Inflammatory mechanisms contribute to the pathophysiology of senile dementia of the Alzheimer typ... more Inflammatory mechanisms contribute to the pathophysiology of senile dementia of the Alzheimer type (sDAT). Previous studies have shown that 57Co single photon emission computed tomography (SPECT) is able to visualize inflammatory lesions, probably by means of the final common pathway of Ca2+ homeostasis disturbance in both neuronal degeneration and inflammation. The aims of this study were: (1) to detect 57Co SPECT changes in sDAT patients; (2) to correlate these findings with those of conventional neuroimaging techniques and neuropsychological testing (NPT); and (3) to compare 57Co SPECT findings in sDAT patients with those in other types of dementia. Six patients suffering from probable sDAT were included and compared with four patients suffering from other types of dementia. All patients had a magnetic resonance imaging (MRI) scan, NPT, 57Co and 99mTc-ethyl cysteinate dimer (ECD) SPECT scan. Perfusion SPECT images were semiquantitatively evaluated by comparison with an age-matche...
The highest concentrations of the peripheral benzodiazepine receptor (PBR) are found in the kidne... more The highest concentrations of the peripheral benzodiazepine receptor (PBR) are found in the kidneys and heart. In addition, the PBR has been reported to reflect neuro-inflammatory damage by co-localisation with activated microglia. PK 11195 is a high-affinity ligand for the PBR. The aim of this study was to investigate in humans the biodistribution and dosimetry of [123I]iodoPK 11195, a potential single-photon emission tomography tracer for the PBR. Five healthy volunteers were injected with 112 MBq of [123I]iodo-PK 11195. Sequential whole-body scans were performed up to 72 h post injection. Multiple blood samples were taken, and urine was collected to measure the fraction voided by the renal system. Decay-corrected regions of interest of the whole-body images were analysed, and geometric mean count rates were used to determine organ activity. Organ absorbed doses and effective dose were calculated using the MIRD method. [123I]iodo-PK 11195 was rapidly cleared from the blood, mainly...
We report the in vivo evaluation (biodistribution, displacement and metabolization in blood, brai... more We report the in vivo evaluation (biodistribution, displacement and metabolization in blood, brain and heart) in mice and the metabolism in blood of human volunteers of iodine-123 labelled 1-(2-iodophenyl)-N-methyl-N-(1-methyl-propyl)-3-isoquinoline carboxamide ([123I]iodo-PK11195), a potential radioligand for visualization of inflammation in humans by single-photon emission tomography. In three series of 18 white mice (NMRI, 20-25 g), the concentration of radioactivity was measured during 48 h. Blood samples were taken, organs and intestines were excised, excretion was collected and all tissues were weighed and counted for radioactivity. The tissue uptake of radioactivity was measured as % of the injected activity/g of tissue. The excretion was expressed as % of the injected activity. Selective tissue uptake was investigated by pretreatment of another three series of 18 mice with cold PK11195 (1 mg/kg body weight). There was an inflow of [123I]iodo-PK11195 in the brain and among pe...
The purpose of this study was to assess the value of 99mTc-pertechnetate scanning in the diagnosi... more The purpose of this study was to assess the value of 99mTc-pertechnetate scanning in the diagnosis of gastric banding leaks. Three patients with morbid obesity received laparoscopic adjustable silicone gastric banding (ASGB), but no significant weight reduction was obtained. To exclude band leakage as the cause, four scintigraphic procedures were performed, consisting of imaging the upper abdomen 30 min and 3 h after injection of 3 mL (111 MBq) pertechnetate solution into the ASGB reservoir. In one patient, the integrity of the ASGB device was first assessed radiologically after injection of a water-soluble contrast agent into the ASGB reservoir. In two normally functioning ASGB devices, radiotracer was observed within the device on both early and late images. In two patients with a surgically proven small leak in the reservoir or the connecting tube, late images showed little tracer in the reservoir and the connecting tube. However, intense tracer accumulation was observed in the s...
