to single fraction study failed to identify sufficient repair in normal tissue tolerance studies of the dog brain utilizing borocaptate sodium (BSH) and epithermal neutron irradiation.1 Many current patients in clinical trials relapse approximately 6 months after their initial BNCT treatment. Many have considered the possibility of retreatment due to the theoretical dose localization in BNCT. A six-month interval would not be sufficient to allow retreatment of a full course of conventional irradiation. Therefore, a study was undertaken to give purpose-bred laboratory dogs an initial BNCT to near tolerance levels followed in six-month by a second identical dose.
Veterinary Radiology <html_ent glyph="@amp;" ascii="&"/> Ultrasound, 1999
Twenty-one dogs with confirmed tumors of the spinal cord or paraspinal tissues were imaged with m... more Twenty-one dogs with confirmed tumors of the spinal cord or paraspinal tissues were imaged with magnetic resonance (MR) imaging. Anatomical location, location in relation to the dura and the medulla (spinal cord), and bone infiltration were assessed on the MR images and compared to findings at surgery or necropsy. Localization of tumors in the intradural-extramedullary compartment was not always possible. Bone infiltration was correctly assessed in all but one dog, and the anatomical locations involved were accurately determined in all dogs. Sagittal T2-weighted images were helpful to determine the anatomical location. Transverse T1-weighted images pre and post Gd-DTPA administration were helpful for additional localization and definition of tumor extension.
Veterinary Radiology <html_ent glyph="@amp;" ascii="&"/> Ultrasound, 2001
The pituitary gland was measured from transverse magnetic resonance T1-weighted images after Gado... more The pituitary gland was measured from transverse magnetic resonance T1-weighted images after Gadolinium administration in 96 dogs weighing from 13 to 45 kg. The measurements were done by hand with calipers. The mean (+/- standard deviation) pituitary gland height was 5.1 mm (+/-0.9 mm). The mean width was 6.4 mm (+/- 1.1 mm). The correlation coefficient between pituitary and brain measurements, between pituitary measurement and body weight, and brain measurements and body weight was 0.0 to 0.3. A hyperintense region was present on T1-weighted images in the center of the pituitary gland in 64% of the dogs. At necropsy the pituitary glands were grossly and histologically normal. No pituitary gland measurements were performed at necropsy.
Veterinary Radiology <html_ent glyph="@amp;" ascii="&"/> Ultrasound, 2000
Skip to Main Content. ...
Veterinary Radiology <html_ent glyph="@amp;" ascii="&"/> Ultrasound, 2003
The purpose of the study was to evaluate the accuracy and precision of a rigid positioning device... more The purpose of the study was to evaluate the accuracy and precision of a rigid positioning device for repositioning the cervical spine accurately and precisely during conformal radiation therapy of dogs. Fifteen purpose bred research dogs in a radiation therapy study were included. The dogs were positioned using a head holder and a deflatable pillow attached to the treatment table. Port films were reviewed retrospectively, and repositioning precision was recorded by measurements in three orthogonal planes of the head, 2nd cervical vertebra and 1st thoracic spinous process. Mean treatment position was compared to the planning position for a measurement of systematic setup error. Mean interfraction position variation of the 2nd cervical vertebra was 0.2, 0.1 and 0.2 cm for the ventrodorsal, caudocranial and laterolateral directions respectively, and the average systematic set up error was 0.2, 0.1 and 0.2 cm for the ventrodorsal, caudocranial and laterolateral directions respectively. Knowledge of the magnitude of reposition errors should be included when determining the margins around the tumor.
Veterinary Radiology <html_ent glyph="@amp;" ascii="&"/> Ultrasound, 2001
A 6 month-old dog was examined for progressive paraparesis. On physical examination bony malforma... more A 6 month-old dog was examined for progressive paraparesis. On physical examination bony malformations were palpated over the cranial lumbar vertebral bodies and on the left metatarsal bone. Neuroanatomic lesion localization for the paraparesis was a T3-L3 spinal cord lesion. Radiographs confirmed bony masses at L1-L2 and on the left 3rd metatarsal bone. Magnetic resonance imaging was performed from T3-L3. Severe spinal cord compression was identified at L1-L2. Surgical decompression and biopsy confirmed the mass to be cartilaginous exostoses. This paper is an example of cartilaginous exostoses imaged with MR.
