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We aimed to evaluate the effectiveness and safety of radiofrequency ablation (RFA) for non-surgical treatment of locally recurrent thyroid cancers, in both well-differentiated and medullary thyroid carcinomas (DTC and MTC) that are not amenable to traditional treatments.We conducted a retrospective review of 48 patients with 103 recurrent tumors (81 DTC, 22 MTC) who underwent ultrasound-guided RFA. Patients were followed for 12-37 months to observe the outcomes and complications.64 tumors (62.1%) completely disappeared at the last follow-up visit with 61 (59.2%) being resolved within 12 months. Technical success (volume reduction ratio (VRR) 50%) was 96% (n = 99) in all tumors. The mean largest diameter of treated tumors decreased from 11.2 ± 5.3 to 2.4 ± 3.4 mm (p value 0.001), and the mean volume decreased from 501.0 ± 807.0 to 41.6 ± 97.1 mmRFA is a safe and effective alternative to repetitive surgeries in recurrent loco-regional DTCs as well as MTCs.Level 3, Non-randomized controlled cohort/follow-up study.

Purpose: 32-time scan duration reduction of 18F-Fluorodeoxyglucose (18F-FDG) Positron Emission Tomography (PET) images through the generation of standard scan duration images using a multi-slice cycle-consistent Generative Adversarial Network (cycle-GAN) was studied. Also, the effect of the image augmentation methods on the performance of the cycle-GAN model was evaluated. Materials and Methods: Four subsets of standard and 32-time short scan duration PET image pairs, each contacting image data of 10 patients were used to train and test (80 percent for training and 20 percent for testing) a multi-slice cycle-GAN separately. Another patient’s image data was used as the validation dataset for different training subsets. When training the cycle-GAN model for each subset, two approaches were followed: with and without image augmentation. Common image quality metrics of Peak Signal-to-Noise Ratio (PSNR), Structural Similarity Index Measure (SSIM), and Normalized Root Mean Squared Error (NRMSE) were used to assess the generation performance of the cycle-GAN model. Paired sample t-test statistical testing with a confidence interval of 0.95 was used to determine whether the differences between approaches were statistically significant or not. Results: For subsets 1-3, both training approaches improved the image quality of the short scan duration inputs (p < 0.001) while for subset 4 only the training approach with image augmentation was capable of improving the image quality. However, the training approach with image augmentation offered better results than the approach without image augmentation (p < 0.001). Conclusion: Employing the training approach with image augmentation, the cycle-GAN model was capable of improving the image quality of 1/32nd short scan duration images through the generation of synthetic standard scan duration images. In the case of the training approach without image augmentation, except for subset 4, the model trained on all subsets 1-3 was capable of improving the image quality. Image augmentation does indeed improve the performance of the cycle-GAN model, especially in the case of insufficient available training datasets.

Purpose we aimed to investigate the effect of various β-value in BSREM algorithm under different lesion sizes, in order to determine an optimal penalty factor for clinical use. Methods The NEMA IQ phantom and 15 patients with prostate cancer were injected with 68Ga-PSMA and scanned by GE Discovery IQ PET/CT scanner. Images were reconstructed using OSEM and BSREM with different β-values and then background variability (BV), contrast recovery (CR), signal-to-noise ratio (SNR), and lung residual error (LE) from phantom data, and Signal-to-Background Ratio (SBR), contrast from clinical data were measured. Results The increment of BV using β-value of 100 was 120% and the decrement of BV using β-value 1000 were 40.5% compared to OSEM. As the β decreased from 1000 to 100, the SUVmax increased by 59% and 26.4% for sphere with diameter of 10 mm and 37 mm, respectively.Δ SNR(100-1000) % increased by 140.5 and 29.0 in the smallest and the largest sphere, respectively. The Δ LE OSEM-100 and Δ LE OSEM-1000 was − 41.1% and − 36.7% respectively. In the clinical study, the lowest SBR and contrast was related to the OSEM. The SBR and contrast, respectively increased by 69.7% and 71.8% in small lesions and 35.6% and 33% in large lesions, respectively, when β-value was decreased from 500 to 100. Conclusions As the lesion size decreased, the optimum β-value decreased. In both studies, a β value of 400 would be optimal for reconstruction of small lesions, whereas for large lesions in phantom and clinical studies respectively, β-value of 600 and 500 is recommended.

