Peter Ell
University College London, Institute of Nuclear Medicine, Faculty Member
We describe the introduction of positron emission tomography/computed tomography (PET/CT) to the investigation of patients with cancer. The first such unit in the UK and its mode of operation is discussed and initial applications shown.... more
We describe the introduction of positron emission tomography/computed tomography (PET/CT) to the investigation of patients with cancer. The first such unit in the UK and its mode of operation is discussed and initial applications shown. Five hundred and thirty-five patients have been scanned with 2-[18F]fluoro-2-deoxy-D-glucose from mid-January 2002 to the end of August 2002. From this initial experience a clear view of the impact of this technology is emerging. It can now be stated that (1) PET/CT does speed up the throughput of patient studies by at least 25% and hence adds to the comfort of patients scanned; and (2) PET/CT leads to greater accuracy in the interpretation of data. In view of the routine availability of high quality PET and CT fused maps a significant development in radiotherapy planning is on the horizon. We discuss our experience at present and point to further developments in the near future.
Research Interests:
To investigate the effect of co-administered polyethylene glycol 400 (PEG 400), a pharmaceutical excipient previously shown to accelerate small intestinal transit, on the absorption characteristics of ranitidine from the gastrointestinal... more
To investigate the effect of co-administered polyethylene glycol 400 (PEG 400), a pharmaceutical excipient previously shown to accelerate small intestinal transit, on the absorption characteristics of ranitidine from the gastrointestinal tract. Ten healthy male volunteers each received, on two separate occasions, an immediate-release pellet formulation of ranitidine (150 mg) encapsulated within a hard gelatin capsule and a liquid preparation consisting of 150 ml orange juice (control) or 150 ml orange juice containing 10 g PEG 400 (test). The liquid preparations were also radiolabelled with indium-III to allow their transit through the gastrointestinal tract to be followed using a gamma camera. On a further occasion an intravenous injection of ranitidine (50 mg) was administered. Blood samples were taken over a 12 h period on each study day to allow a ranitidine plasma and subsequent absorption rate profile to be generated for each oral formulation. Urine was collected for 24 h and ...
Research Interests: Drug interactions, Humans, Pharmaceutical, Blood sampling, Male, and 12 moreIntestinal absorption, Digestive System, Polyethylene Glycol, Gastrointestinal Tract, Water soluble polymers, Orange juice, Ranitidine, Biological Availability, Cross-Over Studies, Transit Time, Polyethylene Glycols, and Small Intestine
Research Interests:
Research Interests:
Research Interests: Psychopharmacology, Schizophrenia, Dopamine, Humans, Vitamin D receptor, and 14 moreCerebral Cortex, Female, Male, dopamine receptor D4, Middle Aged, Single Photon Emission Computed Tomography, Adult, RISPERIDONE, Basal ganglia, Atypical Antipsychotics, Psychotic Disorders, Side Effect, Benzamides, and Piperidines
The novel antipsychotic drug sertindole has an atypical pharmacological profile. We have estimated striatal D2 dopamine binding in schizophrenic patients treated with sertindole using 123I iodobenzamide (IBZM) SPET. Patients were... more
The novel antipsychotic drug sertindole has an atypical pharmacological profile. We have estimated striatal D2 dopamine binding in schizophrenic patients treated with sertindole using 123I iodobenzamide (IBZM) SPET. Patients were recruited from a clinical trial of sertindole's tolerability and efficacy. Striatal D2 binding in sertindole-treated patients (n = 5), was compared with previously reported data from clozapine (n = 10); olanzapine (n = 6); typical antipsychotic responsive (n = 10); and risperidone (n = 6)-treated groups. Mean PANSS (structured clinical interview for the positive and negative syndrome scale) scores showed clinical improvement in the sertindole group. Few extrapyramidal side effects (EPS) were recorded [average Simpson-Angus (SAS) score = 2.6]. Sertindole-treated patients had mean D2 binding indices (+/-SE) significantly lower than clozapine-treated patients (1.19 +/- 0.04) versus (1.49 +/- 0.04), and olanzapine-treated patients (1.41 +/- 0.06); and similar to those of risperidone (1.24 +/- 0.04) and typical antipsychotic responsive (1.25 +/- 0.05) treated patients. In this patient sample the preliminary evidence suggests that sertindole's decreased tendency to induce EPS at clinically therapeutic doses is not due to limited occupancy of striatal D2 receptors in vivo, and as is the case for risperidone, patients are protected from EPS by some other intrinsic effect of the drug.