Left-sided vagus nerve stimulation (VNS) is an efficacious treatment for patients with refractory... more Left-sided vagus nerve stimulation (VNS) is an efficacious treatment for patients with refractory epilepsy. Previous studies have implicated thalamic and mesial temporal involvement in acute stimulation. In this study, acute and chronic effects of VNS in patients with refractory complex partial seizures with or without secondary generalization (CPS +/- SG) were evaluated with respect to the prestimulus condition and long-term follow-up. Twenty-three patients (12 females, 11 males; mean age, 32.4 +/- 10.6 y; mean CPS +/- SG duration, 21.0 +/- 11.7 y) were prospectively included. All patients were considered unsuitable candidates for resective surgery because of nonlocalizing findings in the presurgical evaluation. All underwent a split-dose (99m)Tc-ethyl cysteinate dimer activation study before and immediately after their initial stimulation (0.25 or 0.5 mA, 30 Hz) on a high-resolution triple-head gamma camera. Ten patients also underwent a SPECT activation study 5.7 +/- 1.6 mo after...
Performance on the Verbal Fluency Test, as a measure of the ability of initiating processes, is r... more Performance on the Verbal Fluency Test, as a measure of the ability of initiating processes, is reduced in depressed suicidal patients. The hampered results in this prefrontal executive task parallel the reduction in prefrontal blood perfusion and metabolism in depressed subjects. A neuropsychological activation study with the verbal fluency paradigm could evaluate a possible blunted increase in perfusion in the prefrontal cortex in depressed suicidal patients. Twenty clinically depressed patients who had recently attempted suicide and 20 healthy volunteers were included in a single photon emission computed tomography (SPECT) split-dose activation study following a verbal fluency paradigm. Statistical parametric mapping was used to determine voxelwise significant changes. Differences in regional cortical activation between the letter fluency and category fluency tasks in attempted suicide patients were found. These patients showed a blunted increase in perfusion in the prefrontal co...
2001 IEEE Nuclear Science Symposium Conference Record (Cat. No.01CH37310), 2002
The accurate quantification of emission computed tomography data (PET-SPECT) is limited by partia... more The accurate quantification of emission computed tomography data (PET-SPECT) is limited by partial volume effects (PVE). The influence of these effects on quantification depends on the size of the structure in relation to the spatial resolution and may lead to an over- and/or underestimation of the true tracer concentration. This particularly holds for brain perfusion SPECT imaging, where white matter
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, 2002
The technique of anatomic standardization and comparison with normal templates is increasingly us... more The technique of anatomic standardization and comparison with normal templates is increasingly used in clinical brain SPECT practice and allows automated, operator-independent volume-of-interest (VOI) or voxel-based analysis of whole-brain data. In 2 distinct clinical populations with severe traumatic brain injury and cognitive impairment, this study compared 3 widely available approaches that use normal templates to evaluate SPECT brain perfusion deficits. In total, 74 subjects were studied. These included 14 patients with severe, traumatic brain injury (group 1; 10 males, 4 females; mean age +/- SD, 27.6 +/- 8.2 y) and 15 patients with cognitive impairment (group 2; 7 males, 8 females; mean age, 75.8 +/- 8.6 y). These data were compared with those from, respectively, 25 and 20 age- and sex-adjusted healthy volunteers. All data were analyzed in 4 ways. Three semiquantitative statistical algorithms were used: statistical parametric mapping (SPM) using SPM99, brain registration and a...
This phase I pilot study reports on (1) the safety and feasibility of 99Tc(m)-HL91, an amine oxim... more This phase I pilot study reports on (1) the safety and feasibility of 99Tc(m)-HL91, an amine oxime core radioligand that has shown oxygen dependent binding, and imaging; and (2) its usefulness for the visualization of local tumour recurrence of a biopsy proven squamous cell carcinoma of the head and neck (SCCHN) as compared to spiral computed tomogaphy (CT) and biopsy. Nine men (mean age 33 years, range 34-74 years) were prospectively included. For safety measurements, vital signs were recorded and serum chemical analysis carried out, with a complete blood cell count and urine analysis, and an ECG was performed prior to injection of 99Tc(m)-HL91 and repeated during the investigation. Single photon emission computed tomography (SPECT) scans of the head and neck, and of a standard, were performed at 2 h and 4 h post-injection of 740 MBq 99Tc(m)-HL91. Tumour-to-normal tissue background (T/N) ratios and percentage uptake were measured for all 99Tc(m)-HL91 scans. Spiral CT scans were obt...
