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Objective: To build and merge a diagnostic model called multi-input DenseNet fused with clinical features (MI-DenseCFNet) for discriminating between Staphylococcus aureus pneumonia (SAP) and Aspergillus pneumonia (ASP) and to evaluate the significant correlation of each clinical feature in determining these two types of pneumonia using a random forest dichotomous diagnosis model. This will enhance diagnostic accuracy and efficiency in distinguishing between SAP and ASP., Methods: In this study, 60 patients with clinically confirmed SAP and ASP, who were admitted to four large tertiary hospitals in Kunming, China, were included. Thoracic high-resolution CT lung windows of all patients were extracted from the picture archiving and communication system, and the corresponding clinical data of each patient were collected., Results: The MI-DenseCFNet diagnosis model demonstrates an internal validation set with an area under the curve (AUC) of 0.92. Its external validation set demonstrates an AUC of 0.83. The model requires only 10.24s to generate a categorical diagnosis and produce results from 20 cases of data. Compared with high-, mid-, and low-ranking radiologists, the model achieves accuracies of 78% vs. 75% vs. 60% vs. 40%. Eleven significant clinical features were screened by the random forest dichotomous diagnosis model., Conclusion: The MI-DenseCFNet multimodal diagnosis model can effectively diagnose SAP and ASP, and its diagnostic performance significantly exceeds that of junior radiologists. The 11 important clinical features were screened in the constructed random forest dichotomous diagnostic model, providing a reference for clinicians., Clinical Relevance Statement: MI-DenseCFNet could provide diagnostic assistance for primary hospitals that do not have advanced radiologists, enabling patients with suspected infections like Staphylococcus aureus pneumonia or Aspergillus pneumonia to receive a quicker diagnosis and cut down on the abuse of antibiotics., Key Points: • MI-DenseCFNet combines deep learning neural networks with crucial clinical features to discern between Staphylococcus aureus pneumonia and Aspergillus pneumonia. • The comprehensive group had an area under the curve of 0.92, surpassing the proficiency of junior radiologists. • This model can enhance a primary radiologist's diagnostic capacity., (© 2024. The Author(s).)

Competing Interests: Competing interests: None declared.

A 66-year-old man was transferred to our hospital for pneumonia that was resistant to sulbactam/ampicillin and levofloxacin therapy. Chest computed tomography showed the rapidly progressive formation of multiple cavities. Methicillin-resistant Staphylococcus aureus (MRSA) was isolated, and the patient was diagnosed with necrotizing pneumonia caused by community-acquired MRSA (CA-MRSA). The MRSA strain had type IV staphylococcus cassette chromosome mec and genes encoding Panton-Valentine leucocidin (PVL). CA-MRSA necrotizing pneumonia with the PVL gene is rare; only three cases have been previously reported in Japan. We administered anti-MRSA antibiotics and the patient achieved complete clinical and radiological improvement.

Background: Methicillin-resistant Staphylococcus aureus (MRSA) is an important pathogen in cystic fibrosis (CF), with increasing incidence in recent years. We examined the association between bacterial colonization in the sputum (MRSA with or without pseudomonas (PA)) and computed tomography (CT) scores in CF patients., Methods: MRSA patients were divided according to PA status based on at least three consecutive sputum cultures; controls were patients without MRSA (with or without PA), matched for gender and age at CT. Clinical data and CT scores were compared between groups., Results: Of 33 patients with MRSA, 14 had no PA (MRSA + PA-) and 19 had also PA (MRSA + PA+). MRSA + PA- and MRSA + PA+ patients had CT scores similar to their controls PA+ (38.25 ± 20.18 vs. 32.22 ± 18.74, P = .4, and 41.88 ± 18.18 vs. 45.33 ± 11.5, P = .4, respectively). Although MRSA + PA- had worse CT scores than their matched PA- controls, their mean FEV1 values were similar., Conclusions: Colonization with MRSA in CF is associated with structural CT changes at least similar to those in PA. A cause and effect relationship cannot be established. The current findings call for a larger study assessing longitudinally the impact of MRSA acquisition and eradication protocols., (© 2016 John Wiley & Sons Ltd.)