Research Interests:
. Background: Atypical antipsychotic drugs are thought to show a high degree of 5-HT2A receptor blockade, which may prevent the emergence of extrapyramidal symptoms. Method: 5-HT2A binding was estimated using 123I-5-I-R91150 and single... more
. Background: Atypical antipsychotic drugs are thought to show a high degree of 5-HT2A receptor blockade, which may prevent the emergence of extrapyramidal symptoms. Method: 5-HT2A binding was estimated using 123I-5-I-R91150 and single photon emission tomography (SPET) in six schizophrenic subjects treated with quetiapine at a mean (±SD) daily dose of 350±123 mg for at least 5 weeks and a matched sample of six healthy volunteers. Clinical and side-effect ratings were performed at baseline and at the time of SPET scanning. The reference region approach was used to define a 5-HT2A binding index in the frontal and temporal cortex. Results: Quetiapine treatment resulted in a significant decline in 5-HT2A receptor availability in the frontal cortex (mean 0.98±0.09) relative to healthy volunteers (mean 1.33±0.16). All patients showed improvements in clinical symptom or side-effect ratings. The mean frontal cortex:cerebellum ratio after quetiapine treatment was significantly negatively correlated with reduction in the Abnormal Involuntary Rating scale and Simpson-Angus scores (P<0.05 Bonferroni corrected), but not with the reduction in the scores from the scale for the assessment of positive symptoms, the scale for the assessment of negative symptoms, the Montgomery-Asberg depression rating scale or patient age. Conclusion: Quetiapine treatment results in significant in vivo blockade of cortical 5-HT2A, similar to other atypical antipsychotic drugs. This effect may contribute to its placebo level extrapyramidal side-effect profile.
Research Interests:
Regional cerebral blood flow (rCBF) was investigated in a group of medicated DSM-III-R schizophrenic patients and age, sex and handedness matched normal volunteers using a split-dose 99mTc-HMPAO Single Photon Emission Tomography (SPET)... more
Regional cerebral blood flow (rCBF) was investigated in a group of medicated DSM-III-R schizophrenic patients and age, sex and handedness matched normal volunteers using a split-dose 99mTc-HMPAO Single Photon Emission Tomography (SPET) protocol. Measures were taken during the performance of a verbal memory task aimed at activating the left medial temporal lobe, a region repeatedly suggested to be structurally abnormal in schizophrenia. In normal subjects, the performance of the task was associated with significant rCBF increases in the left medial temporal, left inferior frontal and anterior cingulate cortices, and right cerebellum. Despite their significantly poorer performance on the memory task, the degree of medial temporal activation measured in the schizophrenic patients was not significantly different from that found in the control group. This finding suggests that memory deficits in schizophrenia do not necessarily imply failure to activate the left medial temporal lobe as assessed by 99mTc-HMPAO SPET.
