Standard Clinical Protocol Research Articles

PROPOSALS FOR THE ESTABLISHMENT OF NATIONAL DIAGNOSTIC REFERENCE LEVELS FOR RADIOGRAPHY FOR ADULT PATIENTS BASED ON REGIONAL DOSE SURVEYS IN RUSSIAN FEDERATION.

In 2009-2014, dose surveys aimed to collect adult patient data and parameters of most common radiographic examinations were performed in six Russian regions. Typical patient doses were estimated for the selected examinations both in entrance surface dose and in effective dose. 75%-percentiles of typical patient effective dose distributions were proposed as preliminary regional diagnostic reference levels (DRLs) for radiography. Differences between the 75%-percentiles of regional typical patient dose distributions did not exceed 30-50% for the examinations with standardized clinical protocols (skull, chest and thoracic spine) and a factor of 1.5 for other examinations. Two different approaches for establishing national DRLs were evaluated: as a 75%-percentile of a pooled regional sample of patient typical doses (pooled method) and as a median of 75%-percentiles of regional typical patient dose distributions (median method). Differences between pooled and median methods for effective dose did not exceed 20%. It was proposed to establish Russian national DRLs in effective dose using a pooled method. In addition, the local authorities were granted an opportunity to establish regional DRLs if the local radiological practice and typical patient dose distributions are significantly different.

Abstract B082: Migratory T cells demonstrate superior persistence and enhanced tumor control

Abstract Adoptive cell therapy (ACT) based on the transfer of chimeric antigen receptor (CAR) T cells rendered specific for CD19 has demonstrated significant anti-tumor effects in patients with refractory CD19+ B-cell malignancies. There are however no biomarkers that can predict the potency of T-cell infusion products and thus the ability to enrich functionally superior cells is lacking. Existing clinical data supports at least two important functions of the T cells in mediating tumor regression: (a) immediate cytotoxicity to enable tumor cell killing, and (b) long-term persistence to ensure lasting and durable responses. We demonstrate here that migratory capacity of T cells can be used as a biomarker to segregate functionally superior cells that display enhanced polyfunctionality in vitro and superior tumor control in vivo. The simplicity of sorting cells based on motility and the scalability of the approach imply that these can be routinely adapted in standard GMP settings to enrich for functional T cells among any heterogeneous population. Populations of CD19-specific chimeric antigen receptor (CAR) T cells were biomanufactured using our standard clinical protocol. Timelapse Imaging In Nanowell Grids (TIMING) was used to enable the simultaneous quantification of the interaction between thousands of individual tumor-specific CD8+ T cells and multiple tumor cells. These results demonstrated that IFN-gamma secretion was the most common function elicited upon tumor cell conjugation. We found that CD8+ T cells with killing ability, especially serial killing ability, required shorter durations of target cell conjugation in comparison to IFN-gamma secreting mono-functional cells, indicating rapid synapse termination by T cells capable of killing versus cytokine secretion. Tracking the velocities of these cells by time-lapse imaging revealed that these serial killer T cells (with or without IFN-gamma secretion) had a high out-of-contact basal motility. In order to gain a better understanding of the phenotypic characteristics of the migratory T cells, we performed molecular profiling of T cells identified only by their basal motility (in the absence of tumor cells) using single-cell multiplexed transcriptional profiling, microscopy and flow cytometry, and found that the costimulatory molecules CD2 and CD244, and the chemokine receptor CXCR3 were expressed at higher levels in highly motile T cells compared to the non-motile T cells. In order to test the hypothesis that migratory capacity can serve as a biomarker T cell polyfunctionality, we next sorted motile cells using a modified migration assay, and confirmed that the migrating cells were enriched in highly motile cells. We characterized these cells phenotypically by flow-cytometry and demonstrated that T-cell differentiation markers including CCR7, CD95 and CD45RA were not differentially expressed between the motile and non-motile cells. Consistently however, the migrated cells displayed superior killing and serial killing in comparison to the non-migrated T cells. This superior in vitro polyfunctionality of migratory T cells was confirmed in a mouse xenograft model of leukemia in which motile CAR+ T cells were superior in controlling the disease in comparison to either their non-motile counterparts or the parent unsorted population. In aggregate, these results demonstrate the utility of our TIMING single cell methodology in uncovering not only the dynamic profile of T-cell behavior but also the ability to identify subpopulations of T-cell with enhanced polyfunctionality. Our studies support the use of motility as a surrogate and selective marker of higher CAR+ T cell bioactivity. These results also open up avenues to molecularly engineer T cells for an increased motility that could translate to better in vivo outcomes. Note: This abstract was not presented at the conference. Citation Format: Gabrielle Romain, Harjeet Singh, Ivan Liadi, Jay R Adolacion, Laurence J.N. Cooper, Navin Varadarajan. Migratory T cells demonstrate superior persistence and enhanced tumor control [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr B082.

