Multiclass classification of FDG PET scans for the distinction between Parkinson's disease and atypical parkinsonian syndromes
Garraux, Gaëtan ; Phillips, Christophe ; Schrouff, Jessica et al
in NeuroImage: Clinical (2013), 2
Most available pattern recognition methods in neuroimaging address binary classification problems. Here, we used relevance vector machine (RVM) in combination with booststrap resampling (‘bagging’) for ... [more ▼]
Most available pattern recognition methods in neuroimaging address binary classification problems. Here, we used relevance vector machine (RVM) in combination with booststrap resampling (‘bagging’) for non-hierarchical multiclass classification. The method was tested on 120 cerebral 18fluorodeoxyglucose (FDG) positron emission tomography (PET) scans performed in patients who exhibited parkinsonian clinical features for 3.5 years on average but that were outside the prevailing perception for Parkinson's disease (PD). A radiological diagnosis of PD was suggested for 30 patients at the time of PET imaging. However, at follow-up several years after PET imaging, 42 of them finally received a clinical diagnosis of PD. The remaining 78 APS patients were diagnosed with multiple system atrophy (MSA, N = 31), progressive supranuclear palsy (PSP, N = 26) and corticobasal syndrome (CBS, N = 21), respectively. With respect to this standard of truth, classification sensitivity, specificity, positive and negative predictive values for PD were 93% 83% 75% and 96%, respectively using binary RVM (PD vs. APS) and 90%, 87%, 79% and 94%, respectively, using multiclass RVM (PD vs. MSA vs. PSP vs. CBS). Multiclass RVM achieved 45%, 55% and 62% classification accuracy for, MSA, PSP and CBS, respectively. Finally, a majority confidence ratio was computed for each scan on the basis of class pairs that were the most frequently assigned by RVM. Altogether, the results suggest that automatic multiclass RVM classification of FDG PET scans achieves adequate performance for the early differentiation between PD and APS on the basis of cerebral FDG uptake patterns when the clinical diagnosis is felt uncertain. This approach cannot be recommended yet as an aid for distinction between the three APS classes under consideration. [less ▲]Detailed reference viewed: 70 (14 ULg)
Newer Methods for Improving Yield from FDG-PET Imaging for Accurate Staging, Determining Tumor Biology, and Assessing Prognosis
in PET Clinics (2012), 7(4), 425-430Detailed reference viewed: 8 (1 ULg)
Cluster headache Award 2012: Central modulation in cluster headache patients treated with occipital nerve stimulation
MAGIS, Delphine ; Bruno, Marie-Aurélie ; FUMAL, Arnaud et al
in Journal of Headache & Pain (2012, September 16)Detailed reference viewed: 32 (6 ULg)
Primary hyperparathyroidism confirmed by histology : sensitivity and predictors of 99mTc-Sestamibi/CT scan
VALDES SOCIN, Hernan Gonzalo ; BISOGNI, Carmen ; BETEA, Daniela et al
in Abstract Book - 13th International Workshop on Multiple Endocrine Neoplasia (2012, September)Detailed reference viewed: 38 (7 ULg)
Zolpidem effect on recovery of consciousness: a FDG-PET study
Chatelle, Camille ; Thibaut, Aurore ; Gosseries, Olivia et al
Poster (2012)Detailed reference viewed: 6 (0 ULg)
Preliminary results of (18F)FPRGD2 PET/CT imaging of integrin αvβ3 levels in patients with locally advanced rectal carcinoma.
WITHOFS, Nadia ; MARTINIVE, Philippe ; SCAGNOL, Irène et al
in Journal of Nuclear Medicine (The) (2012), 53(SUPPL), 1703Detailed reference viewed: 51 (29 ULg)
Nodal staging of head and neck squamous cell carcinomas : impact of a dedicated PET/CT protocol.
; CABAY, Jean-Evrard ; DEMEZ, Pierre et al
in Journal of Nuclear Medicine (The) (2012), 53(SUPPL), 1354Detailed reference viewed: 19 (1 ULg)
(18F)FPRGD2 PET/CT imaging of integrin αvβ3 in renal carcinomas : correlation with histopathology.