Research Interests: Psychology, Schizophrenia, Psychological Medicine, Brain, Humans, and 14 moreCerebral Cortex, Psychological, Female, Male, Synaptic Transmission, Middle Aged, Arousal, Single Photon Emission Computed Tomography, Adult, Public health systems and services research, Oximes, Regional Cerebral Blood Flow, Verbal Memory, and Neurosciences
Research Interests: Cognitive Science, Psychiatry, Anxiety Disorders, Brain Mapping, Humans, and 15 moreCaudate Nucleus, Cerebral Cortex, Female, Male, Panic Disorder, Obsessive Compulsive Disorder, Clinical Sciences, Middle Aged, Single Photon Emission Computed Tomography, Adult, Regional Cerebral Blood Flow, Computerised Tomography, Reference Values, Healthy Subjects, and Neurosciences
Research Interests: Cognitive Science, Psychiatry, Auditory Perception, Schizophrenia, Attention, and 19 moreBrain, Humans, Hallucinations, Female, Functional Imaging, Male, Clinical Sciences, Middle Aged, Arousal, Single Photon Emission Computed Tomography, Adult, Oximes, Blood Flow, Basal ganglia, Regional Cerebral Blood Flow, Verbal Memory, Blood Flow Velocity, Neurosciences, and Verbal Learning
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests: Breast Cancer, Quality of life, Treatment Outcome, Risk assessment, Humans, and 18 moreShoulder, Movement, Female, Male, Arm, The, Incidence, Randomized Trial, Length of Stay, Mastectomy, Middle Aged, Drainage, Risk Assessment, Statistical Test, Sentinel Node Biopsy, Lymphedema, Axilla, and Relative Risk
Research Interests:
Research Interests: Immunohistochemistry, Positron Emission Tomography, Colorectal cancer, Cell Division, Prospective studies, and 12 moreHumans, Female, Male, In Vivo Imaging, Clinical Sciences, Aged, Middle Aged, Single Photon Emission Computed Tomography, Gut, Reproducibility of Results, Adenocarcinoma, and Colorectal Neoplasms
Research Interests: Informed Consent, Adolescent, Humans, Female, Male, and 16 moreYoung Adult, Clinical Sciences, European, Aged, Middle Aged, Coronary Angiography, Adult, Blood Flow, Reproducibility of Results, Coronary Artery Disease, Sensitivity and Specificity, Pilot Projects, X ray Computed Tomography, Region of Interest, Contrast Media, and CT angiography
Research Interests: Algorithms, Quality Control, Molecular Imaging, Humans, Image Reconstruction, and 14 moreAttenuation Correction, Statistical Significance, Artifacts, Ct Scan, Clinical Sciences, Image Enhancement, Single Photon Emission Computed Tomography, Clinical Data, Neoplasms, Reproducibility of Results, Sensitivity and Specificity, X ray Computed Tomography, Signal to Noise Ratio, and Whole Body
Research Interests:
Research Interests: Cardiology, Evidence Based Medicine, Nuclear medicine, Humans, Female, and 16 moreMale, Heart, Cost effectiveness, Clinical Sciences, European, Great Britain, Single Photon Emission Computed Tomography, Prognosis, Risk Stratification, Reproducibility of Results, Diagnostic Accuracy, Coronary Artery Disease, Sensitivity and Specificity, Observational Study, Waiting Time, and Chest Pain
Research Interests: Computed Tomography, Positron Emission Tomography, Colorectal cancer, Quantitative analysis, Humans, and 19 moreAttenuation Correction, Female, Blood sampling, Male, Standardisation, Bone marrow, Clinical Sciences, Aged, Middle Aged, Reproducibility of Results, Quantitative Analysis, Radiopharmaceuticals, Thoracic Aorta, Sensitivity and Specificity, Field of View, Region of Interest, Non linear regression, Metastatic Colorectal Cancer, and Colorectal Neoplasms
Three-dimensional positron emission tomography (3D PET) results in higher system sensitivity, with an associated increase in the detection of scatter and random coincidences. The objective of this work was to compare, from a clinical... more
Three-dimensional positron emission tomography (3D PET) results in higher system sensitivity, with an associated increase in the detection of scatter and random coincidences. The objective of this work was to compare, from a clinical perspective, 3D and two-dimensional (2D) acquisitions in terms of whole-body (WB) PET image quality with a dedicated BGO PET system. 2D and 3D WB emission acquisitions were carried out in 70 patients. Variable acquisition parameters in terms of time of emission acquisition per axial field of view (aFOV) and slice overlap between sequential aFOVs were used during the 3D acquisitions. 3D and 2D images were reconstructed using FORE+WLS and OSEM respectively. Scatter correction was performed by convolution subtraction and a model-based scatter correction in 2D and 3D respectively. All WB images were attenuation corrected using segmented transmission scans. Images were blindly assessed by three observers for the presence of artefacts, confidence in lesion detection and overall image quality using a scoring system. Statistically significant differences between 2D and 3D image quality were only obtained for 3D emission acquisitions of 3 min. No statistically significant differences were observed for image artefacts or lesion detectability scores. Image quality correlated significantly with patient weight for both modes of operation. Finally, no differences were seen in image artefact scores for the different axial slice overlaps considered, suggesting the use of five slice overlaps in 3D WB acquisitions. 3D WB imaging using a dedicated BGO-based PET scanner offers similar image quality to that obtained in 2D considering similar overall times of acquisitions.
