Interpretation of CT studies: single-screen workstation versus film alternator

A prototype single-screen workstation with a 2,048 x 2,560-pixel high-brightness monitor, 0.11-second image display time, and simple ergonomic design was compared to a conventional horizontal film alternator in diagnostic interpretation of chest computed tomography (CT) studies. Four radiologists used either the workstation or film alternator in interpretation of studies obtained in 10 patients. A counterbalanced within-subject repeated measures experimental design was used. Response times were analyzed for both methods of interpretation. Grades of excellent, acceptable, and unacceptable were assigned by a blinded "grader" to reports of the radiologists. The average time needed for an interpretation at the workstation was 5.65 minutes. No interpretations were graded unacceptable. Retrospective power analysis showed that 16 observers rather than four would have been required to show that use of the workstation was faster than the alternator. With this 95% confidence interval, the workstation interpretation time is clinically equivalent to that with the alternator. These data show that this type of workstation has practical application in interpretation of CT, magnetic resonance imaging, and ultrasound studies.     

Value of preoperative chest X-ray examinations in children

To assess the value of routine preoperative chest x-ray films in pediatric patients, a prospective study of 1,500 patients, ages newborn to 19 years, was undertaken. Of all the patients, 7.5% demonstrated at least one roentgenographic abnormality, with 4.7% of the patients demonstrating a totally unsuspected significant roentgenographic anomaly. In 3.8% of the patients, surgery was eihter postponed or cancelled or the anesthetic technique was altered as a result of the roentgenographic finding. It is believed that the routine preoperative chest film is justified if the film is evaluated before surgery and the results clinically followed up.     

Basal cell epitheliomas after repeated fluoroscopic examinations of the chest

In two patients who received artificial pneumothorax therapy for pulmonary tuberculosis, many basal cell epitheliomas on the thoracic skin developed 26 and 30 years later. Pneumothorax therapy as done in the 1930s and 1940s required frequent fluoroscopic examinations of the chest for several years, resulting in a considerable cumulative dose of radiation. Skin cancer may now be developing in predisposed individuals after an average latent period of 25 years, making it likely that more of these patients will come to our attention.     

Tuberculosis of the chest wall: CT findings

To assess the CT features of tuberculosis of the chest wall, the CT findings in four patients with documented tuberculous chest wall infection were reviewed. Two patients were Caucasian and two were of Chinese origin. All had normal immune status. In two cases tuberculosis involved the ribs, in one the costal cartilage, and in one the sternoclavicular joint. Computed tomography demonstrated osseous and cartilaginous destruction (in four), soft tissue masses with calcification (in two), and rim enhancement following intravenous contrast medium administration (in two). Underlying pleuroparenchymal tuberculosis was present in two cases. Tuberculosis of the chest wall is characterized by bone or costal cartilage destruction and soft tissue masses that may demonstrate calcification or rim enhancement with or without evidence of underlying lung or pleural disease.     

Objective measurement of motion in patients undergoing spiral CT examinations

PURPOSE: Lateral posterior fossa treatment fields are usually defined on traditional simulation films based on bony landmarks. The superior field border, intended to include the apex of the tentorium cerebelli, is frequently difficult to define. While sagittal magnetic resonance imaging (MRI) images or three-dimensional treatment planning tools are good means to locate the tentorial apex, these are not always available. We herein describe a method for locating the tentorial apex based on bony landmarks. METHODS AND MATERIALS: Midsagittal magnetic resonance images of 53 patients were reviewed. Using a Cartesian grid, the geometric relationship between the tentorial apex and several bony landmarks was assessed. Two lines were defined: the first connected the posterior clinoid and the internal occipital protuberance (AB). The second was perpendicular to the first, included the tentorial apex, and extended from the base of the skull inferiorly to the "crown" of the skull superiorly (DE). Relationships between measurements were made using linear regression and least square fits. RESULTS: Line DE was within 5 mm of the perpendicular bisector of line AB in 83% (44/53) of patients. The tentorial apex was located within 10 mm of the midpoint of DE in 91% (48/53) of patients. CONCLUSION: In the majority of patients, the location of the tentorial apex can be estimated based on bony landmarks, to within approximately 10 mm. The technique described is a useful means of estimating the location of the tentorial apex in patients where sagittal MRI imaging or three-dimensional treatment planning tools are not available.     

