A number of tests to evaluate the image transfer characteristics of laser film digitizers have been developed and these tests have been used to evaluate the performance of a Konica KFDR-S laser film digitizer. These tests were designed to be simple in nature and to use materials readily available in clinical departments. The tests examined (i) the geometric accuracy of the laser film digitizer; (ii) the linearity of the digitizer's characteristic curve; (iii) the temporal/spatial response of the digitizer to abrupt changes in optical density; and (iv) the noise added by the digitizer to the digitized images. The tests were easy to use and could be performed in a short period of time. Results of the tests for the Konica laser film digitizer revealed several problems including minor geometric inaccuracies, structural noise added by a shading correction circuit in the digitizer, and spread of the laser beam before reaching the film plane, possibly caused by the f-theta lens of the digitizer. The light spread made the optical density of small, high density structures measured by the digitizer dependent upon the optical density of the surrounding regions. Therefore, under some circumstances, film digitization with the Konica laser film digitizer could lead to erroneous results. In addition, our measurements suggest that these problems are not unique to the Konica digitizer. Thus, the testing of laser film digitizers is recommended, especially if the digitizer is to be used for quantitative measurements.

Transient erythroblastopenia of childhood is characterized by anemia due to decreased production of red blood cell precursors. It is almost always self-resolving and requires clinical intervention only in severe cases. This article describes 2 cases in half-siblings diagnosed approximately 10 years apart. A review of the literature identifies 11 other sibling pairs. Our case suggests an autosomal dominant pattern of inheritance. To date, the gene involved in the development of transient erythroblastopenia of childhood has not been identified.

Background Major depressive disorder is common, debilitating, and affects feelings, thoughts, mood, and behaviors. Childhood and adolescence are critical periods for the development of depression and adolescence is marked by an increased incidence of mental health disorders. This protocol outlines the planned scope and methods for a systematic review update that will evaluate the benefits and harms of screening for depression in children and adolescents. Methods This review will update a previously published systematic review by Roseman and colleagues. Eligible studies are randomized controlled trials (RCTs) assessing formal screening in primary care to identify children or adolescents not already self-reporting symptoms of, diagnosed with, or treated for depression. If no or only a single RCT is available, we will consider controlled studies without random assignment. Studies of participants with characteristics associated with an elevated risk of depression will be analyzed separately. Outcomes of interest are symptoms of depression, classification of major depressive disorder based on a validated diagnostic interview, suicidality, health-related quality of life, social function, impact on lifestyle behavior (e.g., substance use, school performance, lost time at work, or school), false-positive results, overdiagnosis, overtreatment, labeling, and other harms such as those arising from treatment. We will search MEDLINE, Embase, PsycINFO, CINAHL, the Cochrane Library, and grey literature sources. Two reviewers will independently screen the titles and abstracts using the liberal accelerated method. Full-text screening will be performed independently by two reviewers using pre-specified eligibility criteria. Data extraction and risk of bias assessments will be performed independently by two reviewers. Pre-planned analyses, including subgroup and sensitivity analyses, are detailed within this protocol. Two independent reviewers will assess and finalize through consensus the certainty of evidence using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, and prepare GRADE evidence profiles and summary of findings tables for each outcome of interest. Discussion The systematic review will provide a current state of the evidence of benefits and harms of depression screening in children and adolescents. These findings will be used by the Canadian Task Force on Preventive Health Care to inform the development of recommendations on depression screening. Systematic review registration PROSPERO CRD42020150373

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Magnetic field maps and body surface potential maps can be used to measure cardiac activity. The ability of magnetic and potential body surface maps to identify patients' vulnerable to recurrent sustained ventricular arrhythmia (VA) were compared. Magnetic field maps (MFM) and body surface potential mapping (BSPM) were obtained from 76 normal (N) subjects, 15 myocardial infarct (MI) patients, and 15 VA patients. QRST integral maps were calculated for each subject and nondipolar content was determined using Karhunen-Loeve transform eigen-maps. Although differences in nondipolar content were significant between the normal and patient groups (P = 2.4 x 10(-5) for BSPM and P = 6.0 x 10(-8) for MFM), differences in nondipolar content between MI and VA patients using QRST integral BSPM and MFM maps were not significant. The trajectory of the location of the maxima and minima on the map area during the QRS and ST-T intervals were also constructed. Discrimination between MI and VA patients was based on intergroup differences in the amount of fragmentation of the trajectory plots. The ST-T trajectory plots were significantly more fragmented (P < 0.0001 and P < 0.05 for MFM and BSPM, respectively) for VA than for MI patients. The ST-T interval MFM and BSPM trajectory plots enabled separation of MI and VA patients with accuracies of 83% and 73%, respectively. These results suggest that repolarization MFM and BSPM extrema trajectory plots can be used effectively as a means of identifying patients at risk for VA.