Veterinary Radiology <html_ent glyph="@amp;" ascii="&"/> Ultrasound, 2000
The purpose of this retrospective study was to evaluate the repositioning accuracy of different p... more The purpose of this retrospective study was to evaluate the repositioning accuracy of different positioning devices in order to determine their applicability for potential use in conformal radiation therapy for animals. Forty-four animals with spontaneous tumors of the head were included. The animals were divided into 3 groups determined according to the positioning device used. Group 1 animals were positioned using a thermoplastic mask. Group 2 animals were positioned using a head holder. Group 3 animals were positioned using the head holder and an inflatable pillow. The time of presentation determined which position device was used. Port films of the 44 patients were reviewed retrospectively, and the repositioning precision was recorded by measurements in three orthogonal planes. Groups 2 and 3 had significantly better repositioning accuracy (P &amp;lt; or = 0.05) compared to Group 1. The position variation was not significantly different (P &amp;lt; or = 0.05) between Groups 2 and 3 in the lateral and longitudinal direction. Group 3 had a median reposition variation of 0.5 to 1.0 mm, with a standard deviation of 1.0 to 1.5 mm.
Veterinary Radiology <html_ent glyph="@amp;" ascii="&"/> Ultrasound, 2003
Radiotherapy and Oncology, 2010
Norsk Veterinærtidsskrift, 2010
The clinical utility of boron neutron capture (BNC) with thermal/epithermal neutron beams has bee... more The clinical utility of boron neutron capture (BNC) with thermal/epithermal neutron beams has been limited to tumors located at shallow depths, such as in the brain and skin. Capture of the thermal neutron component within a predominantly fast neutron (FN) beam could selectively enhance cytotoxicity in deeply located tumors, such as lung cancer, thereby increasing the availability of this treatment to far greater numbers of cancer patients.1, 2, 3, 4 Even combining concurrent chemotherapy and photon radiation followed by surgery for treatment of locally advanced non-small cell lung cancer (NSCLC), local recurrence was detected in 40% of treatment failures.5 With improved effectiveness of systemic therapies, local control of bulky disease at the primary site becomes increasingly important for improving median survival and increasing probability of cure. The purpose of this ongoing study was to determine the feasibility and toxicity of BNC/FNT in a trial for dogs with spontaneous NSCLC.
Norsk Veterinærtidsskrift, 2010
Electron microscopy was used to diagnose primary ciliary dyskinesia in a litter of English pointe... more Electron microscopy was used to diagnose primary ciliary dyskinesia in a litter of English pointer dogs and in a golden retriever dog. A technique of membrane solubilization, fixation, and negative staining with glutaraldehyde tannic acid identified abnormally constructed central and B microtubules in respiratory cilia from dogs with primary ciliary dyskinesia. Shortened outer dynein arms commonly associated with primary ciliary dyskinesia actually represents the absence of a specific subset of the three most peripheral components of the whole outer dynein arm structure.
Frontiers in Veterinary Science
BackgroundRadiotherapy (RT) is increasingly being used on dogs with spontaneous head and neck can... more BackgroundRadiotherapy (RT) is increasingly being used on dogs with spontaneous head and neck cancer (HNC), which account for a large percentage of veterinary patients treated with RT. Accurate definition of the gross tumor volume (GTV) is a vital part of RT planning, ensuring adequate dose coverage of the tumor while limiting the radiation dose to surrounding tissues. Currently the GTV is contoured manually in medical images, which is a time-consuming and challenging task.PurposeThe purpose of this study was to evaluate the applicability of deep learning-based automatic segmentation of the GTV in canine patients with HNC.Materials and methodsContrast-enhanced computed tomography (CT) images and corresponding manual GTV contours of 36 canine HNC patients and 197 human HNC patients were included. A 3D U-Net convolutional neural network (CNN) was trained to automatically segment the GTV in canine patients using two main approaches: (i) training models from scratch based solely on cani...
