Middle Lung Regions Research Articles

Pediatric Mycoplasma Pneumonia: The Radiographic Patterns and Review of the Literature.

The purpose of the present paper was to evaluate the clinical and chest radiographic features of pediatric patients with serologically proven Mycoplasma pneumoniae pneumonia. The clinical records and chest radiographs of 55 consecutive patients (28 male, 27 female) with serologically positive IgG mycoplasma pneumonia were reviewed. The pneumonic infiltrates were described on chest radiography into 3 different patterns as a peribronchovascular infiltration, reticulonodular infiltration and consolidation. More than 91% of patients presented with cough and 70% of patients had fever. Chest radiographs displayed three different patterns: (i) peribronchovascular infiltration (n=33, 60%); (ii) reticulonodular infiltration (n=12, 22%); (iii) consolidation (n=10, 18%). Bilateral peribronchovascular infiltration in central and middle lung zones were frequently seen (n=33, 60%). Other radiological features were unilateral lesions in 51% of patients, pleural effusion in 18%, and hilar lymphadenopathy in 20%. There are various radiological features of mycoplasma pneumonia in children. Bilateral peribronchovascular infiltration confined to central and middle lung regions seems to be more closely associated with mycoplasma infection.

Quantitative 18F-fluorodeoxyglucose positron emission tomography/computed tomography to assess pulmonary inflammation in COPD.

RationaleCOPD and smoking are characterised by pulmonary inflammation. 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) imaging may improve knowledge of pulmonary inflammation in COPD patients and aid early development of novel therapies as an imaging biomarker.ObjectivesTo evaluate pulmonary inflammation, assessed by FDG uptake, in whole and regional lung in “usual” (smoking-related) COPD patients, alpha-1 antitrypsin deficiency (α1ATD) COPD patients, smokers without COPD and never-smokers using FDG PET/CT. Secondly, to explore cross-sectional associations between FDG PET/CT and systemic inflammatory markers in COPD patients and repeatability of the technique in COPD patients.MethodsData from two imaging studies were evaluated. Pulmonary FDG uptake (normalised Ki; nKi) was measured by Patlak graphical analysis in four subject groups: 84 COPD patients, 11 α1ATD-COPD patients, 12 smokers and 10 never-smokers. Within the COPD group, associations between nKi and systemic markers of inflammation were assessed. Repeatability was evaluated in 32 COPD patients comparing nKi values at baseline and at 4-month follow-up.ResultsCOPD patients, α1ATD-COPD patients and smokers had increased whole lung FDG uptake (nKi) compared with never-smokers (0.0037±0.001, 0.0040±0.001, 0.0040±0.001 versus 0.0028±0.001 mL·cm−3·min−1, respectively, p<0.05 for all). Similar results were observed in upper and middle lung regions. In COPD participants, plasma fibrinogen was associated with whole lung nKi (β=0.30, p=0.02) in multivariate analysis adjusted for current smoking, forced expiratory volume in 1 s % predicted, systemic neutrophils and C-reactive protein levels. Mean percentage difference in nKi between the baseline and follow-up was 3.2%, and the within subject coefficient of variability was 7.7%.ConclusionsFDG PET/CT has potential as a noninvasive tool to enable whole lung and regional quantification of FDG uptake to assess smoking- and COPD-related pulmonary inflammation.

High Positive End-Expiratory Pressure Renders Spontaneous Effort Noninjurious.

In acute respiratory distress syndrome (ARDS), atelectatic solid-like lung tissue impairs transmission of negative swings in pleural pressure (Ppl) that result from diaphragmatic contraction. The localization of more negative Ppl proportionally increases dependent lung stretch by drawing gas either from other lung regions (e.g., nondependent lung [pendelluft]) or from the ventilator. Lowering the level of spontaneous effort and/or converting solid-like to fluid-like lung might render spontaneous effort noninjurious. To determine whether spontaneous effort increases dependent lung injury, and whether such injury would be reduced by recruiting atelectatic solid-like lung with positive end-expiratory pressure (PEEP). Established models of severe ARDS (rabbit, pig) were used. Regional histology (rabbit), inflammation (positron emission tomography; pig), regional inspiratory Ppl (intrabronchial balloon manometry), and stretch (electrical impedance tomography; pig) were measured. Respiratory drive was evaluated in 11 patients with ARDS. Although injury during muscle paralysis was predominantly in nondependent and middle lung regions at low (vs. high) PEEP, strong inspiratory effort increased injury (indicated by positron emission tomography and histology) in dependent lung. Stronger effort (vs. muscle paralysis) caused local overstretch and greater tidal recruitment in dependent lung, where more negative Ppl was localized and greater stretch was generated. In contrast, high PEEP minimized lung injury by more uniformly distributing negative Ppl, and lowering the magnitude of spontaneous effort (i.e., deflection in esophageal pressure observed in rabbits, pigs, and patients). Strong effort increased dependent lung injury, where higher local lung stress and stretch was generated; effort-dependent lung injury was minimized by high PEEP in severe ARDS, which may offset need for paralysis.