Patch testing with budesonide in serial dilutions: the significance of dose, occlusion time and reading time

Dipeptide transporters in small intestine have a very wide substrate specificity, so that the transporter sometimes serves as a carrier for peptide-like compounds. We have synthesized dipeptide analogues conjugated at an epsilon-amino group of Lys in Val-Lys or Lys-Sar with fluorescent compounds such as fluorescein isothiocyanate and coumarin-3-carboxylic acid. Uptakes of these peptide analogues were examined by measuring intracellular accumulations into monolayers of the human intestinal epithelial cell line Caco-2 expressing the dipeptide transporter PEPT1. Kinetic analysis and effects of addition either of uncoupler (protonophore) or by Gly-Sar, one of the good substrates of PEPT1, revealed that fluorescent dipeptides were taken up by passive diffusion. In contrast, these analogues remarkably inhibited the Gly-Sar uptake by Caco-2 cells. Among the fluorescent analogues synthesized in this paper, Val-Lys(Flu) was the most potent competitive inhibitor against the Gly-Sar uptake with an inhibition constant of 5 microM. This value is the smallest among those ever reported: Val-Lys(Flu) has the highest affinity for PEPT1 among chemicals ever reported. The importance of the hydrophobic part of the substrate was pointed out.     

A long-term follow-up study of patients with ischaemic heart disease versus patients with nonspecific chest pain

Ninety consecutive patients who were admitted to hospital with acute chest pain were followed-up five years later. At the time of the original admission, all of the patients received a detailed physical and psychiatric evaluation. Seventy-one patients were diagnosed as having ischaemic heart disease, and 19 were diagnosed as having nonspecific chest pain. Patients with nonspecific pain were younger, consumed greater amounts of alcohol, smoked more than their organic counterparts, and were more likely to suffer from psychiatric disorder. The five-year assessment was carried out using a self-report questionnaire. Of the original 71 patients with ischaemic heart disease, 14 had died; 43 questionnaires were returned, 80.2% of the original sample. Sixteen (84.9%) of the patients with nonspecific pain were followed up; none had died. Both groups were predominantly male. The patients with nonspecific pain still smoked more than the patients with ischaemic heart disease, and they had significantly more symptoms of anxiety. The overall prevalence of psychiatric morbidity remained high, however, in both groups. Patients who had psychiatric illness at the time of the original assessment were more anxious at follow-up and more likely to complain of chest pain than those who had been well. Patients with nonspecific chest pain continued to seek treatment on a regular basis from their general practitioners either for chest pain or for other symptoms, but few were in frequent contact with hospital services. The possible preventive effects of psychiatric intervention at an earlier stage in both groups of patients needs to be investigated.     

Localizing sequential effects in serial choice reaction time with the information reduction procedure.

Patterns of sequential effects in serial 2-choice reaction time (RT) tasks have been explained by 2 processing mechanisms, automatic facilitation and subjective expectancy, depending on the response-to-stimulus interval (RSI) and stimulus-response compatibility. Both mechanisms were localized in stimulus- or response-related processing stages with 4-stimulus 2-response experiments. Stimuli were presented on the corners of a square and keys were left-right or up-down. Subjective expectancy, appearing at long RSI, was systematically response related. Automatic facilitation, appearing with short RSI, shifted toward stimulus-related processes with noncompatible mappings. The results support the idea that automatic facilitation is related to structural bottom-up processes and is mainly located in stages that gain most from a facilitatory effect, whereas subjective expectancy needs a minimum time and therefore appears in late, response-related stages. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relations between chest CT and pathologic findings in pulmonary infarction associated with lung cancer

Chest radiographic (mainly CT), and pathological findings in pulmonary infarction associated with lung cancer were studied to obtain information useful for the interpretation of CT findings, and to help determine the cause of infarction. Sixteen cases of lung infarction were chosen from among 518 cases of lung cancer. All patients were operated on between January 1980 and December 1990. Sixteen surgical cases and one autopsy case all with evidence of lung cancer and infarction were chosen. There were 13 men and 4 women with a mean age of 56 years. Adenocarcinoma was found in 8 cases, squamous cell carcinoma in 6, adenosquamous carcinoma in 2, and small cell carcinoma in 1. Chest radiographs and CT revealed infarction shadows in 8 of the 16 cases. Typical CT findings for pulmonary infarction were: shadows located in the same lobe and periphery as the cancer; ill-defined, 10-25 mm nodular shadows; and lesions located both in the subpleural zone and apart from the pleura. Lesion counts in each area were about the same. Observation of one patient for 2 months revealed a decrease in the size of the nodular shadows and clarification of their margins. In most cases, centrally extended cancer resulted in vascular stenosis and infarction.     

