Effects of a coccidiosis challenge on dietary methionine recommendations in broilers.

Broilers are commonly exposed to coccidiosis infections, and the use of dietary strategies to reduce losses in growth performance has practical implications for the poultry industry. Methionine (Met) is typically the first limiting amino acid for broilers and is involved in metabolic and immunological pathways; however, literature is conflicting on how dietary Met requirements are affected by environmental stressors. Our objective was to assess how the Met requirement changes during coccidiosis based on results of growth performance, carcass traits, and health outcomes. Two trials were conducted using 780 male Ross 308 broiler chicks in floor pens randomly assigned to 1 of 12 experimental treatments. All birds received common starter (d 0-10) and finisher (d 24-35, Trial 2 only) diets, and only differed based on their assigned experimental grower diet (d 10-24). Trial 1 experimental grower diets ranged from 2.61 to 6.21 g/kg digestible Met. Trial 2 experimental grower diets were formulated to contain 15% below, at, or 15% above the Met requirement determined in Trial 1. Birds were exposed to a coccidiosis challenge on d 11, with blood and tissue collection (1 bird/pen) on d 18 and carcass processing on d 35 (2 birds/pen) in Trial 2. Data were analyzed using a 1- or 2-way ANOVA. A non-linear regression analysis was conducted in Trial 1 to determine the Met requirement of 4.32 g of digestible Met/kg of diet using BW gain. Coccidiosis infection reduced (P < 0.05) growth performance during the experimental grower and overall study periods in Trial 2. Increasing dietary Met from below requirement to meeting requirement during the grower period improved (P < 0.001) BW gain and feed conversion ratio (FCR), but this effect was only significant between treatments below and above the requirement for the overall study period. There was an interactive effect (P = 0.038) on FCR for the overall study period. These findings provide evidence that the Met requirement is likely increased during coccidiosis based on growth performance outcomes.

A case of a giant mucocoele of the appendiceal stump presented with a palpable mass in the right thigh: pre-operative diagnosis based on characteristic multidetector CT findings.

The pre-operative diagnosis of a mucocoele of the appendiceal stump (MAS) may be difficult owing to rarity and non-specific clinical presentation. However, a pre-operative diagnosis of a MAS is important to prevent widespread dissemination by inadvertent spillage of mucous contents. We describe a case of a MAS presenting with a palpable mass in the right thigh in which a pre-operative diagnosis was made by characteristic multidetector CT (MDCT) findings.

Precision placement of instruments for minimally invasive procedures using a "needle driver" robot.

Medical practice continues to move toward less invasive procedures. Many of these procedures require the precision placement of a needle in the anatomy. Over the past several years, our research team has been investigating the use of a robotic needle driver to assist the physician in this task. This paper summarizes our work in this area. The robotic system is briefly described, followed by a description of a clinical trial in spinal nerve blockade. The robot was used under joystick control to place a 22 gauge needle in the spines of 10 patients using fluoroscopic imaging. The results were equivalent to the current manual procedure. We next describe our follow-up clinical application in lung biopsy for lung cancer screening under CT fluoroscopy. The system concept is discussed and the results of a phantom study are presented. A start-up company named ImageGuide has recently been formed to commercialize the robot. Their revised robot design is presented, along with plans to install a ceiling-mounted version of the robot in the CT fluoroscopy suite at Georgetown University.

Magnetic resonance imaging of the chest.

Thoracic magnetic resonance imaging (MRI) has recently undergone important advances, and newer applications could expand the role of thoracic MRI. Existing and developing MRI techniques are described and compared to other imaging techniques with regard to imaging various thoracic regions, structures, and diseases. After an initial discussion of MRI techniques, the role of thoracic MRI in evaluation of the thoracic arteries and veins is described. The next section focuses on specific anatomic regions; namely, the lung, mediastinum, pleural space, thoracic inlet, and diaphragm. The final section reviews some novel techniques that may improve our ability to visualize the pulmonary parenchyma and mediastinum.

Sternal dehiscence in patients with and without mediastinitis.

The authors compared patients with sternal dehiscence (SD) with and without mediastinitis with respect to: 1) time interval from surgery to diagnosis; and 2) frequency of sternal wire abnormalities on chest radiographs (CXR). Using a hospital information system to identify all patients with a diagnosis of SD from January 1993 through April 1999, the authors obtained clinical data by performing a retrospective chart review. For each patient, a CXR from the date of diagnosis of SD was retrospectively compared with the first postoperative CXR to assess for sternal wire displacement, rotation, and disruption. The timing of sternal wire alterations was correlated with clinical findings of SD or mediastinitis. The authors found that sternal wire abnormalities are evident radiographically in the majority of SD patients with and without mediastinitis; there is no significant difference in the frequency of sternal wire abnormalities between these two subgroups. Patients with SD and mediastinitis generally present later in the postoperative period than patients with isolated dehiscence.