Research Interests: Positron Emission Tomography, Image Quality, Humans, 3-D Imaging, Attenuation Correction, and 18 morePET imaging, Female, Male, Three Dimensional Imaging, Statistical Significance, Clinical Sciences, Aged, Image Enhancement, Observer Variation, Neoplasms, Three Dimensional, Reproducibility of Results, Sensitivity and Specificity, Whole-body Imaging, Field of View, Equipment Failure Analysis, Whole Body, and Clinical evaluation
Research Interests: Image Quality, Quality Control, Clinical Practice, Adenosine, Humans, and 17 moreHeart, Artifacts, Organophosphorus Compounds, Clinical Sciences, European, Great Britain, Thallium, Myocardium, Coronary heart disease, Reproducibility of Results, Radiopharmaceuticals, Myocardial Perfusion Imaging, Sensitivity and Specificity, High Sensitivity, Cross Sectional Studies, Exercise Test, and Heart Diseases
Research Interests:
Complete staging is mandatory for the management and therapy of neuroendocrine tumours. Various radiotracers are available but the best imaging strategy has yet to be defined. In this study we retrospectively compared 123I-MIBG,... more
Complete staging is mandatory for the management and therapy of neuroendocrine tumours. Various radiotracers are available but the best imaging strategy has yet to be defined. In this study we retrospectively compared 123I-MIBG, 111In-[D-Phe1]-DTPA-octreotide and 18F-FDG (PET) imaging in 15 patients with metastatic neuroendocrine tumours (11 carcinoid tumours, 4 paragangliomas). Planar images were acquired 1, 4, 24 and 48 h following the injection of 111In-[D-Phe1]-DTPA-octreotide and 123I-MIBG. Whole-body PET scans were performed 45 min after injection of 18F-FDG. 111In-[D-Phe1]-DTPA-octreotide was positive in 11/15 patients and identified 44 lesions, 18F-FDG PET was positive in 11/15 patients and identified 107 lesions and 123I-MIBG was positive in 8/15 patients and identified 67 lesions. No single scintigraphic technique identified all metastatic sites. In one patient all studies were negative. 18F-FDG PET identified more abnormal sites than the other two modalities. Combination of all three imaging modalities with X-ray CT helps to provide a more comprehensive map of the disease.
Research Interests: Image Processing, Tomography, Humans, PET imaging, Female, and 14 moreFunctional Imaging, Male, Clinical Sciences, European, Aged, Middle Aged, Single Photon Emission Computed Tomography, Adult, Retrospective Studies, Radiopharmaceuticals, X ray Computed Tomography, Neuroendocrine Tumors, Whole Body, and Paraganglioma
Research Interests: Positron Emission Tomography, Humans, Image Reconstruction, Attenuation Correction, Thorax, and 10 moreData acquisition, Standardisation, Lung, Clinical Sciences, Single Photon Emission Computed Tomography, Clinical Data, Retrospective Studies, Radiopharmaceuticals, Region of Interest, and Clinical evaluation
... Peter J. Eli 2, Rachel Mulligan 2, Michael J. Travis 3, Jos6e E. Leysen 3, Dominic Lui 3, Sveto Gacinovic 4, Wendy Waddington 2 ... 100-120 min pi Frontal cortex-cere-bellum activity ratios reached values of 1.4, and re-mained stable... more
... Peter J. Eli 2, Rachel Mulligan 2, Michael J. Travis 3, Jos6e E. Leysen 3, Dominic Lui 3, Sveto Gacinovic 4, Wendy Waddington 2 ... 100-120 min pi Frontal cortex-cere-bellum activity ratios reached values of 1.4, and re-mained stable from approximately 100 rain pi onwards. ...