Thyroid remnant after thyroidectomy is a major predictor for future recurrence of thyroid cancers; for which assessment, the accuracy of imaging is not optimal. To evaluate the value of the technetium uptake in the neck compared with neck ultrasonography, this application is used to predict future recurrence of differentiated thyroid cancer (DTC). The neck technetium uptake (NTU) value was acquired 20 min after injection of 1 mCi technetium by a camera. Patients were scheduled for forthcoming iodine ablation. Baseline risk factors were collected. Patients were followed for 10.5 (7 to 12) months when the records of the whole body scan, thyroglobulin, anti-thyroglobulin, neck ultrasonography, and the history of repeated iodine and surgical treatments were collected. The correlation of NTU and recurrence were studied. Out of 73 participants, 63 patients completed the study with established recurrence status and a valid NTU assessment. Baseline lymph node invasion (34.6% vs 80.0%; all 41.9%), extra-thyroid extension (17.0% vs 50.0%; all 22.2%), and tumor size (2.3 ± 2.1 vs 5.2 ± 2.4; all 2.7 ± 2.4) were higher in patients with future recurrence. But the NTU was similar in subjects with and without recurrence (−0.2 ± 0.7 vs 1.7 ± 6.3; all 59 ± 5.3). NTU was significantly lower in subjects with surgeries more extensive than thyroidectomy (P = 0.03). Recurrence cannot be predicted by NTU, but NTU may be used as a surrogate factor to determine the extent and completeness of the thyroidectomy surgery.

This study aimed to evaluate the therapeutic outcomes ofAll post-therapeutic scans were collected retrospectively from patients treated with 100-200 mCiOut of 36 patients (aged 67±8.8 years), 23 underwent at least two treatment cycles. Nineteen patients (82.6%) had bone metastases, 12 (52.2%) had nodal metastases, 5 (21.7%) had liver metastases, and 3 (13.0%) had lung metastases. Eleven patients (47.8%) were considered responsive in the post-therapeutic scans, two of which experienced complete eradication of the metastatic sites. Three patients (13%) were categorized as progressive, and 9 (39.1%) patients remained stable. Regarding mortality, nine patients died during the late follow-up (median of 24 months). In the surviving population, 65% reported no or mild pain in the final follow-up, based on a 5-point scale pain assessment.The treatment of mCRPC patients with

Objective: For preoperative radionuclide myocardial perfusion imaging, metabolic equivalent is one of the key factors to evaluate the appropriateness. Duke Activity Status Index is a practical method to calculate metabolic equivalents. We intended to validate Duke Activity Status Index in our population for the assessment of preoperative myocardial perfusion imaging appropriateness. Methods: A total of 542 patients referred for myocardial perfusion imaging were recruited. A questionary compiled from Duke Activity Status Index was filled out based on which metabolic equivalents were calculated. Demographic data and history of cardiac risk factors were also collected. Myocardial perfusion imaging was performed using a 2-day stress-rest protocol either by exercise tolerance test or by pharmacologic stress through injection of Tc-MIBI and imaging by a dual-head gamma camera. Results: Out of 542 patients, 369 (68.1%) were evaluated for preoperative risk assessment. Metabolic equivalents (oxygen consumption/min/kg) were calculated at 9.3 ± 5.1, 10.8 ± 4.8, and 8.7 ± 5.1 in total, preoperative patients and patients evaluated for ischemia due to nonsurgical purposes, respectively (p = 0.001). The myocardial perfusion imaging was rarely appropriate in 291 (79.5%), maybe appropriate in 67 (18.3%), and appropriate in 8 (2.2%) patients. The prevalence of abnormal myocardial perfusion imaging was 22.5%, 28.4%, and 12.5% in “rarely appropriate,” “maybe appropriate,” and “appropriate” scenarios, respectively. Metabolic equivalents were similar between patients with normal and abnormal myocardial perfusion imaging (8.7 ± 5.0 vs. 8.5 ± 5.4). Conclusion: Either Duke Activity Status Index is not a proper tool for calculation of metabolic equivalents or the appropriate use criteria is not operational in the population of Iranian preoperative patients in which cultural factors may contribute.