Necrotising pneumonia (NP) is a rare but life-threatening complication of pulmonary infection. It is characterised by progressive necrosis of lung parenchyma with cavitating foci evident upon radiological investigation. This article reports the case of a 52-year-old woman, immunocompetent healthcare professional presenting to Accident and Emergency with NP and Staphylococcus aureus septicaemia. The cavitating lesion was not identified on initial chest X-ray leading to a delay in antimicrobial optimisation. However, the patient went on to achieve a full symptomatic recovery in 1 month and complete radiological recovery at 2-year follow-up. Long-term prognosis for adult cases of NP currently remains undocumented. This case serves as the first piece of published evidence documenting full physiological and radiological recovery following appropriate treatment of NP in an immunocompetent adult patient., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Almost all traumatic pulmonary pseudocysts (TPP), such as cavitary pulmonary lesions after blunt chest trauma, resolve spontaneously. On the contrary, secondary infection of a TPP should be considered in the presence of purulent sputum or hemosputum and a persistent cavity. We report a case of an infected TPP that was successfully treated by early surgical treatment. A 25-year-old man was transferred to our hospital with a TPP, shown by computed tomography (CT) as having a thick-walled large cavity, after the acute phase of blunt chest trauma. Purulent hemosputum suggested infection of the cavity. Serial CT scans of the chest revealed a persistent cavity. The thick-walled large cavity was diagnosed as a secondary infection of the TPP, that is, a potential lung abscess. We resected the cavity before a systemic inflammatory reaction occurred.

Objective: To describe two cases of Panton-Valentine leukocidin-producing Staphylococcus aureus (PVL-SA) necrotizing pneumonia treated with ECMO, and complete pulmonary evaluation at six months., Methods: Retrospective analysis of two patients presenting with severe PVL-SA pneumonia who both underwent complete respiratory function testing and chest CT scan six months after hospital discharge., Results: Indications for ECMO were refractory hypoxia and left ventricular dysfunction associated with right ventricular dilatation. Patients were weaned off ECMO after 52 and 5 days. No ECMO-related hemorrhagic complication was observed. Pulmonary function tests performed at six months were normal and the CT scan showed complete regression of pulmonary injuries., Conclusion: PVL-SA pneumonia is characterized by extensive parenchymal injuries, including necrotic and hemorrhagic complications. ECMO may be used as a salvage treatment without any associated hemorrhagic complication, provided anticoagulant therapy is carefully monitored, and may lead to complete pulmonary recovery at six months., (Copyright © 2016 Elsevier Masson SAS. All rights reserved.)

A previously healthy 60-year-old male presented with fever, general pain and a C-reactive protein (CRP) of 160 mg/L. He was prescribed doxycycline. In the emergency room three days later, he was intubated and had a saturation of 70% on 100% oxygen. The chest X-ray showed bilateral lobar pneumonia. Streptococcus pneumonia was later verified. As a Jehovah's Witness, he had refused blood transfusions, but accepted albumin. Two days after admission, veno-venous extracorporeal membrane oxygenation (V-V ECMO) was started and the patient was then transported on ECMO to Stockholm. After two days, echocardiography showed right cardiac failure and the patient had to be converted to veno-arterial ECMO (VV-A ECMO) by cannulation of the left femoral artery. The haemoglobin decreased from 10.0 to 6.0 g/dL. Iron, folic acid, and erythropoietin were administered to stimulate erythropoesis. Romiplostim, to stimulate the production of platelets, was also started immediately. Blood samples were reduced to a minimum. The ECMO circuit was changed twice, using saline for priming, and the blood in the old circuit was then given back to the patient. The haemoglobin concentration varied between 4.5 and 6.0 g/dL during the ECMO treatment and the platelets between 80 and 140 x10(9)/L. After 44 days on ECMO, the patient was weaned off ECMO with 50% oxygen and nitric oxide (NO) at 20ppm in the ventilator. Four days after decannulation, he was transferred to a nearby intensive care unit. Long-term ECMO treatment without transfusion of blood products is possible. Being a Jehovah's Witness should not automatically be a contraindication for ECMO.