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, 2001
Intra- or intersubject registration of anatomically poorly defined SPECT data, such as in neurore... more Intra- or intersubject registration of anatomically poorly defined SPECT data, such as in neuroreceptor imaging, is important for longitudinal or group analysis. However, accurate registration is difficult with only emission CT (ECT) data. We investigated fully automated registration using transmission CT (TCT) data as an intermediary image set. The accuracy of TCT registration was compared to that of ECT registration for four types of data: gray-matter distribution (with [99mTc]ethylcysteinate dimer (ECD)), neocortical distribution (with [123I]R91150, a highly specific 5-HT2a receptor ligand), and striatal distribution of the D2-receptor ligand (with [123I]iodobenzamide (IBZM)) and the dopamine transporter ligand (with [123I]2beta-carbomethoxy-3beta-(4-fluorophenyl)tropane (CIT)). In total, 10 datasets of the various study types were used, all collected on a Toshiba GCA9300 gamma camera with super-high-resolution fanbeam collimators and 3 x 370 MBq of 153Gd transmission sources (4-...
International journal of geriatric psychiatry, Jan 3, 2014
Iodine-123 metaiodobenzylguanidine (MIBG) cardiac scintigraphy has shown the potential to discrim... more Iodine-123 metaiodobenzylguanidine (MIBG) cardiac scintigraphy has shown the potential to discriminate dementia with Lewy bodies (DLB) from Alzheimer's disease (AD). However, these studies did not reflect clinical practice, as patients with ischemic heart disease, heart failure, diabetes mellitus, arterial hypertension, and hyperlipidemia and patients treated with antidepressants like trazodone were excluded. This study aimed to evaluate the use of MIBG cardiac scintigraphy to diagnose DLB in clinical practice. Moreover, the potential diagnostic value of MIBG cardiac scintigraphy in patients with clinically ambiguous dementia diagnosis (DLB versus AD) was tested. Eighty-five patients with a possible clinical diagnosis of DLB entered the study. MIBG uptake was determined by calculating the heart-to-mediastinum-uptake ratio (H/M). The average H/M ratio was 1.42 ± 0.35. The number of core features for DLB and the H/M ratio were negatively correlated (p = 0.001; r = -0.360). With an...
Inflammatory mechanisms contribute to the pathophysiology of senile dementia of the Alzheimer typ... more Inflammatory mechanisms contribute to the pathophysiology of senile dementia of the Alzheimer type (sDAT). Previous studies have shown that 57Co single photon emission computed tomography (SPECT) is able to visualize inflammatory lesions, probably by means of the final common pathway of Ca2+ homeostasis disturbance in both neuronal degeneration and inflammation. The aims of this study were: (1) to detect 57Co SPECT changes in sDAT patients; (2) to correlate these findings with those of conventional neuroimaging techniques and neuropsychological testing (NPT); and (3) to compare 57Co SPECT findings in sDAT patients with those in other types of dementia. Six patients suffering from probable sDAT were included and compared with four patients suffering from other types of dementia. All patients had a magnetic resonance imaging (MRI) scan, NPT, 57Co and 99mTc-ethyl cysteinate dimer (ECD) SPECT scan. Perfusion SPECT images were semiquantitatively evaluated by comparison with an age-matche...
The highest concentrations of the peripheral benzodiazepine receptor (PBR) are found in the kidne... more The highest concentrations of the peripheral benzodiazepine receptor (PBR) are found in the kidneys and heart. In addition, the PBR has been reported to reflect neuro-inflammatory damage by co-localisation with activated microglia. PK 11195 is a high-affinity ligand for the PBR. The aim of this study was to investigate in humans the biodistribution and dosimetry of [123I]iodoPK 11195, a potential single-photon emission tomography tracer for the PBR. Five healthy volunteers were injected with 112 MBq of [123I]iodo-PK 11195. Sequential whole-body scans were performed up to 72 h post injection. Multiple blood samples were taken, and urine was collected to measure the fraction voided by the renal system. Decay-corrected regions of interest of the whole-body images were analysed, and geometric mean count rates were used to determine organ activity. Organ absorbed doses and effective dose were calculated using the MIRD method. [123I]iodo-PK 11195 was rapidly cleared from the blood, mainly...