Medical Physics, 2001
Our objective in this work was to assess the precision and degree of accuracy with which intensit... more Our objective in this work was to assess the precision and degree of accuracy with which intensity modulated radiation therapy ͑IMRT͒ can deliver highly localized dose distributions to tumors near critical structures using the dynamic sliding window technique. Measurements of dose distribution were performed both in vivo and in vitro using a combination of dosimeters ͓thermoluminescent dosimeters ͑TLD's͒, films, and diodes͔. In vivo measurements were performed in two groups of purpose-bred dogs: one receiving four-field three-dimensional ͑3D͒ conformal treatment and the other receiving IMRT. The algorithms used in the inverse planning process included the Macro Pencil Beam ͑MPB͒ model and Projections onto Convex Sets ͑POCS͒. Single beam measurements were performed in phantoms to verify the accuracy of monitor unit settings required for delivering the desired doses. The composite doses from the delivery of the seven beam intensity modulated plans were measured in phantoms and cadavers. Biological end points ͑spinal cord toxicity and neurolgic deficits due to irradiation͒ were evaluated at the end of one year to determine the spatial accuracy of the IMRT treatments over a fractionated course in live subjects. Results in single beam measurements were used at first to improve the dose calculation and translation algorithms. Results of the measurements for the delivery of all seven beams in phantoms confirmed that the system was capable of accurate spatial and dosimetric IMRT delivery. The in vivo results showed dramatic differences between control and IMRT-treated dogs, with the IMRT group showing no adverse effects and the control animals showing severe spinal cord injuries due to irradiation. The measurements presented in this paper have helped to verify the successful and accurate delivery of IMRT in a clinically related model using the University of Washington Medical Center ͑UWMC͒ system.
Journal of the American Veterinary Medical Association, 2001
A 9-year-old cat with hyperthyroidism was referred for radioactive iodine treatment. The cat also... more A 9-year-old cat with hyperthyroidism was referred for radioactive iodine treatment. The cat also had a ventral cervical mass that the owners reported had been present for several years and had increased in size during the past few weeks. On physical examination, the mass was found to have caused lateral displacement of the trachea, esophagus, jugular vein, and common carotid artery. The mass was aspirated and was determined to be cystic in nature. Concentrations of thyroid hormones in the cystic fluid were similar to serum concentrations, and nuclear scintigraphy revealed thyroactive tissue lining the cyst wall. Magnetic resonance imaging suggested that the cyst originated from the right lobe of the thyroid gland. The cat was treated with sodium iodide I 131 but died 4 days later, presumably as a result of aspiration of gastric or esophageal contents. A necropsy was not performed, but histologic examination of a biopsy specimen of the mass indicated that it was a cystic thyroid adenoma.
Veterinary Parasitology, 1997
This is the first report describing the finding of the canine nasal mite, Pneumonyssoides caninum... more This is the first report describing the finding of the canine nasal mite, Pneumonyssoides caninum, in a silver fox (Vulpes vulpes). It is also the first time P. caninum has been found in a species other than the dog (Canis familiaris). A severely debilitated 10-month-old, male silver fox was euthanised due to suspected renal failure. During autopsy, a female mite matching the description of P. caninum was found in the nasal cavity of the fox. The finding of P. caninum in the fox suggests the existence of a new host, or at the very least a transient host. The fox's role in maintaining and/or propagating canine nasal mite infection needs to be explored.
Veterinary Clinics of North America: Small Animal Practice, 1998
This article includes imaging of the glenohumeral (shoulder), elbow, stifle, and tarsal joints. T... more This article includes imaging of the glenohumeral (shoulder), elbow, stifle, and tarsal joints. The imaging modalities discussed are survey radiography, contrast arthrography, linear tomography, ultrasound, computed tomography, scintigraphy and magnetic resonance. Survey radiography is the first choice imaging modality for diagnosing osteochondrosis dissecans in dogs. In cases where survey radiography fail to demonstrate a lesion other modalities such as scintigraphy, linear tomography, computed tomography, and magnetic resonance may be helpful. Survey radiography, contrast arthrography, computed tomography, and magnetic resonance may also provide additional information contributing to early diagnosis and treatment.