Objectives: The purpose of this study was to compare the clinical and thin-section CT findings in patients with meticillin-resistant Staphylococcus aureus (MRSA) and meticillin-susceptible S. aureus (MSSA)., Methods: We retrospectively identified 201 patients with acute MRSA pneumonia and 164 patients with acute MSSA pneumonia who had undergone chest thin-section CT examinations between January 2004 and March 2009. Patients with concurrent infectious disease were excluded from our study. Consequently, our study group comprised 68 patients with MRSA pneumonia (37 male, 31 female) and 83 patients with MSSA pneumonia (32 male, 51 female). Clinical findings in the patients were assessed. Parenchymal abnormalities, lymph node enlargement and pleural effusion were assessed., Results: Underlying diseases such as cardiovascular were significantly more frequent in the patients with MRSA pneumonia than in those with MSSA pneumonia. CT findings of centrilobular nodules, centrilobular nodules with a tree-in-bud pattern, and bronchial wall thickening were significantly more frequent in the patients with MSSA pneumonia than those with MRSA pneumonia (p = 0.038, p = 0.007 and p = 0.039, respectively). In the group with MRSA, parenchymal abnormalities were observed to be mainly peripherally distributed and the frequency was significantly higher than in the MSSA group (p = 0.028). Pleural effusion was significantly more frequent in the patients with MRSA pneumonia than those with MSSA pneumonia (p = 0.002)., Conclusions: Findings from the evaluation of thin-section CT manifestations of pneumonia may be useful to distinguish between patients with acute MRSA pneumonia and those with MSSA pneumonia.

Necrotizing Staphylococcus aureus Panton-Valentine leukocidin (SA-PLV+) accounts for less than 1% of community-acquired lung diseases in children and young adults. Neonatal cases are exceptional. We report the observations of two newborn female twins, who were not breastfed, presenting a necrotizing lung disease due to the same strain of SA-PVL+ despite nasal decolonization measures taken. These two cases are informative and bring to light (1) the possibility of severe SA-PVL+ lung infections in young infants and (2) their strictly intrafamilial mode of transmission for which eradication measures were ineffective., (Copyright © 2011 Elsevier Masson SAS. All rights reserved.)

We report a case of 25-year-old male who presented with high grade fever with cough and expectoration. Chest examination revealed amphoric breath sounds on the right interscapular region. Chest X ray revealed multiple air fluid levels with collapse lung at places. Staph pneumonia with pneumatoceles is common in children but uncommon to in adult population.

Background: Community-acquired Staphylococcus aureus (CA-SA) infections are common among pediatric patients in Hawaii., Objective: We wanted to characterize the radiological features of methicillin-susceptible (CA-MSSA) and methicillin-resistant (CA-MRSA) staphylococcal pneumonia in Hawaiian children., Materials and Methods: We retrospectively reviewed medical records and imaging studies of children with SA pneumonia identified from 1996 through 2007., Results: Of 40 children, 26 (65%) had CA-MRSA pneumonia and 14 patients (35%) had CA-MSSA pneumonia. CA-MRSA patients were significantly younger than CA-MSSA patients (65% younger than 1 year vs. 36% older). In a majority (62%) of CA-MRSA patients, the consolidation was unilateral; in most of the CA-MSSA cases (79%), the consolidation was bilateral. Fifty percent of the patients with CA-MRSA and 21% of those with CA-MSSA had pneumatoceles (P = 0.1). CA-MRSA patients more commonly had pleural effusions (85% vs. 64% for CA-MSSA) and pleural thickening (50% vs. 36% for CA-MSSA)., Conclusion: This case series describes the radiologic characteristics of CA-MRSA and CA-MSSA pneumonia in children in a highly endemic area. We found that CA-MRSA pneumonias are unilateral in a majority of pediatric pneumonia cases, are more common in children 1 year or younger, and have higher rates of complications in comparison to CA-MSSA patients.

