Standardization of a CT Protocol for Imaging Patients with Suspected COVID-19-A RACOON Project.

CT protocols that diagnose COVID-19 vary in regard to the associated radiation exposure and the desired image quality (IQ). This study aims to evaluate CT protocols of hospitals participating in the RACOON (Radiological Cooperative Network) project, consolidating CT protocols to provide recommendations and strategies for future pandemics. In this retrospective study, CT acquisitions of COVID-19 patients scanned between March 2020 and October 2020 (RACOON phase 1) were included, and all non-contrast protocols were evaluated. For this purpose, CT protocol parameters, IQ ratings, radiation exposure (CTDIvol), and central patient diameters were sampled. Eventually, the data from 14 sites and 534 CT acquisitions were analyzed. IQ was rated good for 81% of the evaluated examinations. Motion, beam-hardening artefacts, or image noise were reasons for a suboptimal IQ. The tube potential ranged between 80 and 140 kVp, with the majority between 100 and 120 kVp. CTDIvol was 3.7 ± 3.4 mGy. Most healthcare facilities included did not have a specific non-contrast CT protocol. Furthermore, CT protocols for chest imaging varied in their settings and radiation exposure. In future, it will be necessary to make recommendations regarding the required IQ and protocol parameters for the majority of CT scanners to enable comparable IQ as well as radiation exposure for different sites but identical diagnostic questions.

Comparison of Total Body Irradiation-based Versus Chemotherapy-based Conditionings for Early Complications of Allogeneic Hematopoietic Stem Cell Transplantation in Children With ALL.

BACKGROUND: Total body irradiation (TBI) is the cornerstone of conditioning regimens in pediatric hematopoietic stem cell transplantation for acute lymphoblastic leukemia. As the late effects and survival comparison between TBI and chemotherapy were well analyzed before, in this study, we aim to focus on the first 100 days and early complications of transplantation. METHODS: This retrospective study involves 72 pediatric patients (0 to 18 y) underwent first hematopoietic stem cell transplantation for acute lymphoblastic leukemia between October 2015 and May 2019. Patients are divided into 2 groups regarding conditioning regimens. Conditionings includes either TBI 1200 cGy/6 fractions/3 days and etoposide phosphate or busulfan, fludarabine, and thiotepa. Busulfan was administered IV and according to body weight. RESULTS: The incidences of acute graft versus host disease grade 2 to 4, veno-occlusive disease, capillary leakage syndrome, thrombotic microangiopathy, blood stream infection, hemorrhagic cystitis and posterior reversible encephalopathy syndrome before day 100 were similar for both conditioning regimens; however, patients received TBI-based conditioning had significantly longer neutrophil engraftment time (17.5 vs. 13 d, P=0.001) and tended to have more engraftment syndrome (ES) (45.5% for TBI vs. 24.0% for chemotherapy, P=0.069). Multivariate analysis showed that TBI-based conditioning was associated with a longer neutrophil engraftment time (hazard ratio [HR]=1.20, P=0.006), more cytomegalovirus (CMV) reactivation (HR=3.65, P=0.038) and more ES (HR=3.18, P=0.078). CONCLUSIONS: Our findings support chemotherapy-based regimens with early neutrophil engraftment, less ES and CMV reactivation compared with TBI. Although there is no impact on survival rates, increased incidence of ES and CMV reactivation should be considered in TBI-based regimens.

Homozygous Mutation in the Insulin Receptor Gene Associated with Mild Type A Insulin Resistance Syndrome: A Case Report

Insulin receptor (INSR) mutations lead to heterogeneous disorders that may be as severe as Donohue syndrome or as mild as "type A insulin resistance syndrome". Patients with severe disorders usually harbor homozygous or compound heterozygous mutations. In contrast, type A insulin resistance syndrome has been associated with heterozygous mutations; homozygous mutations are rarely responsible for this condition. We report a novel, homozygous mutation, p.Leu260Arg in exon 3, of the INSR gene in a female adolescent patient with type A insulin resistance syndrome together with clinical details of her medical follow-up. Different mutations in the INSR gene cause different phenotype and vary depending on the inheritance pattern. This report adds to the literature, increases understanding of the disease mechanism and aids in genetic counseling.

Posterior Cervical Keyhole Laminoforaminotomy: A Cadaveric Comparative Study to Evaluate Limits of Bony Resection.

BACKGROUND: The posterior cervical keyhole (KH) laminoforaminotomy has been described to involve the lateral portion of cervical laminae of the upper vertebra alone (small KH) or of both upper and lower vertebrae (large KH). OBJECTIVE: To microscopically compare the two keyhole techniques in terms of their ability to expose the corresponding cervical roots. METHODS: Ten cadaveric specimens were operated bilaterally from C3-4 to C6-7 level to expose a total of 80 nerve roots. The large KH was applied to the left side, the small KH to the right side. The maximal length of exposed nerve roots was measured under microscope. The virtual optimal KH surface area was determined using digital software. Each root was inspected for exposure of its root and axilla. RESULTS: The maximal exposed nerve root length on the large KH side was significantly larger than on the small KH side at C3-4, C5-6, and C6-7 levels (P = .031, P = .002, P = .003). No significance was reported for C4-5 (P = .06). We could expose right axillae in (3/40) and left axillae in (33/40; P < .001). Optimal keyhole surface areas were 37.9, 38.2, 38.7, and 46.2 mm2 in craniocaudal order. CONCLUSION: Large KH defects involving both upper and lower laminae and facets can expose the roots to greater extent than small KH defects at C3-4, C5-6, and C6-7 levels. Large KH defects may allow better exposure of nerve roots axillae than small KH defects.