A comparison of prosthetic ear models created from data captured by computerized tomography, magnetic resonance imaging, and laser scanning

PURPOSE: To compare the dimensional measurements and surface topography of stereolithographic models generated from computerized tomography (CT), magnetic resonance imaging (MRI), and laser scanning (LS) data with the same subjects' natural ears and ear casts. MATERIALS AND METHODS: Stereolithographic models were manufactured from images of the subjects' ears and ear casts recorded by CT, MRI, and LS, and dimensional measurements were compared. In the second part of the study, all stereolithographic models were CT scanned and reconstructed in an STL file format. A comparison of the surface topography of the CT, MRI, and LS model ears was made. RESULTS: Intraclass correlation coefficients indicated that dimensions could be reliably measured on the CT, MRI, and LS stereolithographic models. A 2-way analysis of variance revealed no statistical differences between the various sources of data (P = .991). The smallest differences of surface topography were observed on the MRI/CT superimpositions. CONCLUSION: The dimensional measurements on the stereolithographic models were similar to those from the original source. Only small differences were apparent between the surface topography of the CT, MRI, and LS models. MRI may be particularly appropriate to fabricate a prosthesis because it involves no radiation for the patient and internal form can be reproduced. The use of this technique in clinical practice requires further study.     

Self‐rated preparedness of Australian prevocational hospital doctors for emergencies

Objective: To determine perceived preparedness of Australian hospital‐based prevocational doctors for resuscitation skills and management of emergencies, and to identify differences between doctors who perceive themselves well prepared and those who perceive themselves poorly prepared for emergencies, in demographics and exposure to desired learning methods. Methods: Questionnaire consisting of a mix of graded Likert scales and free‐text answers distributed to 36 Australian hospitals for secondary distribution to hospital medical officers. Results: From 2607 questionnaires posted, 470 (18.1%) were returned. Thirty‐one per cent (95% confidence interval [CI] 26–35%) felt well prepared for resuscitation and management of emergencies, 41% (CI 37–45%) felt adequately prepared and 28% (CI 24–32%) felt they were not well prepared. Those who felt well prepared reported that they had experienced more exposure to a range of educational methods, including consultant contact, supervisor feedback, clinical skills, high fidelity simulator sessions and unit meetings. Well‐prepared and poorly prepared doctors had similar opinions of the usefulness of various learning methods, but the poorly prepared group more frequently expressed a desire for increased exposure to contact with registrars and consultants, clinical skills sessions and hospital and unit meetings. There were no differences in gender, age or country of origin (Australia vs international medical graduates) between those who felt well or poorly prepared. Conclusions: Many prevocational hospital doctors feel inadequately prepared for the management of emergencies. Perceived preparedness is associated with more exposure to particular educational activities. Increasing exposure to learning of emergencies in undergraduate and prevocational years could reduce the number of junior doctors who feel poorly prepared for emergencies.     

Blocking CTGF/CCN2 reverses neural fibrosis and sensorimotor declines in a rat model of overuse-induced median mononeuropathy

Encapsulation of median nerves is a hallmark of overuse-induced median mononeuropathy and contributes to functional declines. We tested if an antibody against CTGF/CCN2 (termed FG-3019 or Pamrevlumab) reduces established neural fibrosis and sensorimotor declines in a clinically relevant rodent model of overuse in which median mononeuropathy develops. Young adult female rats performed a high repetition high force (HRHF) lever-pulling task for 18 weeks. Rats were then euthanised at 18 weeks (HRHF untreated), or rested and systemically treated for 6 weeks with either an anti-CCN2 monoclonal antibody (HRHF-Rest/FG-3019) or IgG (HRHF-Rest/IgG), with results compared with nontask control rats. Neuropathology was evident in HRHF-untreated and HRHF-Rest/IgG rats as increased perineural collagen deposition and degraded myelin basic protein (dMBP) in median nerves, and increased substance P in lower cervical dorsal root ganglia (DRG), compared with controls. Both groups showed functional declines, specifically, decreased sensory conduction velocity in median nerves, noxious cold temperature hypersensitivity, and grip strength declines, compared with controls. There were also increases of ATF3-immunopositive nuclei in ventral horn neurons in HRHF-untreated rats, compared with controls (which showed none). FG-3019-treated rats showed no increase above control levels of perineural collagen or dMBP in median nerves, Substance P in lower cervical DRGs, or ATF3-immunopositive nuclei in ventral horns, and similar median nerve conduction velocities and thermal sensitivity, compared with controls. We hypothesize that neural fibrotic processes underpin the sensorimotor declines by compressing or impeding median nerves during movement, and that inhibiting fibrosis using an anti-CCN2 treatment reverses these effects.     