WITHOFS, Nadia ; ; et al
in Journal of Nuclear Medicine (The) (2012), 53(SUPPL), 1647Detailed reference viewed: 29 (8 ULg)
Acute intramural haematoma of the ascending aorta.
; WITHOFS, Nadia ; et al
in European Journal of Nuclear Medicine and Molecular Imaging (2012), 39(8), 1368-9Detailed reference viewed: 11 (0 ULg)
PET-CT and PET-MRI in Oncology, A practical Guide: Gastrointestinal (135-159)
in PELLER, PATRICK; SUBRAMANIAM, RATHAN; GUERMAZI, ALI (Eds.) MEDICAL RADIOLOGY - DIAGNOSIS IMAGING : PET-CT and PET-MRI in Oncology - A pratical Guide (2012)
PET-CT combines in a single imaging session both anatomical and metabolic information. Depending on the strategy, the CT part of the study may yield only crude anatomical information and attenuation ... [more ▼]
PET-CT combines in a single imaging session both anatomical and metabolic information. Depending on the strategy, the CT part of the study may yield only crude anatomical information and attenuation correction for the PET part, or it may offer full radiological diagnostic features. Regarding the radiotracers for gastrointectinal oncology, FDG remains the mainstay but alternative compounds aimed at more specific biological targets are actively tested. In particular Ga-68-labelled DOTA derivatives image somatostatine receptors with exquisite sensitivity and specificity. In clinical practice, several indications are well recognized for FDG PET-CT. These include the initial staging of esophageal, pancreatic and rectal cancers with a clinical impact in a significal proportion of patients. The metabolic activity, as recorded prior to any treatment, holds prognostic information in esophageal and rectal cancers, as well as GISTs. Methodological issues remain to be solved, but the potential is clearly present so that an increased clinical role is highly likely in the near future. FDG PET-CT is a major clinical tool in the detection and staging of recurrent colorectal cancer, and for determining the resectability of liver metastases. Ongoing developments include technological advances, in particular the combined PET-MR devices, and alternative tracers, such as those imaging angiogenesis. [less ▲]Detailed reference viewed: 78 (7 ULg)
Metabolic activity in external and internal awareness networks in severely brain-damaged patients.
Thibaut, Aurore ; Bruno, Marie-Aurélie ; Chatelle, Camille et al
in Journal of Rehabilitation Medicine (2012), 44(6), 487-94
OBJECTIVE: An extrinsic cerebral network (encompassing lateral frontoparietal cortices) related to external/sensory awareness and an intrinsic midline network related to internal/self-awareness have been ... [more ▼]
OBJECTIVE: An extrinsic cerebral network (encompassing lateral frontoparietal cortices) related to external/sensory awareness and an intrinsic midline network related to internal/self-awareness have been identified recently. This study measured brain metabolism in both networks in patients with severe brain damage. DESIGN: Prospective [18F]-fluorodeoxyglucose-positron emission tomography and Coma Recovery Scale-Revised assessments in a university hospital setting. SUBJECTS: Healthy volunteers and patients in vegetative state/unresponsive wakefulness syndrome (VS/UWS), minimally conscious state (MCS), emergence from MCS (EMCS), and locked-in syndrome (LIS). RESULTS: A total of 70 patients were included in the study: 24 VS/UWS, 28 MCS, 10 EMCS, 8 LIS and 39 age-matched controls. VS/UWS showed metabolic dysfunction in extrinsic and intrinsic networks and thalami. MCS showed dysfunction mostly in intrinsic network and thalami. EMCS showed impairment in posterior cingulate/retrosplenial cortices. LIS showed dysfunction only in infratentorial regions. Coma Recovery Scale-Revised total scores correlated with metabolic activity in both extrinsic and part of the intrinsic network and thalami. CONCLUSION: Progressive recovery of extrinsic and intrinsic awareness network activity was observed in severely brain-damaged patients, ranging from VS/UWS, MCS, EMCS to LIS. The predominance of intrinsic network impairment in MCS could reflect altered internal/self-awareness in these patients, which is difficult to quantify at the bedside. [less ▲]Detailed reference viewed: 307 (59 ULg)
Functional neuroanatomy underlying the clinical subcategorization of minimally conscious state patients.