Background: The application of FDG PET/CT scan for assessment of patients with breast cancer is increasing. The cost effectiveness of the application could be different in a developing country with limited PET scanners and treatment prioritiesMethods: Open discussions of the PET reviewers from 2 out of 4 PET centers of Tehran, the capital city of Iran, were organized to provide insight into their opinions on the indications of FDG PET in breast cancer patients. Results: The sensitivity of FDG PET scan is high for detection of distant metastases; however, assessment of lymph node pathology and the local extension of the breast cancer are questionable. Considering the cost of the procedure itself and the downstream diagnostic procedures, its application and diagnostic accuracy are hindered for breast cancer screening, staging, and assessment of response to treatment and prognosis. The advantages and disadvantages of FDG PET CT and dedicated breast FDG PET scan have been briefed in different clinical scenarios with a focus on limitations faced by a developing country.Conclusion: We suggest reserving the use of FDG PET for selected cases of suspected but not proven recurrent disease and in patients with high risk of metastasis before high risk surgery.

The practical diagnostic performance of Prospective Investigative Study of Acute Pulmonary Embolism Diagnosis (PISAPED) criteria for the detection of acute pulmonary thromboembolism (APTE) in hospitalized patients is not yet well determined. This is the report of the initial results of our recently implemented protocol to employ PISAPED. One hundred and forty-seven pulmonary perfusion scans with 1–3 mCi 99mTc-MAA of patients of a single pulmonologist were included. Patients with suspicious perfusion defects underwent single-photon emission computed tomography. Interpretations were done by consensus of two nuclear medicine specialists. Comparisons were done with chest X-ray or chest computed tomography when available. The interpreters had access to the clinical records. The scans were reported based on the PISAPED criteria as negative or positive for APTE or indeterminate. Patients were followed up for 6.2 ± 5.3 months when the final diagnosis confirming or excluding APTE was achieved. Patients aged 55.9 (17.2) years; 78 (53.1%) of them were female and 64 (43.8%) had high Wells' score. The scans were positive, negative, and indeterminate in 17 (11.6%), 126 (85.7%), and 4 (2.7%) patients, respectively. In 6 out of 147 patients, follow-up was not completed and the final diagnosis was not achieved. APTE was finally diagnosed in 21 (14.3%) patients; 12 (57.1%) of them had positive scans. APTE was excluded in 116 (78.9%) patients; 112 (96.5%) of them had negative scans. The accuracy of the test for the diagnosis of APTE was 87.9%. Lung metastasis was the most frequent reason among false-negative cases. The lung perfusion scan using PISAPED criteria could be used with good accuracy in inpatient settings.

Neuroendocrine tumours (NETs) arise from secondary epithelial cell lines in the gastrointestinal or respiratory system organs. The rate of development of these tumours varies from an indolent to an aggressive course, typically being initially asymptomatic. The identification of these tumours is difficult, particularly because the primary tumour is often small and undetectable by conventional anatomical imaging. Consequently, diagnosis of NETs is complicated and has been a significant challenge until recently. In the last 30 years, the advent of novel nuclear medicine diagnostic procedures has led to a substantial increase in NET detection. Great varieties of exclusive single photon emission computed tomography (SPECT) and positron emission tomography (PET) radiopharmaceuticals for detecting NETs are being applied successfully in clinical settings, including [

Resumen Objetivo La precision diagnostica de la imagen de perfusion miocardica (IPM) no es optima para predecir el resultado de la angiografia. El objetivo del presente estudio es investigar la aplicacion de la red neuronal artificial (RNA) para integrar los datos clinicos con el resultado y la cuantificacion de la IPM. Metodos De 923 pacientes con IPM, se reclutaron 93 que se sometieron a angiografia. Se recogieron los datos clinicos, incluidos los factores de riesgo cardiaco, y se registraron los resultados de la IPM y la angiografia coronaria. Se calculo la cuantificacion de las graficas polares IPM (es decir, los recuentos de 20 segmentos de cada una de las graficas polares de esfuerzo y de reposo) y la puntuacion de Gensini de las angiografias. La RNA fue disenada integrando datos clinicos y de cuantificacion para predecir el resultado de la angiografia (normal vs. anormal), la enfermedad coronaria no obstructiva u obstructiva (EAC) y la puntuacion de Gensini (≥ 10 y Resultados La precision de la IPM para predecir el resultado de la angiografia, la EAC obstructiva y la puntuacion de Gensini aumento del 81,7 al 92,9%, del 65,0 al 85,7% y del 50,5 al 92,9%, respectivamente, mediante la RNA con cuantificacion y factores de riesgo clinicos. Conclusion La precision diagnostica de la IPM podria mejorarse mediante la RNA, utilizando datos clinicos y de cuantificacion.

