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The early stage detection of benign and malignant pulmonary nodules plays an important role in clinical diagnosis. The malignancy risk assessment is usually used to guide the doctor in identifying the cancer stage and making follow-up prognosis plan. However, due to the variance of nodules on size, shape, and location, it has been a big challenge to classify the nodules in computer aided diagnosis system. In this paper, we design a novel model based on convolution neural network to achieve automatic pulmonary nodule malignancy classification. By using our model, the multi-scale features are extracted through the multi-convolution process, and the structure of residual blocks allows the network to capture more high-level and semantic information. Moreover, a strategy is proposed to fuse the features from the last avg-pooling layer and the ones from the last residual block to further enhance the performance of our model. Experimental results on the public Lung Image Database Consortium dataset demonstrate that our model can achieve a lung nodule classification accuracy of 87.5%which outperforms state-of-the-art methods.

Axicabtagene ciloleucel (axi-cel) demonstrated superior efficacy compared to standard of care as second-line therapy in patients with high-risk relapsed/refractory (R/R) large B cell lymphoma (LBCL) considered eligible for autologous stem cell transplantation (ASCT); however, in clinical practice, roughly half of patients with R/R LBCL are deemed unsuitable candidates for ASCT. The efficacy of axi-cel remains to be ascertained in transplant-ineligible patients. ALYCANTE, an open-label, phase 2 study, evaluated axi-cel as a second-line therapy in 62 patients with R/R LBCL who were considered ineligible for ASCT. The primary end point was investigator-assessed complete metabolic response at 3 months from the axi-cel infusion. Key secondary end points included progression-free survival, overall survival and safety. The study met its primary end point with a complete metabolic response of 71.0% (95% confidence interval, 58.1–81.8%) at 3 months. With a median follow-up of 12.0 months (range, 2.1–17.9), median progression-free survival was 11.8 months (95% confidence interval, 8.4–not reached) and overall survival was not reached. There was no unexpected toxicity. Grade 3–4 cytokine release syndrome and neurologic events occurred in 8.1% and 14.5% of patients, respectively. These results support axi-cel as second-line therapy in patients with R/R LBCL ineligible for ASCT. ClinicalTrials.gov Identifier: NCT04531046.

•Favorable outcomes were observed with dose-dense induction and PET-driven consolidation, with 2-year PFS and OS rates of 86.2% and 93.2%.•The interim PET response, based on ΔSUVmax at PET4 (threshold: ≤70% vs >70%), emerged as the most robust predictor of outcomes.

The human brain is the gold standard of adaptive learning. It not only can learn and benefit from experience, but also can adapt to new situations. In contrast, deep neural networks only learn one sophisticated but fixed mapping from inputs to outputs. This limits their applicability to more dynamic situations, where the input to output mapping may change with different contexts. A salient example is continual learning-learning new independent tasks sequentially without forgetting previous tasks. Continual learning of multiple tasks in artificial neural networks using gradient descent leads to catastrophic forgetting, whereby a previously learned mapping of an old task is erased when learning new mappings for new tasks. Herein, we propose a new biologically plausible type of deep neural network with extra, out-of-network, task-dependent biasing units to accommodate these dynamic situations. This allows, for the first time, a single network to learn potentially unlimited parallel input to output mappings, and to switch on the fly between them at runtime. Biasing units are programed by leveraging beneficial perturbations (opposite to well-known adversarial perturbations) for each task. Beneficial perturbations for a given task bias the network toward that task, essentially switching the network into a different mode to process that task. This largely eliminates catastrophic interference between tasks. Our approach is memory-efficient and parameter-efficient, can accommodate many tasks, and achieves the state-of-the-art performance across different tasks and domains.

Technetium-99m (Tc-99m) tetrofosmin, a now myocardial perfusion imaging agent, was evaluated at exercise and rest in 50 patients with documented coronary artery disease to determine myocardial kinetics, redistribution and ideal imaging time. Planar imaging was performed at 5, 30, 60, 90, 120 and 240 minutes after an injection of Tc-99m tetrofosmin (8 to 10 mCi) at peak ergometric exercise. Reinjection (24 to 30 mCi) was performed at rest, 4 hours after the stress injection and also on a separate day, and imaging was repeated. All patients underwent thallium-201 (TI-201) exercise and redistribution (4-hour) imaging Perfusion defect to normal, and heart to lung ratios were calculated for exercise Tc-99m tetrofasmin images at each time point. The mean [+/-] SD defect to normal ratios were 0.75 [+/-] 0.10, 0.75 [+-] 0.10, 0.74 [+/-] 0.09, 0.73 [+/-] 0.10, 0.73 [+/-] 0.10 and 0.72 [+/-] 0.10 at 5, 30, 60, 90, 120 and 240 minutes, respectively (p = NS), suggesting absence of redistribution. There was a significant increase in lung uptake of TI-201 during exercise (p < 0.05), but not with Tc-99m tetrofosmin (p = NS). Wash-out of Tc-99m tetrofosmin was calculated in a subset of patients (n = 23). Rapid background clearance enabled postexercise diagnostic imaging as early as 5 minutes after injection. Myocardial retention curves after rest injection suggested that the optimal time for imaging was approximately 30 minutes later. Slow myocardial washout (4%/hour after exercise and 0.6%/hour after rest injection) enabled diagnostic images to be obtained up to 4 hours after each study. Image quality was generally superior to that with TI-201. Tc-99m tetrofosmin has the advantage of early imaging after exercise, with no evidence of redistribution.