Bruno, Marie-Aurélie ; Majerus, Steve ; Boly, Mélanie et al
in Journal of Neurology (2012), 259(6), 1087-98
Patients in a minimally conscious state (MCS) show restricted signs of awareness but are unable to communicate. We assessed cerebral glucose metabolism in MCS patients and tested the hypothesis that this ... [more ▼]
Patients in a minimally conscious state (MCS) show restricted signs of awareness but are unable to communicate. We assessed cerebral glucose metabolism in MCS patients and tested the hypothesis that this entity can be subcategorized into MCS- (i.e., patients only showing nonreflex behavior such as visual pursuit, localization of noxious stimulation and/or contingent behavior) and MCS+ (i.e., patients showing command following).Patterns of cerebral glucose metabolism were studied using [(18)F]-fluorodeoxyglucose-PET in 39 healthy volunteers (aged 46 +/- 18 years) and 27 MCS patients of whom 13 were MCS- (aged 49 +/- 19 years; 4 traumatic; 21 +/- 23 months post injury) and 14 MCS+ (aged 43 +/- 19 years; 5 traumatic; 19 +/- 26 months post injury). Results were thresholded for significance at false discovery rate corrected p < 0.05.We observed a metabolic impairment in a bilateral subcortical (thalamus and caudate) and cortical (fronto-temporo-parietal) network in nontraumatic and traumatic MCS patients. Compared to MCS-, patients in MCS+ showed higher cerebral metabolism in left-sided cortical areas encompassing the language network, premotor, presupplementary motor, and sensorimotor cortices. A functional connectivity study showed that Broca's region was disconnected from the rest of the language network, mesiofrontal and cerebellar areas in MCS- as compared to MCS+ patients.The proposed subcategorization of MCS based on the presence or absence of command following showed a different functional neuroanatomy. MCS- is characterized by preserved right hemispheric cortical metabolism interpreted as evidence of residual sensory consciousness. MCS+ patients showed preserved metabolism and functional connectivity in language networks arguably reflecting some additional higher order or extended consciousness albeit devoid of clinical verbal or nonverbal expression. [less ▲]Detailed reference viewed: 253 (10 ULg)
Tumor-induced osteomalacia: The tumor may stay hidden!
; CAVALIER, Etienne ; KAUX, Jean-François et al
in Clinical Biochemistry (2011), 44(14-15), 1264-6
We report the case of a patient with severe muscular and articular tenderness that caused almost complete immobility. This subject had severe hypophosphatemia due to hyperphosphaturia. Fibroblast growth ... [more ▼]
We report the case of a patient with severe muscular and articular tenderness that caused almost complete immobility. This subject had severe hypophosphatemia due to hyperphosphaturia. Fibroblast growth factor 23 (FGF-23) was abnormally high and the diagnostic of tumor-induced osteomalacia was made. Despite multiple tests, the tumor was not localized. In this report, we discuss different possible investigations to localize the tumor. Lastly, we review the potential therapy available when tumor is not found and can thus not be excised. [less ▲]Detailed reference viewed: 53 (17 ULg)
Hypophosphatémie et ostéomalacie oncogénique
; CAVALIER, Etienne ; COLSON, Laurent et al
in Revue Médicale Suisse (2011), 7
In this article, we will discuss about hypophosphatemia due to tumor-induced osteomalacia. This disease is characterized by severe muscular and articular tenderness inducing profound walking limitation ... [more ▼]
In this article, we will discuss about hypophosphatemia due to tumor-induced osteomalacia. This disease is characterized by severe muscular and articular tenderness inducing profound walking limitation. Clinical chemistry results show severe hypophosphatemia due to hyperphosphaturia. Fibroblast growth factor 23 (FGG-23) is abnormally high. Physiological role of FGF-23 is examined. We also consider the pathophysiology of tumor induced osteomalacia, the use of different investigations to localize the tumor and therapies available to treat this rare disease. [less ▲]Detailed reference viewed: 122 (9 ULg)
Potentialités quantitatives et qualité d'image de la camera TEMP/TDM Siemens Symbia T6
Seret, Alain ; Nguyen, Daniel ; HUSTINX, Roland et al
in Médecine Nucléaire : Imagerie Fonctionnelle et Métabolique (2011, May 07), 35Detailed reference viewed: 55 (32 ULg)
Central modulation in cluster headache patients treated with occipital nerve stimulation: an FDG-PET study
MAGIS, Delphine ; Bruno, Marie-Aurélie ; FUMAL, Arnaud et al
in BMC Neurology (2011), 11Detailed reference viewed: 32 (10 ULg)
Reduced grey matter metabolism due to white matter edema allows optimal assessment of brain tumors on 18F-FDG-PET.
