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Background: Vaso-occlusive crises (VOCs) cause debilitating pain and are a common cause of emergency department (ED) visits, for people with sickle cell disease (SCD). Strategies for achieving optimal pain control vary widely despite evidence-based guidelines. We tested existing guidelines and hypothesized that a patient-specific pain protocol (PSP) written by their SCD provider may be more effective than weight-based (WB) dosing of parenteral opiate medication, in relieving pain., Methods: This study was a prospective, randomized controlled trial comparing a PSP versus WB protocol for patients presenting with VOCs to six EDs. Patients were randomized to a PSP or WB protocol prior to an ED visit. The SCD provider wrote their protocol and placed it in the electronic health record for future ED visits with VOC exclusion criteria that included preexisting PSP excluding parenteral opioid analgesia or outpatient use of buprenorphine or methadone or highly suspected for COVID-19. Pain intensity scores, side effects, and safety were obtained every 30 min for up to 6 h post-ED bed placement. The primary outcome was change in pain intensity score from placement in an ED space to disposition or 6 h., Results: A total of 328 subjects were randomized; 104 participants enrolled (ED visit, target n = 230) with complete data for 96 visits. The study was unable to reach the target sample size and stopped early due to the impact of COVID-19. We found no significant differences between groups in the primary outcome; patients randomized to a PSP had a shorter ED length of stay (p = 0.008), and the prevalence of side effects was low in both groups. Subjects in both groups experienced both a clinically meaningful and a statistically significant decrease in pain (27 mm on a 0- to 100-mm scale)., Conclusions: We found a shorter ED length of stay for patients assigned to a PSP. Patients in both groups experienced good pain relief without significant side effects., (© 2023 Society for Academic Emergency Medicine.)

Purpose: To evaluate different T 2 -oxygenation calibrations for estimating venous oxygenation in people with sickle cell anemia (SCA)., Methods: Blood T 2 values were measured at 3 T in the internal jugular veins of 12 healthy volunteers and 11 SCA participants with no history of stroke, recent transfusion, or renal impairment. T 2 -oxygenation relationships of both sickled and normal blood samples were calibrated individually and compared with values generated from published models. After converting venous T 2 values to venous oxygenation, whole-brain oxygen extraction fraction and cerebral metabolic rate of oxygen were calculated., Results: Sickle blood samples' oxygenation values calculated from our individual calibrations agreed well with measurements using a blood analyzer, whereas previous T 2 calibrations based on normal blood samples showed 13%-19% underestimation. Meanwhile, oxygenation values calculated from previous grouped T 2 calibration for sickle blood agreed well with experimental measurement on averaged values, but showed up to 20% variation for several individual samples. Using individual T 2 calibrations, the whole-brain oxygen extraction fraction and cerebral metabolic rate of oxygen of SCA participants were 0.38 ± 0.08 and 172 ± 42 µmol/min/100 g, respectively, which were comparable to those values measured on healthy volunteers., Conclusion: Our results confirm that sickle blood T 2 values not only depend on the hematocrit and oxygenation values, but also on other hematological factors. The individual T 2 calibrations minimized the effect of heterogeneity of sickle blood between different SCA populations and improved the accuracy of T 2 -based oximetry. The measured oxygen extraction fraction and cerebral metabolic rate of oxygen of this group of SCA participants were found to not differ significantly from those of healthy individuals., (© 2019 International Society for Magnetic Resonance in Medicine.)

Baseline hematocrit fraction (Hct) is a determinant for baseline cerebral blood flow (CBF) and between-subject variation of Hct thus causes variation in task-based BOLD fMRI signal changes. We first verified in healthy volunteers (n = 12) that Hct values can be derived reliably from venous blood T 1 values by comparison with the conventional lab test. Together with CBF measured using phase-contrast MRI, this noninvasive estimation of Hct, instead of using a population-averaged Hct value, enabled more individual determination of oxygen delivery (DO 2 ), oxygen extraction fraction (OEF), and cerebral metabolic rate of oxygen (CMRO 2 ). The inverse correlation of CBF and Hct explained about 80% of between-subject variation of CBF in this relatively uniform cohort of subjects, as expected based on the regulation of DO 2 to maintain constant CMRO 2 . Furthermore, we compared the relationships of visual task-evoked BOLD response with Hct and CBF. We showed that Hct and CBF contributed 22%-33% of variance in BOLD signal and removing the positive correlation with Hct and negative correlation with CBF allowed normalization of BOLD signal with 16%-22% lower variability. The results of this study suggest that adjustment for Hct effects is useful for studies of MRI perfusion and BOLD fMRI. Hum Brain Mapp 39:344-353, 2018. © 2017 Wiley Periodicals, Inc., (© 2017 Wiley Periodicals, Inc.)

