An evaluation of the diagnostic equivalence of 18F-FDG-PET between hybrid PET/MRI and PET/CT in drug-resistant epilepsy: A pilot study.

OBJECTIVE: Hybrid PET/MRI may improve detection of seizure-onset zone (SOZ) in drug-resistant epilepsy (DRE), however, concerns over PET bias from MRI-based attenuation correction (MRAC) have limited clinical adoption of PET/MRI. This study evaluated the diagnostic equivalency and potential clinical value of PET/MRI against PET/CT in DRE. MATERIALS AND METHODS: MRI, FDG-PET and CT images (n = 18) were acquired using a hybrid PET/MRI and a CT scanner. To assess diagnostic equivalency, PET was reconstructed using MRAC (RESOLUTE) and CT-based attenuation correction (CTAC) to generate PET/MRI and PET/CT images, respectively. PET/MRI and PET/CT images were compared qualitatively through visual assessment and quantitatively through regional standardized uptake value (SUV) and z-score assessment. Diagnostic accuracy and sensitivity of PET/MRI and PET/CT for SOZ detection were calculated through comparison to reference standards (clinical hypothesis and histopathology, respectively). RESULTS: Inter-reader agreement in visual assessment of PET/MRI and PET/CT images was 78 % and 81 %, respectively. PET/MRI and PET/CT were strongly correlated in mean SUV (r = 0.99, p < 0.001) and z-scores (r = 0.92, p < 0.001) across all brain regions. MRAC SUV bias was <5% in most brain regions except the inferior temporal gyrus, temporal pole, and cerebellum. Diagnostic accuracy and sensitivity were similar between PET/MRI and PET/CT (87 % vs. 85 % and 83 % vs. 83 %, respectively). CONCLUSION: We demonstrate here that PET/MRI with optimal MRAC can yield similar diagnostic performance as PET/CT. Nevertheless, further exploration of the potential added value of PET/MRI is necessary before clinical adoption of PET/MRI for epilepsy imaging.

Impact of ABO Blood Group on the Development of Venous Thromboembolism in Children With Cancer: A Systematic Review and Meta-Analysis.

BACKGROUND: Few studies have evaluated the impact of ABO blood group on the risk of venous thromboembolism (VTE) in pediatric populations. We performed a systematic review to determine whether children (0 to 18 y old) with non-O blood group have an increased risk of developing VTE compared with those with O blood group. METHODS: We searched Ovid Medline, Embase, PubMed, Cochrane, Web of Science, and CINAHL online databases from inception to December 2018 to find studies involving blood grouping and VTE. Data was collected regarding patients' underlying diseases, sex, age, ABO blood group, and VTE frequency. A meta-analysis using the random effect model was performed, and heterogeneity was assessed with the I2 value. RESULTS: Among 1280 unique articles identified, 7 studies (3 conference abstracts, 4 peer-reviewed journal articles) involving 609 VTE cases were included in the systematic review. Six studies were eligible for a meta-analysis; all involved patients with cancer. Blood group O was protective against VTE (odds ratio, 0.56; 95% confidence interval, 0.43-0.79). Findings were similar across sensitivity analyses. CONCLUSIONS: This systematic review has documented that O blood group is protective against new-onset VTE in children with cancer. Larger studies across different ethnic backgrounds and disease categories are needed to confirm these findings.

18F-FDG PET-guided diffusion tractography reveals white matter abnormalities around the epileptic focus in medically refractory epilepsy: implications for epilepsy surgical evaluation.

BACKGROUND: Hybrid PET/MRI can non-invasively improve localization and delineation of the epileptic focus (EF) prior to surgical resection in medically refractory epilepsy (MRE), especially when MRI is negative or equivocal. In this study, we developed a PET-guided diffusion tractography (PET/DTI) approach combining 18F-fluorodeoxyglucose PET (FDG-PET) and diffusion MRI to investigate white matter (WM) integrity in MRI-negative MRE patients and its potential impact on epilepsy surgical planning. METHODS: FDG-PET and diffusion MRI of 14 MRI-negative or equivocal MRE patients were used to retrospectively pilot the PET/DTI approach. We used asymmetry index (AI) mapping of FDG-PET to detect the EF as brain areas showing the largest decrease in FDG uptake between hemispheres. Seed-based WM fiber tracking was performed on DTI images with a seed location in WM 3 mm from the EF. Fiber tractography was repeated in the contralateral brain region (opposite to EF), which served as a control for this study. WM fibers were quantified by calculating the fiber count, mean fractional anisotropy (FA), mean fiber length, and mean cross-section of each fiber bundle. WM integrity was assessed through fiber visualization and by normalizing ipsilateral fiber measurements to contralateral fiber measurements. The added value of PET/DTI in clinical decision-making was evaluated by a senior neurologist. RESULTS: In over 60% of the patient cohort, AI mapping findings were concordant with clinical reports on seizure-onset localization and lateralization. Mean FA, fiber count, and mean fiber length were decreased in 14/14 (100%), 13/14 (93%), and 12/14 (86%) patients, respectively. PET/DTI improved diagnostic confidence in 10/14 (71%) patients and indicated that surgical candidacy be reassessed in 3/6 (50%) patients who had not undergone surgery. CONCLUSIONS: We demonstrate here the utility of AI mapping in detecting the EF based on brain regions showing decreased FDG-PET activity and, when coupled with DTI, could be a powerful tool for detecting EF and assessing WM integrity in MRI-negative epilepsy. PET/DTI could be used to further enhance clinical decision-making in epilepsy surgery.