Perception and Barriers to Kangaroo-Mother Care Among Neonatal Intensive Care Unit Nurses

Purpose: To investigate the perception and barriers of Kangaroo-Mother Care (KMC) among nurses in Neonatal Intensive Care Units (NICU). Methods: Participants were 131 nurses working in NICU who completed self-report questionnaires which included information regarding perception, barriers, and practice of KMC. Collected data were analyzed using SPSS 18.0 program for descriptive statistics, t-test, ANOVA, and Pearson correlation coefficients. Results: Of the participants, 33.6% reported the practice of KMC in their NICU, with 75.6% wanting to receive training in KMC and 31.3% having received KMC education. Most of the participants agreed that KMC enhances attachment, parental confidence, and effective breast feeding but they reported a negative perception in providing KMC for premature infants weighing less than 1000 grams or intubated premature infants. Major barriers to practicing KMC were safety of infants, possible work overload for nurses, as well as absence of consistent guidelines. Barriers to KMC among nurses who received the KMC training were lower than nurses who did not receive the KMC training (t=-2.11, p=.037). Conclusion: Education program and standardized clinical practice protocol should be developed to foster the positive perception and to reduce nurse barriers to KMC.

Fast comprehensive single-sequence four-dimensional pediatric knee MRI with T2 shuffling.

To develop and clinically evaluate a pediatric knee magnetic resonance imaging (MRI) technique based on volumetric fast spin-echo (3DFSE) and compare its diagnostic performance, image quality, and imaging time to that of a conventional 2D protocol. A 3DFSE sequence was modified and combined with a compressed sensing-based reconstruction resolving multiple image contrasts, a technique termed T2 Shuffling (T2 Sh). With Institutional Review Board (IRB) approval, 28 consecutive children referred for 3T knee MRI prospectively underwent a standard clinical knee protocol followed by T2 Sh. T2 Sh performance was assessed by two readers blinded to diagnostic reports. Interpretive discrepancies were resolved by medical record chart review and consensus between the readers and an orthopedic surgeon. Image quality was evaluated by rating anatomic delineation, with 95% confidence interval. A Wilcoxon rank-sum test assessed the null hypothesis that T2 Sh structure delineation compared to conventional 2D is unchanged. Intraclass correlation coefficients were calculated for interobserver agreement. Imaging time of the conventional protocol and T2 Sh was compared. There was 81% and 87% concordance between T2 Sh reports and diagnostic reports, respectively, for each reader. Upon consensus review, T2 Sh had 93% sensitivity and 100% specificity compared to clinical reports for detection of clinically relevant findings. The 95% confidence interval of diagnostic or better rating was 95-100%, with 34-80% interobserver agreement. There was no significant difference in structure delineation between T2 Sh and 2D, except for the retinaculum (P < 0.05), where 2D was preferred. Typical imaging time for T2 Sh and the conventional exam was 7 and 13 minutes, respectively. A single-sequence pediatric knee exam is feasible with T2 Sh, providing multiplanar, reformattable 4D images. 2 J. MAGN. RESON. IMAGING 2017;45:1700-1711.