Rituximab plus polychemotherapy is the standard of care in diffuse large B-cell lymphoma (DLBCL). GAINED, a randomized phase 3 trial, compared obinutuzumab to rituximab. Transplant-eligible patients (18-60 years) with an untreated age-adjusted International Prognostic Index (aaIPI) score ≥1 DLBCL were randomized (1:1) between obinutuzumab or rituximab and stratified by aaIPI (1; 2-3) and chemotherapy regimen (doxorubicin, cyclophosphamide, prednisone plus vindesine, bleomycin [ACVBP] or vincristine [CHOP]). Consolidation treatment was determined according to response to interim positron emission tomography (PET). Responders after cycle 2 and 4 (PET2−/PET4−) received immunochemotherapy. Responders after only cycle 4 (PET2+/4−) received transplantation. The primary objective was an 8% improvement (hazard ratio [HR] = 0.73; 80% power; α risk, 2.5%; 1-sided) in 2-year event-free survival (EFS) in the obinutuzumab arm. From September 2012, 670 patients were enrolled (obinutuzumab, n = 336; rituximab, n = 334). A total of 383 (57.2%) were aaIPI 2-3, 339 (50.6%) received CHOP. Median follow-up was 38.7 months. The 2-year EFS was similar in both groups (59.8% vs 56.6%; P = .123; HR = 0.88). The 2-year PFS in the whole cohort was 83.1% (95% confidence interval, 80% to 85.8%). PET2−/4− and PET2+/4− had similar 2-year progression-free survival (PFS) and overall survival (OS): 89.9% vs 83.9% and 94.8% vs 92.8%. The 2-year PFS and OS for PET4+ patients were 62% and 83.1%. Grade 3-5 infections were more frequent in the obinutuzumab arm (21% vs 12%). Obinutuzumab is not superior to rituximab in aaIPI ≥1 DLBCL transplant-eligible patients. This trial was registered at www.clinicaltrials.gov as #NCT01659099.

All randomised phase 3 studies of selective internal radiation therapy for advanced hepatocellular carcinoma published to date have reported negative results. However, these studies did not use personalised dosimetry. We aimed to compare the efficacy of a personalised versus standard dosimetry approach of selective internal radiation therapy with yttrium-90-loaded glass microspheres in patients with hepatocellular carcinoma.

Les tumeurs malignes des gaines nerveuses périphériques (TMGN) sont une des principales causes de mortalité dans la neurofibromatose de type 1 (NF1). Étant donné la multiplicité temporelle et spatiale des lésions suspectes de transformation, le diagnostic histologique de certitude peut entraîner un recours chirurgical potentiellement itératif et délabrant. L’objectif de notre étude était de déterminer les valeurs seuils de métriques métaboliques déterminées en TEP/TDM au 18F-FDG (SUVmax, activité glycolytique totale [TLG], volume métabolique tumoral total [TMTV], rapport tumoral au foie [T/L] et index d’hétérogénéité [HI]), permettant de distinguer au mieux les TMGN et les neurofibromes (NF) simples ou dysplasiques.

Autonomous vehicles differ from many other autonomous systems in the sense that these vehicles have to share the environment with humans (e.g., pedestrians, cyclists, and other drivers in traffic). This requirement poses a challenging perception and planning problem. Our research focuses on the problem of a vehicle sharing the environment with a human passenger/driver and, specifically, of designing a controller that captures the natural tendencies of the human driver so as to guarantee that the resulting control action is comparable to that of the human. In this paper, we propose to use a human driver control model into the autonomous vehicle control framework, which has previously been shown to predict short-term driver actions, and we develop an approach that reliably and accurately estimates input-feature values from driver-point-of-view images. After the feature-input values have been estimated, the human driver control model computes the corresponding steering-wheel angle. We, thus, provide more structure to the overall processing pipeline, compared to the recent end-to-end approaches. The proposed approach is validated using numerical simulations with synthetic images. The results validate the importance of combining traditional structured (e.g., transfer function) models with parsimonious neural-network representations.