Since the release of the 2005 resuscitation guidelines intraosseous infusion has been recognized as the favorite alternative vascular access in emergency patients. It is no longer restricted to paediatric emergencies but is also considered the vascular access of choice for adult patients with difficult venous access. Intraosseous access has been used in an increasing proportion of patients especially in an out-of-hospital emergency care setting while only limited experience exists for in-hospital usage of this technique. This article reports on a case of intraosseous access performed in a critically ill patient directly after admission to the intensive care unit (ICU) due to difficult peripheral venous access. Despite the extensive medical resources available in the ICU (i.e. central venous catheterization) less invasive means were used to render appropriate care. Based on this case different strategies of critical care and possible improvements will be discussed. Intraosseous infusion should be regarded as an infrequently needed but potentially life-saving procedure that is still too often considered as an option at later stages during in-hospital emergency care.

The association between seasonal influenza and staphylococcal pneumonia has long been recognized (Chickering and Park, 1919; Roberts et al, 2008), and both meticillin-resistant Staphylococcus aureus and Panton-Valentine leukocidin S. aureus have been associated with seasonal influenza pandemics (Roberts et al, 2008; Kearns et al, 2009; Murray et al, 2010).

We present a case of community-acquired methicillin-resistant Staphylococcus aureus necrotizing pneumonia, Panton-Valentine leukocidin positive, in a woman at 14 weeks of pregnancy. To our knowledge, this is the first case reporting this critical lung infection occurring during an early phase of pregnancy. This case study alerts physicians to the increasing worldwide spread of these uncommon yet virulent and potentially lethal infections. In our patient, antibiotic therapy with linezolid plus rifampin started at 14 weeks of pregnancy had a successful outcome without inducing toxicity or teratogenesis in the fetus.

The emergence of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) as a cause of severe infections has been described in the recent years. In 2006, the first report of skin and soft tissue infection by CA-MRSA was published in Colombia. Herein, two additional cases of CA-MRSA are reported with a clinical course characterized by rapid progression, prolonged stay in the intensive care unit and complication of pneumonia with the onset of empyema. Both adult patients developed acute renal failure, and were treated with linezolide; the subsequent clinical response showed adequate treatment response. Molecular characterization of the isolates indicated the presence of the mecA gene carrying the cassette SCCmec type IV and the production of the toxin panton-valentine leukocidin.

Postoperative complications after pneumonectomy, lobectomy, or wedge resection are relatively frequent and potentially significant. Chest radiographs and CT have a crucial role in the early detection and prompt management of these complications. The purpose of this paper is to illustrate the most frequent or severe complications, based on the timing of occurrence. Early complications include bronchopleural fistula, empyema, atelectasis, pneumonia, hemothorax, chylothorax, pulmonary edema, lobar torsion, cardiac hernia, gossypiboma and esophagopleural fistula. Late complications include bronchopleural fistula, esophagopleural fistula, postpneumonectomy syndrome, chest wall arteriovenous fistula and local tumor recurrence.

Panton-Valentine leukocidin (PLV) is a toxin produced by Staphylococcus aureus. Previously described as responsible for furunculoses and cutaneous abscesses, it was recently found to cause necrotizing pneumonia, generally lethal. We describe a case of necrotizing pneumonia caused by S. aureus containing PLV with an atypical form (bubble form), which had a good outcome despite several risk factors for death: hemoptysis, leukopenia, erythrodermia.

Objective: Staphylococcal pneumonia typically presents high rates of morbidity and mortality. It typically occurs in cases of influenza (airborne transmission) or during episodes of bacteremia (blood-borne transmission)., Methods: A retrospective and descriptive study was conducted in patients admitted to our hospital between January of 1992 and December of 2003. All of he patients included had been diagnosed with community-acquired pneumonia caused by Staphylococcus aureus. All were older than 14 years of age, and none were intravenous drug users., Results: Community-acquired pneumonia was identified in 332 cases, of which 24 (7.3%) were identified as cases of staphylococcal pneumonia. Age ranged from 14 to 89 years. Fifteen patients were male, and nine were female. Twelve patients met the criteria for severe pneumonia. Chest X-rays showed unilateral consolidation in 14 cases, bilateral consolidation in 10, pleural effusion in 15, rapid radiological progression of pulmonary lesions in 14, cavitation in 6 and pneumothorax in 1. Most of the patients presented comorbidities, of which diabetes mellitus was the most common. Twelve patients presented complications such as empyema and septic shock. Four patients died, translating to a mortality rate of 16.6% in our sample., Conclusions: The clinical presentation of pneumonia caused by S. aureus is similar to that of pneumonia caused by other etiological agents. Radiological findings, epidemiological data and risk factors provide important clues to the diagnosis. These factors are important for clinical suspicion, since S. aureus is not typically addressed in empirical treatment.