Early assessment and identification of posttraumatic stress disorder, satisfaction with appearance and coping in patients with burns

BackgroundThe first year after severe burn is a psychologically challenging period for the patient. Patients may still struggle with burn-related physical and psychological problems such as posttraumatic stress disorder (PTSD) and body image dissatisfaction (BID). AimThis study investigates the presence of PTSD, BID and coping, at three, six and twelve months after discharge for early identification of patients in need of focused support during rehabilitation. MethodsFifty-two adult patients with different degrees of burns were followed at three, six and twelve months after discharge and 36 patients completed all assessment points. A standardized clinical protocol was used for systematic assessment of PTSD (IES-R), BID (SWAP-Swe) and Coping (CBQ). The follow-up included an intervention with a burn nurse as a complement to the existing program. ResultsApproximately half of the patients had a risk of developing PTSD three months after discharge from hospital, and body image dissatisfaction was found to potentially predict risk of PTSD during follow-up. ConclusionsThe findings suggest that it is important to include patients with less extensive burns in follow-up as this group is at risk of development of PTSD. Using standardized questionnaires in early follow-up along with assessment of body image dissatisfaction may facilitate detection of psychological problems.

A Bayesian approach to fiber orientation estimation guided by volumetric tract segmentation

Diffusion magnetic resonance imaging (dMRI) provides information about the microstructure of white matter in the human brain. From dMRI, streamlining tractography is often used to reconstruct computational representations of white matter tracts from which differences in structural connectivity can be explored. In the fiber tracking process, anatomical information can help reduce tracking errors caused by crossing fibers and image noise. In this paper, we propose a Bayesian method for estimating fiber orientations (FOs) guided by anatomical tract information using diffusion tensor imaging (DTI), which is a standard clinical and research dMRI protocol. The proposed method is named Fiber Orientation Reconstruction guided by Tract Segmentation (FORTS). A first step segments and labels the white matter tracts volumetrically, including explicit representations of crossing regions. A second step estimates the FOs using the diffusion information and the anatomical knowledge from segmented white matter tracts. A single FO is estimated in the noncrossing regions while two FOs are estimated in the crossing regions. A third step carries out streamlining tractography that uses information from both the segmented tracts and the estimated FOs. Experiments performed on a digital crossing phantom, a physical phantom, and brain DTI of 18 healthy subjects show that FORTS is able to use the anatomical information to produce FOs with better accuracy and to reduce anatomically incorrect streamlines. In particular, on the brain DTI data, we studied the connectivity of anatomically defined tracts to cortical areas, which is not straightforwardly achievable using only volumetric tract segmentation. These connectivity results demonstrate the potential application of FORTS to scientific studies.

Same day discharge protocol implementation trends in laparoscopic cholecystectomy in pediatric patients

PurposeAfter investigating barriers for same day discharge (SDD) after laparoscopic cholecystectomy (LC), we employed a protocol which we have followed with a prospective, observational study. MethodsA single institution, prospective observational study was performed from July 2014 to 2015 (2nd period). These data were compared to our initial experience with an SDD protocol from January 2013 to July 2014 (1st period). ResultsA total of 191 LCs were analyzed, 116 in the 1st period and 75 in the second period. In the 1st period, 47% were discharged the same day compared to 78% in the 2nd period (P<0.001). There was no difference in postoperative complications or readmissions between those discharged and those who spent the night. Additionally, there was no difference between admitted and SDD patients in age, BMI, or gender. Reasons for admission included pain (12%) and emesis (12%), and 1 patient had a syncopal event. However, the majority stayed with no identifiable patient factor. ConclusionSDD after LC is safe and effective and implementing and revising a standardized clinical protocol can substantially improve the success of SDD. Level of evidenceRetrospective comparative study, level III.

Rod Electroretinograms Elicited by Silent Substitution Stimuli from the Light-Adapted Human Eye.