Image features and clinical significance of pneumoconiosis with large shadow

To investigate the image features, categories, and clinical significances of Pneumoconiosis Ш with large shadow. The research is based on the analysis of image features of 168 pneumoconiosis Ш patients who are directly diagnosed by qualified medical professionals in our institution. These image features are large shadows bigger than 2 cm×1 cm which can be observed by high kilovolt chest radiographs, DR chest radiography and chest CT scan. Large shadows bigger than 2×1 cm show noticeable imaging characteristics, like distribution of superior and middle lung regions (95.2%) , irregular shapes (97.6%) , splayed or sausage like changes on both sides perpendicular with ribs (89.2%) , small shadows of pneumoconiosis (98.8%) , and convergence of large shadow to hilum or mediastinal (53.6%). CT scan is significantly better than DR radiography on detection rate of focal emphysema, focal cavities and swollen lymph node of mediastinal. Combining the image features of high kilovolt chest radiographs, DR chest radiographs and CT scan are the main methods to identify the shadows, and thus direct diagnose pneumoconiosis Ш; CT scan plays an important role in differential diagnosis.

Regional distribution of acoustic-based lung vibration as a function of mechanical ventilation mode

IntroductionThere are several ventilator modes that are used for maintenance mechanical ventilation but no conclusive evidence that one mode of ventilation is better than another. Vibration response imaging is a novel bedside imaging technique that displays vibration energy of lung sounds generated during the respiratory cycle as a real-time structural and functional image of the respiration process. In this study, we objectively evaluated the differences in regional lung vibration during different modes of mechanical ventilation by means of this new technology.MethodsVibration response imaging was performed on 38 patients on assist volume control, assist pressure control, and pressure support modes of mechanical ventilation with constant tidal volumes. Images and vibration intensities of three lung regions at maximal inspiration were analyzed.ResultsThere was a significant increase in overall geographical area (p < 0.001) and vibration intensity (p < 0.02) in pressure control and pressure support (greatest in pressure support), compared to volume control, when each patient served as his or her own control while targeting the same tidal volume in each mode. This increase in geographical area and vibration intensity occurred primarily in the lower lung regions. The relative percentage increases were 28.5% from volume control to pressure support and 18.8% from volume control to pressure control (p < 0.05). Concomitantly, the areas of the image in the middle lung regions decreased by 3.6% from volume control to pressure support and by 3.7% from volume control to pressure control (p < 0.05). In addition, analysis of regional vibration intensity showed a 35.5% relative percentage increase in the lower region with pressure support versus volume control (p < 0.05).ConclusionPressure support and (to a lesser extent) pressure control modes cause a shift of vibration toward lower lung regions compared to volume control when tidal volumes are held constant. Better patient synchronization with the ventilator, greater downward movement of the diaphragm, and decelerating flow waveform are potential physiologic explanations for the redistribution of vibration energy to lower lung regions in pressure-targeted modes of mechanical ventilation.

Measurement of diaphragmatic length during the breathing cycle by dynamic MRI: comparison between healthy adults and patients with an intrathoracic tumor

The purpose of this study was to assess diaphragmatic length and shortening during the breathing cycle in healthy volunteers and patients with a lung tumor using dynamic MRI (dMRI). In 15 healthy volunteers and 28 patients with a solitary lung tumor, diaphragmatic motion and length were measured during the breathing cycle using a trueFISP sequence (three images per second in the coronal and sagittal plane). Time-distance curves and maximal length reduction (= shortening) of the diaphragm were calculated. The influence of tumor localization on diaphragmatic shortening was examined. In healthy volunteers maximal diaphragmatic shortening was 30% in the coronal and 34% in the sagittal orientation, with no difference between both hemithoraces. Tumors of the upper and middle lung region did not affect diaphragmatic shortening. In contrast, tumors of the lower lung region changed shortening significantly ( P<0.05). In hemithoraces with a tumor in the lower region, shortening was 18% in the coronal and 19% in the sagittal plane. The ratio of diaphragmatic length change from inspiration to expiration changed significantly from healthy subjects (inspiration length >> expiratory length, P<0.05) to patients with a tumor in the lower lung region (inspiratory length = expiratory length). dMRI is a simple, non-invasive method to evaluate diaphragmatic motion and shortening in volunteers and patients during the breathing cycle. Tumors of the lower lung region have a significant influence on shortening of the diaphragm.