Purpose: To develop a fast protocol for measuring T 1 values in the internal carotid artery (ICA), to validate this technique with in vitro measurements, and to evaluate its reproducibility., Methods: A modified Look-Locker sequence was optimized to enable rapid determination of T 1 in the ICA at 3T. T 1 values from the ICA were compared with in vitro measurements on individually sampled venous blood oxygenated to arterial levels. A test-retest reproducibility study was also conducted., Results: The group-averaged arterial blood T 1 value was 1908 ± 77 ms for six women (hematocrit = 0.39 ± 0.03) and 1785 ± 55 ms for seven men (hematocrit = 0.45 ± 0.02), which is 100-200 ms longer than the widely adopted value obtained from bovine blood experiments. The arterial T 1 value per subject correlated significantly with individual hematocrit values. The intrasession and intersession coefficients of variation were 1.1% and 2.1%, respectively, indicating good precision and reproducibility of our method. Reasonable agreement was observed between the in vivo and in vitro results with a correlation coefficient of 0.78., Conclusion: The proposed method can provide fast arterial T 1 measurement on individual subjects. When not performing such a subject-specific measurement, we recommend the use of 1908 ms and 1785 ms for healthy women and men, respectively, or 1841 ms for adults in general. Magn Reson Med 77:2296-2302, 2017. © 2016 International Society for Magnetic Resonance in Medicine., (© 2016 International Society for Magnetic Resonance in Medicine.)

Background: Data on sentinel lymph node (SLN) biopsy in children with melanoma are limited. In this study, the authors compared the factors associated with SLN biopsy use and metastases in pediatric and young adult patients with melanoma., Methods: The 2008 Surveillance, Epidemiology, and End Results (SEER) databases were used to examine melanoma cases from 2003 to 2008. Data extracted include age, sex, race, stage, tumor thickness, ulceration, lymph node status, surgical treatment, and survival. Logistic regression models were used for adjusted analyses., Results: In total, 717 children (age <20 years) and 1368 young adults (age 20-24 years) were identified who were diagnosed with melanoma. Factors that were associated with SLN biopsy use included tumor ulceration (odds ratio [OR], 2.4; 95% confidence interval [CI], 1.4-4.3) and greater thickness (OR, 17; 95% CI, 12-24 for >1 mm vs ≤1 mm), but not younger age (OR, 1.3; 95% CI, 0.94-1.8) in adjusted analyses. SLN metastasis was correlated with ulceration (OR, 3.0; 95% CI, 1.6-5.8), increased thickness (OR, 6.8; 95% CI, 3.1-15 for 2.01-4.0 mm vs ≤1 mm), and for the interaction between age <20 years and thickness 1.01 to 2.00 mm (OR, 6.5; 95% CI, 1.7-25) in adjusted analyses. Children with nonulcerated melanomas that measured 1.01 to 2.00 mm in thickness were significantly more likely to have SLN metastases than young adults (24% vs 4%; P < .001)., Conclusions: Thickness and ulceration were strong predictors of both the use of SLN biopsy and positive SLN biopsy results in children and young adults with melanoma. Compared with young adults, children were more likely to have SLN metastases despite having similar rates of SLN biopsy use., (Copyright © 2011 American Cancer Society.)

Current T(1) values for blood at 3T largely came from in vitro studies on animal blood or freshly drawn human blood. Measurement of blood T(1) in vivo could provide more specific information, e.g., for individuals with abnormal blood composition. Here, blood T(1) at 3T was measured rapidly (<1 min) in the internal jugular vein using a fast inversion-recovery technique in which multiple inversion time can be acquired rapidly due to constant refreshing of blood. Multishot EPI acquisition with flow compensation yielded high resolution images with minimum partial volume effect. Results showed T(1) = 1852 ± 104 msec among 24 healthy adults, a value higher than for bovine blood phantoms (1584 msec at Hct of 42%). A second finding was that of a significant difference (P < 0.01) between men and women, namely T(1) = 1780 ± 89 msec (n = 12) and T(1) = 1924 ± 58 msec (n = 12), respectively. This difference in normal subjects is tentatively explained by the difference in Hct between genders. Interestingly, however, studies done on sickle cell anemia patients with much lower Hct (23 ± 3%, n = 10) revealed similar venous blood T(1) = 1924 ± 82 msec, indicating other possible physical influences affecting blood T(1)., (Copyright © 2010 Wiley-Liss, Inc.)