Development process and patient usability preferences for a touch screen tablet-based questionnaire.

We sought to design a touch tablet asthma questionnaire while identifying patient preferences for usability features of such questionnaires. We created an evidence-based prototype and employed rapid-cycle design (semi-structured focus group testing, analysis, corresponding modifications, re-testing) with asthma patients aged ⩾16 years. We analyzed transcripts using deductive and inductive content analysis. Quantitative measures included Likert-type-scale responses, the System Usability Scale, and questionnaire completion times. There were 20 participants across five focus groups (15/20 female, age 49.1 ± 15.6 years). Usability-related themes included (1) "Touch Technology" (hygiene, touch technology familiarity, ease of use) and (2) "Questionnaire Design" (visual characteristics, navigation). Completion time was 11.7 ± 5.9 min. Summative Likert-type scale responses suggested high system usability, as did a System Usability Scale score of 84.2 ± 14.7. In summary, Attention to specific technology- and design-related preferences can result in a highly usable patient-facing touch tablet questionnaire. Our findings can inform touch questionnaire design across other diseases.

Patient preferences for a touch screen tablet-based asthma questionnaire.

OBJECTIVE: Assessment of asthma control and provision of asthma action plans are seldom performed in practice, partly due to limited time for physicians to ascertain required information. A patient-facing electronic asthma questionnaire could facilitate information collection. We sought to design a touch-tablet asthma questionnaire for use in the clinic waiting room and to describe patient preferences for the content of such a questionnaire. METHODS: We created a questionnaire prototype based on best evidence and employed rapid-cycle design (semi-structured focus group testing; analysis; corresponding modifications and re-testing) with asthma patients aged ≥16 years. We analyzed transcripts using deductive and inductive content analysis. Quantitative measures included Likert-scale questions and questionnaire completion times. RESULTS: There were 20 participants across five focus groups (15/20 (75%) female, age 49.1 ± 15.6 years). Content-related themes included: 1) comprehensibility (language) (how questionnaire language affected ease and accuracy of comprehension) and b) information collection (issues arising during information collection in the following identified subthemes: personal asthma symptoms and triggers; asthma control; asthma medications and contact information). Average questionnaire completion time was 11.7 ± 5.9 min. Summative Likert scale responses suggested high levels of question comprehension and confidence with responses. CONCLUSIONS: Our analysis provides novel insight about how best to formulate and present asthma-related content in an electronic questionnaire. Such questionnaires might facilitate quality improvement by improving efficiency of data collection, enabling better assessment of asthma control and medication adherence, and personalization of asthma action plans. Future studies should measure real-world uptake of such a questionnaire and impact on care.

Meningioma recurrence rates following treatment: a systematic analysis.

Recurrence rates of meningiomas have been widely reported in the literature, but it remains challenging for clinicians to predict recurrence rate depending on treatment, patient demographics and tumor characteristics. To address these needs, we performed a systematic analysis of the literature to determine the recurrence rate ranges of meningiomas following surgery or radiation. Our search yielded 13 studies that met all criteria for inclusion, allowing us to include 1539 patients in the assessment. Recurrence rates ranged from 0.00 to 2.36 per 100-person-years for WHO grade I meningiomas; and from 7.35 to 11.46 per 100-person-years for WHO grade II meningiomas. Our findings suggest that (1) reported recurrence rates are variable and complicated by the heterogeneity of study populations; (2) as expected, WHO grade II meningiomas generally have a higher recurrence rate than WHO grade I, when controlling for time of diagnosis (by employing person-years); and (3) there is a need for more rigorous reporting of recurrence rates, WHO grade, and Simpson grading for individual patients in order to determine a robust mean of recurrence across WHO grades.

Plexiform schwannoma of the thoracolumbar spine a rare clinical entity - a case report.

Plexiform schwannomas are peripheral nerve sheath tumours rarely found in the spine. We present a case of a 65-year-old male with a spinal plexiform schwannoma in order to add to the general fund of knowledge regarding the natural history, diagnosis and surgical management of this extremely rare clinical entity.