PurposeTo demonstrate that silent substitution stimuli can be used to generate electroretinograms (ERGs) that effectively isolate rod photoreceptor function in humans without the need for dark adaptation, and that this approach constitutes a viable alternative to current clinical standard testing protocols.MethodsRod-isolating and non-isolating sinusoidal flicker stimuli were generated on a 4 primary light-emitting diode (LED) Ganzfeld stimulator to elicit ERGs from participants with normal and compromised rod function who had not undergone dark-adaptation. Responses were subjected to Fourier analysis, and the amplitude and phase of the fundamental were used to examine temporal frequency and retinal illuminance response characteristics.ResultsElectroretinograms elicited by rod-isolating silent substitution stimuli exhibit low-pass temporal frequency response characteristics with an upper response limit of 30 Hz. Responses are optimal between 5 and 8 Hz and between 10 and 100 photopic trolands (Td). There is a significant correlation between the response amplitudes obtained with the silent substitution method and current standard clinical protocols. Analysis of signal-to-noise ratios reveals significant differences between subjects with normal and compromised rod function.ConclusionsSilent substitution provides an effective method for the isolation of human rod photoreceptor function in subjects with normal as well as compromised rod function when stimuli are used within appropriate parameter ranges.Translational RelevanceThis method of generating rod-mediated ERGs can be achieved without time-consuming periods of dark adaptation, provides improved isolation of rod- from cone-based activity, and will lead to the development of faster clinical electrophysiologic testing protocols with improved selectivity.

Quantitative CT characterization of pediatric lung development using routine clinical imaging.

The use of quantitative CT analysis in children is limited by lack of normal values of lung parenchymal attenuation. These characteristics are important because normal lung development yields significant parenchymal attenuation changes as children age. To perform quantitative characterization of normal pediatric lung parenchymal X-ray CT attenuation under routine clinical conditions in order to establish a baseline comparison to that seen in pathological lung conditions. We conducted a retrospective query of normal CT chest examinations in children ages 0-7years from 2004 to 2014 using standard clinical protocol. During these examinations semi-automated lung parenchymal segmentation was performed to measure lung volume and mean lung attenuation. We analyzed 42 CT examinations in 39 children, ages 3days to 83months (mean ± standard deviation [SD] = 42 ± 27months). Lung volume ranged 0.10-1.72liters (L). Mean lung attenuation was much higher in children younger than 12months, with values as high as -380 Hounsfield units (HU) in neonates (lung volume 0.10L). Lung volume decreased to approximately -650 HU by age 2years (lung volume 0.47L), with subsequently slower exponential decrease toward a relatively constant value of -860 HU as age and lung volume increased. Normal lung parenchymal X-ray CT attenuation decreases with increasing lung volume and age; lung attenuation decreases rapidly in the first 2years of age and more slowly thereafter. This change in normal lung attenuation should be taken into account as quantitative CT methods are translated to pediatric pulmonary imaging.

Commentary on clinical significance of CYP2C9‐status‐guided valproic acid therapy in children

The results of this retrospective study1 suggest a positive effect of cytochrome P450 (CYP)2C9–guided valproate (VPA) treatment when compared with non–CYP2C9-guided treatment, based on the significant lower rate of patients with hyperammonemia in the CYP2C9-guided cohort. Eight of 47 patients in the control group versus one of 51 patients in the CYP2C9-guided group showed hyperammonemia 1 month after the beginning of VPA treatment. We think that the study results should be interpreted with caution, however. In the intervention group, CYP2C9 status was determined, but the incidence of low expressers was higher than expected according to the literature.2 If the expression of the CYP2C9 gene was different in the control group, this could have led to a substantial bias. This potential bias could influence the (significant) higher ratio of patients with a serum VPA concentration outside the therapeutic range. The intervention and control groups also differed with respect to VPA dosing. The control group received a dosing of 20–40 mg/kg. Dosing for the normal expressers in the intervention group was 30–40 mg/kg. The authors did not explain why normal expressers did not receive VPA treatment based on standard clinical protocol, and the mean or average dose in either cohorts were not reported, as could influence outcome. The authors found a higher rate of hyperammonemia in the control group without hepatotoxicity. Literature reports between 100 and 260 clinical apparent cases of hepatotoxicity or hepatotoxicity with a fatal outcome in the period ranging from 1977 until 2013. However, the literature also notes that serious adverse reactions are rare, especially those leading to fatalities.3, 4 One patient with hyperammonemia was observed with secondary symptoms (nausea, vomiting, lack of appetite, fatigue, drowsiness, confusion, cognitive slowing, or loss of consciousness). It is not mentioned if this was in the control or intervention group. Also Segura-Bruna et al.5 have noted that no relationship has been found between the daily doses of VPA and the appearance and severity of valproate-induced hyperammonemic encephalopathy (VHE).6 They also noted no relationship between the development of VHE and serum VPA levels. Others described no correlation between clinical severity of VHE and higher blood ammonium levels when hyperammonemia was confirmed.6 So there does not seem to be a solid relationship between the development of clinically significant VHE and serum VPA levels.5 As is suggested by Monostory et al. In conclusion, in our opinion the authors note this research as a first attempt to establish the influence of CYP2C9 on VPA metabolism. However, based on presented data and given the low prevalence of hepatotoxicity, the study seems to be too small to make firm conclusions such as that CYP2C9-status-guided VPA treatment is preferable to non–CYP2C9-guided treatment and that CYP2C9-guided VPA treatment has demonstrated to improve the safety of VPA treatment. None of the authors has any conflict of interest to disclose. We confirm that we have read the Journal's position on issues involved in ethical publication and affirm that this report is consistent with those guidelines.