Confirmatory factory analysis of the Neck Disability Index in a general problematic neck population indicates a one-factor model

Background contextThe Neck Disability Index frequently is used to measure outcomes of the neck. The statistical rigor of the Neck Disability Index has been assessed with conflicting outcomes. To date, Confirmatory Factor Analysis of the Neck Disability Index has not been reported for a suitably large population study. Because the Neck Disability Index is not a condition-specific measure of neck function, initial Confirmatory Factor Analysis should consider problematic neck patients as a homogenous group.PurposeWe sought to analyze the factor structure of the Neck Disability Index through Confirmatory Factor Analysis in a symptomatic, homogeneous, neck population, with respect to pooled populations and gender subgroups.Study designThis was a secondary analysis of pooled data.Patient sampleA total of 1,278 symptomatic neck patients (67.5% female, median age 41 years), 803 nonspecific and 475 with whiplash-associated disorder.Outcome measuresThe Neck Disability Index was used to measure outcomes.MethodsWe analyzed pooled baseline data from six independent studies of patients with neck problems who completed Neck Disability Index questionnaires at baseline. The Confirmatory Factor Analysis was considered in three scenarios: the full sample and separate sexes. Models were compared empirically for best fit.ResultsTwo-factor models have good psychometric properties across both the pooled and sex subgroups. However, according to these analyses, the one-factor solution is preferable from both a statistical perspective and parsimony. The two-factor model was close to significant for the male subgroup (p<.07) where questions separated into constructs of mental function (pain, reading headaches and concentration) and physical function (personal care, lifting, work, driving, sleep, and recreation).ConclusionsThe Neck Disability Index demonstrated a one-factor structure when analyzed by Confirmatory Factor Analysis in a pooled, homogenous sample of neck problem patients. However, a two-factor model did approach significance for male subjects where questions separated into constructs of mental and physical function. Further investigations in different conditions, subgroup and sex-specific populations are warranted.     

Percutaneous ureteral biopsy: safety and diagnostic yield

Abdominal Radiology - To evaluate safety and diagnostic yield of percutaneous CT-guided biopsy of extrarenal upper urinary tract lesions. Retrospective review of our institutional database of...     

Viral hepatitis-related acute liver failure

OBJECTIVES: Viral hepatitis has previously been the major cause of acute liver failure (ALF) in the United States. We aimed to determine the incidence of viral hepatitis-related ALF and to compare the outcome and clinical and biochemical variables in patients with hepatitis A and B. METHODS: A total of 354 patients with ALF from multiple centers were screened for possible acute viral etiology. RESULTS: Forty-three patients (12.1% of all ALF cases) had acute viral hepatitis: hepatitis A (n = 16), hepatitis B (n = 26), and herpes simplex virus infection (n = 1). There was no difference between groups with regard to age, gender, body mass index, admission or peak coma grade, symptom duration, admission mean arterial pressure, temperature, or biochemical liver tests, creatinine, arterial pH, or rate of infections. Platelet count was significantly higher in hepatitis A patients than in hepatitis B patients. The transplantation-free (spontaneous) survival rate was significantly higher for hepatitis A patients (69%) than for hepatitis B patients (19%, p = 0.007), whereas the liver transplantation rate was higher in hepatitis B patients (62%) than in hepatitis A patients (19%, p = 0.017). Spontaneous survivors had significantly higher mean arterial pressure, higher platelet count, and lower AST/ALT ratio than patients who did not survive spontaneously. CONCLUSIONS: Viral hepatitis now comprises only one-eighth of all ALF cases in the United States. The marked difference in spontaneous survival between hepatitis A and B cannot be explained by the severity of hepatic dysfunction on admission but may rather be an inherent feature of the infections or a bias toward transplanting patients with hepatitis B.