Role of chest CT scanning in the management of patients presenting with head and neck cancer

CONTEXT: Alzheimer disease (AD) susceptibility genes have been identified on chromosomes 1, 14, 19, and 21, and a recent study has suggested a locus on chromosome 12. OBJECTIVE: To confirm or refute the existence of a familial AD susceptibility locus on chromosome 12 in an independent sample of familial AD cases. DESIGN: Retrospective cohort study. DNA data for 6 chromosome 12 genetic markers were evaluated using parametric lod score and nonparametric linkage methods and linkage heterogeneity tests. The latter include the admixture test of homogeneity in the total group of families and the predivided sample test in families stratified by the presence or absence of an apolipoprotein E (APOE) epsilon4 allele among affected members. Parametric analyses were repeated assuming autosomal dominant inheritance of AD and either age- and sex-dependent penetrance or zero penetrance for the analysis of unaffected relatives. SETTING: Clinical populations in the continental United States, Canada, Argentina, and Italy. PATIENTS: Fifty-three white families composed of multiple members affected with AD, from whom DNA samples were obtained from 173 patients with AD whose conditions were diagnosed using established criteria and from 146 nondemented relatives. MAIN OUTCOME MEASURE: Presence of an APOE epsilon4 allele among affected family members. RESULTS: Using parametric methods, no evidence for linkage to the region spanned by the chromosome 12 markers could be detected if familial AD is assumed to arise from the same genetic locus in all 53 families. However, significant evidence for linkage was detected in the presence of locus heterogeneity using the admixture test (odds ratio, 15, 135:1). The estimated proportion of linked families within the 53 families examined varied between 0.40 and 0.65, depending on the genetic model assumed and APOE status. The precise location of the AD gene could not be determined, but includes the entire region suggested previously. Nonparametric linkage analysis confirmed linkage to chromosome 12 with the strongest evidence at D12S96 (P<.001). CONCLUSIONS: Our data provide independent confirmation of the existence of an AD susceptibility locus on chromosome 12 and suggest the existence of AD susceptibility genes on other chromosomes. Screening a larger set of families with additional chromosome markers will be necessary for identifying the chromosome 12 AD gene.     

High-resolution CT of the chest in four patients with pulmonary capillary hemangiomatosis or pulmonary venoocclusive disease

OBJECTIVE: Clinical differentiation of isolated pulmonary hypertensive arteriopathy from pulmonary capillary hemangiomatosis or pulmonary venoocclusive disease can be difficult on a clinical basis alone. Differentiation is important because misdiagnosis of pulmonary capillary hemangiomatosis or pulmonary venoocclusive disease may lead to severe vasodilator-induced pulmonary edema. The objective of our study was to determine whether high-resolution CT of the chest could distinguish pulmonary capillary hemangiomatosis or pulmonary venoocclusive disease from isolated pulmonary hypertensive arteriopathy. CONCLUSION: Pulmonary hypertension in patients who also have pulmonary capillary hemangiomatosis or pulmonary venoocclusive disease shows characteristics on high-resolution CT that are not seen in patients with isolated pulmonary hypertensive arteriopathy.     

The serial use of child neurocognitive tests: Development versus practice effects.

When serial neurocognitive assessments are performed, 2 main factors are of importance: test-retest reliability and practice effects. With children, however, there is a third, developmental factor, which occurs as a result of maturation. Child tests recognize this factor through the provision of age-corrected scaled scores. Thus, a ready-made method for estimating the relative contribution of developmental versus practice effects is the comparison of raw (developmental and practice) and scaled (practice only) scores. Data from a pool of 507 Portuguese children enrolled in a study of dental amalgams (T. A. DeRouen, B. G. Leroux, et al., 2002; T. A. DeRouen, M. D. Martin, et al., 2006) showed that practice effects over a 5-year period varied on 8 neurocognitive tests. Simple regression equations are provided for calculating individual retest scores from initial test scores. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

ROC-analysis of detection performance by analogue and digital plain film systems in chest radiography