We report herein a novel pipet-based “ELISA in a tip” as a new versatile diagnostic tool featuring better sensitivity, shorter incubation time, accessibility, and low sample and reagent volumes compared to traditional ELISA. Capture and analysis of data by a cell phone facilitates electronic delivery of results to health care providers. Pipette tips were designed and 3D printed as adapters to fit most commercial 50–200 μL pipettes. Capture antibodies (Ab1) are immobilized on the inner walls of the pipet tip, which serves as the assay compartment where samples and reagents are moved in and out by pipetting. Signals are generated using colorimetric or chemiluminescent (CL) reagents and can be quantified using a cell phone, CCD camera, or plate reader. We utilized pipet-tip ELISA to detect four cancer biomarker proteins with detection limits similar to or lower than microplate ELISAs at 25% assay cost and time. Recoveries of these proteins from spiked human serum were 85–115% or better, depending slightly on detection mode. Using CCD camera quantification of CL with femto-luminol reagent gave limits of detection (LOD) as low as 0.5 pg/mL. Patient samples (13) were assayed for 3 biomarker proteins with results well correlated to conventional ELISA and an established microfluidic electrochemical immunoassay.

To describe the prevalence of and risk factors for renal infarction (RI) in patients with cardiac amyloidosis.

A 35-year-old 30-week pregnant woman was referred to our institution for initial staging of a triple negative invasive ductal carcinoma of the left breast. To avoid fetal radiation exposure from CT, a whole-body 18F-FDG PET/MRI was performed. Simultaneous acquisition of PET, T1-, T2-, and diffusion-weighted sequences revealed left axillary node extension and no distant metastases. Fetal radiation dose was estimated at 1.9 mGy. Interestingly, low fetal brain uptake and high symmetrical myocardial metabolism in both ventricles were found. Delivery was induced at 37 weeks of amenorrhea, and the patient underwent 4 cycles of neoadjuvant chemotherapy.

Malignant peripheral nerve sheath tumors (MPNST) are the leading cause of death in Neurofibromatosis type 1 (NF1). They can result from premalignant neurofibromas (NF) including NF with atypia and atypical neurofibromatous neoplasms of uncertain biologic potential (ANNUBP). Some phenotypic characteristics have been described as associated with their development. The aim was to outline our use of whole-body 18F-FDG-PET/MRI in adults with NF1, especially in the screening of asymptomatic individuals with a higher risk of developing a MPNST, and to study its impact on NF classification (malignant vs premalignant) and MPNST staging over time. Individuals with NF1 who underwent a 18F-FDG-PET/MRI between 2017 to 2021 were included, analyzing separately the screened population. Maximum standard uptake value and diffusion-weighed imaging were assessed. Biopsy/surgery confirmed the diagnosis. In all, 345 18F-FDG-PET/MRI were performed in 241 patients including 149 asymptomatic (62%), but at risk. Eight MPNST in 8 screened individuals (5%), 6 NF with atypia in 4 (3%) and 29 ANNUBP in 23 (15%) were diagnosed. Over time, the proportion of grade 3 MPNST and the malignant/premalignant ratio in screened individuals significantly decreased (p=0.03 and p<0.001, respectively). This study emphasizes the diagnostic and screening performances of whole-body 18F-FDG-PET/MRI in adults with NF1.

La tomographie par émission de positons (TEP) est une technique d’imagerie fonctionnelle de médecine nucléaire ayant fait la preuve de son intérêt clinique principalement en cancérologie. Ses champs d’application évoluent sans cesse grâce à l’apport de la recherche. L’utilisation de la TEP en cancérologie a fait l’objet de recommandations selon la méthodologie Standard-Options-Recommandations de la Fédération nationale des centres de lutte contre le cancer en 2002, mises à jour en 2003. Cependant, de très nombreux travaux scientifiques ont été publiés depuis 2003 et de nouveaux traceurs ont de plus obtenu une autorisation de mise sur le marché (AMM) en France. L’objectif de ce travail a donc été la réalisation d’une mise à jour des recommandations établies en 2003. Dans ce contexte, en collaboration avec la Société française de médecine nucléaire, un groupe de travail s’est mis en place pour la réalisation d’une recommandation de bonne pratique clinique sous le label méthodologique HAS-INCa (Haute Autorité de Santé, et Institut National du Cancer). Le présent document est l’aboutissement d’une revue exhaustive de la littérature et d’une critique rigoureuse conduite par un panel d’experts nationaux, spécialistes d’organe, oncologues cliniciens, chirurgiens ou spécialistes de l’imagerie. Celui-ci se veut être un guide d’aide à la décision pour les groupes de cancérologie à même de prendre en charge des patients dans des situations variées et pour lesquelles le libellé de l’AMM n’est pas suffisamment précis.

Macrophagic myofasciitis (MMF) syndrome is a subtype of autoimmune/inflammatory syndrome induced by adjuvants (ASIA) or Shoenfeld's syndrome, characterized by the presence of stereotyped inflammatory lesions at muscle biopsy attesting the long-term persistence of aluminum hydroxide particles at the site of previous immunization. Most frequently reported symptoms are chronic arthromyalgias and fatigue and cognitive complaint. MMF-associated cognitive disorder (MACD) is characterized by the dysfunctioning of attention, executive functions, short-term term and long-term memory, and, in some instances, left ear extinction. MACD is expressed in a chronic, nonevolving, well-defined syndromic framework within which the expression in terms of severity differs from one patient to another. While brain MRI is usually noncontributive, functional imaging using SPECT and PET has revealed the existence of a suggestive pathological pattern with involvement of posterior associative areas, temporal lobes, limbic system, and cerebellum. Put together, neuropsychological and functional neuroimaging investigations support the view that MACD relates to organic central nervous system involvement.

