Appropriateness of internal digital phantoms for monitoring the stability of the UBIS 5000 quantitative ultrasound device in clinical trials

In bone status assessment, proper quality assurance/quality control is crucial since changes due to disease or therapeutic treatment are very small, in the order of 2–5%. Unlike for dual X-ray absorptiometry, quality control procedures have not been extensively developed and validated for quantitative ultrasound technology, limiting its use in longitudinal monitoring. While the challenge of developing an ideal anthropometric phantom is still open, some manufacturers use the concept of the internal digital phantom mimicking human characteristics to check the stability of their device. The objective of the study was to develop a sensitive model of quality control suitable for the correction of QUS patient data. In order to achieve this goal, we simulated a longitudinal device lifetime with both correct and malfunctioning behaviors. Then, we verified the efficiency of digital phantoms in detecting those changes and subsequently established the in vitro/in vivo relationship. This is the first time that an attempt to validate an internal digital phantom has made, and that this type of validation approach is used. The digital phantom (DP) was designed to mimic normal bone (BUAP2) and osteoporotic bone (BUAP1) properties. The DP was studied using the UBIS 5000 ultrasound device (DMS, France). Diverse malfunctions of the UBIS-5000 were simulated. Several series of measurements were performed on both BUAP1 and 2 and on 12 volunteers at each grade of malfunction. The effect of each simulated malfunction on in vivo and in vitro results was presented graphically by plotting the average BUA values against the percentage change from baseline. The change from baseline in BUA was modeled using linear regression, and the in vivo/in vitro ratio was obtained from the model. All experimentations influenced the measure of BUAP1 and 2 as well as the measure of our 12 volunteers. However, the degree of significance varied as a function of the severity of the malfunction, and the results also differed substantially in magnitude between in vivo and in vitro. Indeed, the DP was about 10 times more sensitive to variations of the transfer function than was the in vivo measurement, which is very reassuring. The sensitivity of the digital phantoms was reliable in the determination of simulated malfunctions of the UBIS-5000. The digital phantoms provided an accurate evaluation of the acoustic performance of the scanner, including the fidelity of transducers. In light of these results, the QC approach of the UBIS-5000 will be extremely simple to implement compared with other devices. Indeed, since the digital phantom was automatically measured during every patient measurement, the QC approach could be built on an individual level basis rather than on an average basis.     

WONCA Online电子病例介绍——盲肠扭转

·一般情况:患者,女,46岁,因右上腹疼痛并向背部、侧胸部放射就诊,有恶心、呕吐2次.2周前行腹腔镜胆囊切除术,手术顺利无并发症,术后饮食正常.腹部疼痛时不伴有腹泻、腹胀等,无发热、寒战.既往有高血压、高胆固醇血症及胆囊病史,无吸烟及饮酒嗜好.     

Four-year follow-up of body compostion in lung transplant patients

BACKGROUND: Both undernutrition and overnutrition can affect the quality of life and survival of patients with pulmonary disease and lead to quantitative and functional alterations of fat-free mass (FFM). This longitudinal study determines the changes in weight, FFM, and body fat before and up to 4 years after lung transplant (LTR). METHODS: Height, weight, and body composition measurements (bioelectrical impedance) were obtained in 37 LTR patients. FFM and body fat were measured before and at 1, 3, 6, 9, 12, 18, 24, 36, and 48 months after LTR. RESULTS: Weight changed by +16.6%, +3.2%, -0.2%, and -3.2% and FFM by +14.0%, +2.5%, -0.3%, and -1.0% during years 1, 2, 3, and 4, respectively. A diagnosis of obliterative bronchiolitis after LTR was associated with loss of body weight, FFM, and body fat, compared with stable weight or gain in weight, FFM, and body fat in obliterative bronchiolitis-negative subjects; 76.2% and 85.7%, and 28% and 38% of men and women, respectively, demonstrated low FFM at 1 month and at 2 years after LTR, respectively. The FFM change was higher (39% of weight) during year 1 than during year 2 (25%) or year 3 (21%). CONCLUSIONS: After LTR, patients gained weight, FFM, and body fat, and two-thirds reached normal levels of FFM by year 2. A weight increase resulted in an FFM increase. Contrary to studies after heart or liver transplantation, our results suggest that despite posttransplant infections and grafts rejection, LTR permits FFM recovery.     

Blunt Handlebar Injury of the Common Femoral Artery: A Case Report

Bicycle handlebar-related blunt trauma to the femoral vessels with resulting arterial injury has been described previously. However, significant injury to the ileofemoral tree with underlying arterial occlusive disease in the face of handlebar-related trauma has not been reported. We present the case of an all-terrain vehicle accident with isolated injury to the common femoral artery in a patient with underlying atherosclerotic disease.     