We have previously reported that a microcarrier-attached human hepatoma (Hep G2) cell line responds to hydrodynamic shear upon transfer to an agitated, clean, autoclaved spinner flask with a transient increase in cytochrome P450IA1 (CYPIA1) activity. Physiological changes induced by hydrodynamic stress could be problematic in the scaleup of microcarrier cultures. A better understanding of how stress alters cell physiology may assist in reactor scaleup. The induction of CYPIA1 activity was dependent on the agitation level of the cultures, and the level of CYPIA1 induction was comparable to that obtained with exposure to approximately 0.1 nM TCDD (2, 3, 7, 8-tetrachlorodibenzo-p-dioxin). It has been well documented that hydrodynamic shear stress can cause alterations in the metabolism of phospholipid membrane-bound arachidonic acid (AA) in adherent cells in a parallel plate system. The present study was carried out to determine if either AA or a metabolite of AA was involved in the induction of CYPIA1 activity in the microcarrier cultures of Hep G2 cells. Addition of exogenous AA followed by initiation of the stress resulted in an increase in the level of CYPIA1 activity. Pretreatment of the cultures with quinacrine, an inhibitor of phospholipase A2, reduced the stress-induced CYPIA1 activity. Furthermore, addition of propranolol, an inhibitor of phosphatidic acid phosphohydrolase, resulted in an increase in the response in addition to sustaining the induced enzyme activity. Pretreatment with the cyclooxygenase inhibitor, indomethacin, or the lipoxygenase inhibitor, caffeic acid, had no effect on the response, suggesting that the cyclooxygenase and lipoxygenase pathways were not involved in generating AA metabolites that alter CYPIA1 activity. The agent, nordihydroguaiaretic acid, blocks the monooxygenase pathway and blocks CYPIA1 activity increases. These observations suggest a possible mechanism where the stress on the cells induces phospholipase D, resulting in the formation of phosphatidic acid which then activates phospholipase A2, resulting in the release of AA. Further, these results are consistent with a mechanism in which the metabolism of AA, most likely through the monooxygenase pathway, results in a metabolite that by a yet unknown mechanism induced CYPIA1.     

Plain film and CT findings of pulmonary involvement in rheumatoid arthritis

Meiotic recombination of S. cerevisiae contains two temporally coupled processes, formation and processing of double-strand breaks (DSBs). Mre11 forms a complex with Rad50 and Xrs2, acting as the binding core, and participates in DSB processing. Although these proteins are also involved in DSB formation, Mre11 is not necessarily holding them. The C-terminal region of Mre11 is required only for DSB formation and binds to some meiotic proteins. The N-terminal half specifies nuclease activities that are collectively required for DSB processing. Mre11 has a DNA-binding site for DSB formation and another site for DSB processing. It has two regions to bind to Rad50. Mre11 repairs methyl methanesulfonate-induced DSBs by reactions that require the nuclease activities and those that do not.     

Management of flail chest injury: internal fixation versus endotracheal intubation and ventilation

A total of 427 patients with major chest trauma were treated in two major hospitals in Abu Dhabi, United Arab Emirates, during a 10-year period. In 64 of 426 patients, flail chest injury was the dominant factor among other injuries that were insignificant. Among 64 cases of flail chest injury, 25 were managed by internal fixation of ribs, whereas the remaining 38 were managed by endotracheal intubation and intermittent positive-pressure ventilation alone. Of the patients treated by internal fixation 80% (21/26) were weaned from the ventilator within an average of 1.3 days, whereas the remaining 20% (5/26) continued to need assisted ventilation for a longer duration; the total average duration of assisted ventilation for the whole group was 3.9 days. In comparison, among 38 patients with flail chest injury treated by endotracheal intubation and ventilation alone, the average duration of assisted ventilation was 15 days. In the group treated by internal fixation 11% (3/26) of the patients ultimately required a tracheotomy, whereas in the patients treated by intubation and ventilation alone tracheostomy was required in 37% (14/38) of the cases. In the group treated by internal fixation, chest infection was documented in 15% (4/26), septicemia in 4% (1/26), and barotrauma in 0%; in the other group these complications occurred in 50% (19/38), 24% (9/38), and 8% (3/38) of the cases, respectively. The mortality rate was 8% (2/26) in the surgically treated patients, whereas it was 29% (11/38) in the other group. All the deaths in both groups were ascribed to adult respiratory distress syndrome. Average stay in the intensive care unit was 9 days for the patients treated by internal fixation, whereas it was 21 days in the group treated by intubation and ventilation alone. The treatment of flail chest injury in our series by internal fixation resulted in speedy recovery, decreased complications, and better ultimate cosmetic and functional results and proved to be cost effective.