Outcomes for follicular lymphoma (FL) have greatly improved, but most patients will ultimately relapse. High total metabolic tumor volume (TMTV), computed from baseline 18F-fluorodeoxyglucose–positron emission tomography (PET), is associated with shorter progression-free survival (PFS), but circulating tumor cells (CTCs) and cell-free DNA (cfDNA) may also reflect tumor burden and be of prognostic value. The aim of our study was to correlate CTCs and cfDNA with TMTV in FL at diagnosis and to determine their prognostic values. We retrospectively analyzed 133 patients (with previously untreated FL and a baseline PET) from 2 cohorts with either a baseline plasma sample (n = 61) or a bcl2-JH-informative peripheral blood (PB) sample (n = 68). Quantification of circulating bcl2-JH+ cells and cfDNA was performed by droplet digital polymerase chain reaction. A significant correlation was found between TMTV and both CTCs (P < .0001) and cfDNA (P < .0001). With a median 48-month follow-up, 4-year PFS was lower in patients with TMTV > 510 cm3 (P = .0004), CTCs >0.0018 PB cells (P = .03), or cfDNA >2550 equivalent-genome/mL (P = .04). In comparison with TMTV alone, no additional prognostic information was obtained by measuring CTCs. In contrast, Cox multivariate analysis, including cfDNA and TMTV, showed that both cfDNA and TMTV remained predictive of outcome. In conclusion, CTCs and cfDNA correlate with TMTV in FL, and all 3 influence patient outcome. PFS was shorter for patients with high cfDNA and TMTV, suggesting that these parameters provide relevant information for tumor-tailored therapy.

Background: Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is an uncommon peripheral T-cell lymphoma most frequently arising around a textured surface breast implant. It has been shown that capsule infiltration (T2, T3 and T4 of the TNM staging system) was an adverse prognostic factor. In this context, chemotherapy (with or without brentuximab vedotin [BV]) may be proposed, considering other factors such as metastatic disease or incomplete resection. Furthermore, the need for adjuvant chemotherapy in patients with stage IIA (T4N0M0) and complete en-bloc excision without residual disease is debated.

Focal low-signal-intensity areas due to iron deposits occur in some lymphoma lesions, particularly in the spleen and mostly in patients with advanced Hodgkin lymphoma or diffuse large B-cell lymphoma, and are linked to a more pronounced biologic inflammatory syndrome and a higher metabolic tumor volume measured at PET/CT.

We report FDG PET/CT images of a 63-year-old woman referred for characterization of osteolytic lesions of the cervical spine. This patient with chronic renal failure had a history of follicular thyroid carcinoma with undifferentiated cells, treated by a total thyroidectomy, completed by radioactive iodine in 2017. Because of cancer history, a FDG PET/CT was performed and showed multiple moderately hypermetabolic osteolytic lesions of the spine from C3 to T1, with joint erosion on CT. A laminectomy was performed for cervical spinal cord decompression and revealed a gouty tophus.

A 63-year-old woman was referred to our PET/MRI platform to evaluate the possible relapse of a meningeal metastasis, complicating an invasive ductal carcinoma of the left breast. This metastasis was diagnosed on a left hemiparesis and treated by surgery and radiation therapy. One year later, the same symptoms led to another brain MRI examination that found a contrast-enhanced lesion in the operating site. We decided to perform a 18F-DOPA PET/MRI to document this lesion, which confirmed the diagnosis of a probable relapse and revealed a focal uptake on the bone flap.

Nicotine therapy might improve the course of Parkinson's disease. This observational study evaluated the performance of dopamine transporter imaging in follow-up patients under nicotine therapy.

To compare the apparent diffusion coefficient (ADC) on diffusion-weighted imaging (DWI) with the standardized uptake values (SUV) measured by18F-FDG-PET/CT in naïve hepatocellular carcinoma (HCC) nodules, and to determine whether these markers are associated with tumours at high-risk of aggressiveness. From 2007 to 2010, all patients with HCC on the waiting list for liver transplantation and who underwent both FDG-PET/CT and 1.5-T DWI-MRI (b values: 0, 200, 400, and 800 s/mm2) were included in this institutional review board-approved retrospective study. Tumour size, tumour ADC, tumour-to-liver ADC ratio (ADCT/L), maximal tumour SUV and tumour-to-liver SUV ratio (SUVT/L) were measured and compared to serum alpha-fetoprotein (AFP) levels, tumour size and differentiation grade on explanted specimens. A total of 37 HCC nodules in 28 patients were available for correlation between MRI and PET/CT, 7 of which (in 7 patients) showed a SUVT/L> 1.15. We did not find any correlation between tumour ADC or ADCT/Land tumour SUV or SUVT/L. To note, SUVT/Lwas positively correlated with AFP levels (R= 0.95, P ≤ 0.0001), while ADCT/Lwas not (P= 0.73). Twenty-four patients (with 32 nodules) underwent liver transplantation. In this subgroup, an increased SUVT/Lratio was associated with larger tumours (average size, 32 ± 14 mm; range, 18–60 mm; P< 0.0001) and with poor differentiation on pathology (grades 3 and 4; P= 0.04), while ADCT/Lwas neither associated with tumour size or differentiation grade. ADC and SUV measures in HCC nodules are not correlated. SUVT/Lratio correlates with AFP levels, tumour size and poor differentiation, and should probably be integrated as a co-variable in a predictive outcome model of patients on the waiting-list for liver transplantation.