Frontiers in Neutron Capture Therapy, 2001
Dogs develop spontaneous brain tumors as in humans and serve as a large animal model for evaluati... more Dogs develop spontaneous brain tumors as in humans and serve as a large animal model for evaluation of BNCT for treatment of brain tumor. In this study, 13 dogs with spontaneous brain tumors were treated surgery (SX) followed by BNCT and the median survival of was determined. The median survival was also determined for a group of dogs with spontaneous brain tumors previously treated with BNCT alone (n = 20). All dogs had histologic confirmation of tumor type either at the time of surgery or at necropsy. Of the dogs treated surgically, BNCT followed 3 to 6 weeks after surgery. Dogs of each group had various tumor types, however, the majority were meningiomas (13/20 BNCT; 9/13 SX + BNCT). Of the dogs in the surgery group, all had incomplete resections of the tumor primarily due to tumor location or infiltration of surrounding brain. In both groups, BSH or p-BPA were used for the boron agent. Peak brain dose was 10 to 12.5 Gy- equivalent.
The Use of Computers in Radiation Therapy, 2000
Dose distribution delivered in multiple complex field irradiations can often be improved signific... more Dose distribution delivered in multiple complex field irradiations can often be improved significantly by modulation of the 2-D intensity profiles of each beam [?, ?]. Intensity modulated radiation therapy (IMRT) delivered with dynamic multileaf collimators (MLC) promises increased local control of certain tumors by providing improved dose localization within the target volume and minimal damage to surrounding tissues with low tolerance to ionizing radiation. With this irradiation technique, the tumor dose can be substantially escalated, thereby improving the probability of tumor control [?].
The Use of Computers in Radiation Therapy, 2000
Intensity modulated radiation therapy is pushing the frontiers of radiation therapy in several di... more Intensity modulated radiation therapy is pushing the frontiers of radiation therapy in several different areas simultaneously. Broadly speaking, these areas are (a) the dose calculation algorithms, (b) the use of inverse planning or plan optimization algorithms, (c) the complexity of the treatment plan in terms of the large increase in the number of variables that define the treatment, and (d) the enlarged scope of manufacturer-provided software needed to deliver the entire treatment. These advances are, of course, not independent. The optimization algorithms produce fluence distributions that result in a large number of time-dependent variables being required. In turn, this increase in the number of states of the delivery needing to be modelled (such as leaf edge penumbra at nearly every point within the field) has required a more sophisticated dose calculation algorithm, since relatively small errors per field become much more important with so many segments. And finally, the large number of variables results in the need for computer control of the treatment delivery since no person could manage the complexity.
Frontiers in Neutron Capture Therapy, 2001
Boron neutron capture therapy (BNCT) treatments utilizing epithermal neutron beams and available ... more Boron neutron capture therapy (BNCT) treatments utilizing epithermal neutron beams and available boron compounds result in a mixed irradiation field of low and high linear energy components (LET). Previous studies attempting to measure the repair of the low LET component, comparing a multifraction study to single fraction study failed to identify sufficient repair in normal tissue tolerance studies of the dog brain utilizing borocaptate sodium (BSH) and epithermal neutron irradiation.1 Many current patients in clinical trials relapse approximately 6 months after their initial BNCT treatment. Many have considered the possibility of retreatment due to the theoretical dose localization in BNCT. A six-month interval would not be sufficient to allow retreatment of a full course of conventional irradiation. Therefore, a study was undertaken to give purpose-bred laboratory dogs an initial BNCT to near tolerance levels followed in six-month by a second identical dose.
Veterinary Radiology <html_ent glyph="@amp;" ascii="&"/> Ultrasound, 1999
Twenty-one dogs with confirmed tumors of the spinal cord or paraspinal tissues were imaged with m... more Twenty-one dogs with confirmed tumors of the spinal cord or paraspinal tissues were imaged with magnetic resonance (MR) imaging. Anatomical location, location in relation to the dura and the medulla (spinal cord), and bone infiltration were assessed on the MR images and compared to findings at surgery or necropsy. Localization of tumors in the intradural-extramedullary compartment was not always possible. Bone infiltration was correctly assessed in all but one dog, and the anatomical locations involved were accurately determined in all dogs. Sagittal T2-weighted images were helpful to determine the anatomical location. Transverse T1-weighted images pre and post Gd-DTPA administration were helpful for additional localization and definition of tumor extension.