Research Interests:
Research Interests:
Regional variation of tracer distribution is seen in uncorrected thallium-201 images of normal hearts. This study evaluates the effect of attenuation correction on myocardial 201T1 distribution in patients with low risk of coronary artery... more
Regional variation of tracer distribution is seen in uncorrected thallium-201 images of normal hearts. This study evaluates the effect of attenuation correction on myocardial 201T1 distribution in patients with low risk of coronary artery disease. An L-shaped dual-detector single-photon emission tomographic system equipped with a pair gadolinium-153 scanning line sources was used for sequential emission/transmission imaging in 36 patients (14 men and 22 women) with less than 5% risk for coronary artery disease. Uncorrected emission images were reconstructed using filtered back-projection (FBP) whereas the attenuation corrected (AC) images were iteratively reconstructed using the attenuation map computed from the transmission data. Both sets of images were reorientated into short axis, vertical long axis and horizontal long axis images. For quantification data were reconstructed into polar plots and count density estimated in 17 myocardial segments. The population % standard deviation for each segment of AC data was significantly smaller than that for FBP data, indicating improved homogeneity of tracer distribution. In men the anterior-basal inferior activity ratio improved from 1.20 for FBP to 0.96 for AC (stress) and from 1.23 for FBP to 0.98 for AC (delay) (P < 0.0001). In women the anterior-basal inferior activity ratio changed from 1.08 for FBP to 0.94 for AC (stress) and from 1.08 for FBP to 0.93 for AC (delay) (P < 0.001). These ratios reflect appropriate compensation for basal attenuation but a lack of scatter correction. The lateral-septal activity ratio in men changed from 1.05 for FBP to 0.99 for AC (stress) and from 1.02 for FBP to 0.96 for AC (delay), while in women it changed from 1.05 for FBP to 0.98 for AC (stress) and from 1.04 for FBP to 0.98 for AC (delay) (P < 0.005 in all cases). The apex of AC images showed a decrease in activity consistent with wall thining at this site. It is concluded that the use of attenuation correction yields improved homogeneity of myocardial tracer distribution in patients with low risk of coronary artery disease. The diagnostic benefits of attenuation correction are yet to be fully assessed.
Research Interests: Positron Emission Tomography, Adenosine, Humans, Standard Deviation, Attenuation Correction, and 19 moreFemale, Male, Heart, Risk factors, Clinical Sciences, European, Density Estimation, Middle Aged, Regional Variation, Single Photon Emission Computed Tomography, Coronary heart disease, Sex Factors, Time Factors, Risk Factors, Coronary Artery Disease, Low Risk, Sensitivity and Specificity, Exercise Test, and SHORT-AXIS
Technetium-99m-L,L-ethylenedicysteine (99mTc-L,L-EC), a new renal imaging agent, was introduced as an alternative to 99mTc-mercaptoacetyltriglycine (MAG3). This radiopharmaceutical can be easily labelled at room temperature and has high... more
Technetium-99m-L,L-ethylenedicysteine (99mTc-L,L-EC), a new renal imaging agent, was introduced as an alternative to 99mTc-mercaptoacetyltriglycine (MAG3). This radiopharmaceutical can be easily labelled at room temperature and has high radiochemical purity and long stability. The aim of this study was to gain clinical experience in using 99mTc-L,L-EC in normal volunteers and patients. The clearance of this radiopharmaceutical was compared with that of iodine-131 ortho-iodohippurate (OIH) in five healthy volunteers. In addition, conventional renogram and whole-body distribution of 99mTc-L,L-EC (40 min and 3 h post-injection) were evaluated in these subjects. Subsequently, ten patients with suspected obstructive nephropathy, four with renovascular disorders and two in acute renal failure were imaged. In five patients with impaired renal function both 99mTc-MAG3 and 99mTc-L,L-EC studies were performed. In each case the scintigraphic images and time/activity curves were evaluated and various semiquantitative parameters calculated and compared. No adverse effects were noted during and after 99mTc-L,L-EC scintigraphy. The mean clearance values for 99mTc-L,L-EC and 131I-OIH in volunteers were 504 and 663 ml/min respectively. The total plasma clearance of 99mTc-L,L-EC was about 75.8% of the 131I-OIH value. In volunteers the parenchymal transit time index, whole kidney transit time index and mean parenchymal transit time for 99mTc-L,L-EC were 63 s, 124 s and 175 s respectively. The mean time to peak activity was 235 s and the time from peak to 50% of peak activity was 402 s.(ABSTRACT TRUNCATED AT 250 WORDS)
Research Interests:
Tumour thrombus is a rare complication of many solid cancers including renal cell carcinoma,... more
Tumour thrombus is a rare complication of many solid cancers including renal cell carcinoma, Wilms' tumour, testicular tumour, adrenal cortical carcinoma, lymphoma, pancreatic cancer, osteosarcoma and Ewing's sarcoma. We describe six patients who harboured occult tumour thrombus detected by fluorine-18 fluorodeoxyglucose (F-FDG) positron emission tomography (PET)/X-ray computerized tomography (CT) imaging as part of the staging investigations. Recognition of this rare complication by PET/CT can change the management plan and prevent unnecessary long-term anti-coagulation treatment because of wrong diagnosis of cancer-related venous thrombus.