Аналіз ефективності застосування програми ІМSI при заплідненні in vitro

The aim of the study: to analyze the results of the program ІМSI as one of the methods of VRT to ensure in vitro fertilization. Materials and methods. The basis of the study consisted of 100 couples with male factor infertility. Pair was examined and treated at the Institute of reproductive medicine (Kiev) in 2013-2015. The Diagnosis verified, assistance was provided in the framework of standard clinical protocols. The 51 men were diagnosed oligoasthenozoospermia, obstructive and non-obstructive azoospermia - in 28 and 21 men, respectively. Results. There were identified features according to the results of cycles. When native - biochemical pregnancy achieved almost equally often oligoasthenozoospermia and obstructive azoospermia (53.0±6.9% and 53.4±9.4%), whereas non-obstructive in two times less (28.6±9.8%). When critical the difference in results is not traced with obstructive and non-obstructive azoospermia and was 16% lower in cases of oligoasthenozoospermia. Biochemical pregnancies occurred in 63 of the 100 pairs (63.0±4.8%), with oligoasthenozoospermia and 37 of 51 (72.5 per cent), obstructive azoospermia – in 19 of 28 (67.8 per cent), non-obstructive – 7 of 21 (33.3 percent). After reproductive losses (5 of 63, 7.9% as) the end result was lower – 58.0±4.9 per cent. The number of births in total in the group with oligoasthenozoospermia was 35 of 51 (68.6%), obstructive and non-obstructive azoospermia - 17 of 28 (60.7 per cent) and 6 of 21 (28.6 per cent), respectively. Conclusion. The data motivate the need of finding opportunities to improve program performance ІМSI. Promising in this regard is the preparation of the pair to her conduct, which goes beyond the limits of the medical, carried out according to the protocols. An important point should be the identification and leveling of risk factors for general medicine and a social plan. Key words: male infertility, the program ІМSI, results.

Volumetric relationship between 2-hydroxyglutarate and FLAIR hyperintensity has potential implications for radiotherapy planning of mutant IDH glioma patients.

Gliomas with mutant isocitrate dehydrogenase (IDH) produce high levels of 2-hydroxyglutarate (2HG) that can be quantitatively measured by 3D magnetic resonance spectroscopic imaging (MRSI). Current glioma MRI primarily relies upon fluid-attenuated inversion recovery (FLAIR) hyperintensity for treatment planning, although this lacks specificity for tumor cells. Here, we investigated the relationship between 2HG and FLAIR in mutant IDH glioma patients to determine whether 2HG mapping is valuable for radiotherapy planning. Seventeen patients with mutant IDH1 gliomas were imaged by 3 T MRI. A 3D MRSI sequence was employed to specifically image 2HG. FLAIR imaging was performed using standard clinical protocol. Regions of interest (ROIs) were determined for FLAIR and optimally thresholded 2HG hyperintensities. The overlap, displacement, and volumes of 2HG and FLAIR ROIs were calculated. In 8 of 17 (47%) patients, the 2HG volume was larger than FLAIR volume. Across the entire cohort, the mean volume of 2HG was 35.3 cc (range, 5.3-92.7 cc), while the mean volume of FLAIR was 35.8 cc (range, 6.3-140.8 cc). FLAIR and 2HG ROIs had mean overlap of 0.28 (Dice coefficients range, 0.03-0.57) and mean displacement of 12.2 mm (range, 3.2-23.5 mm) between their centers of mass. Our results indicate that for a substantial number of patients, the 2HG volumetric assessment of tumor burden is more extensive than FLAIR volume. In addition, there is only partial overlap and asymmetric displacement between the centers of FLAIR and 2HG ROIs. These results may have important implications for radiotherapy planning of IDH mutant glioma.