Magnetic resonance imaging (MRI) and computed tomography (CT) are not always conclusive for the detection of cerebral venous sinus thrombosis (CVST). 99mTc-HMPAO-labeled platelets may be useful in cases with high clinical suspicion. Three patients with headaches with or without intraparenchymal hemorrhage that were highly suspected to have CVST, despite inconclusive anatomical imaging, were selected for inclusion in the study. Platelets were extracted by two rounds of centrifugation from 49 ml of the patient’s whole blood. The platelets were labeled with 99mTc-HMPAO and any unbound 99mTc was removed by centrifugation. The re-suspension of 99mTc-HMPAO-labeled platelets in cell-free plasma was reinjected into the patients. After 2 h, planar and single photon emission computed tomography (SPECT) images of the head were obtained. Extensive clots were detected in all three patients, illustrated in the planar image and even clearer in the SPECT images. We propose that 99mTc-HMPAO-labeled platelet scan is a favorable imaging method for patients suspected to have CVST with inconclusive CT and MRI results.

Background: The outcome and complications of liver hydatid cyst surgeries with new and old techniques are not well determined. We intended to present the results of operations done for patients with hepatic hydatid cyst in an endemic area. Methods: Data of 112 patients referred and operated for liver hydatid cyst, in Imam Khomeini Hospital complex, Tehran, Iran, from 2015 to 2018, were collected including demographic characteristics, operation parameters and complication related statistics. The variables were presented for different surgical methods including operations with and without omentoplasty. Results: Patients aged 39. 3 ± 13. 9 yr (70 females; 63. 5%). Most frequent clinical complaint was vague abdominal pain (n=45; 40. 2%). The most prevalent comorbidity was hypertension (18; 16.0%). Conservative methods were chosen more frequently including omentoplasty (44; 39. 3%), cyst drainage (27; 24. 1%), cyst resection (19; 17%) and marsupialization (3; 2. 7%). Overall, 56 patients (50%) were operated with omentoplasty as the single method or in combination with segmentectomy. Complications occurred less in patients operated with omentoplasty (41. 1 vs. 23. 2%; P=0. 043); particularly, biloma was more frequent in surgeries without omentoplasty (7. 1 vs 0. 0%; P=0. 042). Persistence and recurrence rates were 12. 5% and 3. 6% with relative predilection in, respectively, segmentectomy and lobectomy surgical methods compared to Omentoplasty. No mortality was recorded. Conclusion: In our case series of hepatic hydatid cyst patients, omentoplasty was safe with less complication and similar long-term recurrence rate.

Estimating glomerular filtration rate (eGFR) using different formulas is common clinical practice for evaluating kidney function and drug dosing. But, the performance of available eGFR equations is questionable during early days after kidney transplantation.This study compared the performance of three common eGFR equations (Cockcroft-Gault (CG), Modification of Diet in Renal Disease (MDRD), and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI)) in relation with measured GFR (mGFR) using clearance of Tc-99m-diethylenetriaminepentaacetic acid, 7 to 10 days post kidney transplantation. Agreement of mGFR and different eGFR equations in the staging of kidney function and dosing of 8 common antimicrobials were assessed.Thirty kidney and 5 simultaneous pancreas-kidney transplant recipients were included. CG applying total body weight (CGTBW) had the lowest bias (-12 mL/min/ 1.73 m2) and the highest percentage of estimation within 30% of mGFR (71.4%). MDRD showed the best precision (13.14 mL/min/ 1.73m2) and linear correlation with mGFR. CKD-EPI and MDRD acted better than CG for staging the level of kidney function. CGTBW had the lowest discordance rate with mGFR for antimicrobials dosing (33.6%). Discordance rates of drug dosing between mGFR and eGFR formulas were greater for drugs that have higher dosing levels such as (val)-ganciclovir (≥ 54.3%).Until developing more accurate methods for estimating kidney function during first 1 to 2 weeks after kidney transplantation, CGTBW method is suggested for drug dose adjustment and MDRD or CKD-EPI equation for the staging of kidney function in these patients, keeping in mind that these formulas underestimate the level of kidney function in new transplant recipients.