Research Interests:
Research Interests:
This study examines a series of coronary artery bypass patients (CABS) for neuropsychological and regional cerebral blood flow (RCBF) changes at 8 days and 8 weeks post surgery. Seventy-three percent were found to have moderate or severe... more
This study examines a series of coronary artery bypass patients (CABS) for neuropsychological and regional cerebral blood flow (RCBF) changes at 8 days and 8 weeks post surgery. Seventy-three percent were found to have moderate or severe neuropsychological deficits at 8 days post operation and 37% at 8 weeks post surgery. A comparison group of major vascular and thoracic surgery
Research Interests:
To compare the interobserver agreement and degree of confidence in anatomical localisation of lesions using 2-[fluorine-18] fluoro-2-deoxy-D-glucose (18 F-FDG) positron emission tomography (PET)/computed tomography (CT) and 18 F-FDG PET... more
To compare the interobserver agreement and degree of confidence in anatomical localisation of lesions using 2-[fluorine-18] fluoro-2-deoxy-D-glucose (18 F-FDG) positron emission tomography (PET)/computed tomography (CT) and 18 F-FDG PET alone in ...
Research Interests:
Research Interests:
Research Interests:
Research Interests: Genetics, Magnetic Resonance Imaging, British, Positron Emission Tomography, Colorectal cancer, and 20 moreMolecular Imaging, Inflammatory Bowel Disease, Case Report, Humans, United States, Inflammatory disease, Alcohol Consumption, Lynch syndrome, Hereditary nonpolyposis colorectal cancer, Genomic DNA, Single Photon Emission Computed Tomography, Prognosis, Adenomatous Polyposis-coli, Population Study, Red meat, Radiopharmaceuticals, Dwell Time, General Population, Magnetic resonance image, and Colorectal Neoplasms
Research Interests:
Research Interests:
Research Interests: Cognitive Science, Anxiety Disorders, Obsessive-Compulsive Disorder, Brain Mapping, Brain, and 23 moreHumans, Cerebral Cortex, Chronic Disease, Female, Male, Obsessive Compulsive Disorder, Differential Diagnosis, Orbitofrontal cortex, Clinical Sciences, Aged, Arousal, High Resolution, Single Photon Emission Computed Tomography, Adult, Analysis of Variance, Oximes, Regional Cerebral Blood Flow, Functional Neuroimaging, Depressive Symptoms, Radiopharmaceuticals, Neurosciences, Region of Interest, and Severity of Illness Index
Research Interests:
We have previously performed quantitative kinetic modeling of [(123)I]CNS 1261, a new SPET ligand for the MK801 intrachannel site of the NMDA receptor. We now report a bolus-infusion protocol, which eliminates the need for arterial blood... more
We have previously performed quantitative kinetic modeling of [(123)I]CNS 1261, a new SPET ligand for the MK801 intrachannel site of the NMDA receptor. We now report a bolus-infusion protocol, which eliminates the need for arterial blood sampling. Dynamic SPET scanning and venous blood sampling were performed in 7 healthy volunteers. Good agreement was obtained between kinetic and equilibrium analysis. SPET scanning with a bolus-infusion protocol is a valid method to estimate the total volume of distribution for [(123)I]CNS 1261 in clinical populations.
Research Interests:
The absorption of drugs from the gastrointestinal tract is a complex process subject to many factors. One well-established factor is that of drug solubility. Poorly water-soluble drugs often exhibit low oral bioavailabilities as a con-... more
The absorption of drugs from the gastrointestinal tract is a complex process subject to many factors. One well-established factor is that of drug solubility. Poorly water-soluble drugs often exhibit low oral bioavailabilities as a con- ... A multi-unit preparation consisting of pellets ...