Material decomposition maps based calibration of dual energy CT scanners for proton therapy planning: a phantom study.

We introduce a new calibration method for dual energy CT (DECT) based on material decomposition (MD) maps, specifically iodine and water MD maps. The aim of this method is to provide the first DECT calibration based on MD maps. The experiments were carried out using a general electric (GE) revolution CT scanner with ultra-fast kV switching and used a density phantom by GAMMEX for calibration and evaluation. The calibration process involves several steps. First, we tested the ability of MD values to reproduce Hounsfield unit (HU) values of single energy CT (SECT) acquisitions and it was found that the errors were below 1%, validating their use for HU reproduction. Next, the different definitions of computedZvalues were compared and the robustness of the approach based on the materials' composition was confirmed. Finally, the calibration method was compared with a previous method by Bourqueet al, providing a similar level of accuracy and superior performance in terms of precision. Overall, this novel DECT calibration method offers improved accuracy and reliability in determining tissue-specific physical properties. The resulting maps can be valuable for proton therapy treatments, where precise dose calculations and accurate tissue differentiation are crucial for optimal treatment planning and delivery.

3'IsomiR Species Composition Affects Reliable Quantification of miRNA/isomiR Variants by Poly(A) RT-qPCR: Impact on Small RNA-Seq Profiling Validation.

Small RNA-sequencing (small RNA-seq) has revealed the presence of small RNA-naturally occurring variants such as microRNA (miRNA) isoforms or isomiRs. Due to their small size and the sequence similarity among miRNA isoforms, their validation by RT-qPCR is challenging. We previously identified two miR-31-5p isomiRs-the canonical and a 3'isomiR variant (3' G addition)-which were differentially expressed between individuals with azoospermia of different origin. Here, we sought to determine the discriminatory capacity between these two closely-related miRNA isoforms of three alternative poly(A) based-RT-qPCR strategies in both synthetic and real biological context. We found that these poly(A) RT-qPCR strategies exhibit a significant cross-reactivity between these miR-31-5p isomiRs which differ by a single nucleotide, compromising the reliable quantification of individual miRNA isoforms. Fortunately, in the biological context, given that the two miRNA variants show changes in the same direction, RT-qPCR results were consistent with the findings of small RNA-seq study. We suggest that miRNA selection for RT-qPCR validation should be performed with care, prioritizing those canonical miRNAs that, in small RNA-seq, show parallel/homogeneous expression behavior with their most prevalent isomiRs, to avoid confounding RT-qPCR-based results. This is suggested as the current best strategy for robust biomarker selection to develop clinically useful tests.

An Uncommon Diagnosis in a Child Presenting With Double Vision and Imbalance.

Acute disseminated encephalomyelitis (ADEM) is exceptionally uncommon, with approximately 3 pediatric cases reported in the United States each year. Given the uncommon nature of ADEM, most of the current data rely heavily on case reports. The overwhelming majority of cases have been reported after an acute viral infection or vaccination. Although up to 90% of cases exhibit full remission after intravenous steroids, those in which treatment is delayed can display debilitating sequelae. Here, we present a case of ADEM in a 7-year-old boy who presented with double vision and imbalance with no recent history of acute viral infections or vaccinations.

Acute Hematogenous Osteomyelitis in a Five-Month-Old Male with Rickets.

Osteomyelitis is defined as an infection of the bone, bone marrow, and the surrounding soft tissues. Most cases of acute hematogenous osteomyelitis in children are caused by Gram-positive bacteria, principally Staphylococcus aureus. We present a case where a 5-month-old male had an acute onset of decreased movement of his left leg and increased irritability and was subsequently diagnosed with rickets and hematogenous osteomyelitis with bacteremia. The case explores a possible association between hematogenous osteomyelitis and rickets.

Children requiring psychiatric consultation in the pediatric emergency department: epidemiology, resource utilization, and complications.

METHODS: A cohort of children younger than 18 years presenting to an urban pediatric emergency department (PED) who underwent psychiatric consultation was analyzed. A standardized data collection sheet was prospectively completed and included: patient characteristics, extent of medical evaluation and findings, ancillary diagnostic studies, resources utilized, dangerous behaviors, and disposition. RESULTS: Two hundred ten patients required psychiatric evaluation. Median age was 14 years; 51.9% were boys; 71.9% had a past psychiatric history; 39.0% had prior psychiatric admission(s), and 40.5% were on psychiatric medications. The admission rate was 49.5%. Patients spent a median of 5.7 hours in the PED. Hospital police monitored 51.9% patients. Forty-five patients had 91 dangerous behaviors. Those patients presenting with a complaint of aggressive behavior (P = 0.00006), a past psychiatric history (P = 0.003), or a history of prior psychiatric hospitalization (P = 0.005) were more likely to have dangerous behaviors. Two hundred nine patients underwent a complete medical evaluation, and 207 were considered medically cleared. Patients who had diagnostic evaluations for medically indicated reasons were significantly more likely to have abnormal results than those requested by the psychiatric consultant for screening purposes (43.6% vs. 9.2%; relative risk, 2.33; 95% confidence interval, 1.33-4.08) but were not statistically more likely to result in medical intervention (5.4% vs. 0%, P = 0.243). CONCLUSIONS: PED patients requiring psychiatric consultation and psychiatric admission had a prolonged PED stay and a high incidence of dangerous behaviors requiring intervention. History and physical examination adequately identified medical illness. Laboratory evaluation obtained for psychiatric transfer or admission purposes was of low yield.

Use of ultrasonography to identify infants for whom urinary catheterization will be unsuccessful because of insufficient urine volume: validation of the urinary bladder index.

STUDY OBJECTIVE: Frequently, attempts to obtain catheter urine samples from infants are unsuccessful because of an empty bladder, with urinary catheterization failure rates reported up to 16%. We seek to validate a sonographic urinary bladder index that will identify patients for whom catheterization will be unsuccessful. METHODS: We conducted a prospective, blinded, observational study enrolling a convenience sample of children younger than 2 years and undergoing urinary catheterization in an urban pediatric emergency department. Failure was defined as a catheterization result of less than 2 mL of urine. Urinary bladder index, a concept we created, is defined as the product of anteroposterior and transverse diameters, expressed in centimeters squared. Sensitivity and specificity were calculated with 95% confidence intervals (CIs). RESULTS: Forty-four patients were enrolled, with a median age of 8 months (range 0.5 to 24 months) and median weight of 7.8 kg (range 1.7 to 17.7 kg). Four children urinated during the procedure and were excluded. Thirty-five had urinary bladder index greater than 2.4 cm2 (range 2.5 to 15.5 cm2 ). All were successfully catheterized. Four children had urinary bladder index less than 2.4 cm2 (range 0 to 1.2 cm 2 ). No adequate samples were obtained from those children. The bladder was not visualized at all in 1 child who was successfully catheterized. Sensitivity of the urinary bladder index to identify failure to obtain 2 mL of urine was 100% (4 of 4; 95% CI 40% to 100%), specificity was 97% (35 of 36; 95% CI 85% to 100%). CONCLUSION: A urinary bladder index less than 2.4 cm2 appears to identify infants for whom urinary catheterization will be unsuccessful because of insufficient urine volume. Ultrasonographic evaluation with urinary bladder index measurement before catheterization may eliminate the incidence of failed procedures.