Development of Medical Countermeasures to Middle East Respiratory Syndrome Coronavirus.

Preclinical development of and research on potential Middle East respiratory syndrome coronavirus (MERS-CoV) medical countermeasures remain preliminary; advancements are needed before most countermeasures are ready to be tested in human clinical trials. Research priorities include standardization of animal models and virus stocks for studying disease pathogenesis and efficacy of medical countermeasures; development of MERS-CoV diagnostics; improved access to nonhuman primates to support preclinical research; studies to better understand and control MERS-CoV disease, including vaccination studies in camels; and development of a standardized clinical trial protocol. Partnering with clinical trial networks in affected countries to evaluate safety and efficacy of investigational therapeutics will strengthen efforts to identify successful medical countermeasures.

High resolution CBV assessment with PEAK-EPI: k-t-undersampling and reconstruction in echo planar imaging.

Achieving higher spatial resolution and improved brain coverage while mitigating in-plane susceptibility artifacts in the assessment of perfusion parameters, such as cerebral blood volume, in echo planar imaging (EPI)-based dynamic susceptibility contrast weighted cerebral perfusion measurements. PEAK-EPI, an EPI sequence with interleaved readout trajectories and three different strategies for autocalibration-signal acquisition (inplace, dynamic extra and extra) is presented. Performance of each approach is analyzed in vivo based on flip angle variation induced dynamics, assessing temporal fidelity, temporal SNR and g-factors. All approaches are compared with conventional GRAPPA reconstructions. PEAK-EPI with inplace autocalibration-signal at R = 5 is then compared with the standard clinical EPI protocol in six patients, using two half-dose dynamic susceptibility contrast weighted cerebral perfusion measurements per subject. PEAK-EPI acquisition facilitates a substantial increase of spatial resolution at a higher number of slices per TR and provides improved SNR compared to conventional GRAPPA. High dependency of the resulting reconstruction quality on the type of autocalibration-signal acquisition is observed. PEAK-EPI with inplace autocalibration-signal achieves high temporal fidelity and initial feasibility is shown. The obtained high resolution cerebral blood volume maps reveal more detailed information than in corresponding standard EPI measurements and facilitate detailed delineation of tumorous tissue. Magn Reson Med 77:2153-2166, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

Evaluation of Rigid-Body Motion Compensation in Cardiac Perfusion SPECT Employing Polar-Map Quantification.

We have recently been successful in the development and testing of rigid-body motion tracking, estimation and compensation for cardiac perfusion SPECT based on a visual tracking system (VTS). The goal of this study was to evaluate in patients the effectiveness of our rigid-body motion compensation strategy. Sixty-four patient volunteers were asked to remain motionless or execute some predefined body motion during an additional second stress perfusion acquisition. Acquisitions were performed using the standard clinical protocol with 64 projections acquired through 180 degrees. All data were reconstructed with an ordered-subsets expectation-maximization (OSEM) algorithm using 4 projections per subset and 5 iterations. All physical degradation factors were addressed (attenuation, scatter, and distance dependent resolution), while a 3-dimensional Gaussian rotator was used during reconstruction to correct for six-degree-of-freedom (6-DOF) rigid-body motion estimated by the VTS. Polar map quantification was employed to evaluate compensation techniques. In 54.7% of the uncorrected second stress studies there was a statistically significant difference in the polar maps, and in 45.3% this made a difference in the interpretation of segmental perfusion. Motion correction reduced the impact of motion such that with it 32.8 % of the polar maps were statistically significantly different, and in 14.1% this difference changed the interpretation of segmental perfusion. The improvement shown in polar map quantitation translated to visually improved uniformity of the SPECT slices.