This study aimed to characterize cerebral perfusion in men with Klinefelter's syndrome, known to present specific deficits in language, using ^99mTc- hexamethylpropylene-amine-oxime scintigraphy and Talairach normalization. While a perfusion asymmetry toward the left hemisphere was found in controls, perfusion was mostly symmetrical in Klinefelter patients in the upper temporal and lower parietal areas. Scores on verbal tests were inversely correlated with perfusion changes, providing neurobiological substrate of anomalous cerebral laterality.

Human immunodeficiency virus‐cognitive motor complex (HIV‐CMC), a common complication of the acquired immunodeficiency syndrome (AIDS), is characterized by progressive cognitive impairment and motor dysfunction. Functional imaging methods, such as single‐photon emission computed tomography (SPECT) and proton magnetic resonance spectroscopy (1H‐MRS), have been applied to assess the severity of brain injury. However, it is unclear which of these two methods is more sensitive in detecting brain abnormalities in patients with early HIV‐CMC. Twenty‐four HIV‐CMC patients were compared with 34 healthy subjects; each had quantitative SPECT (133Xenon‐calibrated 99mTc‐HMPAO) and quantitative 1H‐MRS. Both modalities were co‐registered in order to assess regional cerebral blood flow (rCBF) and metabolite concentrations within the same voxel of interest in four brain regions (midfrontal and midparietal gray matter, temporoparietal white matter, and basal ganglia). On SPECT, only the temporoparietal white matter showed a trend for decreased rCBF in HIV‐CMC patients (−13%, P= 0.06). On MRS, HIV‐CMC patients showed significantly reduced creatine concentration in the basal ganglia (−8%, P= 0.008), as well as increased myoinositol concentrations in the basal ganglia (+25%, P= 0.01) and the temporoparietal white matter (+18%, P= 0.08). There was no significant correlation between SPECT and MRS variables in the patients in any region. 1H MRS showed abnormal neurochemistry in the basal ganglia, whereas rCBF on SPECT was normal in the same region. This finding suggests that metabolite concentrations on 1H MRS are better surrogate markers than rCBF measurements with SPECT for the evaluation of brain injury in early HIV‐CMC. J. Magn. Reson. Imaging 2000;12:859–865. © 2000 Wiley‐Liss, Inc.

Human immunodeficiency virus-cognitive motor complex (HIV-CMC), a common complication of the acquired immunodeficiency syndrome (AIDS), is characterized by progressive cognitive impairment and motor dysfunction. Functional imaging methods, such as single-photon emission computed tomography (SPECT) and proton magnetic resonance spectroscopy (¹H-MRS), have been applied to assess the severity of brain injury. However, it is unclear which of these two methods is more sensitive in detecting brain abnormalities in patients with early HIV-CMC. Twenty-four HIV-CMC patients were compared with 34 healthy subjects; each had quantitative SPECT (¹³³Xenon-calibrated ^99mTc-HMPAO) and quantitative ¹H-MRS. Both modalities were co-registered in order to assess regional cerebral blood flow (rCBF) and metabolite concentrations within the same voxel of interest in four brain regions (midfrontal and midparietal gray matter, temporoparietal white matter, and basal ganglia). On SPECT, only the temporoparietal white matter showed a trend for decreased rCBF in HIV-CMC patients (−13%, P = 0.06). On MRS, HIV-CMC patients showed significantly reduced creatine concentration in the basal ganglia (−8%, P = 0.008), as well as increased myoinositol concentrations in the basal ganglia (+25%, P = 0.01) and the temporoparietal white matter (+18%, P = 0.08). There was no significant correlation between SPECT and MRS variables in the patients in any region. ¹H MRS showed abnormal neurochemistry in the basal ganglia, whereas rCBF on SPECT was normal in the same region. This finding suggests that metabolite concentrations on ¹H MRS are better surrogate markers than rCBF measurements with SPECT for the evaluation of brain injury in early HIV-CMC. J. Magn. Reson. Imaging 2000;12:859–865. © 2000 Wiley-Liss, Inc.

La TEP-TDM au 18-FDG est aujourd’hui un examen essentiel dans la prise en charge des cancers pulmonaires et des paramètres, comme le volume tumoral, ont montré leurs caractères pronostiques et prédictifs de la réponse au traitement. L’essor de l’intelligence artificielle a permis de simplifier le calcul de ces derniers sujets à une variabilité inter-opérateurs grâce à des algorithmes mis à notre disposition pour automatiser la segmentation des lésions tumorales. L’objectif de cette étude est d’évaluer les performances en termes de détection, mais également pour le calcul automatique du volume métabolique, de deux logiciels d’intelligence artificielle dans une cohorte monocentrique de cancers du poumon.