We report the in vivo evaluation (biodistribution, displacement and metabolization in blood, brai... more We report the in vivo evaluation (biodistribution, displacement and metabolization in blood, brain and heart) in mice and the metabolism in blood of human volunteers of iodine-123 labelled 1-(2-iodophenyl)-N-methyl-N-(1-methyl-propyl)-3-isoquinoline carboxamide ([123I]iodo-PK11195), a potential radioligand for visualization of inflammation in humans by single-photon emission tomography. In three series of 18 white mice (NMRI, 20-25 g), the concentration of radioactivity was measured during 48 h. Blood samples were taken, organs and intestines were excised, excretion was collected and all tissues were weighed and counted for radioactivity. The tissue uptake of radioactivity was measured as % of the injected activity/g of tissue. The excretion was expressed as % of the injected activity. Selective tissue uptake was investigated by pretreatment of another three series of 18 mice with cold PK11195 (1 mg/kg body weight). There was an inflow of [123I]iodo-PK11195 in the brain and among pe...
The purpose of this study was to assess the value of 99mTc-pertechnetate scanning in the diagnosi... more The purpose of this study was to assess the value of 99mTc-pertechnetate scanning in the diagnosis of gastric banding leaks. Three patients with morbid obesity received laparoscopic adjustable silicone gastric banding (ASGB), but no significant weight reduction was obtained. To exclude band leakage as the cause, four scintigraphic procedures were performed, consisting of imaging the upper abdomen 30 min and 3 h after injection of 3 mL (111 MBq) pertechnetate solution into the ASGB reservoir. In one patient, the integrity of the ASGB device was first assessed radiologically after injection of a water-soluble contrast agent into the ASGB reservoir. In two normally functioning ASGB devices, radiotracer was observed within the device on both early and late images. In two patients with a surgically proven small leak in the reservoir or the connecting tube, late images showed little tracer in the reservoir and the connecting tube. However, intense tracer accumulation was observed in the s...
Left-sided vagus nerve stimulation (VNS) is an efficacious treatment for patients with refractory... more Left-sided vagus nerve stimulation (VNS) is an efficacious treatment for patients with refractory epilepsy. Previous studies have implicated thalamic and mesial temporal involvement in acute stimulation. In this study, acute and chronic effects of VNS in patients with refractory complex partial seizures with or without secondary generalization (CPS +/- SG) were evaluated with respect to the prestimulus condition and long-term follow-up. Twenty-three patients (12 females, 11 males; mean age, 32.4 +/- 10.6 y; mean CPS +/- SG duration, 21.0 +/- 11.7 y) were prospectively included. All patients were considered unsuitable candidates for resective surgery because of nonlocalizing findings in the presurgical evaluation. All underwent a split-dose (99m)Tc-ethyl cysteinate dimer activation study before and immediately after their initial stimulation (0.25 or 0.5 mA, 30 Hz) on a high-resolution triple-head gamma camera. Ten patients also underwent a SPECT activation study 5.7 +/- 1.6 mo after...
Performance on the Verbal Fluency Test, as a measure of the ability of initiating processes, is r... more Performance on the Verbal Fluency Test, as a measure of the ability of initiating processes, is reduced in depressed suicidal patients. The hampered results in this prefrontal executive task parallel the reduction in prefrontal blood perfusion and metabolism in depressed subjects. A neuropsychological activation study with the verbal fluency paradigm could evaluate a possible blunted increase in perfusion in the prefrontal cortex in depressed suicidal patients. Twenty clinically depressed patients who had recently attempted suicide and 20 healthy volunteers were included in a single photon emission computed tomography (SPECT) split-dose activation study following a verbal fluency paradigm. Statistical parametric mapping was used to determine voxelwise significant changes. Differences in regional cortical activation between the letter fluency and category fluency tasks in attempted suicide patients were found. These patients showed a blunted increase in perfusion in the prefrontal co...