Aim: Bull's eye pattern recognition with artificial neural networks (ANNs) has the potential to assist interpretation of myocardial perfusion images (MPIs). We aimed to develop a model for interpretation of MPI based on the clinical variables and imaging data. Materials and Methods: The study included 208 patients referred to the department of nuclear medicine for 2-day stress-rest ECG-gated MPI. Several ANN models were designed with the following input variables: average count of 20 segments of the bull's eye images of stress and rest MPIs, gender, the constellation of coronary artery disease risk factors and scintigraphic cardiac ejection fraction. The procedure was repeated excluding the data of the rest phase scan. Data of 150 subjects were used for training, 21 subjects for cross-validation and 37 subjects for final operation testing. Several ANN models were examined with different hidden layers and processing elements and functions. The target output variable was the conclusion of the nuclear physician (i.e., normal vs. abnormal scan). Results: A multilayer perceptron (MLP) with two hidden layers trained with both stress and rest data demonstrated the best performance to classify the normal and abnormal MPIs. It showed an overall accuracy of 91.9%, sensitivity of 91.3% and specificity of 92.9%. The accuracy of the similar MLP trained using stress-only myocardial perfusion images reduced to 67.6%. Conclusion: The automated interpretation of MPIs with a 2 hidden layer MLP trained with stress and rest images could be an accurate support system either for the interpretation or quality assurance.

Objectives Clinical difficulty to discriminate between the Alzheimer disease (AD) and dementia with Lewy bodies (DLB) has led researchers to focus on highly sensitive functional imaging modalities. The aim of the present study was to assess 131I-MIBG cardiac imaging to distinguish between AD and DLB. Patients and methods Seventeen patients who were known cases of dementia underwent 131I-MIBG myocardial scintigraphy to differentiate AD from DLB. Planar and 131I-MIBG SPECT were obtained 2 h after the injection of 1 mCi 131I-MIBG on a dual head gamma camera. The visual assessment of the heart uptake compared with lungs and the quantification based on the heart to mediastinal ratio (HMR) were done. The cardiac receiver operating characteristic (ROC) curve was designed for the optimal HMR cut-off values to predict the diagnoses of the patients. The diagnoses were clinically confirmed during the follow up of 14 ± 8.2 months. Results Out of 17 patients (13 males; 76.5%), 10 patients had AD (7 males; 70%) and 7 patients had DLB (6 males; 85%). The pooled HMR was 1.74 ± 0.33 in the study population; with 1.95 ± 0.22 in the AD group and 1.43 ± 0.20 in the DLB group to demonstrate significantly different HMR scores between patients with AD and DLB (p value = 0.001). The visual interpretation was positive in 10 patients (accuracy of 88.2%). The shortest distance on the ROC curve to the optimal value corresponding to HMR = 1.57 identified 10 patients with a high HMR (positive cardiac uptake) and 7 patients with a low HMR (negative cardiac uptake), the accuracy calculated at 88.2%. Conclusion 131I-MIBG myocardial scintigraphy is a potential alternative diagnostic modality for discrimination between AD and DLB when 123I is not available.