L’imagerie hybride TEP/IRM est une innovation technologique permettant de réaliser simultanément l’acquisition des cibles métaboliques et une caractérisation tissulaire fine. Elle est particulièrement indiquée dans les cancers gynécologiques pelviens, pour lesquels la TEP au FDG et l’IRM avec séquences de diffusion sont recommandées, réalisées ici selon le principe du one stop shop. En s’appuyant sur une analyse de la littérature, nous partageons dans cet article notre expérience locale (65 examens chez 47 patientes).

Brain Positron Emission Tomography/Computed Tomography with 18F-fluorodeoxyglucose (FDG PET/CT) was performed in a 44-year-old woman with marked cognitive impairment, diffuse myalgias, sensory, memory and visual disorders, and chronic fatigue, presenting with histopathological features of macrophagic myofasciitis (MMF) at deltoid muscle biopsy. Cerebromedullary Magnetic Resonance Imaging (MRI), electromyography, ophthalmic examination, and cerebrospinal fluid analysis were normal. Visual analysis of FDG PET/CT images showed an atypical pattern of hypometabolism, involving symmetrically the occipital cortex, temporal lobes, and limbic system (including in particular amygdalo-hippocampal complexes), and the cerebellum. Posterior cingulate cortex and parietal areas were preserved. This pattern was confirmed by a voxel-based procedure using Statistical Parametric Mapping (SPM12) that compared a patient’s images to normal reference samples from six healthy subjects with adjustment to age obtained using the same PET/CT camera. These results provide a glucose metabolism substrate for cognitive complaints in patients with long-lasting aluminium hydroxide-induced MMF.

Mounting evidence supports the major role of [18F]FDG PET-CT in the assessment of response to chemotherapy in lymphoma. The five-point scale to grade response is becoming widely used both in practice and response-adapted trials. In 2014, a malignant lymphomas imaging working group composed of representatives from major international cooperative groups published revised guidelines concerning the role of imaging in the staging and response assessment of lymphoma. This paper summarizes the main recommendations to facilitate their clinical routine applications.

Whole-body diffusion-weighted MR imaging is possibly equivalent to PET/CT or CT for use in lymphoma staging and helps in characterization of residual masses by allowing qualitative and quantitative assessment of the apparent diffusion coefficient.

Two different acquisition and processing strategies to determine the regional cerebral blood volume (rCBV) with magnetic resonance imaging (MRI) are compared. The first method is based on the acquisition of the signal time course during a bolus administration of a contrast agent (dynamic method). The second method evaluates signal changes before and after the contrast agent injection (static method), assuming the contrast agent remains primarily intravascular in the brain after the first pass. Both methods were applied to the same data sets, acquired with either echoplanar imaging (EPI, n= 18) or fast low‐angle shot (FLASH, n= 28) techniques. A voxel‐by‐voxel correlation between the static and dynamic method yielded a correlation coefficient of 0.76 ± 0.06 for the EPI and 0.71 ± 0.10 for the FLASH measurements. The static method was less sensitive and showed higher standard deviations for rCBV than the dynamic method. With the development of truly intravascular contrast agents, the static perfusion MRI method, which can be performed with higher signal‐to‐noise ratio and higher spatial resolution, may become an alternative to ultra‐fast MRI for measuring rCBV. Magn Reson Med 41:1264–1268, 1999. © 1999 Wiley‐Liss, Inc.

18F-DOPA PET-MRI was performed on a 38-year-old man referred for complementary imaging after a brain tumor was discovered, according to EANM/RANO recommendations. We performed a simultaneous PET with 3-T brain MRI, which revealed 2 high 18F-DOPA uptakes, with no multimodal MRI sign of aggressiveness. An awake surgery was performed and found a grade III anaplastic astrocytoma IDH1-R132L mutant, according to the 2016 WHO classification. This was probably the aggressive transition of a grade II diffuse astrocytoma. This case illustrates the added value of 18F-DOPA PET to multimodal MRI to distinguish low- and high-grade gliomas.

The aim of this pilot study was to assess post-treatment apparent diffusion coefficient (ADC) changes of diffuse large B-cell lymphoma lesions on respiratory-gated whole-body diffusion-weighted imaging (DWI), with integrated 18F-fluoro-2-deoxyglucose positron emission tomography/computed tomography (PET/CT) as the reference standard.

Phase analysis, developed to assess dyssynchrony from ECG-gated radionuclide ventriculography, has shown promising results. We hypothesized that quantifying the cardiac resynchronization reserve, that is, the extent of response to cardiac resynchronization therapy (CRT), by radionuclide imaging could potentially identify patients who are best suited for CRT.

