Assessing Perceived Image Quality Using Steady-State Visual Evoked Potentials and Spatio-Spectral Decomposition

Steady-state visual evoked potentials (SSVEPs) are neural responses, measurable using electroencephalography (EEG), that are directly linked to sensory processing of visual stimuli. In this paper, SSVEP is used to assess the perceived quality of texture images. The EEG-based assessment method is compared with conventional methods, and recorded EEG data are correlated to obtained mean opinion scores (MOSs). A dimensionality reduction technique for EEG data called spatio-spectral decomposition (SSD) is adapted for the SSVEP framework and used to extract physiologically meaningful and plausible neural components from the EEG recordings. It is shown that the use of SSD not only increases the correlation between neural features and MOS to r = -0.93, but also solves the problem of channel selection in an EEG-based image-quality assessment

Lymph Node Metastases from Differentiated Thyroid Carcinoma: does Radioiodine still play a role?

Ultrasonography and surgery have now become the elective diagnostic and therapeutic tools for neck lymph node (LN) metastases from differentiated thyroid carcinoma (DTC), reserving radioiodine therapy (RAI) for surgery failures. Aim of the present retrospective study was to evaluate results of RAI in cases of LN metastases displaying 131I uptake over a long-term observation period and its possible role today. From a series of 1276 patients who had undergone surgery for DTC, 130 cases were selected showing 131I uptaking LN metastases, detected during follow-up scans and who were then submitted to surgery and/or RAI. Patients were divided into groups according both to extent of surgery, with/without lymphectomy, and to following treatment and outcome. The initial surgical approach does not seem to significantly influence the outcome. 131I therapy alone, sometimes at low doses, can be very effective in the management of LN metastases detected at Whole Body Scan, but multiple doses are often needed. The age at diagnosis is confirmed as a negative prognostic factor. Considered radioprotection questions, RAI may solve 131I uptaking LN metastases, above all if < 10 mm. For larger LN metastases and in the case of failure of RAI surgical excision is mandatory, while a subsequent therapeutic dose of 131I could be useful to reveal incomplete excision

Our experience on pain palliation of bone metastasis with Sr-89 or Sm-153 in cancer patients resistant to a conventional analgesic therapy. A retrospective study

These retrospective study is aimed to evaluate the efficacy of therapy with Stronthium-chloride 89 (89SrCl) and Samarium 153 conjugated with ethylenediaminetetramethylene phosphonic acid (153Sm–EDTMP) in the palliation of bone pain due to metastatic malignancy. The study refers to a presentation sample of 27 patients with bone metastases caused by different cancers (16 prostate, 5 breast, 6 lung) who were enrolled and followed-up for 11.5 ± 6.3 months. 89SrCl (150MBq) was administered in 17 pts, 153Sm–EDTMP (37 MBq/Kg) in 10 pts. All patients showed multiple metastatic sites of 99Tc-HDP uptake documented by a standard bone scintigraphy. Effectiveness of treatment was evaluated by questionnaires about pain and quality of life, Karnofsky index, specific cancer markers, a post-treatment bone scintigraphy. Presence of flare reaction and haematological toxicity were evaluated too. Questionnaire scores decreased both in patients treated with 89SrCl and in those given 153Sm–EDTM, without significant difference. Karnofsky index significantly increased only in patients with prostate cancer. After therapy, there were no significant changes of tumor marker levels, neither in bone scintigraphic pattern. Flare reaction occurred in 44% of the cases within 2 weeks from the therapy. Remarkable variations of platelets and leukocytes occurred in 33.3% and 18.5% of patients, respectively, independently of the radiopharmaceutical used, but reversed within 6 weeks after therapy. Conclusions. Radionuclide therapy with bone-seeker agents 89Sr and 153Sm in the palliation of painful bone metastases allows a partial/total relief of pain with an improvement of quality of life. No tumoricid effect was found. Haematological toxicity was limited and reversible. Patients with prostate cancer seem to have a higher response rate

Across-subject offline decoding of motor imagery from MEG and EEG

Long calibration time hinders the feasibility of brain-computer interfaces (BCI). If other subjects' data were used for training the classifier, BCI-based neurofeedback practice could start without the initial calibration. Here, we compare methods for inter-subject decoding of left- vs. right-hand motor imagery (MI) from MEG and EEG. Six methods were tested on data involving MEG and EEG measurements of healthy participants. Inter-subject decoders were trained on subjects showing good within-subject accuracy, and tested on all subjects, including poor performers. Three methods were based on Common Spatial Patterns (CSP), and three others on logistic regression with l1 - or l2,1 -norm regularization. The decoding accuracy was evaluated using (1) MI and (2) passive movements (PM) for training, separately for MEG and EEG. With MI training, the best accuracies across subjects (mean 70.6% for MEG, 67.7% for EEG) were obtained using multi-task learning (MTL) with logistic regression and l2,1-norm regularization. MEGyielded slightly better average accuracies than EEG. With PM training, none of the inter-subject methods yielded above chance level (58.7%) accuracy. In conclusion, MTL and training with other subject's MI is efficient for inter-subject decoding of MI. Passive movements of other subjects are likely suboptimal for training the MI classifiers.Peer reviewe