Embolization therapy in haemoptysis

Massive haemoptysis is a serious clinical condition to be treated with transcatheter embolotherapy of bronchial and/or other systemic arteries to the lungs. Lung bleeding frequently originates from sites other than bronchials alone. It is important to consider the extensive collateral network between bronchial, intercostal and pulmonary arteries and veins. Between 1980 and 1991, 70 patients were embolized. Fifty individuals were controlled with a mean follow-up time of 62 months. Most frequently pathology was seen in vessels originating from the right upper middle lung region. The embolization agents we used were IBC, NIBC, dura mater particles, and Ivalon + IBC. Recurrent bleeding was noticed in five patients, but not from embolized vessels. No major complications were encountered. Selective embolotherapt with tissue adhesives resulted in good short-term (90%) and long-term (100%) results. In 10% of cases, two or more embolization sessions were needed to cure the patient of haemoptysis.

Exposure to ozone alters regional function and particle dosimetry in the human lung

Effects of experimental exposure to O3 (0.33 ppm) or filtered air on regional lung function were assessed in nine healthy male subjects. Immediately after 2-h chamber exposures, regional ventilation and particle dosimetry were measured by gamma camera imaging. The vertical distributions of a radiolabeled gas (133Xe) and aerosol (3.5-microns-diam insoluble 99mTc-tagged Fe2O3 particles) were quantitated for upper, middle, and lower lung regions; distribution data were corrected for regional differences in lung volume and tissue attenuation. Indexes of mechanical function, inspiratory capacity, and mid-maximal expiratory flow rates were significantly reduced after O3, but functional residual capacity remained unchanged. Exposure to O3 significantly enhanced the fraction of respired aerosol retained by the lung and altered the distribution pattern of deposited aerosol by increasing particle deposition to the middle lung region (P < 0.05). Aerosol penetration indexes, i.e., ratio of particle deposition in central lung regions to that in peripheral lung regions, and particle retention 24 h postinhalation (an index of aerosol deposition within alveoli and slowly clearing bronchioles) indicated that particle filtration efficiency had increased for tracheobronchial and parenchymal lung regions. For seven of the nine subjects, regional ventilation after O3 was reduced by 14% to the lung base and enhanced by 8 and 6% to the upper and middle lung regions, respectively; these changes were significant (P < 0.02) compared with ventilation after filtered air.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of exercise on redistribution and clearance of inhaled particles from hamster lungs

Does exercise alter the redistribution and clearance of particles from the lungs? Sedentary hamsters and hamsters that were exercise trained by voluntary wheel running for the previous 5 wk were exposed to a 198Au-labeled aerosol for 25 min. Six trained and 6 sedentary animals were killed within 5 min after the exposure (day 0); the same number were killed 5 days later. The trained hamsters ran ad libitum during those 5 days. The lungs of all animals were excised, dried at total lung capacity, sliced into 1-mm-thick sections, and dissected into pieces that were counted for radioactivity and weighed. On day 0, trained hamsters had 80% more particles per milligram of lung than sedentary hamsters, although both were exposed under identical conditions of restraint. After five days, exercising hamsters cleared 38% of the particles present at day 0, whereas sedentary animals removed only 15%. Significant clearance was observed from the middle lung regions of sedentary hamsters and from all lung regions in exercising hamsters. We conclude that exercise can enhance the redistribution and clearance of particles from the lungs; the mechanisms responsible are as yet unclear.

Pulmonary permeability in hematologic malignancies. Effects of the disease and cytotoxic agents.

Pulmonary permeability was assessed using the technique of DTPA aerosol transfer in untreated patients with chronic lymphocytic leukemia (CLL) and in patients with a variety of hematologic malignancies that had all been treated with alkylating agents. Two findings emerged: In the untreated CLL patients, the permeability of the upper and middle lung regions was reduced. This may be due to diffuse infiltration by the CLL; and Treatment with cytotoxic agents increased epithelial permeability in both middle and lower lung regions. Further prospective studies are required to determine the cause of the long T50 values in untreated CLL and to confirm that the DTPA transfer test is a sensitive indicator of the damage which eventually leads to pulmonary fibrosis.

Regional Lung P erf u si on and Ventilation with Radioisotopes in Cervical Cord-injured Patients

In general, cervical cord-injured patients present with restrictive pulmonary dysfunction resulting from paralysis of the intercostal muscles. Vital capacity frequently decreases below 50% of that in normal subjects, and their respiratory pattern frequently includes paradoxical movement in which the intercostal spaces sink and the abdomen distends at inspiration. Ventilation scintigraphy using Xe-133 and pulmonary perfusion scintigraphy using Tc-99m macroaggregated albumin (MAA) were performed on nine cervical cord-injured patients and four normal subjects to investigate regional lung functions in the cervical cord-injured patients. Pulmonary perfusion scintigraphy, in which measurement was made in the supine position, revealed no differences between the patients and the normal subjects. The inhomogeneous ventilation/perfusion distribution was presumed to have resulted from change in regional intrapleural pressure due to paradoxical movement of the thoracic cage. Washing and washout times were prolonged by paralysis of the intercostal muscles. These phenomena were particularly apparent in the upper and middle lung regions where compensating action by movement of the diaphragm is small.