; ; et al
in Hellenic journal of nuclear medicine (2011), 14(3), 219-23
The main aim of this research was to demonstrate that the cortical and subcortical grey matter hypometabolism as revealed by fluorine-18 fluorodesoxyglucose-positron emission tomography ((18)F-FDG-PET ... [more ▼]
The main aim of this research was to demonstrate that the cortical and subcortical grey matter hypometabolism as revealed by fluorine-18 fluorodesoxyglucose-positron emission tomography ((18)F-FDG-PET) imaging in brain tumors is related to associated edema as demonstrated by magnetic resonance imaging (MRI). This in turn enhances the ability to assess disease activity in the tumor and the degree of loss of cerebral function in the adjacent and distant structures. We evaluated brain T1 and T2 weighted MRI and (18)F-FDG-PET scans of 29 patients (19 adult, 10 pediatric) with history of brain tumor. Tumor histology types included 21 gliomas, 1 melanoma, 1 primitive neuroectodermal tumor, 3 medulloblastomas and 3 ependymomas. The majority of scans were performed within the same week (94% <1 month. The extent of hypo and hypermetabolism was assessed on the (18)F-FDG-PET scans. A template of 12 regions of interest (ROI) was applied and the laterality indices of the regional counts (signal intensity) were computed. Extent of edema, enhancement, and anatomical change were assessed on the MRI scans. Extent of edema in the same ROI was evaluated by a 6-point semiquantitative scale and laterality indices were generated. Metabolic activity of the grey matter was correlated with the extent of edema using these indices. In all cases where edema was present, significant hypometabolism was observed in the adjacent structures. Overall, there was a strong correlation between the extent of edema and severity of hypometabolism (r=0.92, P=0.01). This was true regardless of the location of edema, whether there was history of radiation treatment (r=0.91, P=0.03), or not (r=0.97, P=0.17). In conclusion, edema independent of underlying variables appeared to contribute significantly to cortical and sub-cortical grey matter hypometabolism observed in patients with brain tumors. This would indicate that brain tumors can be successfully assessed by (18)F-FDG-PET and therefore the efforts for utilizing other tracers may not be justified. [less ▲]Detailed reference viewed: 16 (0 ULg)
2-18F-Fluoro-L-tyrosine in the suspicion of recurrence of previously treated gliomas.
; NAMUR, Gauthier ; et al
in European Journal of Nuclear Medicine and Molecular Imaging (2011), 38(SUPPL), 219Detailed reference viewed: 20 (1 ULg)
Assessment of Crohn’s disease activity by FDG-PET/CT through a novel quantitative approach.
; HUSTINX, Roland ; et al
in Journal of Nuclear Medicine (The) (2011), 52(SUPPL), 284Detailed reference viewed: 6 (0 ULg)
Evaluation of the homing process in the treatment of atrophic nonunion fractures by percutaneous autologous osteoblast cell implantation.
; HAUZEUR, Jean-Philippe ; LECHANTEUR, Chantal et al
in Journal of Nuclear Medicine (The) (2011), 52(SUPPL), 510Detailed reference viewed: 20 (0 ULg)