Background: Necrotizing pneumonia caused by Staphylococcus aureus producing Panton Valentine Leukocidine (PVL) has been described recently and is associated with a high mortality (75%)., Observation: We report a case of pneumonia due to PV secreting Staphylococcus aureus in a healthy young adult, complicated by multiple necrotizing lung lesions and major cystic changes, with a favourable final outcome. Acute respiratory failure with haemodynamic failure and ARDS developed a few days after an influenza-like illness. The appearances at fibreoptic bronchoscopy were atypical, consisting of a purulent, necrotic tracheo- bronchitis with desquamation. The initial unfavourable progress despite broad spectrum antibiotic therapy and, finally, the identification of PV leukotoxin in blood cultures and tracheal aspirate, led to the diagnosis. During the clinical course there were repeated pneumothoraces (8 drains) due to multiple bilateral cystic lesions. Ultimately progress was favourable following treatment with antibiotics (flucloxacillin and clindamycin) and steroids., Conclusion: It is important to consider pulmonary complications of the Panton-Valentine leukotoxin in a healthy young adult who presents with necrotizing pneumonia and an unfavourable outcome in spite of broad spectrum antibiotics. Treatment is difficult on account of the extent of the necrotizing lesions and the need to use antibiotics effective against both the bacterium and its toxin.

Community-acquired methicillin-resistant Staphylococcus aureus is increasingly recognized as an important pathogen causing skin and soft tissue infections. We report a case of severe necrotizing pneumonia caused by community-acquired methicillin-resistant S. aureus in a peripartum woman. This case illustrates that community-acquired methicillin-resistant S. aureus must be considered as a potential pathogen in severe community-acquired pneumonia.

We report the first two cases of community-acquired necrotizing pneumonia and bacteremia complicated by acute respiratory distress syndrome (ARDS) due to Panton-Valantine leukocidin-producing methicillin-resistant Staphylococcus aureus (MRSA-PVL) in Greece, together with a short literature review. Diagnosis was made by culture and broad spectrum PCR of respiratory secretions and blood. One patient received appropriate therapy and recovered fully. The other one died rapidly due to septic shock and life-threatening hemoptysis. Clinicians should be suspicious of community-acquired pneumonia due to MRSA-PVL strain, because rigorous microbiological diagnosis, early and appropriate therapy is essential for favorable outcome.

Background: We report a case of methicillin-resistant Staphylococcus aureus (MRSA) sepsis and pneumonia in a postpartum patient., Case: A 21-year-old gravida 1 para 1 presented on postpartum day 9 with persistent elevated fever, dyspnea, cellulitis of the upper extremities, and an infected episiotomy site. Computed tomography of the chest revealed multiple widely distributed nodules and bilateral infiltrates with central cavitations. Sputum, blood, urine, and episiotomy site cultures grew MRSA, subsequently demonstrated by molecular fingerprinting and antibiotic susceptibility to be community acquired. A magnetic resonance imaging of the pelvis demonstrated pelvic thrombophlebitis., Conclusion: Community-acquired MRSA is an emerging problem, which may present as skin and soft tissue infections or sepsis. Seeding from an infected episiotomy site seems to be a potential route of systemic infection. The use of empirical treatment with beta-lactam agents may fail. Appropriate cultures should be obtained and if MRSA is diagnosed, vancomycin should be employed.

The staphylococcal pneumonia is the prerogative of the infant but rare cases were observed in the childhood. We report the observation of two children aged respectively of six years and three years and a half having presented a particular form of severe staphylococcal pneumonia apart from any context of immunodepression. The identification of the particular strains producing toxins Like the Panton and Valentine leukocidin constitutes the first stage of the comprehension of this atypical form of pneumonia. Through these observations and with a review of literature we underline the specific clinical and biological aspects of this form.