Platelet concentrate effects on thromboelastography

This study evaluated platelet effects on thromboelastography to determine how morphologically abnormal platelets affected native whole blood analysis. Prospective, controlled comparison. Tertiary care university hospital. Volunteer cardiac surgery patients. Fresh platelets were obtained from volunteers and were either treated normally or cryodisrupted with liquid nitrogen. Fresh platelets, liquid nitrogen-treated platelets, or an equivalent quantity of the patient's blood were added to whole blood samples obtained from cardiac surgery patients before heparinization. Thromboelastographic parameters sensitive to platelet effects were measured in each of the three groups.

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Maximum amplitude and a-angle significantly increased in the two groups receiving added platelets. There were no differences between the fresh platelet and the liquid nitrogen-treated platelet groups (Student's paired t-test). The R-time decreased significantly in both platelet-treated groups compared with the group that did not receive additional platelets. Viscoelastic changes in whole blood coagulation after the addition of platelet concentrates are not dependent on morphologically intact or functionally normal platelets. This in vitro study predicts that transfusion of poorly preserved platelet concentrates as well as fresh platelets would increase clot strength on thromboelastography if the recipient's blood were tested immediately after administration.     

Extra-abdominal desmoid tumor: an unusual subcutaneous lesion presenting as shoulder pain

A 50-year-old Hispanic woman presented to the medical walk-in clinic of a local community hospital complaining of shoulder pain. The problem had begun 9 months previously, and first manifested as dull right shoulder pain that developed after she carried a bag of groceries up one flight of stairs. A diagnosis of “muscle strain” and “arthritis” was made for which nonnarcotic analgesics were prescribed. The pain persisted, and 2 months later she was re-evaluated and diagnosed with degenerative joint disease. An orthopedics consultation was sought for further evaluation. During this examination, she pointed out to the physician that she had a “lump in her shoulder,” but she was informed that this was of no consequence and that her complaints were due to arthritis. Roentgenograms of the right shoulder and thoracic spine were performed and determined to be within normal limits. Once again she attempted to control the pain with nonsteroidal anti-inflammatory agents to no avail. Because the pain had become unbearable, she sought relief at the medical walk-in clinic. Physical examination was remarkable for a solitary, skin-colored, firm, deeply-seated tumor measuring 3×4 cm located over the right posterior of the deltoid. The mass was exquisitely tender to palpation and was fixed to the underlying muscle. There was a full range of motion as well as good muscle strength of the shoulder, but movement of the arm in any direction was painful. The patient subsequently underwent a deep, partial excisional biopsy of the lesion, and a firm white tumor mass of about 3 × 3 cm in size was dissected away from the deltoid muscle. Although the majority of the tumor was excised, visible portions of the lesion were not removed because they were present deep within the bulk of the muscle. Histopathologic examination revealed a large, deeply-seated poorly-circumscribed fibrous proliferation containing areas in which there were numerous spindle cells arranged in fascicles ( Figs 1, 2, and 3 ). Neither cellular atypia nor mitotic figures were seen. The diagnosis of extra-abdominal desmoid tumor was made. The patient subsequently underwent a wide re-excision of the area and tolerated the procedure well, developing normal function of the arm following surgery, although there was slight persistent tenderness of the deltoid. Because of the known association of desmoid tumors with familial polyposis coli ¹ , a barium enema was performed. No colonic polyps were demonstrated.

Figure 1 Open in figure viewer PowerPoint Histopathology of desmoid tumor at scanning magnification. There is a large, poorly-circumscribed, diffuse spindle cell proliferation that extends into the subcutis, muscle, and fascia (hematoxylin and eosin; original magnification, ×10)     

Depression in children and adolescents: Does gender make a difference?

The occurrence of depression is higher in females after puberty, suggesting a gender-related difference. This article reviews studies that have examined gender differences in the presentation and treatment of depression in adults and discusses how this information applies to depressed children and adolescents. The adult literature suggests that men and women vary in presentation of depression. In addition, differences exist in the pharmacokinetic properties of various medications, but it is unclear how they affect clinical treatment response. Studies of gender differences in child and adolescent depression are limited. Some studies suggest that differences seen in adults may also apply to children and adolescents. Studies of gender differences in treatment response are not available, however. Further study and evidence-based exploration are required to better understand gender differences in depression in children and adolescents.     

Sport and exercise-induced migraines

Sport and exercise-induced migraines are difficult to distinguish from benign exertional headaches and other headache syndromes. Exertion can be the sole cause, or may be among multiple triggers for an individual’s headache. Because approximately 10% of these headaches have an organic origin, a careful history and physical examination is necessary. The hallmark of treatment for exercise-induced migraines tends to be proper warmup before exercise, minimization of environmental risks, proper sleep hygiene, and good nutrition and hydration; however, in many cases, the pharmacologic solutions that are applied to other types of headaches may also be necessary. Because there is a lack of large trial studies on the athletic headache population, more research on the topic is needed in the future to help clarify the mechanisms, classification, and treatments of these headaches.