L’utilité de la TEP au FDG a été bien établie dans le diagnostic du carcinome colorectal récidivant ou métastatique. Plusieurs séries de cas montrent que la TEP au FDG est souvent à l’origine de la découverte fortuite de polypes adénomateux ou d’adénocarcinomes colorectaux. L’objectif de notre travail est de déterminer rétrospectivement la signification clinique des fixations focales du FDG découvertes fortuitement au niveau colorectal grâce à une corrélation aux données de la coloscopie.

A 67-year-old man was referred for fluctuating neuropsychiatric symptoms, featuring depression, delirious episodes, recurrent visual hallucinations and catatonic syndrome associated with cognitive decline. No parkinsonism was found clinically even under neuroleptic treatment. 18F-FDG PET/CT showed hypometabolism in the posterior associative cortex including the occipital cortex, suggesting Lewy body dementia, but 123I-FP-CIT SPECT was normal and cardiac 123I-MIBG imaging showed no signs of sympathetic denervation. Alzheimer's disease was excluded by a normal 18F-florbetaben PET/CT. This report suggests a rare case of α-synucleinopathy without brainstem involvement, referred to as "cerebral type" of Lewy body disease.

Future interactive virtual environments will be “attention-aware,” capable of predicting, reacting to, and ultimately influencing the visual attention of their human operators. Before such environments can be realized, it is necessary to operationalize our understanding of the relevant aspects of visual perception, in the form of fully automated computational heuristics that can efficiently identify locations that would attract human gaze in complex dynamic environments. One promising approach to designing such heuristics draws on ideas from computational neuroscience. We compared several neurobiologically inspired heuristics with eye-movement recordings from five observers playing video games, and found that human gaze was better predicted by heuristics that detect outliers from the global distribution of visual features than by purely local heuristics. Heuristics sensitive to dynamic events performed best overall. Further, heuristic prediction power differed more between games than between different human observers. While other factors clearly also influence eye position, our findings suggest that simple neurally inspired algorithmic methods can account for a significant portion of human gaze behavior in a naturalistic, interactive setting. These algorithms may be useful in the implementation of interactive virtual environments, both to predict the cognitive state of human operators, as well as to effectively endow virtual agents in the system with humanlike visual behavior.

AimThe aim of this work is to study the influence of medium density on the CT or external source attenuation corrected images, by simulation on a phantom, with various positron emission tomographs.Material and methodA series of experiments on a cylindrical phantom filled with water marked with [18F]-FDG, containing six vials filled per pair with mediums of different densities or solutions of KI, CaCl2 and saccharose with various densities, was carried out under comparable conditions on three different tomographs. In only one of the vials of each pair, an identical radioactivity of [18F]-FDG was added, three to five fold the surrounding activity. The reconstructions and attenuation corrections suggested by the manufacturers, were carried out under the usual conditions of each site. The activity of each structure was estimated by the methods of profiles and regions of interest, on the non attenuation corrected images (NAC), the images corrected by CT (CTAC), and/or external source (GPAC).ResultsWith all three tomographs, the activities estimated on the NAC images present an inverse correlation to the medium density (important absorption by dense material). On CTAC images, we observed with only two of the three tomographs, an overestimation of the activity in the “radioactive” vials, depending on the medium mean Z number and density (over correction), and a artefactual “activity” in the denser “cold” vial (incorrect attenuation correction. The dense saccharose solutions, with non elevated Z number, do not affect the CT attenuation correction.

Introduction

An increased glucose metabolic rate is observed with various degrees of intensity in different subtypes of aggressive lymphomas. [18F]Fluorodeoxyglucose (FDG)–positron emission tomography (PET; FDG-PET) allows functional imaging of this phenomenon through 3-dimensional tomographic slices, which are now easily fused with computed tomography (CT) images. [18F]Fluorodeoxyglucose–positron emission tomography staging appears superior to conventional staging modalities for detecting nodal and extranodal lymphoma. When performed after first-line chemotherapy, FDG-PET is more efficient than CT and conventional diagnostic methods to predict the disease outcome. Some studies have reported that the relapse rate is 100% in patients with positive PET findings after treatment and 17% in patients with negative PET findings. This imaging modality can also assess early response after 1-2 cycles of chemotherapy, thus identifying responders from patients whose cancer will fail to respond to first-line therapy or will relapse shortly after having exhibited a partial or complete remission. [18F]Fluorodeoxyglucose–PET also seems useful for an accurate selection of patients who will benefit from highly intensive treatment.