Severe infections are the most dangerous complications in liver transplantation and their prevention is one of the major goals. A 60-year-old Saudi-Arabian female with decompensated hepatitis C liver cirrhosis received a right-lobe liver graft from her healthy daughter. After 9 days, the patient developed a rapidly progressive necrotizing pneumonia that was fatal in spite of extracorporal lung assist. The pneumonia was due to a Panton-Valentine Leucocidine-positive (PVL) methicillin-resistant Staphylococcus aureus (MRSA), or "community-acquired" MRSA, that had not been detectable in the patient preoperatively. The same strain of PVL-MRSA could be demonstrated in the nares of the asymptomatic donor, but not of other relatives, patients, or medical staff. These findings strongly suggest transmission of PVL-MRSA from the donor to the recipient. This case demonstrates a previously unknown, and potentially fatal, risk in living-donor liver transplantation: transmission of a severe infection from a healthy donor to the recipient.

Problem: Infections with Methicillin-resistant Staphylococcus aureus are reported increasingly in intensive care unit and ward, that means not only a dangerous disease but also a considerable expenditure factor., Methods: In trauma surgery we could observe the Linezolid treatment of 2 patients with a MRSA infection. After treatment with Vancomycin and further evidence of MRSA the application of Linezolid was continued during 3 weeks accompanied by further microbiologic investigations., Results: In a 73 year old man with humerus shaft fracture the MRSA osteomyelitis was eradicated with Linezolid (600 mg/day per os over 3 weeks) after radical débridement and reosteosynthesis. The MRSA pneumonia in a 14 year old girl was treated successfully by Linezolid (600 mg/day i.v. over 3 weeks) and pneumotherapy. Follow up excluded further MRSA infection., Conclusions: Linezolid represents an efficient new reserve antibiotic. In case of pneumonia, severe skin and soft tissue infections good results can be expected. The treatment of osteomyelitis has been reported only in single cases.

Hyperimmunoglobulinaemia E (hyper-IgE) syndrome (Job's syndrome) is a rare disease that presents with recurrent cutaneous and sinopulmonary infections, and which begins in infancy and is associated with extreme hyper-IgE. The pulmonary imaging features typically consist of recurrent alveolar lung infections, pneumatocoeles and, occasionally, pneumothorax. Various other causes of pneumatocoeles in children can be excluded on the basis of clinical history and other data. Computed tomography may add valuable information for the management of these patients.

Objective: This prospective study was carried out to assess the usefulness of high-resolution CT (HRCT) of the chest in immunocompromised renal transplant patients with suspected pulmonary infections., Material and Methods: Twenty-one consecutive renal transplant patients with clinically suspected pulmonary infections underwent chest radiography, HRCT and other tests including bronchoalveolar lavage (BAL). HRCT was performed using a high spatial frequency algorithm with 2-mm-thick sections at 10-mm intervals from apices to domes of the diaphragm. The findings on chest radiography and HRCT were interpreted by two thoracic radiologists and the usefulness of HRCT was evaluated. The images were interpreted independently by two radiologists, who were blinded to the findings of other imaging modalities and the final diagnosis. Any differences regarding the imaging findings were resolved through consensus., Results: Final diagnosis was obtained in 17 patients, and no cause for symptomatology was established in 4 patients. The spectrum of infections included pulmonary tuberculosis (TB) in 11 patients, cytomegalovirus pneumonia (CMV) in 2 patients, cryptococcal and streptococcal pneumonia, pulmonary aspergillosis and esophageal candidiasis in 1 patient each. Compared to chest radiography, HRCT revealed additional findings in 11 patients. HRCT findings were suggestive of underlying infection in 11 patients. The final diagnosis coincided with HRCT diagnosis in all but 1 patient. HRCT findings were non-specific in 3 patients and normal in 7. The findings were concordant in 19 cases. The results were not in agreement in only 2 cases., Conclusion: HRCT can provide useful information and suggest the diagnosis in a significant proportion of renal transplant patients with pulmonary infection.