Newly diagnosed pulmonary sarcoidosis in HIV-infected patients.

PURPOSE: To determine the radiologic and clinical features of newly diagnosed pulmonary sarcoidosis in human immunodeficiency virus (HIV)-infected patients. MATERIALS AND METHODS: Ten HIV-infected patients (seven women, three men; age range, 26-66 years; mean age, 37 years) with newly diagnosed sarcoidosis between 1989 and 1997 were retrospectively identified. Charts were reviewed for the interval between the two diagnoses, CD4 cell count, signs or symptoms, angiotensin-converting enzyme level, and initiation of highly active antiretroviral therapy (HAART). Chest radiographs (n = 10) and computed tomographic (CT) scans (n = 8) were assessed for lymphadenopathy, pulmonary nodules, focal consolidation, reticular or granular opacities (thickened interlobular septa and ground-glass opacities at CT), cysts or cavities, and fibrosis. RESULTS: Mean interval between the two diagnoses was 3 years. Mean CD4 cell count was 213 cells per cubic millimeter. When sarcoidosis was diagnosed, eight patients had pulmonary signs or symptoms. The angiotensin-converting enzyme level was elevated in five of six patients; two developed sarcoidosis after beginning HAART. Chest radiographs revealed lymphadenopathy, pulmonary nodules, focal consolidation, reticular opacities, granular opacities, and cysts or cavities. Chest CT scans revealed lymphadenopathy, nodules, thickened interlobular septa, focal consolidation, reticular opacities, ground-glass opacities, and cysts or cavities. There was no relationship between the radiographic findings of sarcoidosis and the CD4 cell count. CONCLUSION: The radiologic features of newly diagnosed sarcoidosis in HIV-infected patients resemble the findings of sarcoidosis in non-HIV-infected patients. In HIV-infected patients receiving HAART, sarcoidosis may be a manifestation of disease related to restoration of the immune system.

Transbronchial needle aspiration: guidance with CT fluoroscopy.

BACKGROUND: Bronchoscopy with transbronchial needle aspiration (TBNA) is valuable to diagnose lesions in the mediastinum and lung, but conventional fluoroscopic guidance may be suboptimal. We describe the use of CT fluoroscopy to provide real-time, transaxial TBNA localization, thus facilitating biopsy. METHODS: Patients were selected because of prior unsuccessful bronchoscopy or anticipated difficulty owing to small size or inaccessibility of the lesion. CT fluoroscopy consists of a spiral CT scanner adapted using a rapid-reconstruction algorithm and hardware that permits real-time in-room imaging. The bronchoscope was inserted on the CT scanner, which was used to guide TBNA instruments into the target lesion. RESULTS: Of 27 patients who underwent TBNA with CT fluoroscopic assistance, 15 had mediastinal nodes, and 12 had lung nodules or focal infiltrates. Mean lesion size was 1.7 cm in the mediastinum, 2. 2 cm in the lung. A correct diagnosis was established in 10 of 12 mediastinal lesions (83%) for which follow-up was available and in 8 lung lesions (67%). Diagnoses included small cell and non-small cell lung cancer and invasive aspergillosis. False-negative results were caused by sampling errors or inability to reach the lesion as documented by CT fluoroscopy. Postprocedure CT fluoroscopy revealed no complications. CONCLUSION: CT fluoroscopy provides effective, real-time guidance for TBNA and may be particularly valuable in patients with small or less accessible mediastinal or lung lesions.

Diseases of the hepatopulmonary axis.

Hepatopulmonary syndrome is the most widely recognized of the processes associated with end-stage liver disease. Chronic liver dysfunction is associated with pulmonary manifestations due to alterations in the production or clearance of circulating cytokines and other mediators. Hepatopulmonary syndrome results in hypoxemia due to pulmonary vasodilatation with significant arteriovenous shunting and ventilation-perfusion mismatch. Hepatic hydrothorax may develop in patients with cirrhosis and ascites. Rarely, pulmonary hypertension occurs in the setting of portal hypertension. A second group of disorders may primarily affect the lungs and liver (the hepatopulmonary axis). Among these are the congenital conditions alpha(1)-antitrypsin deficiency and cystic fibrosis. Autoimmune liver disease may be associated with lymphocytic interstitial pneumonitis, fibrosing alveolitis, intrapulmonary granulomas, and bronchiolitis obliterans with organizing pneumonia. Sarcoidosis affects the lung and liver in up to 70% of patients. Medications such as amiodarone can result in a characteristic radiologic appearance of pulmonary and hepatic toxic effects. Knowledge of these associations will assist the radiologist in forming a meaningful differential diagnosis and may influence treatment decisions.