Using digital phantoms as an atlas compared to acquiring CT data for internal radionuclide dosimetry decreases patient overall radiation dose and reduces the required analysis effort and time for organ segmentation. The drawback is that the phantom may not match exactly with the patient. We assessed the effect of varying BMIs on dosimetry results for a bone pain palliation agent, 153Sm-EDTMP. The simulation was done using the GATE Monte Carlo code. Female XCAT phantoms with the following different BMIs were employed: 18.6, 20.8, 22.1, 26.8, 30.3 and 34.7 kg/m2. S-factors (mGy/MBq.s) and SAFs (kg−1) were calculated for the dosimetry of the radiation from major source organs including spine, ribs, kidney and bladder into different target organs as well as whole body dosimetry from spine. The differences in dose estimates from different phantoms compared to those from the phantom with BMI of 26.8 kg/m2 as the reference, were calculated for both gamma and beta radiations. The relative differences (RD) of the S-factors or SAFs from the values of reference phantom were calculated. RDs greater than 10% and 100% were frequent in radiations to organs for photon and beta particles, respectively. The relative differences in whole body SAFs from the reference phantom were 15.4%, 7%, 4.2%, −9.8% and −1.4% for BMIs of 18.6, 20.8, 22.1, 30.3 and 34.7 kg/m2, respectively. The differences in whole body S-factors for the phantoms with BMIs of 18.6, 20.8, 22.1, 30.3 and 34.7 kg/m2 were 39.5%, 19.4%, 8.8%, −7.9% and −4.3%, respectively. The dosimetry of the gamma photons and beta particles changes substantially with the use of phantoms with different BMIs. The change in S-factors is important for dose calculation and can change the prescribed therapeutic dose of 153Sm-EDTMP. Thus a phantom with BMI better matched to the patient is suggested for therapeutic purposes where dose estimates closer to those in the actual patient are required.

Technetium thyroid uptake (TTU) is not inhibited by antithyroid drugs (ATD) and reflects the degree of thyroid stimulation. We intended to predict the relapse rate from hyperthyroidism based on TTU measurement.Out of 44 initially enrolled subjects, 38 patients aged 41.6 ± 14.6 with Graves disease (duration: 84 ± 78 months) completed the study. TTU was performed with 40-second imaging of the neck and mediastinum 20 minutes after injection of 1 mCi technetium-99m pertechnetate. TTU was measured as the percentage of the count of activity accumulated in the thyroidal region minus the mediastinal background uptake to the count of 1 mCi technetium-99m under the same acquisition conditions. Then methimazole was stopped and patients were followed. The optimal TTU cutoff value for Graves relapse prediction was calculated using Youden's J statistic.Hyperthyroidism relapsed in 11 (28.9%) patients 122 ± 96 (range: 15-290) days post-ATD withdrawal. The subjects in remission were followed for 209 ± 81 days (range: 88-390). TTU was significantly higher in patients with forthcoming relapse (12.0 ± 8.0 vs. 3.9 ± 2.0, P = .007). The difference was significant after adjustment for age, sex, history of previous relapse, disease duration, and thyroid-stimulating hormone (TSH) levels before withdrawal. The area under the receiver operative characteristic (ROC) curve was 0.87. The optimal TTU cutoff value for classification of subjects with relapse and remission was 8.7 with sensitivity, specificity, and positive and negative predictive value of 73%, 100%, 100%, and 90%, respectively (odds ratio [OR] = 10.0; 95% confidence interval [CI]: 3.4-29.3).TTU evaluation in hyperthyroid patients receiving antithyroid medication is an accurate and practical method for predicting relapse after ATD withdrawal.ATD = antithyroid drugs RIU = radio-iodine uptake TSH = thyroid-stimulating hormone TSI = thyroid-stimulating immunoglobulin TTU = technetium thyroid uptake.

The absorbed doses in the liver and adjacent viscera in Yttrium‐90 radioembolization therapy for metastatic liver lesions are not well‐documented. We sought for a clinically practical way to determine the dosimetry of this advent treatment. Six different female XCAT BMIs and seven different male XCAT BMIs were generated. Using Monte Carlo GATE code simulation, the total of 100MBq 90Y was deposited uniformly in the source organ, liver. Self‐irradiation and absorbed doses in lung, kidney and bone marrow were calculated. The mean energy of Yittrium‐90 (i.e., 0.937 MeV) was used. The S‐values and equivalent doses in target organs were estimated. The dose absorbed in the liver was between 84 and 53 Gy and below the target of 80 to 150 Gy. The absorbed dose in the bone marrow, lungs, and kidneys are very low and below 0.1 , 0.4, and 0.5 Gy respectively. Our study indicates that larger activities than the conventional dose of 3 GBq may be both required and safe. Further confirmations in clinical settings are needed.