The authors describe a patient with spontaneous pneumopericardium complicating staphylococcal pneumonia and empyema that resulted in cardiac tamponade. Spontaneous pneumopericardium is an unusual disorder. The causes and clinical findings of pneumopericardium are reviewed, as are the radiographic features that differentiate this condition from pneumomediastinum. Early recognition of pneumopericardium is important, because emergent pericardiocentesis may be required if there is clinical evidence of tamponade.

Purpose: To evaluate thoracic CT findings of long-term hemodialysis patients., Material and Methods: Thoracic CT findings of 117 uremic patients (61 men, 56 women) with complaints of cough, dyspnea, low-grade pyrexia, malaise, weight loss, and profuse perspiration were retrospectively documented., Results: Atelectasis (60%), cardiomegaly (60%), pleural effusion (51%), vascular congestion (44%), parenchymal consolidation (38%), parenchymal scarring-fibrosis (31%), and lymphadenopathy (29%) were the most common CT findings in the thoraces of the long-term hemodialysis patients. Staphylococcus aureus was detected in 13 patients (11%) who had parenchymal infiltration. Thoracic tuberculosis was identified in 15 patients (13%), 11 of these cases being confined to the lung parenchyma, 3 to the pleura, and 1 involving the pleura and pericardium., Conclusion: In patients under long-term hemodialysis treatment, parenchymal consolidation, secondary to infectious agents such as S. aureus and Mycobacterium tuberculosis, is the most important CT finding since these lesions can be detected and treated successfully if they are considered as etiologic factors early on.

Background: Clinical and laboratory features do not accurately correlate with the cause of community acquired pneumonia. A study was performed to examine whether the radiographic features of staphylococcal pneumonia are sufficiently distinct to aid early diagnosis., Methods: The chest radiographs of 34 patients (including eight children) with proven staphylococcal pneumonia were reviewed by two experienced observers using methods described previously. Features on presentation and follow up were noted., Results: The most striking features were the presence of multilobar consolidation on presentation, cavitation, pneumatocoeles and spontaneous pneumothorax, together with a tendency to radiographic deterioration after admission in both adults and children. Some of these features are much less common with other causes of community acquired pneumonia. However, most of the cases did not have these classic features., Conclusions: The presence of certain radiographic features, including multilobar shadowing, cavitation, pneumatocoeles, and spontaneous pneumothorax, are seen with staphylococcal pneumonia in adults and children, but their absence does not exclude the diagnosis.

Multiple defects in host defense mechanisms produce an increased incidence of community-acquired bacterial pneumonia in individuals infected with the human immunodeficiency virus. Clinical studies suggest that Staphylococcus aureus is an uncommon cause of such infections, though its incidence is increased in the setting of intravenous drug use, indwelling vascular catheter, and coexistent pulmonary Kaposi's sarcoma or pneumonia due to Pneumocystis carinii. The significantly higher incidence of S aureus pneumonia documented in autopsy series suggests that the infection frequently remains undiagnosed ante mortem. The clinical and radiologic presentation of staphylococcal pneumonia in HIV-seropositive patients is similar to that seen in immunocompetent hosts. However, atypical radiographic patterns can occur. We describe a case of S aureus pneumonia manifested as an infiltrate with focal predominance and multiple cavitary lesions. Such a radiologic appearance has not previously been described in this population. Given the likelihood that pneumonia due to S aureus is significantly underdiagnosed ante mortem, a high index of clinical suspicion is warranted.

In a prospective study we examined the diagnostic ranking of CT and MR in 52 immunocompromised patients with nodular pulmonary lesions and clinical suspicion of invasive pulmonary aspergillosis (IPA). For early diagnosis of IPA (clinical symptoms having existed for less than 10 days) the CT halo sign proved highly sensitive and specific. MRT showed at this time a comparatively high sensitivity but only low specificity that could not be improved upon after Gd-DTPA. At a later stage of the aspergillosis infection (clinical symptoms manifested for more than 10 days) MR identified aspergillus-specific lesions with on-target characteristics (marked enhancement of margins after Gd-DTPA) or the so-called "reverse" target phenomenon (T2-weighted sequences). Such lesions were never seen in the early stage of the disease in patients with nodular pulmonary lesions of different aetiology (pseudomonal or staphylococcal pneumonia).