Inaccuracies associated with the automated measurement of mean cell hemoglobin concentration in dehydrated cells

Because of discrepancies between electronically and manually measured values of mean cell hemoglobin concentration (MCHC) encountered in studies of pathologic red cells, we studied the effect of cell water content on MCHC measurements by both methods. A series of red cell samples with varying water contents (54%-164% normal) were prepared from normal cells using the antibiotic nystatin. MCHC was then measured, using the microhematocrit centrifuge and three different electronic cell counters in common laboratory use. For MCHC values above 36 g/dl as measured by the spun hematocrit method, all three electronic counters under estimmated the MCHC, with increasing error as the true MCHC increased. For MCHC values below 30 g/dl, the values from two conductivity based instruments agreed with those from the spun hematocrit method, whereas one instrument based on light scattering overestimated the MCHC. These results indicate that inaccuracies in the measured mean cell volume (MCV) of dehydrated or otherwise undeformable cells may lead to spurious values for MCHC when electronic cell counters are used.     

一体化PET/MR检查临床护理操作规范(2017版)

一体化PET/MR检查护理规范是关于PET/MR检查过程中对于护理人员的工作要求,包括检查前准备、注射药物护理、检查时护理、检查后护理、对比剂不良反应处理和个人辐射防护。旨在为核医学科护士在临床PET/MR检查中提供实用且行之有效的处理操作规范。     

Bone marrow imaging: magnetic resonance studies related to age and sex

Measurements of T1 and T2 relaxation values and spin density of the lumbar vertebral bone marrow were performed in 212 patients, and the results were correlated with the patients' age and sex. T1 and T2 relaxation times for bone marrow in the lumbar vertebral bodies showed a progressive decrease with age for both sexes (except for the T2 relaxation values in female patients). The replacement of hematopoietic marrow by fatty marrow could explain the decrease in T1 and T2. The T1 and T2 values were in the same range for the first two age groups (age 1-10 years and age 21-40 years) and became slightly greater for the older female patients (age 51 years and older) than for the older males. This could be due to the loss of bone and mineral content, which is more rapid and significant for women. These normal T1 and T2 values may provide a baseline for future evaluation of diseases involving the lumbar spine.     

Practice MRI: Reducing the need for sedation and general anaesthesia in children undergoing MRI

The aim of this study was to evaluate the effectiveness of a practice magnetic resonance unit, in preparing children to undergo magnetic resonance procedures without general anaesthesia (GA) or sedation. The records of children who attended the practice MRI between February 2002 and April 2004 were retrospectively reviewed. Each record was assessed as to whether the child had passed or failed the practice MRI intervention. Those children who were considered to have passed and were proceeded to a clinical non‐GA MRI had the report of the clinical scan reviewed. If the scan had been reported as non‐diagnostic because of movement artefact it was classified as a failed scan, otherwise it was considered a pass. One hundred and thirty‐four children undertook a practice MRI (age range 4.1–16.1 years, median age 7.7 years, 47% boys) and 120/134 (90%) passed the practice session. In all, 117/120 (98%) subsequently had a clinical non‐GA MRI and 110/117 (94%) passed (median age 7.8 years, 47% boys). Preparation is a safe and effective method to reduce the need for sedation and GA in children undergoing a clinical MRI scan. It provides a positive medical experience for children, parents and staff, and results in cost savings for the hospital.     

Double blind, placebo controlled study of nedocromil sodium in asthma

After a two week baseline, 209 asthmatic children (mean age 10 years, range 6-17) were randomly allocated to receive 4 mg nedocromil sodium (n = 110) or placebo (n = 99) four times daily for 12 weeks in addition to their current treatment. The children completed daily diary cards and visited the clinic at four week intervals. Statistically significant differences in favour of nedocromil sodium were seen for clinician assessment of asthma severity and diary card symptom scores, pulmonary function and inhaled beta 2 bronchodilator use. Total symptom score decreased by 50% from baseline in the nedocromil sodium group and by 9% in the placebo group during the final four weeks. Nedocromil sodium was considered very or moderately effective by 78% of children/parents (placebo 59%) and 73% of clinicians (placebo 50%). Nausea, headache and sleepiness, and dyspnoea led to withdrawal of one child from nedocromil sodium and placebo treatments, respectively. Reports of sore throat and headache were marginally greater with the nedocromil sodium treatment. It is concluded that nedocromil sodium was both effective and safe in the treatment of asthma in children.