Purpose Respiratory motion in the chest region during single photon emission computed tomography (SPECT) is a major degrading factor that reduces the accuracy of image quantification. This effect is more notable when the tumor is very small, or the spatial resolution of the imaging system is less than the respiratory motion amplitude. Small animals imaging systems with sub-millimeter spatial resolution need more attention to the respiratory motion for quantitative studies. We developed a motion-embedded four-dimensional (4D)-multi pinhole SPECT (MPS) reconstruction algorithm for respiratory motion correction. This algorithm makes full use of projection statistics for reconstruction of every individual frame. Methods The ROBY phantom with small tumors in liver was generated in eight different phases during one respiratory cycle. The MPS projections were modeled using a fast ray tracing method simulating an MPS acquisition. Individual frames were reconstructed and used for motion estimation. The Demons non-rigid registration algorithm was used to calculate deformation vector fields (DVFs) for simultaneous motion correction and image reconstruction. A motion-embedded 4D-MPS method was used to reconstruct images using all the projections and corresponding DVFs, simultaneously. The 4D-MPS reconstructed images were compared to the low-count single frame (LCSF) reconstructed image, the three-dimensional (3D)-MPS images reconstructed using individual frames, and post reconstruction registration (PRR) that aligns all individual phases to a reference frame using Demons-derived DVFs. The tumor volume relative error (TVE), tumor contrast relative error (TCE), and dice index (DI) for 2, 3, and 4 mm liver were calculated and compared for different reconstruction methods. Results For the 4D-MPS reconstruction method, TVE was reduced and DI was higher compared to PRR, 3D-MPS, and LCSF. The extent of the improvement was higher for the small tumor size (i.e. 2 mm). For the biggest tumor in contrast 3 (i.e. 4 mm) TVE for 4D-MPS, PRR, 3D-MPS and, LCSF were 1.33%, 8%, 8%, and 14.67%, respectively. Conclusions The results suggest that motion-embedded 4D-MPS method is an effective and practical way for respiratory motion correction. It reconstructs high quality gated frames while using all projection data to reconstruct each frame.

Background The aim of the present study was to determine the prevalence of metabolic syndrome and its individual components among the Iranian adult population in 2011 and to investigate changes between 2007 and 2011. Methods Data from two rounds of the Surveillance of Risk Factors of Non-communicable Diseases national surveys conducted in 2007 and 2011 were pooled. Metabolic syndrome was defined according to International Diabetes Federation criteria. Results In 2007, the prevalence of metabolic syndrome among adults aged 25–64 years was 35.95 (95% confidence interval [CI] 34.27–37.63), which decreased to 32.96 (95% CI 30.73–35.18) in 2011 (P = 0.0108). Despite this overall decline, the prevalence of central obesity (P = 0.1383), raised triglycerides (P = 0.3058), and reduced high-density lipoprotein cholesterol (HDL-C; P = 0.5595) remained constant. There was a trend towards a decline in the proportion of individuals with increased blood pressure (P = 0.0978), and the proportion of adults with increased fasting plasma glucose (FPG) increased (P < 0.0001). In 2011, the prevalence of central obesity, raised triglycerides, reduced HDL-C, increased blood pressure and increased FPG was 51.88 (95% CI 48.97–54.79), 36.99 (95% CI 34.52–39.45), 54.72 (95% CI 50.87–58.57), 38.92 (95% CI 36.19–41.64), and 24.97 (95% CI 22.02–27.93) respectively. Conclusions Over the period 2007–11, the prevalence of metabolic syndrome has decreased slightly in Iran, although prevalence of increased FPG has increased significantly. One-third of the Iranian adult population is diagnosed with metabolic syndrome.

Needle insertion during electromyography (EMG) may cause varying levels of pain that could lead to inaccurate assessment and premature termination of the procedure. The aim of this study is to compare paracetamol 325 mg/tramadol 37.5 mg with placebo in relieving pain before EMG. This is a randomized, crossover, placebo-controlled, double-blind clinical trial; forty-four healthy individuals, including 27 males with a mean age of 35.3 years (range 18-59 years), entered this study. The needles were inserted unilaterally 2 h after administration of two analgesic tablets of paracetamol 325 mg/tramadol 37.5 mg or two placebo tablets. The pain was scored through a 100-mm visual analog scale (VAS) immediately and 2 h after the procedure. The side effects were also recorded. Within a week, the procedure was repeated on the other upper limb, changing the treatment and placebo. The immediate and 2-h VAS scores were notably lower after administration of treatment compared to placebo (immediate pain: 17.5 ± 12.8 vs. 32.1 ± 16.0, P

Magnetic resonance imaging (MRI) and computed tomography (CT) are not always conclusive for the detection of cerebral venous sinus thrombosis (CVST).