MO-DE-207B-07: Assessment of Reproducibility Of FDG-PET-Based Radiomics Features Across Scanners Using Phantom Imaging

Purpose: Use a NEMA-IEC PET phantom to assess the robustness of FDG-PET-based radiomics features to changes in reconstruction parameters across different scanners. Methods: We scanned a NEMA-IEC PET phantom on 3 different scanners (GE Discovery VCT, GE Discovery 710, and Siemens mCT) using a FDG source-to-background ratio of 10:1. Images were retrospectively reconstructed using different iterations (2–3), subsets (21–24), Gaussian filter widths (2, 4, 6mm), and matrix sizes (128,192,256). The 710 and mCT used time-of-flight and point-spread-functions in reconstruction. The axial-image through the center of the 6 active spheres was used for analysis. A region-of-interest containing all spheres was able to simulate a heterogeneous lesion due to partial volume effects. Maximum voxel deviations from all retrospectively reconstructed images (18 per scanner) was compared to our standard clinical protocol. PET Images from 195 non-small cell lung cancer patients were used to compare feature variation. The ratio of a feature's standard deviation from the patient cohort versus the phantom images was calculated to assess for feature robustness. Results: Across all images, the percentage of voxels differing by 3) were observed for routinely used SUV metrics (e.g. SUVmean and SUVmax) as well as some radiomics features (e.g. co-occurrence contrast, co-occurrence energy, standard deviation, and uniformity). Similar standard deviation ratios were observed across scanners. Conclusions: Our method enabled a comparison of feature variability across scanners and was able to identify features that were not robust to changes in reconstruction parameters.

SU‐F‐SPS‐03: Direct Measurement of Organ Doses Resulting From Head and Cervical Spine Trauma CT Protocols

Purpose:This retrospective study analyzes the exposure history of emergency department (ED) patients undergoing head and cervical spine trauma computed tomography (CT) studies. This study investigated dose levels received by trauma patients and addressed any potential concerns regarding radiation dose issues.Methods:Under proper IRB approval, a cohort of 300 trauma cases of head and cervical spine trauma CT scans received in the ED was studied. The radiological image viewing software of the hospital was used to view patient images and image data. The following parameters were extracted: the imaging history of patients, the reported dose metrics from the scanner including the volumetric CT Dose Index (CTDIvol) and Dose Length Product (DLP). A postmortem subject was scanned using the same scan techniques utilized in a standard clinical head and cervical spine trauma CT protocol with 120 kVp and 280 mAs. The CTDIvol was recorded for the subject and the organ doses were measured using optically stimulated luminescent (OSL) dosimeters. Typical organ doses to the brain, thyroid, lens, salivary glands, and skin, based on the cadaver studies, were then calculated and reported for the cohort.Results:The CTDIvol reported by the CT scanner was 25.5 mGy for the postmortem subject. The average CTDIvol from the patient cohort was 34.1 mGy. From these metrics, typical average organ doses in mGy were found to be: Brain (44.57), Thyroid (33.40), Lens (82.45), Salivary Glands (61.29), Skin (47.50). The imaging history of the cohort showed that on average trauma patients received 26.1 scans over a lifetime.Conclusion:The average number of scans received on average by trauma ED patients shows that radiation doses in trauma patients may be a concern. Available dose tracking software would be helpful to track doses in trauma ED patients, highlighting the importance of minimizing unnecessary scans and keeping doses ALARA.