2001 IEEE Nuclear Science Symposium Conference Record (Cat. No.01CH37310), 2002
The accurate quantification of emission computed tomography data (PET-SPECT) is limited by partia... more The accurate quantification of emission computed tomography data (PET-SPECT) is limited by partial volume effects (PVE). The influence of these effects on quantification depends on the size of the structure in relation to the spatial resolution and may lead to an over- and/or underestimation of the true tracer concentration. This particularly holds for brain perfusion SPECT imaging, where white matter
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, 2002
The technique of anatomic standardization and comparison with normal templates is increasingly us... more The technique of anatomic standardization and comparison with normal templates is increasingly used in clinical brain SPECT practice and allows automated, operator-independent volume-of-interest (VOI) or voxel-based analysis of whole-brain data. In 2 distinct clinical populations with severe traumatic brain injury and cognitive impairment, this study compared 3 widely available approaches that use normal templates to evaluate SPECT brain perfusion deficits. In total, 74 subjects were studied. These included 14 patients with severe, traumatic brain injury (group 1; 10 males, 4 females; mean age +/- SD, 27.6 +/- 8.2 y) and 15 patients with cognitive impairment (group 2; 7 males, 8 females; mean age, 75.8 +/- 8.6 y). These data were compared with those from, respectively, 25 and 20 age- and sex-adjusted healthy volunteers. All data were analyzed in 4 ways. Three semiquantitative statistical algorithms were used: statistical parametric mapping (SPM) using SPM99, brain registration and a...
This phase I pilot study reports on (1) the safety and feasibility of 99Tc(m)-HL91, an amine oxim... more This phase I pilot study reports on (1) the safety and feasibility of 99Tc(m)-HL91, an amine oxime core radioligand that has shown oxygen dependent binding, and imaging; and (2) its usefulness for the visualization of local tumour recurrence of a biopsy proven squamous cell carcinoma of the head and neck (SCCHN) as compared to spiral computed tomogaphy (CT) and biopsy. Nine men (mean age 33 years, range 34-74 years) were prospectively included. For safety measurements, vital signs were recorded and serum chemical analysis carried out, with a complete blood cell count and urine analysis, and an ECG was performed prior to injection of 99Tc(m)-HL91 and repeated during the investigation. Single photon emission computed tomography (SPECT) scans of the head and neck, and of a standard, were performed at 2 h and 4 h post-injection of 740 MBq 99Tc(m)-HL91. Tumour-to-normal tissue background (T/N) ratios and percentage uptake were measured for all 99Tc(m)-HL91 scans. Spiral CT scans were obt...
Journal of nuclear medicine : official publication, Society of Nuclear Medicine, 2001
Intra- or intersubject registration of anatomically poorly defined SPECT data, such as in neurore... more Intra- or intersubject registration of anatomically poorly defined SPECT data, such as in neuroreceptor imaging, is important for longitudinal or group analysis. However, accurate registration is difficult with only emission CT (ECT) data. We investigated fully automated registration using transmission CT (TCT) data as an intermediary image set. The accuracy of TCT registration was compared to that of ECT registration for four types of data: gray-matter distribution (with [99mTc]ethylcysteinate dimer (ECD)), neocortical distribution (with [123I]R91150, a highly specific 5-HT2a receptor ligand), and striatal distribution of the D2-receptor ligand (with [123I]iodobenzamide (IBZM)) and the dopamine transporter ligand (with [123I]2beta-carbomethoxy-3beta-(4-fluorophenyl)tropane (CIT)). In total, 10 datasets of the various study types were used, all collected on a Toshiba GCA9300 gamma camera with super-high-resolution fanbeam collimators and 3 x 370 MBq of 153Gd transmission sources (4-...
International journal of geriatric psychiatry, Jan 3, 2014
Iodine-123 metaiodobenzylguanidine (MIBG) cardiac scintigraphy has shown the potential to discrim... more Iodine-123 metaiodobenzylguanidine (MIBG) cardiac scintigraphy has shown the potential to discriminate dementia with Lewy bodies (DLB) from Alzheimer's disease (AD). However, these studies did not reflect clinical practice, as patients with ischemic heart disease, heart failure, diabetes mellitus, arterial hypertension, and hyperlipidemia and patients treated with antidepressants like trazodone were excluded. This study aimed to evaluate the use of MIBG cardiac scintigraphy to diagnose DLB in clinical practice. Moreover, the potential diagnostic value of MIBG cardiac scintigraphy in patients with clinically ambiguous dementia diagnosis (DLB versus AD) was tested. Eighty-five patients with a possible clinical diagnosis of DLB entered the study. MIBG uptake was determined by calculating the heart-to-mediastinum-uptake ratio (H/M). The average H/M ratio was 1.42 ± 0.35. The number of core features for DLB and the H/M ratio were negatively correlated (p = 0.001; r = -0.360). With an...
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Papers by Jan Versijpt