Veterinary Radiology <html_ent glyph="@amp;" ascii="&"/> Ultrasound, 2001
The pituitary gland was measured from transverse magnetic resonance T1-weighted images after Gado... more The pituitary gland was measured from transverse magnetic resonance T1-weighted images after Gadolinium administration in 96 dogs weighing from 13 to 45 kg. The measurements were done by hand with calipers. The mean (+/- standard deviation) pituitary gland height was 5.1 mm (+/-0.9 mm). The mean width was 6.4 mm (+/- 1.1 mm). The correlation coefficient between pituitary and brain measurements, between pituitary measurement and body weight, and brain measurements and body weight was 0.0 to 0.3. A hyperintense region was present on T1-weighted images in the center of the pituitary gland in 64% of the dogs. At necropsy the pituitary glands were grossly and histologically normal. No pituitary gland measurements were performed at necropsy.
Veterinary Radiology <html_ent glyph="@amp;" ascii="&"/> Ultrasound, 2000
Skip to Main Content. ...
Veterinary Radiology <html_ent glyph="@amp;" ascii="&"/> Ultrasound, 2003
The purpose of the study was to evaluate the accuracy and precision of a rigid positioning device... more The purpose of the study was to evaluate the accuracy and precision of a rigid positioning device for repositioning the cervical spine accurately and precisely during conformal radiation therapy of dogs. Fifteen purpose bred research dogs in a radiation therapy study were included. The dogs were positioned using a head holder and a deflatable pillow attached to the treatment table. Port films were reviewed retrospectively, and repositioning precision was recorded by measurements in three orthogonal planes of the head, 2nd cervical vertebra and 1st thoracic spinous process. Mean treatment position was compared to the planning position for a measurement of systematic setup error. Mean interfraction position variation of the 2nd cervical vertebra was 0.2, 0.1 and 0.2 cm for the ventrodorsal, caudocranial and laterolateral directions respectively, and the average systematic set up error was 0.2, 0.1 and 0.2 cm for the ventrodorsal, caudocranial and laterolateral directions respectively. Knowledge of the magnitude of reposition errors should be included when determining the margins around the tumor.
Veterinary Radiology <html_ent glyph="@amp;" ascii="&"/> Ultrasound, 2001
A 6 month-old dog was examined for progressive paraparesis. On physical examination bony malforma... more A 6 month-old dog was examined for progressive paraparesis. On physical examination bony malformations were palpated over the cranial lumbar vertebral bodies and on the left metatarsal bone. Neuroanatomic lesion localization for the paraparesis was a T3-L3 spinal cord lesion. Radiographs confirmed bony masses at L1-L2 and on the left 3rd metatarsal bone. Magnetic resonance imaging was performed from T3-L3. Severe spinal cord compression was identified at L1-L2. Surgical decompression and biopsy confirmed the mass to be cartilaginous exostoses. This paper is an example of cartilaginous exostoses imaged with MR.
Veterinary Radiology <html_ent glyph="@amp;" ascii="&"/> Ultrasound, 2000
The purpose of this retrospective study was to evaluate the repositioning accuracy of different p... more The purpose of this retrospective study was to evaluate the repositioning accuracy of different positioning devices in order to determine their applicability for potential use in conformal radiation therapy for animals. Forty-four animals with spontaneous tumors of the head were included. The animals were divided into 3 groups determined according to the positioning device used. Group 1 animals were positioned using a thermoplastic mask. Group 2 animals were positioned using a head holder. Group 3 animals were positioned using the head holder and an inflatable pillow. The time of presentation determined which position device was used. Port films of the 44 patients were reviewed retrospectively, and the repositioning precision was recorded by measurements in three orthogonal planes. Groups 2 and 3 had significantly better repositioning accuracy (P &amp;lt; or = 0.05) compared to Group 1. The position variation was not significantly different (P &amp;lt; or = 0.05) between Groups 2 and 3 in the lateral and longitudinal direction. Group 3 had a median reposition variation of 0.5 to 1.0 mm, with a standard deviation of 1.0 to 1.5 mm.
Veterinary Radiology <html_ent glyph="@amp;" ascii="&"/> Ultrasound, 2003
Radiotherapy and Oncology, 2010