SU-F-R-21: The Stability of Radiomics Features On 4D FDG-PET/CT Images

Purpose: The aim of our study was to perform a stability analysis of 4D PET-derived features in non-small cell lung carcinoma (NSCLC) based on six different respiratory phases. Methods: The 4D FDG-PET/CT respiratory phases were labeled as T0%, T17%, T33%,T50%, T67%, T83% phases, with the T0% phase approximately corresponding to the normal end-inspiration. Lesions were manually delineated based on fused PET-CT, using a standardized clinical delineation protocol. Six texture parameters were analyzed. Results: Results showed that the majority of assessed features had a low stability such as Homogeneity (0.385–0.416), Dissimilarity (3.707–3.861), Angular two moments (0.013–0.019), Contrast (39.782–49.562), Entropy(4.683–5.002) and Inverse differential moment (0.317–0.362) on different respiratory phases. Conclusion: This study suggest that further research of quantitative PET imaging features is warranted with respect to respiratory motion.

Does the Post-Systolic Shortening of the Left Ventricle by Tissue Doppler Imaging Predict Coronary Artery Disease?

Background: Abnormalities in the velocity and pattern of myocardial shortening on tissue Doppler imaging (TDI) have been pro- posed to aid in the noninvasive diagnosis of coronary artery disease (CAD). Objectives: We investigated the diagnostic value of post-systolic shortening (PSS), a delayed ejection velocity of the myocardium after the closure of the aortic valve, on TDI in the diagnosis of CAD among patients with chest pain and normal resting wall motion on standard 2D echocardiography. Methods: Eighty consecutive patients (49% female) with typical ischemic chest pain but without prior myocardial infarction, coro- nary revascularization, arrhythmia, or heart failure, who had no regional wall motion abnormalities on resting echocardiography and who were scheduled to undergo coronary angiography, were selected. TDI was performed in each patient before coronary an- giography at 2 levels (basal and mid left ventricle (LV)) in each of the 4 LV walls (i.e., septal, anterior, inferior, and lateral). Coronary angiography was performed and interpreted per standard clinical protocols. Results: Compared to the patients with normal coronaries, those with angiographic CAD showed significantly increased myocar- dial isovolumic relaxation time (IVRT) velocity (P 4.0 m/sec, a positive PSS velocity had about 65% sensitivity and 85% specificity with a positive predictive value > 90% in predicting angiographic CAD. Conclusions: Among patients with chest pain and normal LV wall motion on 2D echocardiography, a prominent and prolonged IVRT on TDI may help predict the presence of significant CAD.

Tuberculosis among transhumant pastoralist and settled communities of south-eastern Mauritania

BackgroundTranshumant pastoralists of Mauritania were assumed to have a high prevalence of tuberculosis (TB) because of reduced access to diagnostic testing. No population-based survey on TB has been published for Mauritania.ObjectiveThe goal of this study was to estimate the prevalence of presumptive TB cases among mobile pastoralists and villagers in a remote zone of Mauritania.DesignIn the south-eastern province of Hodh Ech Chargui, 250 adult pastoralists and 250 villagers were randomly enrolled using multistage cluster sampling in February 2012. A TB centre nurse examined participants using a standard clinical protocol, and a participant questionnaire was completed. Focus group discussions and interviews were conducted with community members and health personnel, respectively.ResultsFourteen new presumptive TB cases were identified, leading to an overall prevalence of 2.8%, (95% confidence interval (CI) 1.5–4.7%). The prevalence was non-significantly higher among villagers than pastoralists (3.6% vs. 2.0%). Assuming illness duration was 3 years and all presumptive cases started treatment, an overall crude incidence of 933 cases/100,000 was derived. Five of six presumptive cases in Djiguenni were confirmed by sputum smear microscopy, but none out of eight presumptive cases were confirmed in Néma, although the same nurse performed all clinical examinations in both departments. This result was attributed to the use of expired reagents in Néma. Communities mentioned distance rather than lack of information as the main constraint to seeking diagnosis, but poor diagnostic centre performance also delayed decision-making.ConclusionsTB prevalences were high among both pastoralists and villagers. None of the 14 presumptive cases sought prior diagnostic testing. TB diagnostic centres in the remote rural study zone were poorly equipped. These centres must remain in operation to reduce TB incidence in vulnerable communities in insecure remote rural zones and to reach national health goals.