Background: The assessment of body composition during the course of treatment of hemodialysis patients is crucial for optimal treatment. We intended to assess the diagnostic performance of bioelectrical impedance analysis (BIA), which could be used at the bedside in dialysis wards, and compare it with the results of dual-energy X-ray absorptiometry (DEXA). Methods: In a cross-sectional study, 43 patients with end-stage renal disease (ESRD) after hemodialysis sessions underwent direct segmental multi-frequency BIA. Volume status and body composition indices with eight electrodes connected to four limbs were measured at 1, 5, 50, 250, 500, and 1000 kHz frequencies. Then, the patients were sent to the nuclear ward for the corresponding assessments by DEXA. The results of the two methods were compared by a paired t-test and the correlations were assessed using general linear models and regression analyses. For the assessment of agreements, Bald-Altman plots were used. Results: The whole body values for bone, fat, and lean body mass were different between BIA (3.4, 22, and 44.5 kg, respectively) and DEXA (1.5, 28.5, and 40.4 kg, respectively). However, the results were strongly linearly correlated even after adjustment for age and sex (r = 0.67, P = 0.001 for bone mass; r = 0.93, P = 0.001 for fat mass; and r = 0.96, P = 0.001 for lean body mass). The same strong correlation was found for the segmental values. Conclusions: The results of BIA and DEXA are correlated strongly and are interchangeable. As the BIA is more easily available and less expensive, the routine use of BIA at hemodialysis departments is reasonable.

Diagnostic accuracy of myocardial perfusion imaging (MPI) is not optimal to predict the result of angiography. The current study aimed at investigating the application of artificial neural network (ANN) to integrate the clinical data with the result and quantification of MPI.Out of 923 patients with MPI, 93 who underwent angiography were recruited. The clinical data including the cardiac risk factors were collected and the results of MPI and coronary angiography were recorded. The quantification of MPI polar plots (i.e. the counts of 20 segments of each stress and rest polar plots) and the Gensini score of angiographies were calculated. Feed-forward ANN was designed integrating clinical and quantification data to predict the result of angiography (normal vs. abnormal), non-obstructive or obstructive coronary artery disease (CAD), and Gensini score (≥10 and10). The ANNs were designed to predict the results of angiography using different combinations of data as follows: reports of MPI, the counts of 40 segments of stress and rest polar plots, and the count of these 40 segments in addition to age, gender, and the number of risk factors. The diagnostic performance of MPI with different ANNs was compared.The accuracy of MPI to predict the result of angiography, obstructive CAD, and Gensini score increased from 81.7% to 92.9%, 65.0% to 85.7%, and 50.5% to 92.9%, respectively by ANN using counts and clinical risk factors.The diagnostic accuracy of MPI could be improved by ANN, using clinical and quantification data.

Patients with diabetes have higher stress-to-rest mean left ventricular volume (SRLVV) ratio in myocardial perfusion imaging (MPI) and hyperhomocysteinemia. We studied the effect of folate therapy on SRLVV ratio and plasma homocysteine levels in patients with diabetes. Forty patients were enrolled and thirty-two completed the study. The patients underwent a 2-day pharmacological stress test and rest MPI before and 2 months after treatment with either 5 mg folic acid or placebo. SRLVV ratios were calculated, and plasma homocysteine levels were measured, before and after treatment. Among the 32 patients who completed the study, 15 received folic acid and 17 received placebo. The age of subjects (folate 51.5 ± 6.1 years; placebo 50.6 ± 8.1 years), male/female ratio (folate 6/11; placebo 9/6),or MPI findings (proportion of normal results: folate 80.0 %; placebo 94.1 %) were similar between the two groups. The baseline SRLVV ratio was similar between groups (folate: 1.00 ± 0.09 vs. placebo: 0.97 ± 0.13); however, the post-treatment SRLVV ratio was significantly lower (P