Assessment of early therapeutic response using metabolic imaging is potentially useful to determine prognosis in aggressive lymphoma. Between January 2000 and January 2004, 90 patients with newly diagnosed aggressive lymphoma (median age 53 years, 94% diffuse large B-cell) were prospectively explored with [18F]fluoro-2-deoxy-d-glucose positron emission tomography (FDG-PET) prior to induction chemotherapy, after 2 cycles (“early PET”), and after induction completion. Therapeutic response was evaluated using conventional diagnostic methods at 4 cycles. Induction treatment with an anthracycline-containing regimen was administered to all patients, associated with rituximab in 41%. According to the International Prognostic Index (IPI), 37 patients and 53 patients belonged to the lower- and higher-risk groups, respectively. At midinduction, “early PET” was considered negative in 54 patients and positive in 36. After completion of induction, 83% of PET-negative patients achieved complete remission compared with only 58% of PET-positive patients. Outcome differed significantly between PET-negative and PET-positive groups; the 2-year estimates of event-free survival reached 82% and 43%, respectively (P < .001), and the 2-year estimates of overall survival reached 90% and 61%, respectively (P = .006). Predictive value of “early PET” was observed in both the lower-risk and higher-risk groups, indicating prognostic independence from the IPI. Therefore, FDG-PET should be an early guide to first-line strategies in aggressive lymphoma. (Blood. 2005;106:1376-1381)

The assessment of lung ventilation by radionuclide imaging has proved useful for the optimization of aerosol therapy in children with cystic fibrosis. Further analysis of lung perfusion may provide additional information.

OBJECTIVE: Dedifferentiation of thyroid cancer leads to an inability of thyroid cells to concentrate iodine. In these cases, imaging methods that allow an accurate detection of recurrence and/or metastases at an early stage are essential for an adequate management of patients. Positron emission tomography using [18F]-2-fluoro-2-deoxy-d-glucose and a dedicated (dPET-FDG) or non-dedicated (nPET-FDG) camera has been suggested as a potential tool for the detection of tumour foci. DESIGN AND METHODS: This prospective study was undertaken to evaluate nPET-FDG in 51 consecutive patients (18 men, 33 women) with differentiated thyroid cancer (33 papillary, 11 follicular, four insular and three oncocytic (Hurthle-cell) thyroid carcinomas). Selection criteria were high thyroglobulin (Tg) levels (>10 ng/ml off-levothyroxine treatment) and no detectable radioiodine uptake, on a whole body scan performed with a high dose, in the absence of iodine contamination. RESULTS: Results were interpreted in terms of assumed presence of tumoral tIssue. Sensitivity of nPET-FDG was similar to that of conventional imaging modalities (67%). False negative nPET-FDG (n=16) were observed mostly in cases of micro-lesions (lymph nodes or lung metastases). Conversely, nPET-FDG identified new tumoral sites in 11 cases. Better sensitivity was found for nPET-FDG in patients with Tg levels higher than 15 microg/l (P<0.05). On a patient basis, results of nPET-FDG were equivalent to that of dPET-FDG. Finally, nPET-FDG changed treatment strategy in seven patients. CONCLUSIONS: nPET-FDG has a high sensitivity for the detection of tumour sites in patients when pathological iodine uptake cannot be demonstrated and appears to be a useful method in patients with elevated Tg levels, especially when dedicated PET is either unavailable or impractical.

Objective: To evaluate the feasibility of using [18F]fluorodeoxyglucose (18FDG) triple-head coincidence imaging as a potential cost-effective alternative to positron emission tomography in the setting of suspected recurrence of papillary thyroid carcinoma. Methods: We retrospectively studied 10 patients with suspected recurrence of papillary carcinoma of the thyroid, who underwent 18FDG coincidence imaging,131I scanning, and a reference anatomic scan (computed tomography, magnetic resonance imaging, or both) within 1 year in most cases. Results: The 131I scan detected the recurrence in five patients (62.5%) and failed to reveal recurrent cancer in three patients (37.5%); in contrast,18FDG imaging detected the recurrence in eight patients (100%) and was true negative in two patients in whom the scans were performed more than 1 year after effective therapy for the recurrence. The sensitivity of detection was unrelated to lesion size. The 18FDG imaging results led to additional radiotherapy in all 131I-negative patients, two of whom had high thyroglobulin levels and one of whom had a low thyroglobulin concentration but the presence of antithy-roglobulin antibodies. Conclusion: We conclude that 18FDG triple-head coincidence imaging is useful for routine management of patients with thyroid cancer who have no abnormalities detected on 131I scans but have high serum thyroglobulin levels. This technique, however, may not be as sensitive as a dedicated positron emission tomographic device, particularly for the assessment of small tumors. (Endocr Pract. 2003;9:273-279)

Since the 1990s, there has been a steady decrease in the death rate from breast cancer in the United States, much of which can be attributed to earlier detection from physical examination and screening x-ray mammography (XMM). Several techniques, including scintimammography (SMM), have been proposed to aid in the imaging of particular clinical scenarios in which XMM has limited performance. In a modified meta-analysis of recent literature, it has been determined that the overall sensitivity and specificity of SMM for the detection of primary breast cancer average 83.3 and 81.3, respectively, with histopathology as the gold standard. However, the use of SMM is limited by the relative inability to reliably detect small (<1 cm) cancers and by false-positive images represented by inflammatory and proliferative fibroadenomas. Several techniques have been described to optimize SMM imaging and avoid common pitfalls. The complementary role of SMM in the management of breast cancer needs to be clearly established and the availability of new dedicated detectors will certainly accelerate this process. In light of experience in this field and the analysis of the literature, potential indications for SMM in clinical practice are proposed and discussed in this article.